Is alanine aminotransferase a good marker of histologic hepatic damage in renal transplant patients with hepatitis C virus infection?

Non-Invasive Assessment of Liver Fibrosis and Steatosis in End-Stage Renal Disease Patients Undergoing Renal Transplant Evaluation

Background

Non-alcoholic fatty liver disease (NAFLD) has an increased prevalence in end-stage renal disease (ESRD) due to similar risk factors. The aim of this study was to assess non-invasive testing including transient elastography (TE) for liver stiffness (LS), controlled attenuated parameter (CAP) for steatosis, Fibrosis-4 (FIB-4) score, aspartate aminotransferase (AST) to platelet ratio index (APRI) and NAFLD fibrosis score (NFS), for evaluation of NAFLD along with advanced fibrosis (AF) in patients with ESRD undergoing renal transplant evaluation.

Methods

Data were retrospectively collected within 12 weeks of TE. Primary outcomes were AF, defined by LS ≥ 9 kPa compared to APRI > 1.5, FIB-4 > 2.67, and NFS of 0.675, and ≥ 5% steatosis by CAP ≥ 263 dB/m compared to liver histology when available.

Results

A total of 171 patients were evaluated: mean age 56, 65% male, 36% obese, 47% had diabetes, 96% hypertension, and 56% dyslipidemia. Mean LS was 6.5 kPa with 21% having AF. Mean CAP was 232 dB/m, with 25% having steatosis. Those with AF were older with higher NFS. Those with steatosis were obese and had diabetes without higher LS or fibrosis scores. Only NFS was associated with LS ≥ 9 kPa. In those with liver histology, AF was associated with LS ≥ 9 kPa but not with APRI, FIB-4, or NFS.

Conclusions

Despite normal liver enzymes, non-invasive assessment via TE in ESRD patients exhibited high prevalence of AF and steatosis not detected by APRI or FIB-4 scores. This high prevalence was secondary to the common risk factors such as obesity and diabetes, among patients with NAFLD and ESRD.

Diagnostic Accuracy of Noninvasive Tests to Detect Advanced Hepatic Fibrosis in Patients With Hepatitis C and End-Stage Renal Disease

BACKGROUND & AIMS

For patients with liver disease from hepatitis C virus (HCV) infection complicated by end-stage renal disease (ESRD), it is important to assess liver fibrosis before kidney transplantation. We evaluated the accuracy of non-invasive tests to identify advanced hepatic fibrosis in patients with HCV and ESRD.

METHODS

In a retrospective study, we collected data on ratio of aspartate aminotransferase:alanine aminotransferase (AST:ALT), AST platelet ratio index (APRI), FIB-4 score, fibrosis index score, and King's score from 139 patients with ESRD and HCV infection (mean age, 52.8 y; 76.3% male; 86.4% African American; 45.3% with increased level of ALT). Results were compared with findings from histologic analyses of biopsies (reference standard). The primary outcome was detection of advanced fibrosis, defined as either bridging fibrosis or cirrhosis. Area under the receiver operating characteristic (AUROC) curves were constructed and optimal cutoff values were determined for each test. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated. We repeated the analysis with stratification for normal levels of ALT (≤ 35 U/L for men and ≤ 25 u/L for women) and increased levels of ALT.

RESULTS

FIB-4 scores identified patients with advanced fibrosis with an AUROC of 0.71 (95% CI, 0.61-0.80), the King's score with an AUROC of 0.69 (95% CI, 0.58-0.80), and the APRI with and AUROC of 0.68 (95% CI, 0.59-0.79). The accuracy of these tests increased when they were used to analyze patients with increased levels of ALT. All tests produced inaccurate results when they were used to assess patients with normal levels of AST and ALT.

CONCLUSIONS

In patients with ESRD and HCV infection, FIB-4 scores, King's scores, and the APRI identify those with advanced fibrosis with AUROC values ranging from 0.68-0.71. Accuracy increased modestly when patients with increased levels of ALT were tested, but the tests produced inaccurate results for patients with a normal level of ALT.

