title: HLA-DR53 protects against thrombotic thrombocytopenic purpura/adult hemolytic uremic syndrome.
abstract: Class I and Class II HLA antigens were tested in patients treated for thrombotic thrombocytopenic purpura or hemolytic uremic syndrome (TTP/HUS) to determine whether there is a disease association. Based on the results of a pilot trial, retrospective HLA-typing of 18 patients with a diagnosis of TTP/HUS and prospective typing of 12 newly diagnosed patients with TTP/HUS were performed. Twenty-one patients were non-Hispanic Caucasians, 7 were African-Americans, and 2 were Hispanic-Caucasians. Of 30 patients tested, 28 were positive for DR52 (chi-squared = 5.14, P < 0.05), and only two were positive for DR53 compared to 57% of controls (chi-squared = 18.5, P < 0.0005). Diverse DR52 subtypes (DRB3*0101, DRB3*02, and DRB3*0301) were found by oligonucleotide testing in 15 patients, suggesting the association was not with DR52 but with absence of the DR53 antigen. The 2 patients with DR53 were not homozygous. This study suggests that the supertypic antigen, DR53, may govern susceptibility to TTP/HUS, since the relative risk of this disease among DR53 positives is reduced at 0.09 (95% confidence interval, 0.01-0.28). This finding indicates a possible immunogenetic component in the pathogenesis of TTP.
authors.affiliation: Department of Pathology, University of Louisville, Kentucky.
authors.forename: G
authors.initials: G
authors.lastname: Joseph
authors.forename: K J
authors.initials: KJ
authors.lastname: Smith
authors.forename: T J
authors.initials: TJ
authors.lastname: Hadley
authors.forename: B
authors.initials: B
authors.lastname: Djulbegovic
authors.forename: G M
authors.initials: GM
authors.lastname: Troup
authors.forename: J
authors.initials: J
authors.lastname: Oldfather
authors.forename: R L
authors.initials: RL
authors.lastname: Barker
mesh_terms: D000328:Adult; D001483:Base Sequence; D004247:DNA / Q000032:analysis / Q000235:genetics; D004198:Disease Susceptibility; D005260:Female; D006684:HLA-DR Antigens / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D059845:HLA-DRB4 Chains; D006463:Hemolytic-Uremic Syndrome / Q000175:diagnosis / Q000276:immunology / Q000517:prevention & control*; D006650:Histocompatibility Testing; D006720:Homozygote; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010865:Pilot Projects; D016133:Polymerase Chain Reaction; D011697:Purpura, Thrombotic Thrombocytopenic / Q000175:diagnosis / Q000276:immunology / Q000517:prevention & control*; D012189:Retrospective Studies
chemical_list: D006684:HLA-DR Antigens; C050610:HLA-DR53; D059845:HLA-DRB4 Chains; D004247:DNA