Prognostic Value of the Fibrosis-4 Index in Human Immunodeficiency Virus Type-1 Infected Patients Initiating Antiretroviral Therapy with or without Hepatitis C Virus

Abstract

Objective: To evaluate the Fibrosis (FIB)-4 index as a predictor of major liver-related events (LRE) and liver-related death (LRD) in human immunodeficiency virus (HIV) type-1 patients initiating combination antiretroviral therapy (cART).

Design: Retrospective analysis of a prospective cohort study.

Setting: Italian HIV care centers participating to the ICONA Foundation cohort.

Participants: Treatment-naive patients enrolled in ICONA were selected who: initiated cART, had hepatitis C virus (HCV) serology results, were HBsAg negative, had an available FIB-4 index at cART start and during follow up.

Methods: Cox regression models were used to determine the association of FIB4 with the risk of major LRE (gastrointestinal bleeding, ascites, hepatic encephalopathy, hepato-renal syndrome or hepatocellular carcinoma) or LRD.

Results: Three-thousand four-hundred seventy-five patients were enrolled: 73.3% were males, 27.2% HCV seropositive. At baseline (time of cART initiation) their median age was 39 years, had a median CD4+ T cell count of 260 cells/uL, and median HIV RNA 4.9 log copies/mL, 65.9% had a FIB-4 <1.45, 26.4% 1.45-3.25 and 7.7% >3.25. Over a follow up of 18,662 person-years, 41 events were observed: 25 major LRE and 16 LRD (incidence rate, IR, 2.2 per 1,000 PYFU [95% confidence interval, CI 1.6-3.0]). IR was higher in HCV seropositives as compared to negatives (5.9 vs 0.5 per 1,000 PYFU). Higher baseline FIB-4 category as compared to <1.45 (FIB-4 1.45-3.25: HR 3.55, 95% CI 1.09-11.58; FIB-4>3.25: HR 4.25, 1.21-14.92) and time-updated FIB-4 (FIB-4 1.45-3.25: HR 3.40, 1.02-11.40; FIB-4>3.25: HR 21.24, 6.75-66.84) were independently predictive of major LRE/LRD, after adjusting for HIV- and HCV-related variables, alcohol consumption and type of cART.

Conclusions: The FIB-4 index at cART initiation, and its modification over time are risk factors for major LRE or LRD, independently of infection with HCV and could be used to monitor patients on cART.

Fig 1. Kaplan-Meier curves showing the estimated probability of major liver events or liver-related death in HIV-infected individuals after cART initiation, according to baseline FIB-4 index category: panel (a) in the whole study population, 41 events in 3475 patients, overall log-rank between categories p<0.001; (b) in the HCV antibody positive population, 35 events in 944 subjects (overall log-rank p<0.001) and (c) in the HCV antibody negative population, 6 events in 2531 individuals (overall log-rank p = 0.031).

Dotted line = baseline FIB-4 <1.45, dashed line baseline FIB-4 ≥1.45 and ≤3.25, continuous line = baseline FIB-4 >3.25. Y-axis indicated the proportion of patients with major liver events or liver-related death.