OBJECTIVETo investigate the effect of telbivudine on peripheral blood regulatory T cells and its significance in patients with chronic hepatitis B (CHB).

METHODSThirty-six HbeAg positive chronic hepatitis B patients were recruited and received telbivudine treatment for 9 months. Before and during the 3, 6, 9 months of treatment, flow cytometry was used to detect the proportion of peripheral blood Tregs; real-time PCR was used to detect the levels of HBV DNA in the serum. Markers of hepatitis B virus infection were detected by ELISA assay and levels of alanine aminotransferase in the serum were measured.

RESULTSThe proportion of peripheral blood Tregs in patients with CHB was significantly higher than that in healthy controls and decreased over 6 or 9 months of telbivudine treatment to a level comparable to that of the healthy controls. After 3 months of telbivudine treatment, the rate of undetectable HBV DNA in patients whose proportion of peripheral blood Tregs was decreased was higher than those whose Tregs had been reduced, but the difference was not statistically significant (P more than 0.05). Three, 6 or 9 months of telbivudine treatment resulted in HbeAg negativity in 4 (11.1%) patients, 7 (19.4%) patients or 9 (25.0%) patients respectively. In 7 (19.4%) patients who had seroconversion from HBeAg to anti-HBeAg, after 3 or 6 months of telbivudine treatment, their proportion of peripheral blood Tregs had decreased to a level comparable to that of the healthy controls.

CONCLUSIONTelbivudine treatment reduces HBV replication and the proportion of peripheral blood Tregs. In addition, patients who have their proportion of peripheral blood Tregs decreased quickly at the early phase of telbivudine treatment are prone to have HBeAg to anti-HBeAg seroconversion.