Comparison between autoantibodies in malaria and leprosy with lupus

Sera from 16 patients with falciparum malaria, 16 patients with vivax malaria and 31 patients with leprosy were tested for autoantibodies to intracellular proteins and nucleic acids. Precipitating antibodies to soluble protein extracts were not detected in any serum. Sera from malaria patients showed prominent immunofluorescence staining of the HEP2 nuclear membrane as well as frequent 75% (24/32) and intense Western blot reactivity. In contrast, only 20% and 36% of patients with leprosy had positive immunofluorescence or positive immunoblots respectively, and reactivity was weak in most cases. Neither the malaria nor leprosy sera contained autoantibodies with specificities similar to the characteristic lupus autoantibodies such as double stranded DNA (dsDNA), Ro/SSA, La/SSB, Sm, RNP and P proteins. Low levels of antibodies to single stranded (ssDNA) were however found in 11 (34%) malaria sera and in seven (23%) leprosy sera. Thirteen percent of patients with leprosy had anti-histone antibodies. These findings demonstrate considerable differences in the capacity of infectious agents to induce autoantibodies and also the infrequency with which autoantibodies characteristic of idiopathic systemic lupus erythematosus are induced.