C. Andrew Bonham, MD

Abstract

INTRODUCTION: Recent trends in the incidence and mortality of biliary tract cancers are unknown. We estimated the trends in biliary tract cancers-related incidence and mortality stratified by anatomical site, age, sex, and race/ethnicity in the US adults.METHODS: We performed a population-based trend analysis using the US national incidence (2009-2017) and mortality records (2009-2018). We identified age-standardized incidence and mortality from intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer using appropriate ICD-10 code. Temporal mortality was calculated by joinpoint trend analysis with estimates of annual percentage change (APC) described as each trend segment.RESULTS: The incidence rates of ICC increased linearly (APC 8.9%, 95% confidence interval [CI] 7.8%-10.0%) while gallbladder cancer-related incidence rates remained stable early and decreased significantly later in the study (APC -2.8%, 95% CI -5.5% to -0.0% [2014-2017]). Age-standardized mortality from biliary tract cancers steadily increased with an annual increase of 2.0% (95% CI 1.6%-2.3%). Although there was a linear increase in the ICC-related mortality (APC 3.5%, 95% CI 3.1%-3.8%), extrahepatic cholangiocarcinoma-related mortality tended to remain stable earlier and increased later (APC 7.0%, 95% CI 4.6%-9.5% [2013-2018]). By contrast, gallbladder cancer-related mortality steadily decreased over 10 years (APC -1.6%, 95% CI -2.1% to -1.1%). Significant differences in mortality and changes in trends over time were observed in non-Hispanic blacks, Hispanics, and non-Hispanic Asians.DISCUSSION: In this analysis of nationally representative data, changing mortality trends in various biliary tract cancers was noted with a disproportionately higher burden of fatality in minorities.

View details for DOI 10.14309/ajg.0000000000001151

View details for PubMedID 33929380

Abstract

Combined heart-liver transplant is an emerging option for patients with indications for heart transplantation and otherwise prohibitive hepatic dysfunction. Heart-liver transplantation is particularly relevant for patients with single ventricle physiology who often develop Fontan-associated liver disease and fibrosis. While only performed at a limited number of centers, several approaches to combined heart-liver transplantation have been described. The en bloc technique offers several potential advantages over the traditional sequential technique. Specifically, en bloc heart-liver transplantation may allow improved hemodynamics, decreased bleeding, reduced liver allograft ischemic time, and may result in reduced rates of graft dysfunction. Here we describe our center's en bloc heart-liver procurement technique in detail, with the aim of allowing broader use and standardization of this technique. Supplemental Visual Abstract; http://links.lww.com/TP/C147.

View details for DOI 10.1097/TP.0000000000003697

View details for PubMedID 33606485

Abstract

Infections following orthotopic liver transplant (OLT) result in significant morbidity and mortality, warranting careful consideration of risks associated with antibiotic overuse and benefits of infection prevention. In the absence of specific guidelines for antimicrobial prophylaxis in pediatric OLT, we developed a standardized approach to post-operative (post-op) antimicrobial therapy including 48 hours of antibiotics, no vancomycin for post-op fever within the first 48 hours, and caspofungin only for certain situations. The goal was to reduce antimicrobial utilization and adverse outcomes associated with longer duration of and broader treatment while maintaining good outcomes. The impact of this standardization on antimicrobial utilization and clinical outcomes at the largest pediatric liver transplant center in the United States is described. All individuals receiving an OLT from 1/1/17-9/30/17 (N=38) and 3/14/18-12/13/18 (N=27) were included in the pre-intervention (PreI) and post-intervention (PostI) groups, respectively. The intervention resulted in a significant reduction in individuals receiving post-op broad-spectrum gram-negative antibiotics for > 48 hours (76% PreI vs 44% PostI OLT recipients, P = 0.01) and post-op vancomycin use (50% PreI, vs 7.4% PostI, P < 0.001). There were no statistically significant differences between groups for post-op fever, positive pre-/post-operative cultures, receipt of massive transfusion, or hospital length of stay. In conclusion, following the implementation of a standardized approach to post-op prophylaxis, antimicrobial exposure was significantly reduced without affecting OLT recipient outcomes.

View details for DOI 10.1111/tid.13538

View details for PubMedID 33252820

View details for Web of Science ID 000618872101233

View details for Web of Science ID 000618872101149

Abstract

INTRODUCTION: Transfusion protocols are not well-studied for pediatric patients with acute liver failure (ALF). This study evaluates the utility of an international normalized ratio (INR)-based transfusion threshold for these patients.METHODS: Forty-four ALF pediatric patients from 2009 to 2018 were reviewed and divided into two groups: (1) a threshold group including patients between 2009-2015 who were transfused for an INR above 3.0, per institutional policy (n=30), and (2) a post-threshold group including patients after 2015 through 2018 who were transfused based on clinical judgment (n=14). Preoperative INRs, preoperative transfusions, intraoperative transfusions, early reoperation, renal function, graft function and deaths were compared.RESULTS: Liver failure severity was similar between threshold and post-threshold groups. Threshold patients had a lower average INR prior to transplantation, 2.8 (range 1.8-3.8) versus 4.4 (range 2.1-9.0), respectively (p=0.01). Twenty-six threshold patients (87%) received preoperative FFP compared to seven post-threshold patients (50%, p=0.0088). Two threshold patients (7%) received preoperative cryoprecipitate compared to five post-threshold patients (36%, p=0.014). The incidence of pre-transplant bleeding, operative transfusions and one-year patient and graft survival did not differ significantly.CONCLUSION: Clinical judgment versus an INR-based threshold for transfusions did not increase perioperative complications in children with ALF.

View details for DOI 10.1111/ctr.13819

View details for PubMedID 32037570

View details for Web of Science ID 000488653502295

Abstract

The liver parenchyma is composed of hepatocytes and bile duct epithelial cells (BECs). Controversy exists regarding the cellular origin of human liver parenchymal tissue generation during embryonic development, homeostasis or repair. Here we report the existence of a hepatobiliary hybrid progenitor (HHyP) population in human foetal liver using single-cell RNA sequencing. HHyPs are anatomically restricted to the ductal plate of foetal liver and maintain a transcriptional profile distinct from foetal hepatocytes, mature hepatocytes and mature BECs. In addition, molecular heterogeneitywithin the EpCAM+ population of freshly isolated foetal and adult human liver identifies diverse gene expression signatures of hepatic and biliary lineage potential. Finally, we FACS isolate foetal HHyPs and confirm their hybrid progenitor phenotype in vivo. Our study suggests that hepatobiliary progenitor cells previously identified in mice also exist in humans, and can be distinguished from other parenchymal populations, including mature BECs, by distinct gene expression profiles.

