The enhanced liver fibrosis (ELF)-Index predicts hepatic fibrosis superior to FIB4 and APRI in HIV/HCV infected patients.

BACKGROUND Accurate non-invasive biomarkers of fibrotic progression are important for HCV management, but commonly used modalities may have decreased efficacy in HIV/HCV-coinfected persons. The enhanced liver fibrosis (ELF)-index is a highly sensitive non-invasive marker of hepatic fibrosis that has had limited assessment in the HIV/HCV population. We compared ELF-index performance to FIB4 and APRI at different stages of liver fibrosis as determined by liver histology, and validated the efficacy of the three non-invasive biomarkers in HIV/HCV-coinfected versus HCV-monoinfected. METHODS The ELF-index was determined in 147 HIV/HCV-coinfected and 98 HCV-monoinfected persons using commercial ELISA assays for the component elements of the index. Area under the receiver-operator curve was used to validate ELF and to compare its performance to liver histology as well as to other non-invasive biomarkers of liver fibrosis, FIB4 and APRI. RESULTS The ELF-index increased with histological stage of liver fibrosis and exhibited a linear relationship with Metavir score in all subjects. ELF performance was comparable between HIV/HCV and HCV with advanced liver fibrosis/ cirrhosis. In the HIV/HCV cohort ELF cut-offs of 8.45 and 9.23 predicted mild and moderate fibrosis with 85% sensitivity, while the ELF cut-off of 9.8 had the highest specificity for advanced fibrosis and the cut-off of 10.4 was 99% specific for cirrhosis. ELF performance was superior to FIB4 and APRI in all subjects regardless of HIV status. CONCLUSIONS ELF-index demonstrated excellent characteristics towards accurate prediction of liver fibrosis and cirrhosis with superior performance to APRI and FIB4 in HIV/HCV infection. Applying this non-invasive biomarker index for diagnosis of liver fibrosis and progression in HIV/HCV is warranted.