Differentiating acute hepatitis B from the first episode of symptomatic exacerbation of chronic hepatitis B

In countries with intermediate or high endemicity for chronic hepatitis B virus (HBV) infection, exacerbations of chronic hepatitis B (CHB) are common. We studied the clinical, biochemical, and virologic characteristics of patients first presenting clinically with features of acute icteric hepatitis B, to identify features that might differentiate between acute viral hepatitis B (AVHB) from first episode of exacerbation of chronic hepatitis (ECHB). We retrospectively analyzed 79 patients (mean age 35.4 +/- 14 years; M:F = 60:19) who first presented clinically as AVHB, within 4 weeks of onset of symptoms. Patients who on follow-up cleared HBsAg and/or did not develop any clinical, radiologic, or histologic evidence of chronic liver disease (CLD) were categorized as AVHB (group 1). Patients who had persistence of HBsAg and developed clinical, biochemical, radiologic, or histologic evidence of chronic liver disease were categorized as ECHB (group 2). Forty-nine patients were in group 1 and 30 in group 2. The 2 groups were comparable with respect to prodrome, onset of jaundice, serum bilirubin, ALT, prothrombin time prolongation, serum albumin, and A/G ratio. Among group 1 patients, 78% had IgM anti-HBc positive in titers > 1:1000; in group 2, there were negative or positive in titers < 1:1000 in 70% patients (P < .001). Forty-seven of 49 (95.9%) patients in group 1 had HBV-DNA levels < 0.5 pg/mL, whereas 26 of 30 (86.73%) patients in group 2 had levels > 0.5 pg/mL (P < or = .001). Quantitative HBV DNA and IgM anti-HBc titers at initial presentation can differentiate patients with a true episode of acute hepatitis B from patients with first episode of symptomatic exacerbation of chronic hepatitis B. Clinical and biochemical features do not help in differentiating the two.