Acute Hepatitis B or Chronic Hepatitis B with Acute Exacerbation: Differentiating Clinical, Biochemical, Immunonological, and Virological Parameters

Background and Aims: Acute hepatitis B virus (HBV) infection and chronic HBV infection presenting as acute illness have differing prognosis. Differentiation between acute viral hepatitis B (AVH-B) and chronic hepatitis B with an acute exacerbation (CHB-AE) is difficult if prior hepatitis B surface antigen (HBsAg) status is unknown. This prospective study was undertaken to screen various factors that could help with this differentiation. Methods: All consecutive patients presenting with AVH-B like illness were enrolled in this study and were evaluated as per predefined study protocol. Patients were divided into AVH-B and CHB-AE groups based on HBsAg status at the end of 6 months. Results: Significant differences in clinical and laboratory parameters were found between AVH-B and CHB-AE. No statistically significant difference in prodromal symptoms and jaundice was seen. Ascites (40%) and hepatic encephalopathy (10%) were seen only in patients with CHB-AE (P = 0.002 and 0.244, respectively). Anti-hepatitis B virus core antigen immunoglobulin M (IgM anti-HBc) levels ≥10.15 signal-cutoff-ratio (S/CO) had positive predictive value (PPV) and negative predictive value (NPV) of 90% for diagnosis of AVH-B. Hepatitis B virus deoxyriboNucleic acid (HBV DNA) levels ≥25032 IU/mLhas 62.5% PPV and 69% NPV for diagnosis of CHB-AE. Alpha-feto protein (AFP) at >22.5 ng/mLmL for diagnosing CHB-AE has PPV and NPV of 83% and 62%, respectively. All six mortalities were seen in CHB-AE group with median survival of 2 months. Conclusions: Differentiation of AVH-B and CHB-AE is important as management and prognosis differ. Low IgM anti-HBc levels (22.5 ng/mL) favor CHB-AE over AVH-B.