[A nested case-control study on factors affecting hepatitis B surface antigen natural clearance in community...

Objective: To understand the molecular epidemiological characteristics and influencing factors of natural scavengers of hepatitis B surface antigen (HBsAg) in the community population. Methods: From 2010 to 2015, people from the Wuwei Hepatitis B Prevention and Treatment Demonstration Zone were used as the research object to conduct health examinations and follow-up visits. Using the nested case-control study method, 99 HBsAg natural clearancers during the follow-up period were selected as the case group, and 316 HBsAg natural clearancers who did not have HBsAg natural clearance were selected as the control group. Data were collected using questionnaires, serology, and single-nucleotide polymorphism detection. Results: Among the 99 HBsAg natural clearance cases, 45 cases were male (45.45%) and 54 cases were female (54.55%); among the 316 control cases, 156 cases were male (49.37%) and 160 cases were female (50.63%); the genotypes of Notch3 gene rs1043994 loci CC, CT and TT genotypes accounted for 63.64%, 32.95% and 3.41%, respectively, and the frequency in the control group was 77.21%, 21.84% and 0.95%, respectively. The difference in genotype distribution between the two groups was statistically significant (P=0.014). The distribution frequencies of the Notch4 gene rs367398 AA, AG, and GG genotypes in the case group were 11.36%, 50.00% and 38.64%, respectively. In the control group, the frequencies were 5.38%, 43.99% and 50.63%, respectively. The genotype distribution difference between the two groups was statistically significant (P=0.043). Analysis of multivariate logistic regression model showed that factors related to the natural clearance of HBsAg include age ≥60 years old (OR=3.14, 95%CI: 1.33-7.41, P=0.009), Notch3 gene rs1043994 locus CT genotype (OR=1.82, 95%CI: 1.06-3.13, P=0.031), and TT genotype (OR=5.58, 95%CI: 1.05-29.59, P=0.044), Notch4 gene rs367398 locus AA genotype (OR=2.89, 95%CI: 1.17-7.13, P=0.021). Conclusion: In a community-based population of HBsAg carriers, individuals aged ≥60 years, those with the Notch3 gene rs1043994 locus (CT, TT) and the Notch4 gene rs367398 locus (AA) were more likely to experience natural clearance of HBsAg.