Abstract

Background and study aims: Differentiating acute hepatitis B from reactivation of chronic hepatitis B (CHB) is essential. We evaluated consecutive patients presenting with prodrome and jaundice and detected to be HBsAg positive for the first time.
Patients and methods: All patients presenting with jaundice over a 6month period to the Kasturba Hospital of Infecious Disease (KHID), Mumbai between February and July 2015 with Hepatitis B surface antigen (HBsAg) positivity were included. Patients with previous knowledge of hepatitis B or cirrhosis, history of decompensation, significant alcohol or recent intake of hepatotoxic drugs were excluded. All patients were evaluated by a detailed history of clinical features and risk factors, examination, laboratory parameters and hepatitis B serological parameters. These patients were followed up for six months for determining their outcome.
Results: Of 1835 patients presenting with acute prodrome and jaundice, 65 patients were detected to be HBsAg positive. 51 patients completed the follow up of 6 months. 13 patients had acute hepatitis B and 38 had chronic hepatitis B (13 with superimposed acute hepatitis A or E over chronic hepatitis B and 25 patients with reactivation of hepatitis B). The hemogram and liver profile failed to differentiate acute from reactivation of hepatitis B. Though median HBV load at presentation was higher in chronic hepatitis B it failed to be statistically significant between the groups (AUROC 0.6). HBeAg and Anti HBe failed to differentiate the two entities. IgM Anti HBc was more commonly positive in AHB and the sample/cutoff ratio was significantly higher in AHB with an AUROC of 0.81. The cutoff of 11 reliably differentiates the two with a specificity of 100 and sensitivity of 57.1.
Conclusion: In patients presenting with jaundice and prodrome, nearly 75% are CHB. A Sample/cutoff ratio >11 for IgM Anti HBc can be used to identify patients with AHB.
 

Keywords

IgM Anti HBc, chronic hepatitis B, drug toxicity, bilirubin, transaminases, alkaline phosphatase