Partially restricted antitoxins of tetanus and diphtheria in man.

Antibodies of restricted specificity have been identified in the human in response to certain antigens. The present study analyzed tetanus and diphtheria antitoxins isolated from selected human sera and suggested a restricted response in antibody production to each of these antigens. Purified antibodies from eight serum specimens with elevated hemagglutination titers to tetanus and four to diphtheria yielded only IgG proteins in concentrations of 160-500 microgram/ml. Although some of the tetanus specimens were derived from cord sera and tetanus immunoglobulin, none of the total group had antibodies of the IgA and IgM classes. Utilizing immunoelectrophoresis against heavy chain subclasses, genetic markers, and kappa and lambda quantitations, a predeliction for the kappa IgG1 subclass was established for both tetanus and diphtheria antibodies. The lambda light chains were present in diminished quantities, IgG2 heavy chains were absent, and the IgG3 and IgG4 chains were variably identified.