title: Circulating antipericyte autoantibodies in diabetic retinopathy.
abstract: OBJECTIVE
  A number of reports suggest that autoimmune mechanisms may play a role in diabetic microangiopathy, and the existence of circulating antiendothelial cell autoantibodies in diabetic retinopathy has been reported. Because capillary pericyte injury/dysfunction is considered to be an early event in the pathogenesis of diabetic retinopathy and pericyte "drop out" or loss is considered pathognomonic in diabetic retinopathy, we screened diabetic sera for the presence of circulating antipericyte autoantibodies.
  
  
  METHODS
  Diabetic sera were screened for the presence of antipericyte autoantibodies by indirect immunofluorescence on tissue cultured bovine retinal pericytes. Analysis of autoantibody prevalence data was performed with 2x2 contingency tables analyzed using Fisher's exact test.
  
  
  RESULTS
  Diabetic subjects were found to have autoantibodies to microvascular pericytes in their circulation. The prevalence of these antibodies declines with increasing severity of retinopathy. A peak of antibody prevalence was seen at 5-10 years' duration of diabetes. These autoantibodies were found in both Type I and Type II diabetics and in pred iabetics.
  
  
  CONCLUSIONS
  The finding of antipericyte autoantibodies in the circulation of a subpopulation of diabetic subjects suggests that the immune system may play a role in the early pathophysiology of diabetic retinopathy in some patients. These results may contribute to understanding why retinopathy progresses in some patients despite consistent reduction of blood sugar.
authors.affiliation: Elliott P. Joslin Research Laboratories, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Attawia
authors.forename: R C
authors.initials: RC
authors.lastname: Nayak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000276:immunology; D003930:Diabetic Retinopathy / Q000097:blood / Q000276:immunology* / Q000473:pathology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005951:Glucose Tolerance Test; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D008297:Male; D008875:Middle Aged; D020286:Pericytes / Q000276:immunology*; D015995:Prevalence; D012720:Severity of Illness Index
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D001786:Blood Glucose