Background Rheumatoid Arthritis (RA) is a complex, multifactorial autoimmune disease, whose etiopathogenesis involves genetic and environmental factors.
Objectives The aim of the study was the assessment of the association of HLA-DRB1*-SE in the presence/absence of anti-CCP autoimmunity in Greek patients with RA (smokers and non-smokers).
Methods Eighty-three (83) RA patients (41 smokers, 42 have never smoked) were typed for HLA-DRB1* alleles by molecular techniques (PCR-SSOP and -SSP). In 62 out of 83 (74.7%) anti-CCP abs were detected by ELISA.
Results In RA pts and in comparison to the controls, increased frequency of HLA-DRB1*01:01 (28.9% vs 6.8%, OR=4.4), *10:01 (16.9% vs 2.4%, OR=8.4), *04:01 (3.6% vs 2%, OR=1.8), *04:04 (7.2% vs 1%, OR=7.6) and *04:05 (15.7% vs 3.7%, OR=4.8), as well as decreased frequency of *04:02 (1.2% vs 2%, OR=0.6) and *04:03 (4.8% vs 6.8%, OR=0.7) were found. Among the RA patients, 77.1% possess 1SE vs 18.9% of controls (OR=14.4), whereas 10.8% possess 2SE vs 1% of controls (OR=11.8). In CCP (+) RA patients and in comparison to CCP (-) an increased frequency of HLA-DRB1*01:01 (27.4% vs 14.3%, OR=2.3) and *10:01 (21% vs 4.8%, OR=5.3) was observed. Furthermore, 88.7% of CCP (+) carry 1SE vs 42.9% of CCP (-) patients (OR=10.5). CCP (+) smokers patients in comparison to CCP (+) non-smokers are presented with an increased frequency of DRB1*01:01 (41.9% vs 12.9%, OR=4.9). Among the CCP (+) smokers, 96.8% possess 1SE vs 80.6% of CCP (+) non-smokers (OR=7.2), whereas 12.9% possess 2SE vs 12.9% of CCP (+) non-smokers (OR=1).
Conclusions a) An increased frequency of HLA-DRB1*01:01, *10:01, *04:05 alleles, as well as the protective role of *04:02, *04:03 alleles in Greek patients with RA were confirmed b) The presence of any SE, particularly *10:01 allele, strongly influences the production of anti-CCP abs and c) Interaction between smoking and any SE, particularly *01:01 allele, is associated with anti-CCP positive RA in Greek patients.
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Disclosure of Interest None declared