View details for DOI 10.1038/s41467-019-11266-x

View details for PubMedID 31350390

View details for DOI 10.1111/jvh.12750

View details for Web of Science ID 000416320500015

Abstract

Background and Aims: Utilization of living donor liver transplantation (LDLT) and its relationship with recipient Model for End-Stage Liver Disease (MELD) needs further evaluation in the United States (U.S.). We evaluated the association between recipient MELD score at the time of surgery and survival following LDLT. Methods: All U.S. adult LDLT recipients with MELD < 25 were evaluated using the 1995-2012 United Network for Organ Sharing registry. Survival following LDLT was stratified into three MELD categories (MELD < 15 vs. MELD 15-19 vs. MELD 20-24) and evaluated using Kaplan-Meier methods and multivariate Cox proportional hazards models. Results: Overall, 2,258 patients underwent LDLT. Compared to patients with MELD < 15, overall 5-year survival following LDLT was similar among patients with MELD 15-19 (80.9% vs. 80.3%, p = 0.77) and MELD 20-24 (81.2% vs. 80.3%, p = 0.73). When compared to patients with MELD < 15, there was no significant difference in long-term post-LDLT survival among those with MELD 15-19 (HR: 1.11, 95% CI: 0.85-1.45, p = 0.45) and a non-significant trend towards lower survival in patients with MELD 20-24 (HR: 1.28, 95% CI: 0.91-1.81, p = 0.16). Only 14% of LDLTs were performed in patients with MELD 20-24 and the remaining 86% in patients with MELD < 20. Conclusion: LDLT is underutilized in patients with MELD 20 and higher.

View details for PubMedID 27777886

Abstract

Hepatoblastoma (HBL) and hepatocellular cancer (HCC) are the most common primary hepatic malignant neoplasms in childhood. Given the rarity of these childhood tumors and their propensity to present at advanced stages, updated long-term data are needed.To determine the efficacy of liver transplant in children with HBL or HCC.This single-institution retrospective medical record review and analysis spanned from January 1, 1997, through September 17, 2014, at Stanford University School of Medicine. A total of 40 patients younger than 18 years underwent liver transplant for treatment of HBL (n=30) or HCC (n=10) during the study period, with follow-up until September 17, 2014. Patients who underwent transplant for HCC included those with tumors that were greater in size than what is proposed by the Milan (a single tumor measuring 5 cm or 3 nodules measuring 3 cm) and University of California, San Francisco (single tumor measuring 6.5 cm or 3 nodules measuring 4.5 cm and a total diameter of 8 cm), criteria.Disease-free and overall patient survival and graft survival.Using a Kaplan-Meier survival analysis, 1-, 5-, and 10-year disease-free survival after liver transplant was 93%, 82%, and 82%, respectively, for 30 patients with HBL and 90%, 78%, and 78%, respectively, for 10 patients with HCC. Risk factors associated with HBL recurrence after transplant included having pretreatment extent of disease stage IV lesions and a longer waiting list time and being older at the time of the transplant. Recurrence was found in 2 of 7 patients with HBL and pretransplant metastases, which were not found to be an independent risk factor for recurrence. Patients with HCC larger than the proposed Milan and University of California, San Francisco, criteria experienced good 5-year disease-free (82%) and overall (78%) survival after transplant. Being older at the time of transplant (18 vs 11 years; P=.04) and the presence of metastatic disease (1 patient vs none; P=.05) were associated with HCC tumor recurrence.Liver transplant combined with chemotherapy is an excellent treatment that provides long-term disease-free survival in children diagnosed with advanced HBL and HCC. Early addition to a waiting list and aggressive multimodal therapy provide excellent results. Transplant should still be considered in children with HCC larger than the Milan and University of California, San Francisco, criteria.

View details for DOI 10.1001/jamasurg.2015.1847

View details for Web of Science ID 000367990700010

Abstract

The frequency of simultaneous liver kidney transplantation (SLKT) has been increasing over the past decade. Hepatitis C virus (HCV) infection is the most common indication for liver transplantation in the United States. Given the rising prevalence of HCV-related SLKT, it is important to understand the impact of HCV in this patient population.We conducted a retrospective cohort study using data from the United Network for Organ Sharing registry to assess adult patients undergoing SLKT in the United States from 2003 to 2012. Patient survival following SLKT was assessed using Kaplan-Meier methods and multivariate Cox proportional hazards models.Patients infected with non-HCV have significantly lower survival following SLKT compared to non-HCV patients at three (three-yr survival: 71.0% vs. 78.9%, p<0.01) and fiveyr (five-yr survival: 61.4% vs. 72.5%, p<0.01). The results of multivariate regression analyses demonstrated that patients infected with HCV had significantly lower survival following SLKT than patients with non-HCV disease (HR 1.41, 95% CI, 1.19-1.67, p<0.001). In addition, lower post-SLKT survival was noted among patients with diabetes (HR 1.34, 95% CI, 1.13-1.58, p<0.001) and hepatocellular carcinoma (HR 1.60, 95% CI, 1.17-2.18, p<0.01).Hepatitis C infection is associated with lower patient survival following SLKT.

View details for DOI 10.1111/ctr.12598

View details for PubMedID 26205329

Abstract

To assess biochemical, surgical, and long-term outcomes of liver (LT) or liver-kidney transplantation (LKT) for severe, early-onset methylmalonic acidemia/acid (MMA).A retrospective chart review (December 1997 to May 2012) of patients with MMA who underwent LT or LKT at Lucile Packard Children's Hospital at Stanford.Fourteen patients underwent LT (n = 6) or LKT (n = 8) at mean age 8.2 years (range 0.8-20.7). Eleven (79%) were diagnosed during the neonatal period, including 6 by newborn screening. All underwent deceased donor transplantation; 12 (86%) received a whole liver graft. Postoperative survival was 100%. At a mean follow-up of 3.25 4.2 years, patient survival was 100%, liver allograft survival 93%, and kidney allograft survival 100%. One patient underwent liver re-transplantation because of hepatic artery thrombosis. After transplantation, there were no episodes of hyperammonemia, acidosis, or metabolic decompensation. The mean serum MMA at the time of transplantation was 1648 1492 mol/L (normal <0.3, range 99-4420). By 3 days, post-transplantation levels fell on average by 87% (mean 210 154 mol/L), and at 4 months, they were 83% below pre-transplantation levels (mean 305 108 mol/L). Developmental delay was present in 12 patients (86%) before transplantation. All patients maintained neurodevelopmental abilities or exhibited improvements in motor skills, learning abilities, and social functioning.LT or LKT for MMA eradicates episodes of hyperammonemia, results in excellent long-term survival, and suggests stabilization of neurocognitive development. Long-term follow-up is underway to evaluate whether patients who undergo early LT need kidney transplantation later in life.

View details for DOI 10.1016/j.jpeds.2015.01.051

View details for PubMedID 25771389

Abstract

To assess biochemical, surgical, and long-term outcomes of liver (LT) or liver-kidney transplantation (LKT) for severe, early-onset methylmalonic acidemia/acid (MMA).A retrospective chart review (December 1997 to May 2012) of patients with MMA who underwent LT or LKT at Lucile Packard Children's Hospital at Stanford.Fourteen patients underwent LT (n = 6) or LKT (n = 8) at mean age 8.2 years (range 0.8-20.7). Eleven (79%) were diagnosed during the neonatal period, including 6 by newborn screening. All underwent deceased donor transplantation; 12 (86%) received a whole liver graft. Postoperative survival was 100%. At a mean follow-up of 3.25 4.2 years, patient survival was 100%, liver allograft survival 93%, and kidney allograft survival 100%. One patient underwent liver re-transplantation because of hepatic artery thrombosis. After transplantation, there were no episodes of hyperammonemia, acidosis, or metabolic decompensation. The mean serum MMA at the time of transplantation was 1648 1492 mol/L (normal <0.3, range 99-4420). By 3 days, post-transplantation levels fell on average by 87% (mean 210 154 mol/L), and at 4 months, they were 83% below pre-transplantation levels (mean 305 108 mol/L). Developmental delay was present in 12 patients (86%) before transplantation. All patients maintained neurodevelopmental abilities or exhibited improvements in motor skills, learning abilities, and social functioning.LT or LKT for MMA eradicates episodes of hyperammonemia, results in excellent long-term survival, and suggests stabilization of neurocognitive development. Long-term follow-up is underway to evaluate whether patients who undergo early LT need kidney transplantation later in life.

