Elevated levels of antibodies against sulphatide are present in all chronic chagasic and dilated cardiomyopathy sera

A natural anti-sulphatide antibody was found to be present in the serum of every normal individual studied. The reactivity of the antibody was assessed by its interaction with galactosylceramide-I3-sulphate. Antigen-antibody binding was strongly blocked by 1 mM heparin, dextran sulphate and chondroitin sulphate A, and by 5 mM chondroitin sulphate B. Antibodies avidly absorb to rabbit erythrocytes, but discretely to rat erythrocytes, suggesting that they are different from galactocerebroside antibodies. Elevated levels of sulphatide antibodies were present in all of 102 chronic Trypanosoma cruzi-infected patients studied, but not in other patients having cutaneous or visceral leishmaniasis, T. rangeli infection or several other protozoal, helminthic or mycotic infections. Interestingly, 100% of 40 dilated cardiomyopathy patients also have elevated levels of sulphatide antibodies. As T. cruzi is rich in galactocerebroside sulphate, it is proposed that in chagasic patients this glycolipid could act as an immunogen, inducing elevated titres of sulphatide antibodies, which could be important in the pathogenesis of cardiac or peripheral nerve symptoms.