Liver function tests and fibrosis scores in a rural population in Africa: a cross-sectional study to estimate the burden of disease and associated risk factors

Abstract

ObjectivesLiver disease is a major cause of morbidity and mortality in sub-Saharan Africa, but its prevalence, distribution and aetiology have not been well characterised. We therefore set out to examine liver function tests (LFTs) and liver fibrosis scores in a rural African population.DesignWe undertook a cross-sectional survey of LFTs. We classified abnormal LFTs based on reference ranges set in America and in Africa. We derived fibrosis scores (aspartate aminotransferase (AST) to Platelet Ratio Index (APRI), fibrosis-4, gamma-glutamyl transferase (GGT) to platelet ratio (GPR), red cell distribution width to platelet ratio and S-index). We collected information about alcohol intake, and infection with HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV).SettingWe studied a population cohort in South-Western Uganda.ParticipantsData were available for 8099 adults (median age 30 years; 56% female).ResultsThe prevalence of HBV, HCV and HIV infection was 3%, 0.2% and 8%, respectively. The prevalence of abnormal LFTs was higher based on the American reference range compared with the African reference range (eg, for AST 13% vs 3%, respectively). Elevated AST/ALT ratio was significantly associated with self-reported alcohol consumption (p<0.001), and the overall prevalence of AST/ALT ratio >2 was 11% (suggesting alcoholic hepatitis). The highest prevalence of fibrosis was predicted by the GPR score, with 24% of the population falling above the threshold for fibrosis. There was an association between the presence of HIV or HBV and raised GPR (p=0.005) and S-index (p<0.001). By multivariate analysis, elevated LFTs and fibrosis scores were most consistently associated with older age, male sex, being under-weight, HIV or HBV infection and alcohol consumption.ConclusionsFurther work is required to determine normal reference ranges for LFTs in this setting, to evaluate the specificity and sensitivity of fibrosis scores and to determine the aetiology of liver disease.

Increased Prevalence of Liver Fibrosis and HIV Viremia among Patients with HIV, HBV, and Tuberculosis in Botswana

“…Local ALT and AST reference ranges are yet to be defined specifically for men and women in our setting. A recent study, using African reference ranges versus American reference ranges emphasized the need to have specific ranges for different populations to avoid overestimation or underestimation of abnormalities [ 36 ]. FibroTest and FibroScan may be preferred over APRI and FIB-4 but may not be suitable for resource-limited settings.…”

Treatment advantage in HBV/HIV coinfection compared to HBV monoinfection in a South African cohort

“…Local guidelines were used to define thresholds. 21 We defined the upper limit of normal (ULN) for ALT as 19 U/L for females and 30 U/L for males, 16 , 14 ULN for AST as 40 U/L, ULN for BR as 17 mmol/L. We calculated liver fibrosis scores, AST to Platelet Ratio Index (APRI) and Fibrosis-4 (FIB-4) as follows:…”

“…We found no difference in the prevalence of elevated hepatic transaminases between monoinfected and coinfected patient groups. It is important to recognise that appropriate thresholds for the ULN of liver enzymes have not been clearly determined for African populations, 21 and that significant evidence of progressive liver disease can be present even in the absence of abnormalities in liver enzymes. This highlights the lack of sensitivity of liver function tests as biomarkers; clinical surveillance may need to incorporate other markers, laboratory-based fibrosis scores, and/or or elastography results.…”

“…The sensitivity and specificity of APRI and FIB-4 varies between settings, with recent studies suggesting that cut-off thresholds for patients with chronic HBV may need revising. 50 Further evaluation is specifically required in African populations, 21 particularly in the context of high HIV prevalence. 51 The gamma-glutamyl transpeptidase to platelet ratio (GPR) may be a more accurate biomarker of liver disease, 21 , 52 although poor correlation with elastography scores is reported in HIV coinfected individuals.…”

Estudo comparativo de prevalência de Hepatite C entre laboratório público e privado do estado de Goiás, Brasil

“…Em associação aos testes diagnósticos, são realizados testes de função hepática utilizando biomarcadores de inflamação como a aspartato aminotransferase (AST), alanina aminotransferase (ALT), fosfatase alcalina (ALP), gama-glutamil transferase (GGT) e bilirrubina (BR), que geralmente são a primeira abordagem realizada para avaliar a doença hepática. No entanto, esses biomarcadores costumam ser inespecíficos para a Hepatite C, apesar de alterações persistentes poderem indicar doença hepática crônica 1,8,13 .…”