View details for DOI 10.1016/j.jpeds.2015.01.051

View details for Web of Science ID 000355018200025

View details for PubMedID 25771389

Abstract

We aimed to determine the incidence and predictors of recurrent hepatocellular carcinoma (HCC) after partial hepatectomy.Liver transplantation is the preferred treatment for selected patients with HCC, but access to donor organs is limited. Partial hepatectomy is another accepted treatment option; however, postoperative recurrence is frequently observed.This is a retrospective cohort study of 107 consecutive patients who underwent partial hepatectomy for HCC between January 1993 and February 2011 at a US University Medical Center. Study endpoints were recurrent HCC, death, loss to follow-up, or last visit without HCC.The study cohort was 78% male with a median age of 61 years and 59% Asians. A total of 50 patients developed recurrent HCC (46.7%) after a median follow-up of 12 (1 to 69) months postresection. Recurrent HCC was significantly higher in patients with left-sided resection (41% at year 1, 54% at year 2, 62% at year 3, 81% at year 4, and 90% at year 5) compared with right-sided resection (18% at year 1, 34% at year 2, 36% at year 3, 44% at year 4, and 72% at year 5). In multivariate Cox proportional hazards model also inclusive of anatomic resection and TNM stage 3/4, left-sided resection was significantly associated with increased HCC recurrence (hazard ratio, 2.13; P=0.02; 95% confidence interval, 1.08-4.2) compared with right-sided resection.HCC recurrence rate is higher among those undergoing left-sided resection: 54% at year 2 and 81% at year 4. Liver transplantation should be considered in patients who are at high risk for recurrence.

View details for DOI 10.1097/MCG.0000000000000144

View details for PubMedID 24804988

View details for DOI 10.1007/s10620-014-3220-5

View details for Web of Science ID 000344348700009

Abstract

There is an increasing trend of patients with hepatocellular carcinoma (HCC) and non-alcoholic fatty liver disease undergoing liver transplantation in the U.S. Our study utilized data from the 2002-2012 United Network for Organ Sharing registry to evaluate MELD era trends in U.S. liver transplantations focused on patients with non-alcoholic steatohepatitis (NASH), hepatitis C (HCV), alcoholic liver disease, and HCC. Survival outcomes were stratified by liver disease etiology and compared across time periods using Kaplan Meier and Cox proportional hazards models. Patients with NASH were more likely to be women, had higher body mass index, and higher prevalence of diabetes and cardiac disease. However, overall long term survival was significantly higher in NASH and alcoholic liver disease patients (p < 0.001). Compared to HCV, NASH patients had significantly higher post-transplantation survival (HR 0.69, 95% CI 0.63-0.77), and lower risk of graft failure (HR 0.76, 95% CI 0.69-0.83). Despite having higher body mass index and higher prevalence of diabetes and cardiac disease, NASH patients had better post-liver transplantation survival compared to patients with HCV or HCC. Patients with alcoholic liver disease also had superior survival outcomes. However, these survival differences were limited to patients without HCC that underwent liver transplantation. This article is protected by copyright. All rights reserved.

View details for DOI 10.1111/ctr.12364

View details for PubMedID 24654688

Abstract

Hepatocellular carcinoma (HCC) is a leading cause of mortality worldwide. Existing studies comparing outcomes after liver transplantation (LT) versus surgical resection among transplant-eligible patients are conflicting.The purpose of this study was to compare long-term survival between consecutive transplant-eligible HCC patients treated with resection versus LT.The present retrospective matched case cohort study compares long-term survival outcomes between consecutive transplant-eligible HCC patients treated with resection versus LT using intention-to-treat (ITT) and as-treated models. Resection patients were matched to LT patients by age, sex, and etiology of HCC in a 1:2 ratio.The study included 171 patients (57 resection and 114 LT). Resection patients had greater post-treatment tumor recurrence (43.9 vs. 12.9%, p<0.001) compared to LT patients. In the as-treated model of the pre-model for end stage liver disease (MELD) era, LT patients had significantly better 5-year survival compared to resection patients (100 vs. 69.5%, p=0.04), but no difference was seen in the ITT model. In the multivariate Cox proportional hazards model, inclusive of age, sex, ethnicity, tumor stage, and MELD era (pre-MELD vs. post-MELD), treatment with resection was an independent predictor of poorer survival (HR 2.72; 95% CI, 1.08-6.86).Transplant-eligible HCC patients who received LT had significantly better survival than those treated with resection, suggesting that patients who can successfully remain on LT listing and actually undergo LT have better outcomes.

View details for DOI 10.1007/s10620-013-2947-8

View details for PubMedID 24282054

Abstract

LT has emerged as a surgical treatment for UCDs. We hypothesize that LT can be safely and broadly utilized in the pediatric population to effectively prevent hyperammonemic crises and potentially improve neurocognitive outcomes. To determine the long-term outcomes of LT for UCDs, charts of children with UCD who underwent LT were retrospectively reviewed at an academic institution between July 2001 and May 2012. A total of 23 patients with UCD underwent LT at a mean age of 3.4 yr. Fifteen (65%) patients received a whole-liver graft, seven patients (30%) received a reduced-size graft, and one patient received a living donor graft. Mean five-yr patient survival was 100%, and allograft survival was 96%. Mean peak blood ammonia (NH(3) ) at presentation was 772 mol/L (median 500, range 178-2969, normal <30-50). After transplantation, there were no episodes of hyperammonemia. Eleven patients were diagnosed with some degree of developmental delay before transplantation, which remained stable or improved after transplantation. Patients without developmental delay before transplantation maintained their cognitive abilities at long-term follow-up. LT was associated with the eradication of hyperammonemia, removal of dietary restrictions, and potentially improved neurocognitive development. Long-term follow-up is underway to evaluate whether LT at an early age (<1 yr) will attain improved neurodevelopmental outcomes.

