Serum HBsAg quantification in treatment-naïve Indian patients with chronic hepatitis B.

BACKGROUND AND AIMS There is paucity of Indian data regarding serum HBsAg levels (qHBsAg) in treatment-naïve chronic hepatitis B (CHB). This study was done to determine correlation of qHBsAg with hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA levels and its ability to independently categorize subgroups of CHB. METHODS We studied 131 treatment-naive CHB patients and initially classified them based on HBeAg status. The HBeAg-positive group was further classified into immune tolerance (IT) and immune clearance (IC) phases based on serum alanine aminotransferase. HBeAg-negative patients were classified into low replicators (LR) and HBeAg-negative chronic hepatitis (ENH) based on DNA levels. HBsAg quantification was performed using the Architect chemiluminescence system. RESULTS HBeAg-positive patients had higher DNA (7.89 vs. 2.69 log10 IU/mL) and higher qHBsAg (4.60 vs. 3.85 log10 IU/mL) compared to the HBeAg-negative group. Good correlation between qHBsAg and DNA was seen in HBeAg-positive (ρ = 0.6, p < 0.001) but not in HBeAg-negative CHB (ρ = 0.2). A qHBsAg level greater than 4.39 log10 IU/mL predicted HBeAg-positive state with 81 % sensitivity and 85 % specificity. However, among HBeAg-negative CHB, qHBsAg failed to discriminate between LR and ENH. CONCLUSIONS A single point estimation of qHBsAg in treatment-naïve patients could predict replicative HBeAg-positive CHB, but was not helpful in defining replicative status in the HBeAg-negative CHB.