Functional restoration of CD56bright NK cells facilitates immune control via IL-15 and NKG2D in patients under antiviral treatment for chronic hepatitis B

Background and aims Hepatitis B virus (HBV) is intrinsically immunogenic, with long-lasting immune control in many patients. However, the mechanisms and key cell types underlying effective immune control are incompletely understood. Methods We studied the restoration of natural killer (NK) cell numbers and function post antiviral treatment in 52 hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients who received telbivudine (LdT) for 48 weeks. Blood samples were collected at week 0, 12, 24, 36, and 48 and tested for HBV DNA, hepatitis B surface antigen (HBsAg), HBeAg, liver enzymes, and NK cell parameters. Results Compared with baseline, the number of peripheral CD3 − CD56 bright NK cells increased significantly from week 24 to 48, especially in patients with baseline alanine transaminase (ALT) two- to fivefold the upper line of normal (ULN) or HBV DNA