View details for DOI 10.1111/petr.12041

View details for PubMedID 23347504

View details for Web of Science ID 000312540200091

Abstract

Pediatric CHLT is rarely performed in transplant centers and even fewer are performed en bloc. In the hands of an experienced surgeon with the appropriate patient selection, CHLT performed en bloc may have several operative and immunologic benefits, thereby resulting in improved outcomes for the transplant recipient. A single-institutional, retrospective review from 1/1/06 to 12/31/10 was conducted. Three pediatric patients with end-stage heart and liver disease who were considered low immunologic risk were included. All were managed by the same surgeon with a herein-described CHLT donor and recipient operation. Data were collected on patient and graft survival, rejection episodes, infectious complications, operative time, intraoperative transfusion requirements, and immunosuppression regimens. One-yr patient and graft survival rates were 100%. No patients experienced antibody-mediated or cell-mediated rejection. No patients had postoperative infections, and all patients were free of opportunistic infections at one-yr post-transplant. All patients were maintained safely on steroid-free immunosuppression. There were no intraoperative complications. In pediatric end-stage heart and liver disease patients with low immunologic risk, it is reasonable to proceed with en bloc CHLT so long as there is an experienced surgeon to perform the case. This offers operative and immunologic advantages to the recipient while maintaining equivalent, if not improved, recipient and graft outcomes.

View details for DOI 10.1111/j.1399-3046.2012.01695.x

View details for Web of Science ID 000303998800024

View details for PubMedID 22583978

View details for Web of Science ID 000299772000262

Abstract

Patients with autogenous native vessel portosystemic shunts, whether surgical or congenital, may experience complications of excess shunt flow, including hepatopulmonary syndrome (HPS), hepatic encephalopathy (HE), and hepatic insufficiency. The authors explored endovascular reduction or occlusion of autogenous portosystemic shunts using methods commonly employed in transjugular intrahepatic portosystemic shunt (TIPS) reduction in four pediatric patients. Before treatment, the patients had hypoplastic, atrophic, or thrombosed portal veins. Following intervention, symptoms of overshunting resolved or improved in all patients without major complications. The innate plasticity of the pediatric portal venous system allowed for hypertrophy or development and maturation of cavernous transformations to accommodate increased hepatopetal blood flow and pressure.

View details for DOI 10.1016/j.jvir.2011.01.438

View details for PubMedID 21801995

View details for Web of Science ID 000293251100149

View details for Web of Science ID 000289318401235

View details for DOI 10.1007/s10620-010-1470-4

View details for PubMedID 21053076

View details for DOI 10.1007/s10620-010-1353-8

View details for Web of Science ID 000283300400008

View details for PubMedID 20844961

View details for DOI 10.1007/s10620-010-1318-y

View details for Web of Science ID 000280595500006

View details for PubMedID 20635145

Abstract

Spontaneous liver rupture is a rare occurrence during pregnancy.A young woman presented early in her pregnancy with severe abdominal pain, tachycardia, and hypotension. She was taken emergently to the operating room with a presumed diagnosis of ruptured ectopic pregnancy. Exploration revealed that her hemoperitoneum resulted from large fractures within her liver. During her resuscitation and treatment, a transvaginal ultrasound scan revealed a hydatidiform molar pregnancy. On resolution of postoperative complications and complete recovery, the patient was discharged home.This case illustrates that, although very unusual, hydatidiform molar pregnancies should be considered as a precipitating factor for spontaneous liver rupture.

View details for Web of Science ID 000273872800016

View details for PubMedID 20093872

View details for DOI 10.1007/s10620-008-0626-y

View details for Web of Science ID 000261653400007

View details for PubMedID 19034649

View details for Web of Science ID 000303378800021

Abstract

We report a 4-year experience of a new program in pediatric intestinal transplantation. Among 50 children referred for evaluation, 27 were listed for transplantation. Two children originally listed for combined liver/small bowel transplant were changed to isolated intestinal transplant as rehabilitation efforts resulted in full recovery of hepatic function. Eighteen children received 18 grafts: 12 liver/intestine, 5 isolated intestine, and 1 multivisceral. Mean age at transplant was 3.6 year with 75% of patients aged 0 to 2 years. Five listed children died while waiting and four were still on the list. Immunotherapy included antithymocyte globulin induction and tacrolimus, sirolimus, and prednisone maintenance. At 1 year, patient and graft survivals were 75% and 67%, respectively. For isolated intestine, 1 year survivals were 100% and 75%, while for combined liver/intestine, they were 71% for both. Enteral autonomy is 100% with total parenteral nutrition stopping by 35.8 days (mean). We had two patients develop posttransplant lymphoproliferative disorder and three, exfoliative rejection, one of whom recovered completely. In conclusion, our program in pediatric intestinal transplantation has become well established with a high proportion of smaller/younger children receiving grafts. Outcomes achieved levels expected based on The Intestinal Transplant Registry and UNOS criteria, which were better than expected for isolated intestinal transplants and achievement of enteral autonomy.

View details for DOI 10.1016/j.transproceed.2006.05.038

View details for Web of Science ID 000240051700022

View details for PubMedID 16908259

Abstract

Dendritic cells (DC) are specialized antigen-presenting cells with powerful immunostimulatory properties. Their use for induction of anti-tumor immunity has been limited by several factors, including identification of appropriate tumor-associated antigens, delivery of antigens to DC, and maintaining DC in a highly activated state. Here, DC propagated in vitro were transduced with an adenoviral (Ad) vector to express hepatitis B surface antigen (HBsAg), an antigen present in hepatocellular carcinoma (HCC). Many patients with HCC demonstrate evidence of prior HBV exposure, suggesting that the presence of the virus in a quiescent state may promote tumorigenesis. Ad-HBsAg-transduced DC stimulated strong cytotoxic T lymphocyte (CTL) responses to HBsAg-expressing tumor cells, and protected mice from lethal tumor challenge. Immunity was antigen-specific, as wild-type tumor (HBsAg -) grew normally. Furthermore, DC transduced with an irrelevant vector had no effect. Vaccination with HBsAg protein, a clinically utilized preparation that confers immunity to HBV infection, did not protect against tumor challenge even though it induced a strong antibody response. These studies describe for the first time the contributions of humoral and cellular immune responses to tumor immunity induced by Ad-transduced DC compared to protein vaccination.

View details for DOI 10.1007/s00432-004-0616-1

View details for Web of Science ID 000229641700003

View details for PubMedID 15818505

Abstract

The suppressive effect of rapamycin on T cells has been extensively studied, but its influence on the function of APC is less clear. The data in this study demonstrated that immunostimulatory activity of B10 (H2(b)) dendritic cells (DC) exposed to rapamycin (rapa-DC) was markedly suppressed as evidenced by the induction of low proliferative responses and specific CTL activity in allogeneic (C3H, H2(k)) T cells. Administration of rapa-DC significantly prolonged survival of B10 cardiac allografts in C3H recipients. Treatment with rapamycin did not affect DC expression of MHC class II and costimulatory molecules or IL-12 production. Rapamycin did not inhibit DC NF-kappaB pathway, however, IL-12 signaling through Janus kinase 2/Stat4 activation was markedly suppressed. Indeed, Stat4(-/-) DC similarly displayed poor allostimulatory activity. The Stat4 downstream product, IFN-gamma, was also inhibited by rapamycin, but DC dysfunction could not solely be attributed to low IFN-gamma production as DC deficient in IFN-gamma still exhibited vigorous allostimulatory activity. Rapamycin did not affect DC IL-12R expression, but markedly suppressed IL-18Ralpha and beta expression, which may in turn down-regulate DC IL-12 autocrine activation.

