Cell mediated immunity in school children assessed by Multitest CMI skin testing II. Epidemiologic factors affecting immune responsiveness.

The Multitest CMI system was used to measure cutaneous delayed type hypersensitivity (DTH) to a standardized battery of seven recall antigens in 448 healthy school children in relation to sex, age, race, and socioeconomic groups. Blacks demonstrated highest overall DTH, hispanics were intermediate, and whites were lowest. There was a trend for males to be more reactive than females at certain ages in each race. Incidence of reduced DTH scores (relative to adult values) was somewhat increased in the youngest school children, chiefly whites. Incidence and size of DTH responses to certain antigens were consistently higher in the blacks and/or hispanics as compared with whites. Blacks lived almost exclusively in the "poorer" school district, hispanics were evenly divided in both districts, while whites were mostly from the "affluent" district. Level of DTH appeared to be greatest in children from relatively poor homes possibly reflecting more intense and frequent exposure to ubiquitous microorganisms.