Ataxia telangiectasia: An autoimmune disease associated with a cytotoxic antibody to brain and thymus

Abstract The association of autoimmunity with ataxia telangiectasia and studies linking both immunoglobulin deficiency and thymic deficiencies to autoimmunity prompted our search for anti-thymic antibodies in a patient with ataxia telangiectasia. Immunologic studies revealed both cellular and humoral deficits. An immunoglobulin M complement-dependent antibody which appeared to be specific for T-cells and brain cells was demonstrated by cytotoxicity, immunofluorescence, and absorption studies. A similar antibody was detected in the sera of three patients. We speculate that this is an autoantibody which may be important in the pathogenesis of the disease.