Non-invasive biomarkers of liver fibrosis in liver transplant patients with hepatitis C: can we avoid liver biopsies?

The performance of enhanced liver fibrosis (ELF) test for the staging of liver fibrosis: a meta-analysis

BACKGROUND

The enhanced liver fibrosis test (ELF) has been shown to accurately predict significant liver fibrosis in several liver diseases.

AIMS

To perform a meta-analysis to assess the performance of the ELF test for the assessment of liver fibrosis.

STUDY

Electronic and manual searches were performed to identify studies of the ELF test. After methodological quality assessment and data extraction, pooled estimates of the sensitivity, specificity, area under the receiver operating characteristic curve (AUROC), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and summary receiver operating characteristics (sROC) were assessed systematically. The extent of heterogeneity and reasons for it were assessed.

RESULTS

Nine studies were identified for analysis. The pooled sensitivity, specificity, positive LR, negative LR, and DOR values of ELF test, for assessment of significant liver fibrosis, were 83% (95% CI=0.80-0.86), 73% (95% CI=0.69-0.77), 4.00 (95% CI=2.50-6.39), 0.24 (95% CI=0.17-0.34), and 16.10 (95% CI=8.27-31.34), respectively; and, for evaluation of severe liver fibrosis, were 78% (95% CI=0.74-0.81), 76% (95% CI=0.73-0.78), 4.39 (95% CI=2.76-6.97), 0.27 (95% CI=0.16-0.46), and 16.01 (95% CI: 7.15-35.82), respectively; and, for estimation of cirrhosis, were 80% (95% CI=0.75-0.85), 71% (95% CI=0.68-0.74), 3.13 (95% CI=2.01-4.87), 0.29 (95% CI=0.19-0.44), and 14.09 (95% CI: 5.43-36.59), respectively.

CONCLUSIONS

The ELF test shows good performance and considerable diagnostic value for the prediction of histological fibrosis stage.

Progression of liver fibrosis in post-transplant hepatitis C: mechanisms, assessment and treatment

Liver fibrosis results from an excessive wound healing response in most chronic liver diseases, such as hepatitis C. Despite great advances in antiviral therapy in recent years, progressive liver fibrosis remains a major problem for patients with recurrent hepatitis C after liver transplantation. Liver biopsy remains a central tool in the management of HCV-positive liver transplant recipients, but reliable non-invasive methods for the assessment of liver fibrosis, such as ultrasound elastography, are increasingly being incorporated in the management of post-transplant patients, helping predict prognosis, guide treatment decisions, and stratify patients for emerging antifibrotic therapies. In this manuscript, we will review the natural history as well as tools to monitor fibrosis progression in the HCV-positive liver transplant recipient, the mechanisms underlying rapid fibrosis progression in up to 30% of these patients, the effect of antiviral therapies and highlight promising antifibrotic approaches.

Ultrasound-based transient elastography for the detection of hepatic fibrosis in patients with recurrent hepatitis C virus after liver transplantation: a systematic review and meta-analysis

Ultrasound-based transient elastography (TE) is a promising noninvasive alternative to liver biopsy for the detection of hepatic fibrosis due to recurrent hepatitis C virus (HCV) after liver transplantation (LT). However, its overall test performance in various settings remains unknown. The aim of this study was to perform a systematic review and diagnostic accuracy meta-analysis of studies comparing ultrasound-based TE to liver biopsy for the detection of hepatic fibrosis due to a recurrent HCV infection after LT. Electronic and manual bibliographic searches (including scientific abstracts) were performed to identify potential studies. A meta-analysis was conducted to generate pooled estimates of the sensitivity values, specificity values, likelihood ratios, and diagnostic odds ratios of individual studies. The extent of the heterogeneity and the reasons for it were assessed. Six fully published studies were identified for analysis. Five studies that evaluated significant fibrosis were identified. Among these studies, the pooled estimates were 83% for sensitivity [95% confidence interval (CI) = 77%-88%], 83% for specificity (95% CI = 77%-88%), 4.95 for the positive likelihood ratio (95% CI = 3.4-7.2), 0.17 for the negative likelihood ratio (95% CI = 0.09-0.35), and 30.5 for the diagnostic odds ratio (95% CI = 12.8-72.4). For the 5 studies that assessed cirrhosis, the pooled estimates were 98% for sensitivity (95% CI = 90%-100%), 84% for specificity (95% CI = 80%-88%), 7 for the positive likelihood ratio (95% CI = 2.8-17.3), 0.06 for the negative likelihood ratio (95% CI = 0.02-0.19), and 130 for the diagnostic odds ratio (95% CI = 36.5-462.1). A diagnostic threshold (or cutoff value) bias was identified as an important cause of heterogeneity for the pooled results of both patient groups. In conclusion, ultrasound-based TE has excellent diagnostic accuracy for identifying cirrhosis due to a recurrent HCV infection after LT. The detection of significant fibrosis is more accurate for these patients versus patients whose native liver is chronically infected with HCV.

Prospective validation of a noninvasive index for predicting liver fibrosis in hepatitis C virus-infected liver transplant recipients

We previously developed a mathematical model, the Hospital Universitario La Fe (HULF) index, as an alternative to protocol liver biopsy (PLB) to estimate significant fibrosis (SF) in patients who underwent liver transplantation (LT) for liver damage caused by chronic HCV infection. In the present study, we sought to validate this noninvasive index. The commonly derived clinical and laboratory data for calculating the HULF index were prospectively collected over 2.7 years from patients undergoing LT and PLB. The sensitivity, specificity, positive and negative predictive values, and diagnostic capacity were evaluated with receiver operating characteristic curve analysis. Biopsy was performed 93 times in 86 LT patients. The prevalence of SF (F3-F4 on the Knodell scoring system) was 32%. The intraobserver and interobserver concordance was high (kappa = 0.94 and kappa = 0.75, respectively) in identifying SF in PLB. For low scores, the HULF index discarded an SF diagnosis with a sensitivity of 90% and a negative predictive value of 89%. The area under the receiver operating characteristic curve was 0.68. The precision of the HULF index did not improve with the incorporation of donor age and body mass index into the multivariate analysis. Applying the index would have prevented 24% of the biopsy procedures performed. In conclusion, the HULF index was prospectively validated with data commonly obtained in standard clinical practice. Because the index distinguishes a subgroup of HCV LT patients with a low probability of having SF, PLB would be avoided in those patients.