Dynamic changes and clinical significance of HBcAg18-27 specific cytotoxic T lymphocytes in acute hepatitis B patients

Abstract

This report aims to investigate the dynamical changes of HBcAg18-27 epitope specific cytotoxic T lymphocytes(CTL), alanine aminotransferase (ALT), HBV DNA and HBsAg in peripheral blood of acute hepatitis B patients, and to explore the roles of HBcAg18-27-specific CTLs in virus clearance and liver injury. Acute hepatitis B (AHB) and chronic hepatitis B (CHB) patients were divided into two groups according to results of HLA-A0201. Patients with positive HLA-A0201 were classified into HBcAg-specific CTL group and those with negative HLA-A0201 were referred as control group. The specific CTLs were stained with HLA-A0201 limited HBcAg18-27 epitope MHC-Pentamer and the frequencies of CTLs, T, B, NK and NKT cells were detected by flow cytometry (FCM). The serum ALT, HBV DNA and HBsAg were examined using speed analysis, quantitative PCR and abbott chemiluminescent technology. The frequencies of HBcAg18-27-specific CTLs in AHB patients were higher in the early three weeks as compared to the late three weeks. The apex time of HBV-specific CTL frequencies lagged behind those of HBV DNA, HBsAg and ALT. The loss of HBsAg in patients with high frequencies of HBV-specific CTL was earlier than that in patients with low frequencies (t = 2.018, P value is less than 0.05). In the second week the peak frequencies of CD3+CD8+ cells overlapped with that of HBcAg18-27-specific CTLs and with a positive correlation between (r = 0.420, P value is less than 0.05). During the early stages of AHB, the frequencies of NK and NKT cells were found significantly lower than that of control group and CHB group and the levels were back to normal after recovery. Moreover, a negative correlation existed between the frequencies of NK cells and the dynamic changes of HBcAg18-27-specific CTLs (r = -0.435, P value is less than 0.01) in AHB group. The frequencies of HBcAg18-27-specific CTLs were significantly higher as compared to CHB group in the first three weeks (z = -3.258, -4.04, and -3.259, P value is less than 0.01). The early loss of HBsAg was closely related to the high frequencies of HBcAg18-27 specific CTLs in AHB patients. HBcAg-specific CTL frequencies in peripheral blood could be used to predict clinical outcome after HBV infection. The frequencies of CD8+ T cells can reflect the changes of frequencies of HBcAg-specific CTL during acute HBV infection.