Objective: to assess the association between different HLA class II polymorphisms and the development of long-term antibody response following primary vaccination against hepatitis B in the first 6 months of life.
Design: case-control study.
Setting: multicentre hospital-based study in rural and urban areas of the Jiangsu province (China).
Study population: the study included 374 children born between 2003-2004 in hospitals in the province of Jiangsu, China (including rural and urban regions) that underwent routine primary vaccination against hepatitis B (three doses at 0-1-6 months). Children that had received a booster at a later time were excluded, as were those with antibodies indicating a self-resolved natural infection.
Risk factor assessment: determination of ten HLA class II alleles previously reported to be associated with a reduced antibody response against hepatitis B following primary vaccination.
Outcome measurement: quantification of the levels of hepatitis B surface antigen antibodies (by immunoassay) 5-7 years following primary vaccination to classify the cases included in the study into two groups: “non-responders”, with levels < 10 mIU/ml, and “responders”, with levels ≥ 10 mIU/ml. All children were tested for 10 different alleles in the HLA DR (DRB1*01, DRB1*03, DRB1*04, DRB1*07, DRB1*08, DRB1*11 and DRB1*1301/1302) and DQ (DQB1*0201, DQB1*0401 and DQB1*0501) regions by polymerase chain reaction with sequence-specific primers, and allele frequencies compared in the two groups. The authors calculated the adjusted odds ratios (aORs) for age and sex as potential confounders.
Main results: of the total 297 children finally included in the study, 211 (71%) were classified as responders and 86 (29%) as non-responders. The mean age was 6 years, and 168 were boys (56.5%) and 129 girls (43.5%). There were no differences in vaccine antigen-specific antibody production between boys and girls.
The comparison of the allele frequencies in the two groups did not reveal significant differences between them, with the sole exception of the DQB1*0401 allele (P = .047), although this difference was no longer statistically significant once the Bonferroni correction for multiple comparisons was applied. The authors also calculated the frequencies and aORs adjusted for age and sex, which were similar to the unadjusted values.
Conclusion: none of the alleles under study was associated with a risk of decreased long-term vaccine immunogenicity against hepatitis B, even after adjusting results for age and sex.
Conflicts of interest: none declared.
Funding source: grants from the Department of Science and Technology of Nanjing City, the Jiangsu Provincial Department of Health and Science and Technology Department of Jiangsu Province, and the National Natural Science Foundation of China.