title: FcγRIIa and FcγRIIIb polymorphisms and associations with clinical manifestations in systemic lupus erythematosus patients.
abstract: In this study, we aimed to investigate whether the distribution of the FcγRIIa and FcγRIIIb polymorphisms determines susceptibility to systemic lupus erythematosus (SLE) and acts as predictors of SLE clinical manifestations in the Brazilian patients. A total of 157 patients that fulfilled the American College of Rheumatology classification criteria for SLE and 160 healthy volunteers were included in this study. FCGR2A and FCGR3B genotypes were determined by polymerase chain reaction-based allotyping methods with allele-specific primers; the clinical features were obtained from the patients' official medical records. In the case of FcγRIIa polymorphism, it was observed association of the allele FCGR2A-R-131 (p = 0.02, odds ratio (OR)=1.44) and genotype RR-131 (p = 0.03, OR = 2.09) with SLE. These associations were higher with allele (p < 0.01, OR = 1.67) as well genotype (p = 0.01, OR = 2.85) when lupus nephritis was considered. In contrast, the allele FCGR2A-H-131 was associated with susceptibility to arthritis and anti-DNA antibodies (p = 0.05 for both). As for FcγRIIIb polymorphism, skewing did not differ significantly between patients and controls, however the genotype FCGR3B*02*02 was associated with susceptibility to arthritis (p = 0.02) and malar rash (p = 0.03), but no association with nephritis was found. The results demonstrate that FcγRIIa polymorphism is associated with susceptibility to SLE in Brazilian patients, whereas for FcγRIIIb polymorphism no association was found. However, notably, both polymorphisms present allelic variants that influence the clinical manifestations and may contribute to the pathogenesis of the disease. In addition, to our knowledge, this is the first study considering the frequency of FcγRIIIb polymorphism in Brazilian SLE patients.
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto-SP , Brasil .
authors.forename: Isabel Cristina Costa
authors.initials: IC
authors.lastname: Vigato-Ferreira
authors.forename: Juliana Escher
authors.initials: JE
authors.lastname: Toller-Kawahisa
authors.forename: João Alexandre Trés
authors.initials: JA
authors.lastname: Pancoto
authors.forename: Celso Teixeira
authors.initials: CT
authors.lastname: Mendes-Junior
authors.forename: Edson Zangiacomi
authors.initials: EZ
authors.lastname: Martinez
authors.forename: Eduardo Antônio
authors.initials: EA
authors.lastname: Donadi
authors.forename: Paulo
authors.initials: P
authors.lastname: Louzada-Júnior
authors.forename: José Eduardo Cavalcanti
authors.initials: JE
authors.lastname: Del Lama
authors.forename: Cleni Mara
authors.initials: CM
authors.lastname: Marzocchi-Machado
mesh_terms: D000328:Adult; D000483:Alleles; D001938:Brazil; D018450:Disease Progression; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics / Q000276:immunology; D020022:Genetic Predisposition to Disease; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics* / Q000276:immunology
chemical_list: C445323:FCGR2A protein, human; C428200:FCGR3B protein, human; C080568:Fc gamma receptor IIA; D058851:GPI-Linked Proteins; D017452:Receptors, IgG
keywords: Fcγ receptors; SLE; genetic polymorphisms