View details for Web of Science ID 000188378700004

View details for PubMedID 14734710

Abstract

Bone marrow-derived dendritic cells (DCs) can be genetically engineered using adenoviral (Ad) vectors to express immunosuppressive molecules that promote T cell unresponsiveness. The success of these DCs for therapy of allograft rejection has been limited in part by the potential of the adenovirus to promote DC maturation and the inherent ability of the DC to undergo maturation following in vivo administration. DC maturation occurs via NF-kappaB-dependent mechanisms, which can be blocked by double-stranded "decoy" oligodeoxyribonucleotides (ODNs) containing binding sites for NF-kappaB. Herein, we describe the combined use of NF-kappaB ODNs and rAd vectors encoding CTLA4-Ig (Ad CTLA4-Ig) to generate stably immature murine myeloid DCs that secrete the potent costimulation blocking agent. These Ad CTLA4-Ig-transduced ODN DCs exhibit markedly impaired allostimulatory ability and promote apoptosis of activated T cells. Furthermore, administration of Ad CTLA4-Ig ODN-treated donor DCs (C57BL10; B10(H-2b)) before transplant significantly prolongs MHC-mismatched (C3HHeJ; C3H(H-2k)) vascularized heart allograft survival, with long-term (>100 days) donor-specific graft survival in 40% of recipients. The mechanism(s) responsible for DC tolerogenicity, which may involve activation-induced apoptosis of alloreactive T cells, do not lead to skewing of intragraft Th cytokine responses. Use of NF-kappaB antisense decoys in conjunction with rAd encoding a potent costimulation blocking agent offers promise for therapy of allograft rejection or autoimmune disease with minimization of systemic immunosuppression.

View details for Web of Science ID 000177958200072

View details for PubMedID 12218160

Abstract

Solid organ transplantations have been performed successfully in selected HIV-positive patients with highly active antiretrovirus therapy (HAART). However, some of the medications in the HAART regimen require metabolism via the cytochrome P4503A, the same enzyme complex responsible for clearance of the calcineurin inhibitors cyclosporine and tacrolimus. Several case reports have described significant interactions between the agents used in HAART and immunosuppressive drugs. The goal of this report is to examine the extent of potential drug interactions between antiretroviral agents and tacrolimus after liver and kidney transplantation. Seven liver transplant (LTx) patients (M = 6, F = 1) and four kidney transplant (KTx) patients (M = 4) infected with HIV underwent surgery between September 1997 and January 2001. Initial immunosuppression consisted of tacrolimus and steroids for LTx patients or tacrolimus, steroids, and mycophenolate mofetil for KTx recipients. Their current baseline immunosuppression and HAART regimen were examined retrospectively. Of the seven liver recipients, one (case 4) died 2 weeks after LTx and never received HAART therapy posttransplantation. The remaining six patients were placed on a regimen consisting of two nucleoside reverse transcriptase inhibitors (NRTI) and one protease inhibitor (PI) (nelfinavir in 5, indinavir in 1) based on known viral sensitivities or history of a previous clinical response. Kidney recipients received NRTI and nonnucleoside reverse transcriptase inhibitors (NNRTI). The mean dose of tacrolimus in liver recipients was 0.6 mg/d, with mean trough concentration of 9.7 mg/mL. Compared with historic controls (liver transplant patients not on HAART), the average tacrolimus dose was 16-fold lower in patients on HAART. In contrast to liver recipients, HIV-positive kidney recipients not on PI therapy required a mean tacrolimus dose of 9.5 mg/d to maintain a mean trough concentration of 9.6 ng/mL. Of the two protease inhibitors used, nelfinavir seems to have a more profound effect than indinavir. When patients on nelfinavir alone (n = 5) were compared with a control group not on antiretroviral therapy, the need for a tacrolimus dose was 38 times lower (mean dose, 0.26 mg/d). Profound drug interactions between PI and tacrolimus have been observed requiring up to 50-fold reductions in dosage. This effect seems to be most pronounced with the use of nelfinavir as opposed to indinavir, although further experience is required to confirm this observation. In contrast, HAART using NRTI and NNRTI without the use of PI, as shown in kidney recipients, produces less significant effects on tacrolimus metabolism. Great caution and frequent drug level monitoring are necessary when HAART is introduced or withdrawn in HIV-positive recipients of organ transplants.

View details for DOI 10.1053/jlts.2002.34880

View details for Web of Science ID 000177738500018

View details for PubMedID 12200788

View details for Web of Science ID 000177369700012

View details for PubMedID 12176411

Abstract

Dendritic cells (DCs) induce and regulate T-cell-mediated immune responses. Circulating precursor (p)DC1 and pDC2 from patients with chronic hepatitis B virus (HBV) infection were quantified by flow cytometry. To assess their function, DC1 were cultured from patients and compared to those of healthy volunteers. HBV patients exhibited a significant decrease in the proportion of freshly isolated pDC1 to pDC2. DC1 propagated from patients showed lower expression of costimulatory molecules and impaired allostimulatory capacity in comparison to controls. After exposure to proinflammatory cytokines, expression of costimulatory molecules, secretion of interleukin-12 (IL-12) and allostimulatory properties increased, but capacity for T-cell stimulation and IL-12 production remained inferior to that of control DCs. HBV-DNA was amplified by polymerase chain reaction in DC1 cultured from all patients. Viral particles were visible in DC1 by electron microscopy. These results suggest that intracellular presence of HBV impairs DC1 functional maturation and subsequent deficits in T-lymphocyte activation may contribute to viral persistence.

View details for DOI 10.1006/clim.2002.5245

View details for Web of Science ID 000178054500006

View details for PubMedID 12165275

View details for Web of Science ID 000177369700075

View details for PubMedID 12176474

Abstract

Leukocytes resident in the liver may play a role in immune responses. We describe a cell population propagated from mouse liver nonparenchymal cells in IL-3 and anti-CD40 mAb that exhibits a distinct surface immunophenotype and function in directing differentiation of naive allogeneic T cells. After culture, such cells are DEC-205(bright)B220+CD11c-CD19-, and negative for T (CD3, CD4, CD8alpha), NK (NK 1.1) cell markers, and myeloid Ags (CD11b, CD13, CD14). These liver-derived DEC205+B220+ CD19- cells have a morphology and migratory capacity similar to dendritic cells. Interestingly, they possess Ig gene rearrangements, but lack Ig molecule expression on the cell surface. They induce low thymidine uptake of allogeneic T cells in MLR due to extensive apoptosis of activated T cells. T cell proliferation is restored by addition of the common caspase inhibitor peptide, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk). T cells stimulated by liver-derived DEC205+B220+D19- cells release both IL-10 and IFN-gamma, small amounts of TGF-beta, and no IL-2 or IL-4, a cytokine profile resembling T regulatory type 1 cells. Expression of IL-10 and IFN-gamma, but not bioactive IL-12 in liver DEC205+B220+CD19- cells was demonstrated by RNase protection assay. In vivo administration of liver DEC205+B220+CD19- cells significantly prolonged the survival of vascularized cardiac allografts in an alloantigen-specific manner.

