Association of serum gamma-glutamyl transferase with treatment outcome in chronic hepatitis B patients

AIM:To investigate the association of serum gammaglutamyl transferase(GGT) levels with chronic hepatitis B infection and hepatitis B e antigen(HBe Ag) seroconversion.METHODS:A retrospective study was performed on clinical data collected from patients who had been positive for hepatitis B surface antigen for > 6 mo and who were antiviral-treatment na?ve(n = 215) attending the Hepatitis Clinic at Nanjing Drum Tower Hospital between August 2010 and December 2013. Healthy individuals without liver disease(n = 83) were included as controls. Patients were categorized into four groups based on disease status as recommended by the European Association for the Study of the Liver:immune tolerance(IT; n = 47),HBe Ag-positive hepatitis(EPH; n = 93),HBe Ag-negative hepatitis(ENH;n = 20),and inactive carrier(IC; n = 55). Prediction of complete response(CR) based on serum GGT was also examined in EPH patients(n = 33) treated for 48 wk with nucleos(t)ide analogue(NA) therapy,including lamivudine plus adefovir combination therapy(n = 20) or entecavir monotherapy(n = 13). CR was defined as a serum hepatitis B virus DNA level < 500 copies/m L and HBe Ag seroconversion by 48 wk of treatment. RESULTS:Serum GGT levels were significantly increased in EPH and ENH patients relative to the IT,IC,and healthy control groups(P < 0.01 for all). However,no significant difference in serum GGT levels was found between the EPH and ENH groups. Baseline serum GGT levels were significantly higher in patients who achieved CR(7/33; 21.2%) compared to patients in the non-CR group(26/33; 78.8%; P = 0.011). In addition,the decline in serum GGT was greater in CR patients compared to non-CR patients after 24 wk and 48 wk of treatment(P = 0.012 and P = 0.008,respectively). The receiver operating characteristic curve yielded a sensitivity of 85.71% and a specificity of 61.54% at a threshold value of 0.89 times the upper limit of normal for baseline serum GGT in the prediction of CR following NA therapy. CONCLUSION:Serum GGT is significantly elevated in EPH and ENH patients and is a potential biomarker for the prediction of HBe Ag seroconversion following NA therapy.