Immunologic Studies in Ataxia-Telangiectasia

Abstract

The capacity to develop contact-type delayed hypersensitivity to simple chemicals was markedly depressed in 19 patients with ataxia-telangiectasia. Serum IgA levels in these patients varied widely, but tended to be low; none of the patients showed a complete absence of IgA. No correlation existed between IgA levels and ability to become sensitized, nor was there a correlation with age, sex, or severity of the disease. Forty-six immediate family members were similarly tested with simple chemicals and found to have a moderately reduced frequency of reaction. The serum IgA levels of the parents generally were within normal limits, but a number of healthy siblings had low serum IgA levels. The findings are discussed in terms of their relationship to the pathogenesis of this rare neuro-cutaneous syndrome.