Biomedical subjects

Russell H Wiesner

Publications and source records attributed to Russell H Wiesner.

41 records · Page 3Linked to original sources

PubMed2002

Treatment of posttransplantation recurrence of hepatitis C with interferon and ribavirin: lessons on tolerability and efficacy.

Recurrence of hepatitis C virus (HCV) infection after orthotopic liver transplantation is a major cause of graft failure. The aim of our study was to determine the safety, efficacy, and tolerability of combination therapy with interferon and ribavirin in the treatment of recurrent hepatitis after liver transplantation. Twenty-six patients (18 men) with histologically established HCV recurrence after liver transplantation for cirrhosis secondary to chronic HCV infection were treated with a combination of interferon alfa-2b (3 million units three times weekly) and ribavirin (800 to 1,000 mg/d). Dosage modifications were according to a standard protocol incorporating laboratory values and clinical side effects. Fifty percent of patients completed 1 year or more of therapy. On an intention-to-treat basis, nine patients (35%) showed an end-of-treatment virological response. Six of these nine patients completed greater than 6 additional months of follow-up, and all have had sustained virological responses. A histological response (decrease in histological activity index > or = 2) was seen in 75% of virological responders and 67% of nonresponders. Adverse events requiring dose modification or cessation of therapy occurred in 66% of patients. Adjuvant therapies used to support hemoglobin levels included erythropoietin and red blood cell transfusions. There were no independent pretreatment predictors of a virological response, perhaps because of the small sample size. Combination therapy with interferon and ribavirin may be beneficial in patients with recurrent HCV after liver transplantation. The majority of patients require dose modifications because of side effects. Histological response is common in virological nonresponders.

Adult↗

PubMed2002

Differential allograft gene expression in acute cellular rejection and recurrence of hepatitis C after liver transplantation.

Treatment of acute cellular rejection (ACR) is associated with increased viral load, more severe histologic recurrence, and diminished patient and graft survival after liver transplantation for hepatitis C virus (HCV). Recurrence of HCV may be difficult to distinguish histologically from ACR. Because the immunologic mechanisms of ACR and HCV recurrence are likely to differ, we hypothesized that ACR is associated with the expression of a specific subset of immune activation genes that may serve as a diagnostic indicator of ACR and provide mechanistic insight into the pathophysiology of ACR and recurrence of HCV. The goal of the study was to study intragraft gene expression patterns in ACR and during recurrence of HCV in HCV-infected recipients. High-density microarrays were used to determine relative intragraft gene expression in two groups of HCV-infected liver transplant recipients: four with steroid responsive ACR by Banff criteria and four age- and gender-matched HCV-infected recipients with similar necroinflammatory activity but without histological criteria for rejection (no cholangitis or endotheliitis). Immunosuppression was similar in both groups. Other etiologies of graft dysfunction were excluded by ultrasound, cholangiography, and cultures. High-quality total RNA was extracted from snap frozen liver biopsies, reverse transcribed, labeled with biotin, and fragmented according to established protocol. Twenty-five genes were relatively overexpressed, and 15 were relatively underexpressed by > or = twofold in the ACR when compared with the HCV group. ACR was most notably associated with the relative overexpression of genes associated with major histocompatibility complex I and II, insulin-like growth factor-1 expression, apoptosis induction, and T-cell activation. In HCV-infected liver transplant recipients, ACR is associated with an intragraft gene expression profile that is distinct from that seen during recurrence of HCV. These experiments provide evidence that alloimmunity, as indicated by expression of T-cell activation and apoptosis-inducing genes, is less important in recurrence of HCV than in ACR. Further studies are required to determine whether gene expression profiles, either intragraft or in serum, can be used for the diagnosis and differentiation of ACR from recurrence of HCV.

Adult↗

PubMed2002

Chronic renal dysfunction late after liver transplantation.