View details for Web of Science ID 000170949000006

View details for PubMedID 11390448

View details for Web of Science ID 000167629900097

View details for PubMedID 11266790

View details for Web of Science ID 000167629900690

View details for PubMedID 11267383

View details for Web of Science ID 000167629900692

View details for PubMedID 11267385

View details for Web of Science ID 000167629900099

View details for PubMedID 11266792

Abstract

To evaluate the long-term survival outcomes of a large cohort of liver transplant recipients and to identify static and changing factors that influenced these outcomes over time.Liver transplantation has been accepted as a therapeutic option for patients with end-stage liver disease since 1983, with continual improvements in patient survival as a result of advances in immunosuppression and medical management, technical achievements, and improvements in procurement and preservation. Although many reports, including registry data, have delineated short-term factors that influence survival, few reports have examined factors that affect long-term survival after liver transplantation.Four thousand consecutive patients who underwent liver transplantation between February 1981 and April 1998 were included in this analysis and were followed up to March 2000. The effect of donor and recipient age at the time of transplantation, recipient gender, diagnosis, and year of transplantation were compared. Rates of retransplantation, causes of retransplantation, and cause of death were also examined.The overall patient survival for the entire cohort was 59%; the actuarial 18-year survival was 48%. Patient survival was significantly better in children, in female recipients, and in patients who received transplants after 1990. The rates of retransplantation for acute or chronic rejection were significantly lower with tacrolimus-based immunosuppression. The risk of graft failure and death was relatively stable after the first year, with recurrence of disease, malignancies, and age-related complications being the major factors for loss.Significantly improved patient and graft survival has been observed over time, and graft loss from acute or chronic rejection has emerged as a rarity. Age-related and disease-related causes of graft loss represent the greatest threat to long-term survival.

View details for Web of Science ID 000089602400007

View details for PubMedID 10998647

Abstract

The prevention of recurrent hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) with hepatitis B immunoglobulin (HBIG) is expensive and requires indefinite parenteral administration. Lamivudine is a nucleoside analogue capable of inhibiting HBV replication. The aim of this study is to determine the efficacy of lamivudine in the prevention of recurrent HBV infection after a course of HBIG in patients who were hepatitis B surface antigen (HBsAg) positive and hepatitis Be antigen (HBeAg) negative before OLT. Patients at high risk for recurrent HBV infection (HBeAg positive and HBV DNA positive) were excluded. Thirty HBsAg-positive, HBeAg-negative patients underwent OLT from January 1993 to June 1997. All 30 patients were administered HBIG after OLT and, after 2 years, were given the option of continuing with HBIG or switching to lamivudine. Five patients were excluded: 3 patients were lost to follow-up and 2 patients died of technical complications. Three patients terminated HBIG therapy at 8, 24, and 29 months after OLT, and reinfection with HBV occurred in 1 patient. Six patients elected to continue HBIG therapy for life; 1 patient died of melanoma and the remaining 5 patients are HBsAg negative, with an average follow-up of 73 months. Sixteen patients were converted to lamivudine after a course of HBIG, and all 16 patients are HBsAg negative, with an average follow-up of 51 months after OLT. Five patients have been on lamivudine monotherapy for more than 24 months. These results suggest that lamivudine administered after a posttransplantation course of HBIG can effectively prevent the recurrence of HBV infection in patients who are HBsAg positive and HBeAg negative before OLT.

View details for Web of Science ID 000088523100007

View details for PubMedID 10915164

Abstract

Dendritic cells (DC) classically promote immune responses but can be manipulated to induce antigen-specific hyporesponsiveness in vitro. The expression of costimulatory molecules (CD40, CD86, CD80) at the DC cell surface correlates with their capacity to induce or suppress immune responses. Expression of these molecules is associated with NF-kB-dependent transcription of their genes. DC tolerogenicity has been associated with impaired NF-kB-dependent transcription of costimulatory genes as well as NF-kB translocation to the nucleus. In this report, we demonstrate that double-stranded oligodeoxyribonucleotides containing binding sites for NF-kB (NF-kB ODN) are efficiently incorporated by bone marrow-derived DC and specifically inhibit NF-kB-dependent transcription of a reporter gene. Moreover, exposure of DC to the oligonucleotide decoys inhibited lipopolysaccharide (LPS)-induced nitric oxide production, a marker of DC maturation. Treatment of bone marrow-derived DC progenitors with NF-kB ODN selectively suppressed the cell-surface expression of costimulatory molecules without interfering with MHC class I or class II expression. Furthermore, NF-kB ODN DC induced allogeneic donor-specific hyporesponsiveness in mixed leukocyte cultures, and this was associated with inhibition of Th1-type cytokine production. Finally, infusion of NF-kB ODN-modified bone marrow-derived DC into allogeneic recipients prior to heart transplantation resulted in significant prolongation of allograft survival in the absence of immunosuppression. Specific interference with NF-kB and other transcriptional pathways involved in immune stimulation in DC using ODN decoy approaches could be one means to promote tolerance induction in organ transplantation.

View details for Web of Science ID 000090048100008

View details for PubMedID 10933964

Abstract

The pathologic TNM (pTNM) staging system was designed to aid in determining the prognosis of cancer patients and in planning and evaluating their treatment. The current pTNM classification system was not found to be predictive for patients undergoing orthotopic liver transplantation (OLTx) in the presence of hepatocellular carcinoma (HCC). Therefore, the authors examined the current system to determine whether improvements would allow the development of a more predictive system.Three hundred seven patients with HCC underwent OLTx between 1981 and 1997. Risk factors for recurrence were identified using the Kaplan-Meier method with the log rank test. The Cox proportional hazards model was used to identify factors independently predictive of recurrence which were then used to create a new staging system.There was neither a direct correlation between the current pTNM system and tumor free survival nor homogeneity in outcomes for patients within certain current pTNM categories. Depth of vascular invasion, lobar distribution, lymph node status, and largest tumor size were found to be independent predictors of tumor free survival; tumor number was not found to be significant in multivariate analysis. A new staging system is proposed, which takes into account the results of the multivariate analysis in which tumor free survival correlates directly with stage.The proposed staging system is superior to the current pTNM staging system in predicting tumor free survival following OLTx with HCC. Further studies will determine the appropriateness of this system for staging HCC after subtotal hepatic resection.

View details for Web of Science ID 000084874900007

View details for PubMedID 10649244

Abstract

The shortage of donor organs occasionally mandates the use of hepatic allografts from anti-HBc+ donors in recipients who are susceptible to de novo hepatitis B virus (HBV) infection. The efficacy of hepatitis B immune globulin and lamivudine to prevent de novo HBV infection in anti-HBs negative recipients of allografts from anti-HBc+ donors has not been investigated.After liver transplantation with an allograft from a donor positive for anti-HBc, recipients who were anti-HBs-, HbsAg- received hepatitis B immune globulin (HBIG) 10,000 IU i.v. daily for 7 days and monthly for 6 months. After 6 months, 1000 IU of HBIG was given IM. every 2 weeks for 18 months. Patients transplanted after 4/1/97 were given lamivudine 150 mg daily starting postoperative day 1.Between 8/14/96 and 6/10/98, 264 orthotopic liver transplants were performed and 16 anti-HBs-, HbsAg- patients received an hepatic allograft from a donor positive for anti-HBc. HBIG mono-therapy was administered to one patient. HBIG and lamivudine combination therapy was administered to 15 patients. Of the 16 patients, 8 were positive only for anti-HBc before transplant, and 8 were naive (anti-HBs-, anti-HBc-). The single patient who received HBIG monotherapy became HbsAg+ at 6 months. All patients receiving combination therapy with HBIG and lamivudine have remained HbsAg-. The average follow-up is 459 days (range 170-754). Two patients died from unrelated causes.Combination therapy with HBIG and lamivudine may prevent de novo HBV infection in anti-HBs-, HbsAg- recipients of hepatic allografts from anti-HBc+ donors.

