Evaluation of human antibody responses to diphtheria toxin subunits A and B in various age groups

Karakus R., Caglar K., Aybay C.

CLINICAL MICROBIOLOGY AND INFECTION, vol.13, no.11, pp.1065-1071, 2007 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 13 Issue: 11
  • Publication Date: 2007
  • Doi Number: 10.1111/j.1469-0691.2007.01804.x
  • Page Numbers: pp.1065-1071


This study aimed to evaluate human antibody responses to diphtheria toxin subunits in various age groups. Antibodies against the intact diphtheria toxin and the diphtheria toxin subunits A and B were evaluated in 1319 individuals using a double-antigen ELISA. Although high levels of protection (83.6%, 95% CI 79.2-87.4) were found in children and adolescents, the middle-aged adult population was less protected (28.8%, 95% CI 24.3-33.6). An increase in age was associated with a decrease in the frequency of protected individuals in the 0-39-year age group (p < 0.001). Anti-subunit B levels correlated well (p < 0.01) with levels of antibodies against the intact toxin. In children aged <= 16 years, the intervals at which the peaks in geometric mean titres of anti-subunit B antibodies were observed were found to correlate with the ages at which booster doses are administered. Overall, males appeared to be more protected than females (OR 1.67, 95% CI 1.34-2.08, p < 0.001). A small group of individuals had antibody levels of >= 0.1 IU/mL against the intact toxin, but did not have protective antibody against subunit B. Determination of anti-subunit B antibody levels should help in evaluating the effectiveness of diphtheria boosters and other aspects of diphtheria immunity.