Factors Differentiating Acute Hepatitis B from Acute Exacerbation of Chronic Hepatitis B in Prospective-retrospective Cohort

Introduction and aim: It is difficult to distinguish acute hepatitis B (AVH-B) from chronic hepatitis B with an acute exacerbation (CHB-AE) in patients whose prior history of HBV infection is unknown. The present study aimed to screen laboratory parameters at presentation to discriminate between these two conditions.

Materials and methods: A prospective study was conducted in patients presenting clinically as AVH-B without known previous chronic hepatitis B status. Patients were divided into AVH-B and CHB-AE at end of six months follow up. Clinical and laboratory profiles were compared between these two groups at presentation.

Results: There was no significant difference in clinical presentation and risk factors profile in patients of both the groups. Mean age of presentation in AVH-B was 31.8 ± 14.9 years while, 47.2 ±17.3 years in CHB-AE group (p=0.005). Mean IgM anti-HBc levels were higher in AVH-B than in the CHB-AE group (p=0.001). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of IgM anti-HBc [>12.14 S/CO (Sample/Cut-off )] for diagnosis of AVH-B was 76.9%, 71.4%, 76.9% and 71.4 % respectively. Quantitative HBV DNA levels were significantly higher in CHB-AE group than in AVH-B group (p=0.015). Sensitivity, specificity, PPV and NPV of HBV DNA ( > 15390 IU/ml) for diagnosis of CHB-AE was 78.6%, 46.2%, 44% and 80% respectively.

Conclusion: A high percentage of patients with apparent AVH-B might be cases of CHB-AE. Elderly patient (mean 47.2 years), high titers of HBV DNA (>15390 IU/ mL) and low IgM anti-HBc titer (<12.14 S/CO) favours CHB-AE over AVH-B.