With the increasing success of liver transplantation, more patients are developing late complications such as renal dysfunction. The goal of the current study was to assess the prevalence of renal dysfunction years after liver transplantation and to identify patients at risk for the development of this complication. Of the 527 liver transplantations performed at our institution between April 1990 and October 1998, 353 had pretransplantation and posttransplantation glomerular filtration rate (GFR) determinations by iothalamate clearance. From this entire group, 198 patients had actual 4-year follow-up and 52 had actual 6-year follow-up. In addition, 191 of these patients had intensive follow-up with GFR measurements pretransplantation and at 1 and 3 years posttransplantation (complete follow-up group). All patients received either tacrolimus- or cyclosporine-based immunosuppression. The overall mean GFR levels in both of these groups was acceptable and was not different in cyclosporine- versus tacrolimus-based immunosuppressive regimens. Renal dysfunction was progressive, with 27.5% of patients in the intensive group having a GFR < 40 mL/min/body surface area 5 years after transplantation. GFR pretransplantation did not correlate well with late renal function; however, GFR at 1 year identified patients with subsequent renal dysfunction. The cumulative incidence of renal failure for the entire group was 6.25% at 7 years and 10% at 10 years. Renal dysfunction is a major late complication after liver transplantation. The GFR at 1 year correlates best with late renal function. Patients with a low GFR at 1 year (< 40 mL/min/BSA) are a high-risk group that might benefit from early therapeutic interventions aimed at preventing subsequent renal failure.

Chronic Disease↗

PubMed2002

The new liver allocation system: moving toward evidence-based transplantation policy.

In 1999, the Institute of Medicine suggested that instituting a continuous disease severity score that de-emphasizes waiting time could improve the allocation of cadaveric livers for transplantation. This report describes the development and initial implementation of this new plan. The goal was to develop a continuous disease severity scale that uses objective, readily available variables to predict mortality risk in patients with end-stage liver disease and reduce the emphasis on waiting time. Mechanisms were also developed for inclusion of good transplant candidates who do not have high risk of death but for whom transplantation may be urgent. The Model for End-Stage Liver Disease (MELD) and Pediatric End-Stage Liver Disease (PELD) scores were selected as the basis for the new allocation policy because of their high degree of accuracy for predicting death in patients having a variety of liver disease etiologies and across a broad spectrum of liver disease severity. Except for the most urgent patients, all patients will be ranked continuously under the new policy by their MELD/PELD score. Waiting time is used only to prioritize patients with identical MELD/PELD scores. Patients who are not well served by the MELD/PELD scores can be prioritized through a regionalized peer review system. This new liver allocation plan is based on more objective, verifiable measures of disease severity with minimal emphasis on waiting time. Application of such risk models provides an evidenced-based approach on which to base further refinements and improve the model.

Evidence-Based Medicine↗

PubMed2002

Ultrasound-assisted percutaneous liver biopsy performed by a physician assistant.

OBJECTIVE: Percutaneous liver biopsy is an essential diagnostic tool utilized in the management of patients with liver disease. This procedure is generally performed by a physician and has a small but well-defined complication rate. We report on the complication rate and efficiency of ultrasound-assisted percutaneous liver biopsy performed by an experienced physician assistant. METHODS: One thousand eighty-six consecutive outpatient liver biopsies (847 hepatic allografts and 239 native livers) were performed at a single center by a physician assistant between June, 1996 and June, 2000. Patients with hepatic mass lesions, unusual hepatic anatomy, and uncorrectable coagulopathy (international normalized ratio > 1.7, platelet count < 50 x 10(9)/L) were excluded. Bedside ultrasonography was used to determine the optimal site for the liver biopsy. Liver biopsies were performed with a 15-gauge Jamshidi aspiration biopsy needle. Patients were observed for 3 h after biopsy, followed by dismissal with subsequent contact in 24 h to assess outcome and complications. RESULTS: Adequate tissue was obtained in 1084 cases (99.8%), with a mean tissue length of 3.2 cm. After the procedure, narcotic analgesia was necessary in 116 (10%) of the patients undergoing liver biopsies. The overall complication rate requiring hospitalization was 0.6%. Major complications requiring intervention occurred in four patients (0.4%). There were no deaths resulting from liver biopsies. CONCLUSION: We conclude that outpatient percutaneous liver biopsy can be safely and effectively performed by a trained physician assistant.

Biopsy↗