Detection of the covalently closed circular DNA in peripheral blood mononuclear cells of hepatitis B patients and its clinical significance / 中华传染病杂志

ABSTRACT

Objective To analyze the correlation between covalently closed circular DNA (cccDNA) in the peripheral blood mononuclear cells (PBMC) of hepatitis B virus (HBV)-infected patients and serum HBV DNA,hepatitis B surface antigen (HBsAg),hepatitis B e antigen (HBeAg) and liver histology of hepatitis B patients,and to explore the clinical significance of HBV cccDNA detection in PBMC.Methods One hundred and eight patients with chronic HBV infection were involved in this study.PBMC were extracted using density gradient centrifugation.HBV cccDNA in PBMC and serum HBV DNA were detected by real-time fluorescence quantitative polymerase chain reaction.HBsAg and HBeAg were detected by chemiluminescence immunoassay.Liver biopsy was conducted in 59 out of the 108 patients.Chi-square test was used to compare the categorical variables.Correlation analysis was used to compare quantitative variables.Nonparametric test was used to compare the non-normal distribution parameters.Results In the overall population,HBV cccDNA in PBMC was positive in 59 patients (54.6％).Eleven of the 15 patients with liver failure were found to be HBV cccDNA positive,which was significantly higher than that in the acute hepatitis B group (only 2 of the 8 patients were HBV cccDNA positive; x2 =4.960,P＜0.05).One hundred and eight patients were categorized into three groups according to their serum HBV DNA levels,with group A＞5 lg copy/mL,group B3-5 lg copy/mL and group C＜3 lg copy/mL.The proportions of HBV cccDNA positivity in PBMC in three groups were 76.1％ (51/67),5/18 and 13.0％ (3/23),respectively.Comparing with patients with lower HBV DNA (group B and C),the proportion of HBV cccDNA positivity was higher in patients with higher HBV DNA (group A; x2=14.751,P＜0.05 and x2 =28.384,P＜0.05,resepectively).The HBV cccDNA quantitation in PBMC was positively correlated with the serum HBV DNA level and HBsAg quantification (r=0.554,P＜0.05 and r=0.497,P＜0.05,respectively).The proportion of HBV cccDNA positivity in PBMC of patients with liver histology ≥G2 and/or ≥S2 was significantly higher than that in patients with liver histology ＜ G2/S2 (x2 =9.159,P＜0.05).Conclusions HBV cccDNA exists in PBMC of hepatitis B patients.The HBV cccDNA quantitation in PBMC is positively correlated with the serum level of HBV DNA and HBsAg quantification,and is also associated with liver histology injury.