RESUMO
O presente estudo teve por objetivo investigar o perfil de auto-anticorpos em 241 amostras de sangue de 176 indios Kaingang 6 65 indios Guarani de tres populacoes das reservas indigenas do Rio das Cobras e Ivai, no Estado do Parana, regiao Sul do Brasil. Foram investigados os anticorpos antimusculo liso, antimitocondrias, antinucleares, anticelulas gastricas parietais e antimicrossomas de figado e rim, por metodo de imunofluorescencia indireta. Os resultados foram comparados com os de um grupo de 100 individuos sadios, pertencentes a populacao geral. Obteve-se uma positividade total de 9 por cento para a populacao indigena investigada e 4 por cento para os controles, com resultado significativo para prevalencia dos anticorpos antimusculo liso nas populacoes Kaingang e Guarani do Rio das Cobras (P= 0,03). E provavel que as praticas culturais envolvendo escarificacoes, tatuagens e processamento oral de alimentos, aliadas ao processo de aculturacao e maior convivio com populacoes nao indigenas, exponham os indios a doencas infecciosas anteriormente inexistentes entre os mesmos. Possiveis mecanismos de mimetismo molecular a antigenos virais ou bacterianos poderiam explicar a presenca desses auto-anticorpos nessas populacoes indigenas
This study investigated the autoantibody profile of 241 blood samples from 176 Kaingang and 65 Guarani Indians from three populations living on the Rio das Cobras and Ivaí reservations, in the state of Paraná, in southern Brazil. The presence of antimitochondrial, antismooth muscle, antinuclear, antiparietal cell, and anti-liver-kidney microsome antibodies was determined by indirect immunofluorescence. These results were compared with samples from 100 healthy Caucasian individuals from the general population of the state. Total positivity was 9% for the indigenous population and 4% for the control population. The prevalence of antismooth muscle antibodies was significantly higher among the Guarani and Kaingang individuals from the Rio das Cobras reservation (P = 0.03). It is likely that the increased exposure that these indigenous Brazilians have to infectious diseases that were previously unknown to them comes from more contact with nonnative populations, growing acculturation, and cultural practices that include scarification and tattooing. The presence of autoantibodies in these Brazilian Indians may be related to mechanisms of molecular mimicry with viral or bacterial antigens.