A time-to-event analysis describing virologic response in patients with chronic hepatitis C infection

The objective of this project was to describe longitudinal change in chronic hepatitis C virologic reponse using time-to-event (TTE) analysis and to identify patient characteristics that determine the dynamics of this change. We compiled demographic, clinical, and genetic data from 715 chronic hepatitis C virus (HCV) patients treated with pegylated interferon (PEG-IFN) alfa-2a and ribavirin. TTE modelling described the time between antiviral treatment initiation and the first observation of undetectable HCV RNA. A lognormal TTE model was selected to describe time to first undetectable HCV RNA. The identified predictors of prolonged time to achieve undetectable HCV RNA include HCV genotype 1, low pre-treatment ALT level, older age, or with elevated baseline haemoglobin level. In conclusion, a cohort of patients with low probability of achieving SVR can be identified. This project identifies patients with a low risk of responding to PEG-IFN alfa-2a and ribavirin combination.

Prediction of significant liver fibrosis in kidney transplant patients with chronic hepatitis C virus infection: the TX-3 index

HCV infection is highly prevalent among kidney transplant (KT) recipients. The natural history and management of these patients are controversial. We sought to assess the diagnostic value of noninvasive markers of liver fibrosis in KT HCV-infected patients. This cross-sectional study included 102 KT individuals with positive HCV-RNA. Bivariate and multivariate analyses were used to identify variables associated with significant fibrosis (METAVIR > or = F2). Significant fibrosis was observed in 20 patients (20%). Time after transplantation, AST level, and platelet count were identified as independent predictors of significant fibrosis. Based on the regression model, a simplified index was devised. The AUROC for the TX-3 model was 0.867 +/- 0.081 (0.909, when adjusted by DANA). Values < or =4.0 of TX-3 showed a NPV of 97% and scores >9.6 exhibited a PPV of 71%. If biopsy indication was restricted to scores in the intermediate range of TX-3, this could have been correctly avoided in 68% of cases. The APRI score provided a correct diagnosis in only 47 individuals (46%) and exhibited lower diagnostic indices for both cutoffs, as compared to the TX-3 index. Comparison of AUROCs showed a trend towards superior diagnostic accuracy for TX-3 over APRI, although the difference between AUROCs did not reach statistical significance (0.867 +/- 0.053 vs 0.762 +/- 0.066, respectively, P = 0.064). In conclusion, significant liver fibrosis can be reliably predicted in KT HCV-infected subjects by simple and widely available parameters. If additional studies confirm our results, this model might obviate the requirement for a liver biopsy in a significant proportion of those patients.

Efficacy and safety of pegylated-interferon α-2a in hemodialysis patients with chronic hepatitis C

AIM: To evaluate the efficacy and safety of pegylated-interferon alpha-2a in hemodialysis patients with chronic hepatitis C.

METHODS: Thirty-six hemodialysis patients with chronic hepatitis C were enrolled in a controlled and prospective study. All patients were treatment naive, positive tested for anti-HCV antibodies, and positive tested for serum HCV-RNA. Twenty-two patients received 135 &mgr;g peglyated-interferon α-2a weekly for 48 wk (group A). The remaining patients were left untreated, eleven refused therapy, and three were not candidates for kidney transplantation and were allocated to the control group (group B). At the end of the treatment biochemical and virological response was evaluated, and 24 wk after completion of therapy sustained virological response (SVR) was assessed. Side effects were monitored.

RESULTS: Of 22 hemodialysis patients, 12 were male and 10 female, with a mean age of 35.2 ± 12.1 years. Virological end-of-treatment response was observed in 14 patients (82.4%) in group A and in one patient (7.1%) in group B (P = 0.001). Sustained virological response was observed in 11 patients (64.7%) in group A and in one patient in group B (7.1%). Biochemical response parameters normalized in 10/14 patients (71.4%) at the end of the treatment. ALT levels in group B were initially high in six patients and normalized in one of them (25%) at the end of the 48 wk. In five patients (22.7%) therapy had to be stopped at mo 4 due to complications of weakness, anemia, and bleeding.

CONCLUSION: SVR could be achieved in 64.7% of patients on hemodialysis with chronic hepatitis C by a treatment with peglyated-interferon α-2a. Group A had a significantly better efficacy compared to the control group B, but the side effects need to be concerned.