Share epitope, citrullinated cyclic peptide antibodies and smoking in Brazilian rheumatoid arthritis patients.
The events involved in the pathogenesis of rheumatoid arthritis (RA) still remain unclear, but certainly the etiology is multifactorial. Shared epitope (SE) of HLADRbeta1 is the most important genetic risk factor. Environmental risk factors are less understood. Smoking is a candidate, associated with the rising of citrullinated cyclic peptide antibodies (anti-CCP). Anti-CCP antibodies are highly specific for RA. In this study, we investigated whether the association between anti-CCP production and smoking was influenced by carriage of SE in a highly miscegenated population of patients with RA. One hundred Brazilian patients were inquired about cigarette smoking. For all of them, DNA for HLA typing and serum to anti-CCP antibodies quantification were obtained. Forty-two were smokers and 58 were nonsmokers. The SE was present in 61 patients and the anti-CCP was positive in 71 patients. We found that, among smokers, 25 were SE-positive, 22 presented with anti-CCP and 3 without anti-CCP, and 17 were SE-negative, 9 presented with anti-CCP and 8 without anti-CCP (OR 6.5, 95% CI 1.40 to 30.20). These results suggest that environmental factors contribute to the raising of anti-CCP in individuals with HLA background to RA, smoking being a strong candidate.
Oliveira
Rene Donizeti
RD
Division of Clinical Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
Junta
Cristina Maria
CM
Oliveira
Fabíola Reis
FR
Silva
Lucienir Maria
LM
Donadi
Eduardo Antonio
EA
Louzada-Junior
Paulo
P
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000235:genetics / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001938:Brazil; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry; D010456:Peptides, Cyclic / Q000276:immunology*; D012907:Smoking
D001323:Autoantibodies; D000939:Epitopes; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide