Clinical features of HBs Ag seroclearance in hepatitis B virus carriers in South Korea: A retrospective longitudinal study

摘要

AIM To investigate the characteristic features of hepatitis B surface antigen(HBs Ag) seroclearance among Korean hepatitis B virus(HBV) carriers.METHODS Carriers with HBs Ag seroclearance were selected by analyzing longitudinal data collected from 2003 to 2015. The period of time from enrollment to the negative conversion of HBs Ag(HBs Ag-NC) was compared by stratifying various factors, including age, sex, hepatitis B e antigen(HBe Ag), HBV DNA, sequential changes in the signal-to-cutoff ratio of HBs Ag(HBs Ag-SCR), as measured by qualitative HBs Ag assay, and chronic liver disease on ultrasonography(US-CLD). Quantification of HBV DNA and HBs Ag(HBs Ag-QNT) in the serum was performed by commercial assay.RESULTS Among the 1919 carriers, 90(4.7%) exhibited HBs AgNC at 6.2 ± 3.6 years after registration, with no differences observed among the different age groups. Among these carriers, the percentages of those with asymptomatic liver cirrhosis(LC) and hepatocellular carcinoma(HCC) at registration were 31% and 7.8%, respectively. The frequency of HBs Ag-NC significantly differed according to the HBV DNA titer and US-CLD. HBe Ag influenced HBs Ag-NC in the 40-50 and 50-60 year age groups. HBs Ag-SCR < 1000 was correlated with an HBs Ag-QNT < 200 IU/m L. A gradual decrease in the HBs Ag-SCR to < 1000 predicted HBs Ag-NC. Six patients developed HCC after registration, including two before and four after HBs Ag-NC. The rate at which the patients developed new HCC after HBs Ag seroclearance was 4.8%. LC with excessive drinking and vertical infection were found to be risk factors for HCC in the HBs Ag-NC group.CONCLUSION HCC surveillance should be continued after HBs Ag seroclearance. An HBs Ag-SCR < 1000 and its decrease in sequential testing are worth noting as predictive markers of HBs Ag loss.