Bilirubin, aspartate aminotransferase and platelet count score: a novel score for differentiating patients with chronic hepatitis B with acute flare from acute hepatitis B

BACKGROUND Early therapy improves the outcome in patients with chronic hepatitis B with acute flare (CHB-AF). However in mesoendemic countries, it is difficult to differentiate CHBAF from acute hepatitis B (AHB). The aim of this study was to formulate a clinical score to differentiate CHB-AF from AHB in patients presenting with an acute hepatitis-like picture. METHODS Patients with a protracted clinical course of >2 months with elevated liver enzymes and positive hepatitis B virus DNA, who had undergone liver biopsy were included in this study. The clinical and laboratory profiles were compared between patients with biopsy suggestive of CHB-AF and AHB. RESULTS Of the 75 patients included, 32 patients had a liver biopsy suggestive of CHB-AF. At 6 months, HBsAg clearance was lower in the CHB-AF group (9.4 vs. 76.7%). Presence of prodrome, platelet count, aspartate aminotransferase (AST), alanine aminotransferase and bilirubin levels and presence of anti-core antibody (IgM anti HBc) were lower in CHB-AF group (P<0.01). Using the receiver operating characteristic curve, peak bilirubin level, peak AST levels and least platelet count within the first 8 weeks had the highest predictive power. Optimal values of platelet <2.4×105/µL, peak bilirubin <4.5 mg/dL and AST <550 IU/L were given a point each. On internal validation a score of 2 had 86% specificity, 70.1% sensitivity and 82.7% diagnostic accuracy in predicting CHB-AF. CONCLUSION Bilirubin, AST and platelet count (BAP) score may be helpful in differentiating CHB-AF from AHB. A score of >2 could strongly suggest CHB-AF. However the score requires further validation.