Abstract: Objective: To analyze the effects of serum hepatitis B virus covalently closed circular DNA(HBV-cccDNA)level on the liver and kidney functions, detection of HBV antigens in kidney tissue, pathological grading and staging of liver tissue in the children with hepatitis B virus associated glomerulonephritis (HBV-GN), and to evaluate the clinical value of HBV-cccDNA level detection in the diagnosis of the children with HBV-GN.Methods: A total of 39 HBV-GN children (observation group) were selected and all of them underwent the liver and kidney biopsy. A total of 40 HBV-carried children with normal liver function were selected as control group. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of the children were detected.Molecular beacons PCR method was used to detect the serum HBV-cccDNA level of the children. The morphology of liver and kidney tissues of the children was detected with HE staining.The detection rates of HBsAg, HBeAg and HBcAg in kidney tissue of the children were detected by immunofluorescence. Receiver operating characteristic(ROC) curve and area under the ROC curve (AUC) were used to evaluate the value of HBV-cccDNA level detection in the diagnosis of HBV-GN. The Ax fluorescence value of HBV-cccDNA > 21 was determined as positive, and the Ax fluorescence value of HBV-cc cDNA < 21 was determined as negative; the children with HBV-GN were divided into HBV-cccDNA positive group(n=24) and HBV-cccDNA negative group(n=15). The serum levels of HBV DNA and HBV-cccDNA were measured at the 2nd, 4th, 8th and 12th weeks after antiviral therapy.Results: The abnormal rates of ALT and AST levels,positive rates of HBeAg and urine protein of the children in HBV-cccDNA positive group were higher than those in HBV-cccDNA negative group(χ²=4.454,P=0.035;χ²=5.912,P=0.022;χ²=8.770,P=0.007).There were no significant differences in the degrees of liver inflammation and fibrosis in the children between HBV-cccDNA positive and negative groups (P>0.05). Membranous nephropathy (MN) was the main pathological type of kidney biopsy in the HBV-GN.HBeAg and HBcAg were the main components of HBV antigens. The detection rates of HBeAg and HBcAg of the children in HBV-cccDNA positive group were significantly higher than those in HBV-cccDNA negative group(χ²=5.652, P=0.027; χ²=12.523,P=0.001). The ROC curve analysis results showed that the HBV-cccDNA level detection could effectively distinguish the HBV-GN children in observation group from those in control group, AUC=0.804 (95% CI 0.709-0.883).The levels of HBV-cccDNA of 10 cases of HBV-GN children underwent standardized treatment with complete follow-up treatment data were decreased significantly at the 2nd week after treatment. At the 12th week after treatment, in 7 cases the HBeAg turned negative, without proteinuria and hematuria symptoms, and the AST and ALT levels were normal. The HBV-cccDNA levels of 3 cases with ineffective treatment were higher than that those of the remaining 7 cases.Conclusion: The high expression of HBV-cccDNA is closely related to the liver function, proteinuria and HBV antigen detection in kindney tissue of the HBV-GN children. The detection of HBV-cccDNA level has potential clinical value for the auxiliaty diagnosis and evaluation on the curative effect of the HBV-GN.

Key words: hepatitis B virus associated glomerulonephritis, hepatitis B virus covalently closed circular DNA, children, hepatitis B virus