Use of simple noninvasive biomarkers to predict liver fibrosis in HIV/HCV coinfection in routine clinical practice

Use of Non-invasive Testing to Stage Liver Fibrosis in Patients with HIV

Patients with HIV have a proclivity to develop liver fibrosis, especially when associated with other conditions such as HCV, HBV, and NAFLD. Identifying HIV-infected patients with significant fibrosis or cirrhosis plays an important role in clinical and therapeutic decision-making. Liver biopsy is currently considered as the gold standard for fibrosis assessment but carries many shortcomings (cost, invasiveness, complications, false negative rate of 20 %). Multiple non-invasive methods of liver fibrosis assessment have been developed, but not all have been studied in HIV-infected individuals. Non-invasive liver fibrosis tools include both serologic-based testing scores (rely on direct and/or indirect markers) such as APRI, FIB4, FibroTest, FibroSpect II, HepaScore, or imaging-based methods such as vibration controlled liver elastography. There is validated data to support the use of non-invasive modalities of fibrosis assessment in HIV-HCV co-infected individuals for the exclusion of cirrhosis, but may be poorly reliable or not enough data exists for the assessment of other co-morbid disease processes.

Overestimate of Fibrosis by FIBROSpect® II in African Americans Complicates the Management of their Chronic Hepatitis C

BACKGROUND

Evaluation of advanced fibrosis in patients with hepatitis C virus (HCV) infection is used to facilitate decisions on treatment strategy and to initiate additional screening measures. Unfortunately, most studies have predominately Caucasian (Cau) patients and may not be as relevant for African Americans (AA).

AIMS

This study specifically addresses the issue of defining minimal vs. significant fibrosis in African Americans (AA) with chronic hepatitis C (CHC) using noninvasive assays.

METHODS

All patients (n = 319) seen between 1 January 2008 and 30 June 2013 for whom a FibroSpect II® (FSII) assay was performed and had data for calculation of aspartate aminotransferase (AST) platelet ratio index (APRI) and Fibrosis-4 (FIB-4) were identified using the medical records.

RESULTS

When liver biopsy score and FSII assay results for the AA patients with CHC were compared, 31% of AA had advanced FSII fibrosis scores (F2-F4) despite a biopsy score of F0-F1. In contrast, 10% of Cau over-scored. The AA false positive rate was 14% for APRI and 34% for FIB-4. Combining FSII with either APRI (7% false positive) or FIB-4 (10% false positive) improved the false positive rate in AA to 7% (FSII + APRI) and 10% (FSII + FIB-4) but reduced the sensitivity for significant fibrosis.

CONCLUSIONS

The FSII assay overestimates fibrosis in AA and should be used with caution since these patients may not have significant fibrosis. If the APRI or FIB-4 assay is combined with the FSII assay, minimal fibrosis in AA can be defined without subjecting the patients to a subsequent biopsy.

Prevalence of and progression to abnormal noninvasive markers of liver disease (aspartate aminotransferase-to-platelet ratio index and Fibrosis-4) among US HIV-infected youth

OBJECTIVE

To longitudinally characterize noninvasive markers of liver disease in HIV-infected youth.

DESIGN

HIV infection, without viral hepatitis coinfection, may contribute to liver disease. Noninvasive markers of liver disease [FIB-4 (Fibrosis-4) and APRI (aspartate aminotransferase-to-platelet ratio index)] have been evaluated in adults with concomitant HIV and hepatitis C, but are less studied in children.

METHODS

In prospective cohorts of HIV-infected and HIV-uninfected youth, we used linear regression models to compare log-transformed FIB-4 and APRI measures by HIV status based on a single visit at ages 15-20 years. We also longitudinally modeled trends in these measures in HIV-infected youth with two or more visits to compare those with behavioral vs. perinatal HIV infection (PHIV) using mixed effect linear regression, adjusting for age, sex, body mass index, and race/ethnicity.

RESULTS

Of 1785 participants, 41% were men, 57% black non-Hispanic, and 27% Hispanic. More HIV-infected than uninfected youth had an APRI score more than 0.5 (13 vs. 3%, P < 0.001). Among 1307 HIV-infected participants with longitudinal measures, FIB-4 scores increased 6% per year (P < 0.001) among all HIV-infected youth, whereas APRI scores increased 2% per year (P = 0.007) only among PHIV youth. The incidence rates (95% confidence interval) of progression of APRI to more than 0.5 and more than 1.5 were 7.5 (6.5-8.7) and 1.4 (1.0-1.9) cases per 100 person-years of follow-up, respectively. The incidence of progression of FIB-4 to more than 1.5 and more than 3.25 were 1.6 (1.2-2.2) and 0.3 (0.2-0.6) cases per 100 person-years, respectively.

