title: Association of human leukocyte class II antigens with rheumatic fever or rheumatic heart disease in a Brazilian population.
abstract: BACKGROUND
  The incidence of rheumatic heart disease is great in Brazil. We analyzed the distribution of human leukocyte (HLA) antigens in a Brazilian population sample with rheumatic fever or rheumatic heart disease, with the aim of better understanding the mechanisms involved.
  
  
  RESULTS
  HLA class I (A, B, and C) and class II (DR and DQ) antigen distribution was studied in 40 patients with diagnosis of rheumatic fever or rheumatic heart disease and compared with a control group of 617 healthy individuals for class I typing, from which 118 were drawn for class II typing. A strong correlation between rheumatic fever and rheumatic heart disease and HLA-DRw53 (72.9% in the disease group versus 39% in the control group: p = 0.00061, relative risk, 4.2; etiologic fraction, 0.43) was found. We also found an increase in the frequency of HLA-DR7 (57.5% in the disease group versus 26.3% in control group: p = 0.00715; relative risk, 3.8; etiologic fraction, 0.56). HLA class I and HLA-DQ typing did not point to any association with these diseases.
  
  
  CONCLUSIONS
  HLA-DR7 and HLA-DRw53 are markers for susceptibility to rheumatic fever and rheumatic heart disease in Brazil. These results could be explained by genetic differences resulting from racial or geographical diversity.
authors.affiliation: Heart Institute, Hospital of Clinics, Faculty of Medicine, University of São Paulo, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Guilherme
authors.forename: W
authors.initials: W
authors.lastname: Weidebach
authors.forename: M H
authors.initials: MH
authors.lastname: Kiss
authors.forename: R
authors.initials: R
authors.lastname: Snitcowsky
authors.forename: J
authors.initials: J
authors.lastname: Kalil
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D005260:Female; D006683:HLA-DQ Antigens / Q000032:analysis; D006684:HLA-DR Antigens / Q000032:analysis; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007962:Leukocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012213:Rheumatic Fever / Q000276:immunology* / Q000473:pathology; D012214:Rheumatic Heart Disease / Q000276:immunology* / Q000473:pathology
chemical_list: D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II