Functions of NK cells in chronic hepatitis B patients treated with interferon

Abstract

Objective To elucidate the functions of peripheral blood NK cells in chronic hepatitis B patients treated with interferon. Methods Venous whole blood samples were obtained from patients in the immune clearance (IC) phase treated with peg-interferon-alpha-2a (Peg-IFNα-2a) at baseline (t=0), 12 weeks (t=12) and 24 weeks (t=24). The frequencyies of peripheral blood CD3-CD56+ NK cells, CD56brightNK cells and CD56dimNK cells, the expression level of IFNAR2 and NKp46 on NK cells were detected by flow cytometry. The levels of serum HBV DNA, HBsAg, HBeAg and ALT were detected by Ditan Hospital clinical laboratory. Results Forty-one patients in the IC phase treated with Peg-IFNα-2a, including 21 poor response (PR) patients and 20 good response (GR) patients, were recruited for this study. Theresult were as follows: The frequency of peripheral blood CD3-CD56+ NK cells was increased at week 24 in GR compared with the baseline(11.74, 5.69%-18.15% vs 13.7, 9.36-20.18%, P>0.05), and it also was increased in PR(8.94, 6.26%-14.15% vs 12.5, 7.64-16.55%, P>0.05). The frequency of peripheral blood CD56brightNK cells was increased at week 24 in GR compared with the baseline(9.49, 6.2%-12.48% vs 12.98, 7.75%-20.93%, P>0.05), and it also was increased in PR(11.45, 8.27%-19.13% vs 17.52, 12.3%-22.42%, P=0.0239). The expression level of NKp46 on NK cells was significantly increased at week 24 in GR compared with the baseline(90.55, 83.8-94.78 vs 93.8, 92.28-96.4, P=0.0263), but it was not increased in PR(95, 90.6-96.15 vs 94.3, 92.1-95.6, P>0.05). The expression level of NKp46high on NK cells was significantly increased at week 24 in GR compared with the baseline(12.4, 8.58-19.08 vs 39.3, 23.15-49.3, P=0.0011), at that range of the increase was significantly higher than PR(14.2, 9.78-17.65 vs 27.58, 19.13-36.56, P=0.006). Conclusions The frequencies of peripheral blood CD3-CD56+ NK cells and CD56brightNK cells were increased from patients in the IC phase treated with Peg-IFNα-2a. The expression level of NKp46 on NK cells was increased in GR patients treated with Peg-IFNα-2a. The expression level of NKp46high on NK cells was significantly increased, especially in GR patients treated with Peg-IFNα-2a. Key words: Hepatitis B virus; NK cells; Immunopathogenesis; Interferon-alpha