View details for Web of Science ID 000083163800028

View details for PubMedID 10532552

Abstract

Dendritic cells (DC) are highly specialized antigen-presenting cells (APC) that initiate and modulate immune responses. They are essential for naive T cell activation, but may also play roles both in central and peripheral tolerance. Blockade of costimulatory pathways that provide the crucial second signal for lymphocyte activation is one strategy to augment the potential tolerogenicity of DC. Here, in vitro propagated DC were transduced using an adenoviral (Ad) vector to express the gene encoding cytotoxic T lymphocyte antigen 4-immunoglobulin (CTLA4lg), which blocks interaction of CD80 and CD86 on DC with CD28 on T cells. Supernatants of AdCTLA4lg-transduced DC strikingly inhibited mixed leukocyte reactions (MLR) induced by non-transduced DC. Whereas transduction of marker genes (LacZ or enhanced green fluorescence protein (EGFP)) did not alter their potent allostimulatory activity, DC transduced with CTLA4lg exhibited striking reductions in cell surface staining for CD86, but not MHC class II, and were poor stimulators of T cell proliferation and cytotoxic T lymphocyte (CTL) responses. In addition, they induced alloantigen-specific T cell hyporesponsiveness. They were detected, following local injection, in significantly increased numbers in the lymphoid tissue of unmodified allogeneic recipients. This is the first report of the functional properties of DC genetically engineered to express CTLA4lg.

View details for Web of Science ID 000079560200012

View details for PubMedID 10476215

View details for Web of Science ID 000078960600268

View details for PubMedID 10083259

View details for Web of Science ID 000078960600189

View details for PubMedID 10083180

Abstract

Our organ procurement organization has been forced to liberalize the donor criteria in order to expand the donor pool for pancreas transplantation. In this report, we describe our experience using whole organ pancreatic grafts from "marginal" donors, which include grafts obtained from donors over 45 years of age and from donors who were identified to be hemodynamically unstable at the time of organ retrieval.A prospective study was performed between July 1994 and March 1998, during which time 137 pancreas transplants were performed at our center using organs procured by our own surgeons (organs sent by other teams were excluded). The rapid en bloc technique was used exclusively. The use of pancreatic grafts from marginal donors was analyzed for short-term and overall graft survival, and for delayed graft function and complications.Overall pancreas graft survival for our series was 83%, with a mean follow-up of 23 months. There were 22 pancreas grafts from donors over 45 years of age, 13 of whom were greater than 50 years of age. The actual graft survival rate of the over-45 donor group was 86%. Fifty-one grafts were removed from hemodynamically unstable donors on high-dose vasopressors. The actual graft survival in this group was 86%. There was no significant difference found in graft survival between recipients of pancreatic grafts from marginal and nonmarginal donors. Delayed graft function was exhibited by more recipients of grafts from donors on high-dose vasopressors (P<0.05), but this had no effect on long-term graft survival and endocrine function. Recipients of marginal donor grafts did not have higher rates of complication compared to recipients of nonmarginal grafts.Based on our results, we currently employ a graft selection strategy not limited by donor age or hemodynamic stability. Our selection of pancreas organs for transplantation is based on careful inspection of the pancreas and determination of the adequacy of the ex vivo flush. Our results suggest that the current pancreas donor pool may be expanded substantially.

View details for Web of Science ID 000078352000017

View details for PubMedID 10075595

Abstract

Precise diagnosis of central nervous system (CNS) lesions in liver transplant recipients remains problematic. Brain biopsies are often not feasible as a result of coagulopathy. We sought to determine whether selected clinical or radiologic characteristics can predict the likely etiology of CNS lesions in liver transplant recipients and thus obviate the need for diagnostic brain biopsies.A 4-year prospective, observational, cohort study was conducted at liver transplant centers at four geographically diverse medical institutions. A total of 1730 consecutive liver transplant recipients were evaluated for CNS lesions; 60 patients with radiologically documented CNS lesions comprised the study sample.Vascular events (52%, 31/60), infections (181%, 11/60), immunosuppressive associated leukoencephalopathy (12%, 7/60), central pontine myelinolysis (8%, 5/60), and malignancy (3%, 2/60) were the predominant etiologies of CNS lesions. CNS lesions were most likely to occur within 30 days of transplantation (43%, 26/60); central pontine myelinolysis, subdural hematoma, acute infarcts, and Aspergillus brain abscesses were the predominant etiologies during this time. All brain abscesses were fungal; 73% (8/11) of these patients concurrently had documented extraneural (pulmonary) infection as a result of the same fungal pathogen. Thus, a diagnostic brain biopsy is not warranted in these patients. Patients on dialysis were more likely to have ischemic or infectious CNS lesions (P=0.03). Vascular events were more likely to occur in repeat transplant recipients (P=0.03). Twenty-five percent (15/60) of the CNS lesions occurred more than 1 year after transplantation; small vessel ischemic lesions, malignancy, or non-Aspergillus fungal brain abscesses accounted for all such lesions.A presumptive etiologic diagnosis can be established in a vast majority of CNS lesions in liver transplant recipients based on identifiable presentation that includes time of onset, unique risk factors, and neuroimaging characteristics. Empiric therapy of brain abscesses in liver transplant recipients should include antifungal and not antibacterial agents.

View details for Web of Science ID 000077958500005

View details for PubMedID 9884245

View details for Web of Science ID 000074150800262

View details for PubMedID 9636637

View details for Web of Science ID 000072657300036

View details for PubMedID 9532047

Abstract

The influence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and the recently identified hematopoietic stem-progenitor cell mobilizing factor flt3 ligand (FL) on donor leukocyte microchimerism in noncytodepleted recipients of allogeneic bone marrow (BM) was compared. B10 mice (H2b) given 50x10(6) allogeneic (B10.BR [H2k]) BM cells also received either GM-CSF (4 microg/day s.c.), FL (10 microg/day i.p.), or no cytokine, with or without concomitant tacrolimus (formerly FK506; 2 mg/kg) from day 0. Chimerism was quantitated in the spleen 7 days after transplantation by both polymerase chain reaction (donor DNA [major histocompatibility complex class II; I-E(k)]) and immunohistochemical (donor [I-E(k)+] cell) analyses. Whereas GM-CSF alone significantly augmented (fivefold) the level of donor DNA in recipients' spleens, FL alone caused a significant (60%) reduction. Donor DNA was increased 10-fold by tacrolimus alone, whereas coadministration of GM-CSF and tacrolimus resulted in a greater than additive effect (28-fold increase). A much more striking effect was observed with FL + tacrolimus (>125-fold increase in donor DNA compared with BM alone). These findings were reflected in the relative numbers of donor major histocompatibility complex class II+ cells (many resembling dendritic cells) detected in spleens, although quantitative differences among the groups were less pronounced. Evaluation of cytotoxic T lymphocyte generation by BM recipients' spleen cells revealed that FL alone augmented antidonor immunity and that this was reversed by tacrolimus. Thus, although FL may potentiate antidonor reactivity in nonimmunosuppressed, allogeneic BM recipients, it exhibits potent chimerism-enhancing activity when coadministered with recipient immunosuppressive therapy.

