Aim: To investigate the association of serum gamma-glutamyl transferase (GGT) levels with chronic hepatitis B infection and hepatitis B e antigen (HBeAg) 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 naïve (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), HBeAg-positive hepatitis (EPH; n = 93), HBeAg-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/mL and HBeAg 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 HBeAg seroconversion following NA therapy.
Keywords: Gamma-glutamyl transferase; Hepatitis B; Hepatitis B e antigen; Natural history; Nucleos(t)ide analogues; Seroconversion.