Mac-2 binding protein glycosylation isomer (M2BPGi) to evaluate liver fibrosis and cancer in HBV-infected in West Africa

Background To reduce mortality associated with hepa-titis B virus (HBV) infection, timely detection of cirrhosis and early-stage hepatocellular carcinoma (HCC) is essen-tial. In low-income countries, however, HBV-infected peo-ple have limited access to liver histopathology, a reference test. Recently, Asian studies have suggested the usefulness of an inexpensive serum biomarker called Mac-2 binding protein glycosylation isomer (M2BPGi) in staging liver fi-brosis and predicting HCC in HBV-infected patients.Methods We systematically searched PubMed for studies examining the performance of M2BPGi in staging liver fi-brosis in HBV-infected people, published up to Septem-ber 21, 2021, to elucidate the knowledge gap. We then conducted a cross-sectional study of 339 HBV-infected pa-tients in The Gambia (cirrhosis = 65, HCC = 73, non -cir-rhosis non-HCC = 201). We evaluated the association of M2BPGi with cirrhosis and HCC by computing odds ra-tios (ORs) derived from logistic regression. We also as-sessed the performance of M2BPGi to stage liver fibrosis in 49 patients who underwent liver biopsy (derivation set) and 217 patients with transient elastography (validation set). Using the derivation set we drew the receiver operat-ing characteristics (ROC) curves to identify optimal M2B-PGi thresholds to indicate significant fibrosis and cirrhosis using biopsy as a reference. We then applied these cut-offs to the validation set to obtain its sensitivity and specificity for indicating significant fibrosis and cirrhosis using tran-sient elastography as a reference.Results The systematic review identified 13 studies, all of which were conducted in East Asia and none in Africa. In The Gambia, positive M2BPGi was significantly associated with both cirrhosis (adjusted OR = 7.8, 95% CI = 3.1-19.7) and HCC (adjusted OR = 10.1, 2.6-40.2). The areas under the ROC curve (AUROC) in the derivation and validation set were 0.62 and 0.78, respectively, to diagnose signifi-cant fibrosis, and 0.80 and 0.89, respectively, to diagnose cirrhosis. By applying the optimal cut-offs, the sensitivity and specificity in the validation set were 61.5% and 93.4%, respectively, to diagnose significant fibrosis, and 72.5% and 92.2%, respectively, for cirrhosis.Conclusions To the best of our knowledge, this is the first evaluation of M2BPGi in HBV-infected Afri-can population. The findings supported its accuracy in the diagnosis of cirrhosis in HBV-infected patients in West Africa.