title: Familial systemic lupus erythematosus: the role of genetic and environmental factors.
abstract: OBJECTIVE
  To examine the contribution of genetic and environmental factors to disease occurrence in 26 families with two or more members affected with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Genetic and environmental factors were examined by HLA-A, B, C/DR typing and by determining the presence of lymphocytotoxic antibodies (LCA) in patients and their consanguineous and non-consanguineous relatives.
  
  
  RESULTS
  No association between SLE and HLA-A, B, C antigens was found. There was, however, a significant association with HLA-DR2 in white subjects with SLE. The most striking finding was that HLA sharing was increased among the affected members, suggesting genetic similarities. Seven of 14 sib pairs (50%) who had concordant SLE were HLA identical as opposed to an expected 25%. Another interesting finding was that 15/18 (83%) patients with SLE and 11/22 (50%) consanguineous relatives had LCA, while 1/9 (11%) spouses, and 2/42 (5%) healthy controls had these antibodies.
  
  
  CONCLUSIONS
  Genetic factors have a role in the development and expression of SLE. Environmental factors may trigger the disease in genetically susceptible hosts.
authors.affiliation: Department of Medicine, Division of Allergy and Clinical Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA. geroglu@cs.com
authors.forename: G E
authors.initials: GE
authors.lastname: Eroglu
authors.forename: P F
authors.initials: PF
authors.lastname: Kohler
mesh_terms: D000293:Adolescent; D000328:Adult; D000961:Antilymphocyte Serum / Q000276:immunology; D016010:Binomial Distribution; D016022:Case-Control Studies; D016001:Confidence Intervals; D003241:Consanguinity; D005260:Female; D015234:HLA-A Antigens / Q000276:immunology; D015235:HLA-B Antigens / Q000276:immunology; D015236:HLA-C Antigens / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D018454:Spouses
chemical_list: D000961:Antilymphocyte Serum; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D006684:HLA-DR Antigens