Serological surveillance and IL-10 genetic variants on anti-HBs titers: hepatitis B vaccination 20 years after neonatal immunization in Taiwan.

BACKGROUND: The national hepatitis B (HB) vaccination program in Taiwan that began in 1984 has resulted in a significant reduction in the carrier rate among children. However, a significant proportion of Taiwanese neonatal HB immunization recipients have exhibited low anti-HBs titers that fall to non-protective or undetectable levels. METHODS: We recruited 1677 entering freshman and graduate student participants at a Taiwanese university health center, grouped them into three age groups representing three stages of Taiwan's HB vaccination program, then conducted hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) serological surveillances for each individual. Univariate and multivariate regression analyses of clinical characteristics and Interleukin-10 (IL-10) genetic variations were also conducted. RESULTS: A trend toward a decreasing HBsAg carrier rate was observed over the starting dates of the vaccination program (11.7%, 1.6% and 1.7% for age groups 1, 2 and 3, respectively), but we also observed an increasing rate of non-protective anti-HBs titers (15%, 26% and 50.3% for cohorts 1-3, respectively). The percentage of students with non-protective anti-HBs titers increased from 23.1% for students born in 1984, to 25.2% for those born in 1985, to 39.4% for birth-year 1986 students, to 45.7% for birth-year 1987 students, and to 56.5% for birth-year 1988 students. The risk for low anti-HBs titers increased concurrently with increases in systolic blood pressure (BP), the IL-10 ATA/ACC haplotype, and the IL-10 ATA present haplotype. Risk for low anti-HBs titers decreased with concurrent decreases in glucose ante cibum (AC, before meals) and the IL-10 ACC/ACC haplotype. CONCLUSIONS: These results suggest that the genetic determinants may also contribute to variations in anti-HBs titers in immune responses to HB vaccination.