The effects of sex and age on serum IgE concentrations in three ethnic groups.

Serum IgE concentrations were measured using a radio-radial immunodiffusion method in 4,440 blood donors resident in the Western Cape Province, South Africa, and the following differences were observed. Firstly, in all three ethnic groups studied, that is the Whites, the Cape Coloureds and the Africans, there was a tendency for males to have higher serum IgE concentrations than females. This differences was highly significantly in Whites. Secondly, in the Whites, serum IgE concentrations tended to be lower with advancing age. Thirdly, previous reports of elevated serum IgE concentration in indigenous African population were confirmed. No clearly defined cause for these differences emerged rom this study.