title: Defect of a complement receptor 3 epitope in a patient with systemic lupus erythematosus.
abstract: Complement receptor 3 (CR3) is expressed on cells of the reticuloendothelial system and involved in the clearance of immune complexes. In this article a patient with a deficiency of the C3bi binding site of this receptor is described. Clinically this patient exhibited predominantly cutaneous manifestations of a systemic lupus erythematosus with an immune vasculitis and panniculitis. The deficiency of the CR3 epitope was demonstrated using flow cytometry. The functional relevance of this defect was demonstrated in a rosetting assay with C3bi-loaded erythrocytes. C3bi binding was found to be significantly decreased. Furthermore, there was an impairment of phagocytosis of opsonized Escherichia coli. The CR3 defect is not due to an autoantibody but is assumed to have a genetic basis. These data suggest that the defect of the CR3 may be involved in the pathogenesis of the immune vasculitis in this patient.
authors.affiliation: Abteilung Klinische Immunologie und Dermatologie, Medizinische Hochschule Hannover, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Witte
authors.forename: F L
authors.initials: FL
authors.lastname: Dumoulin
authors.forename: J E
authors.initials: JE
authors.lastname: Gessner
authors.forename: J
authors.initials: J
authors.lastname: Schubert
authors.forename: O
authors.initials: O
authors.lastname: Götze
authors.forename: C
authors.initials: C
authors.lastname: Neumann
authors.forename: R F
authors.initials: RF
authors.lastname: Todd
authors.forename: H
authors.initials: H
authors.lastname: Deicher
authors.forename: R E
authors.initials: RE
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D003179:Complement C3b / Q000378:metabolism; D000939:Epitopes; D005434:Flow Cytometry; D006801:Humans; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D016177:Macrophage-1 Antigen / Q000276:immunology* / Q000378:metabolism; D008297:Male; D010587:Phagocytosis
chemical_list: D000939:Epitopes; D016177:Macrophage-1 Antigen; D003179:Complement C3b