Performance of low-cost non-invasive blood markers of liver cirrhosis in adults with chronic hepatitis B infection with and without comorbid alcohol use in Zambia

BackgroundDiagnosis of liver cirrhosis in patients with chronic hepatitis B is challenging given rare use of biopsy. In low and middle-income countries, transient elastography (TE), a recommended non-invasive imaging test for cirrhosis is rarely accessible. We therefore investigated the performance of multiple low-cost and more accessible blood-based liver fibrosis markers in patients with chronic hepatitis B infection in Zambia. As alcohol use complicates the assessment and outcomes of hepatitis B, we also considered alcohol use patterns in our evaluation. MethodsWe performed a hospital-based cross-sectional study, in Lusaka, Zambia, among consecutive treatment-naive adults with chronic hepatitis B mono-infection (i.e., HIV-negative) presenting to our hospital. The reference test for cirrhosis was TE of >/=9.6 kPa. Low-cost markers were the AST-to-platelet ratio index (APRI) at recommended threshold >2, as well as lower proposed alternative thresholds for Africa, >0.5 and >0.65, AST/ALT ratio and FIB-4 index >3.25. We evaluated the performance of each marker versus TE. In a secondary analysis, we evaluated marker performance in participants with current alcohol use versus lifetime abstinence. ResultsAmong 239 adults with HBV mono-infection analyzed, the mean age was 34.7 years and 53 (22.2%) reported current alcohol use. The prevalence of cirrhosis by TE was 16.3% (95% CI: 11.87-21.63). The area under the receiver operating characteristic curve was 0.83, 0.80, 0.79 and 0.73 for FIB-4, APRI >0.5, APRI >0.65 and APRI >2 respectively. Virtually all indices performed less well in people with current alcohol use. ConclusionThese data support the adoption of a lower APRI threshold in Africa, and the use of the FIB-4 index, for diagnosis of cirrhosis among patients with chronic hepatitis B infection. The currently-recommended APRI threshold may exclude people with cirrhosis who need antiviral therapy. Clinicians adopting these markers should screen for alcohol use and consider re-assessment of cirrhosis after alcohol reduction.