A natural history of efavirenz drug-induced liver injury

Abstract

Background. Efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor, has been a component of first-line antiretroviral therapy (ART) in the South African HIV/AIDS programme since 2004. It is extensively used in ART programmes in other low- and middle-income countries. The natural history of the previously recognised EFV drug-induced liver injury (DILI) is not known.

Objectives. To define and establish a causality assessment for EFV DILI and document its natural history by detailing a patient cohort. All relevant features characterising the patterns of clinical and histological injury, the duration of clinical and biochemical recovery and the associated mortality rate were documented. Factors associated with specific histological patterns of liver injury were analysed.

Methods. Patients were prospectively included after meeting causality and inclusion criteria for EFV DILI. Clinical, demographic and liver histological features (where possible) were documented from the time of presentation and throughout follow-up. Prednisone at 0.25 - 0.5 mg/kg was initiated at the discretion of the treating hepatologist.

Results. Fifty patients were prospectively included in the analysis. The median age was 34 (interquartile range (IQR) 29 - 39) years, males being older than females (p=0.014). Most (92%) were female, and 86% were of black African ethnicity. The median duration of ART at presentation was 6 months, with half of the women having initiated ART during pregnancy, at a median gestation of 24 (IQR 11 - 36) weeks. The median CD4 nadir at ART treatment initiation was 517 cells/µL, with no significant difference in CD4 nadir between those who were pregnant and those who were not (p=0.6). The median RUCAM (Roussel Uclaf Causality Assessment Method) score was 7, and among the 75% of patients who had liver biopsies, three histological patterns were identified: submassive necrosis (60%), nonspecific hepatitis (35%), and mixed cholestatic hepatitis (5%). On multivariate analysis, predictors for the development of submassive necrosis included younger age (<30 years; p=0.045), ART initiation in pregnancy (p=0.02), and a baseline CD4 count >350 cells/µL (p=0.018). For the nonspecific hepatitis group, pregnancy was also an associated factor (p=0.04). The mortality rate was 14%, with a median time from admission to death of 15 days. The median (IQR) time to initial hospital discharge was a lengthy 33 (24 - 52) days. Biochemical recovery was prolonged, necessitating a follow-up period of more than a year at an outpatient specialist clinic, with 86% of patients initiating a protease inhibitor-based ART regimen successfully.

Conclusions. EFV DILI is a severe drug complication of ART with appreciable mortality and significant inpatient morbidity, requiring prolonged hospitalisation and follow-up.