The Enhanced Liver Fibrosis Index Predicts Hepatic Fibrosis Superior to FIB4 and APRI in HIV/HCV Infected Patients

Background. Accurate noninvasive biomarkers of fibrotic progression are important for hepatitis C virus (HCV) management, but commonly used modalities may have decreased efficacy in human immunodeficiency virus (HIV)/HCV-coinfected persons. The enhanced liver fibrosis (ELF) index is a highly sensitive noninvasive marker of hepatic fibrosis that has had limited assessment in the HIV/HCV population. We compared ELF index performance to FIB4 and aspartate to platelet ratio index (APRI) at different stages of liver fibrosis as determined by liver histology, and validated the efficacy of the three noninvasive 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 noninvasive 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 cutoffs of 8.45 and 9.23 predicted mild and moderate fibrosis with 85% sensitivity, whereas the ELF cutoff of 9.8 had the highest specificity for advanced fibrosis and the cutoff 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 toward accurate prediction of liver fibrosis and cirrhosis with superior performance to APRI and FIB4 in HIV/HCV coinfection. Applying this noninvasive biomarker index for diagnosis of liver fibrosis and progression in HIV/HCV is warranted.