CONCLUSION

APRI and FIB-4 scores were higher among HIV-infected youth. Progression to scores suggesting subclinical fibrosis or worse was common.

Heroin use promotes HCV infection and dysregulates HCV-related circulating microRNAs

Hepatitis C virus (HCV) infection is common among injection drug users (IDUs). There is accumulating evidence that circulating microRNAs (miRNAs) are associated with HCV infection and disease progression. The present study was undertaken to determine the in vivo impact of heroin use on HCV infection and HCV-related circulating miRNA expression. Using the blood specimens from four groups of the study subjects (HCV-infected individuals, heroin users with/without HCV infection, and healthy volunteers), we found that HCV-infected heroin users had significantly higher viral load than HCV-infected non-heroin users (p = 0.0004). Measurement of HCV-related circulating miRNAs in plasma showed that miRs-122, 141, 29a, 29b, and 29c were significantly increased in the heroin users with HCV infection, whereas miR-351, an HCV inhibitory miRNA, was significantly decreased in heroin users as compared to control subjects. Further investigation identified a negative correlation between the plasma levels of miR-29 family members and severity of HCV infection based on aspartate aminotransferase to platelet ratio index (APRI). In addition, heroin use and/or HCV infection also dysregulated a panel of plasma miRNAs. Taken together, these data for the first time revealed in vivo evidence that heroin use and/or HCV infection alter circulating miRNAs, which provides a novel mechanism for the impaired innate anti-HCV immunity among IDUs.

Assessment of liver disease (noninvasive methods)

PURPOSE OF REVIEW

The purpose of this review is to highlight new findings published in 2010-2011 related to noninvasive fibrosis assessment in HIV/hepatitis C virus (HCV) co-infected patients. Overall, in 2010-2011, 15 studies were published, of which two were excluded because they were published in languages other than English.

RECENT FINDINGS

Eleven studies focused on serum marker panels. Studies sought to validate established panels in HIV/HCV co-infected patients often by comparing multiple serum marker panels in the same population; establish new marker panels using combinations of markers used in previously validated panels; and develop new marker panels using novel methodology. Overall, all panels performed within similar ranges of diagnostic accuracy as measured by the area under the receiver operating characteristic curve (AUROC) but the FibroMeter panel and its derivations achieved the highest performance. Four studies focused on transient elastography. Two studies confirmed its accuracy for identifying fibrosis and cirrhosis and two studies confirmed that misclassification rates are higher in the presence of elevated triglycerides and steatosis.

SUMMARY

Overall, performance of transient elastography appeared superior to the majority of serum marker panels for the detection of significant fibrosis and cirrhosis in HIV/HCV co-infected patients. Challenges of widespread application of transient elastography remain high misclassification in some subgroups, lack of standardized cut-points and lack of widespread availability. Panels that were newly developed in 2010-2011 specifically for HIV/HCV appeared to perform better than existing panels such as APRI and FIB-4; however, additional external validation will be needed to confirm their accuracy.

A comparison of four fibrosis indexes in chronic HCV: development of new fibrosis-cirrhosis index (FCI)

BACKGROUND

Hepatitis C can lead to liver fibrosis and cirrhosis. We compared readily available non-invasive fibrosis indexes for the fibrosis progression discrimination to find a better combination of existing non-invasive markers.

METHODS

We studied 157 HCV infected patients who underwent liver biopsy. In order to differentiate HCV fibrosis progression, readily available AAR, APRI, FI and FIB-4 serum indexes were tested in the patients. We derived a new fibrosis-cirrhosis index (FCI) comprised of ALP, bilirubin, serum albumin and platelet count. FCI = [(ALP × Bilirubin) / (Albumin × Platelet count)].

RESULTS

Already established serum indexes AAR, APRI, FI and FIB-4 were able to stage liver fibrosis with correlation coefficient indexes 0.130, 0.444, 0.578 and 0.494, respectively. Our new fibrosis cirrhosis index FCI significantly correlated with the histological fibrosis stages F0-F1, F2-F3 and F4 (r = 0.818, p < 0.05) with AUROCs 0.932 and 0.996, respectively. The sensitivity and PPV of FCI at a cutoff value < 0.130 for predicting fibrosis stage F0-F1 was 81% and 82%, respectively with AUROC 0.932. Corresponding value of FCI at a cutoff value ≥1.25 for the prediction of cirrhosis was 86% and 100%.

CONCLUSIONS

The fibrosis-cirrhosis index (FCI) accurately predicted fibrosis stages in HCV infected patients and seems more efficient than frequently used serum indexes.