View details for Web of Science ID A1997WZ23100001

View details for PubMedID 9158008

View details for Web of Science ID A1997WM12700491

View details for PubMedID 9123225

View details for Web of Science ID A1997BJ40F00046

View details for PubMedID 9286374

Abstract

Dendritic cells (DC) are the most potent known antigen presenting cells, and play important roles both in immunity and tolerance induction. Nitric oxide (NO) is an important effector molecule that is involved in numerous aspects of the immune response. There have been no accounts to date of efforts to determine NO generation by well-characterized DC. In this report we describe the production of NO by highly purified DEC 205+ DC propagated from mouse bone marrow in response to granulocyte/macrophage-colony stimulating factor (GM-CSF) + interleukin-4 (IL-4). NO synthesis was induced in DC by interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS), and was blocked by the inhibitor of nitric oxide synthase (NOS), NG-monomethyl-L-arginine (NMMA). Both "mature" B7-2+ (CD86+) DC and B7-2- (CD86-) DC progenitors could be induced to release NO. NO was also recovered from the supernatants of primary mixed leukocyte cultures containing comparatively high concentrations of B7-2+ DC in relation to purified allogeneic T cells. Furthermore, inhibition of NO release in these cultures by NMMA resulted in an increase in T cell proliferation. These observations suggest that NO may be an important soluble mediator of the interaction between DC and activated T cells. In addition to its ability to inhibit T cell proliferation, NO was also shown to induce programmed cell death in DC. This was visualized by the detection of DNA strand breaks with in situ nick translation. The percentage of DC apoptosis correlated with the level of NO in the cultures. Apoptosis was inhibited by the addition of NMMA. These results indicate that DC have the capacity both to stimulate and potentially limit the same allogeneic T cell response, in accordance with their production of NO.

View details for Web of Science ID A1996WA91600033

View details for PubMedID 8990379

Abstract

Nitric oxide (NO) is an important effector molecule that is involved in immune regulation and host defense. In this study, highly purified NLDC 145+ (DEC-205+) MHC class II(bright) B7-2+ dendritic cells (DC) propagated from normal mouse bone marrow in response to granulocyte-macrophage CSF + IL-4 were induced to produce NO by IFN-gamma and LPS. NO production was inhibited by the nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (NMMA). Nitrite also accumulated in mixed leukocyte culture supernatants as the result of coculture of DC with purified naive allogeneic T cells. Furthermore, NO production was induced by CD40 ligation. Suboptimal T cell proliferation observed at high relative concentrations of DC correlated with increased NO production and was mitigated by NMMA. Induction of mRNA for an inducible NOS (iNOS) in DC was confirmed by Northern blotting, whereas intracellular iNOS was visualized by two-color flow cytometry and by both immunofluorescent and immunogold labeling in a subpopulation of IFN-gamma + LPS-stimulated cells. Both endogenous NO production and exposure of unstimulated DC to the NO donor S-nitroso-N-acetyl-penicillamine (SNAP) resulted in DC apoptosis. Thus, although DC function initially as the most potent APCs for T cell activation, DC induced to synthesize NOS by IFN-gamma may inhibit (allogeneic) T cell proliferation: NO may suppress lymphocyte proliferation and also induce apoptosis of the most potent source of alloantigenic stimulation.

View details for Web of Science ID A1996VP22600047

View details for PubMedID 8871658

Abstract

Transforming growth factor-beta (TGF-beta) exhibits strong antiproliferative effects upon lymphocytes and inhibits many of the effector functions of activated immune cells. However, its influence on the inductive phase of immune responses, and in particular its effect on antigen-presenting cells (APC), has not been well studied. In this investigation, we examined the influence of human TGF-beta 1 on the antigen-presenting function of human bone marrow (BM)-derived APC propagated in liquid culture for 11-17 days in response to granulocyte/macrophage colony-stimulating factor (GM-CSF). These cells were predominantly macrophages, accompanied by a minor population of dendritic cells. TGF-beta 1 had no effect upon the allostimulatory function of vertebral body whole BM cells cultured for 3-5 days in GM-CSF. However, it markedly reduced the allostimulatory capacity of BM-derived APC exposed to the cytokine for the last 3 days of culture. This inhibitory action could not be ascribed to cytokine 'carry-over', or to any consistent changes in the expression of cell surface molecules implicated in antigen presentation (HLA-DR), intercellular adhesion (ICAM-1; CD54), or costimulatory activity (B7-1; CD80). Mechanisms that may underlie the inhibitory action of TGF-beta on APC function and the immunologic and possible clinical implications of the findings are discussed.

View details for PubMedID 8893447

Abstract

Tacrolimus, formerly known as FK506, is a macrolide antibiotic with immunosuppressive properties. Although structurally unrelated to cyclosporin A (CsA), its mode of action is similar. It exerts its effects principally through impairment of gene expression in target cells. Tacrolimus bonds to an immunophilin, FK506 binding protein (FKBP). This complex inhibits calcineurin phosphatase. The drug inhibits calcium-dependent events, such as interleukin-2 gene transcription, nitric oxide synthase activation, cell degranulation, and apoptosis. Tacrolimus also potentiates the actions of glucocorticoids and progesterone by binding to FKBPs contained within the hormone receptor complex, preventing degradation. The agent may enhance expression of the transforming growth factor beta-1 gene in a fashion analogous to that demonstrated for CsA. T cell proliferation in response to ligation of the T cell receptor is inhibited by tacrolimus. Type 1 T helper cells appear to be preferentially suppressed compared with type 2 T helper cells. T cell-mediated cytotoxicity is impaired. B cell growth and antibody production are affected indirectly by the suppression of T cell-derived growth factors necessary for these functions. Antigen presentation appears to be spared. The molecular events affected by tacrolimus continue to be discovered.

View details for Web of Science ID A1995TF69700007

View details for PubMedID 8588225

View details for Web of Science ID A1995RY73500001

View details for PubMedID 7554374

Abstract

Theoretically, drugs that inhibit programmed cell death could be used to inhibit the increased apoptotic decay of lymphocyte populations in human immunodeficiency virus (HIV) infection. The concept that immunopathologic processes cause immune suppression provides a further rationale for the use of agents such as cyclosporin A (CsA) or tacrolimus (formerly known as FK506) early in HIV infection to reduce cytotoxic CD8+ T cell-mediated destruction of HIV-infected target cells.

View details for Web of Science ID A1995BD53D00018

View details for PubMedID 7572394