ASSOCIATION OF THE SHARED EPITOPE WITH RADIOLOGICAL SEVERITY OF RHEUMATOID-ARTHRITIS

Objective. To investigate the association between radiological severit y of rheumatoid arthritis (RA) and the presence of the shared epitope. Methods, Ninety unrelated adult Spanish patients with RA with a disea se duration of at least 3 years, selected according to the American Co llege of Rheumatology criteria, were radiologically assessed (shoulder s, elbows, wrists, hands, hips, knees, and feet) and classified as hav ing severe or nonsevere RA. DNA oligotyping was used to determine DR s pecificities and to detect DR4 and DR1 alleles. Results. Forty-one pat ients (45.5%) had severe RA. Sixty-six patients (73.3%) carried the sh ared epitope and 18 (20%) had double expression of the shared epitope. Thirty-seven (90%) of the 41 patients with severe RA expressed the sh ared epitope. Logistic regression analysis showed that both single and double expression of the shared epitope were strongly related to the radiological severity of RA (odds ratio = 6.3 and 9.4, respectively). Conclusion, Our results show that radiological severity of RA is highl y associated to the shared epitope.