Objectives. To investigate the role of shared epitope (SE) alleles in the short-term clinical response to leflunomide for the treatment of active RA. Methods. In an open-label, multi-centre study of 16-weeks duration, 93 patients (82% female) fulfilling ARA 1987 RA criteria were treated with leflunomide (100 mg loading dose for 3 days, then 20 mg/day as the maintenance dose). The primary efficacy criterion was the response status according to the European League Against Rheumatism (EULAR)

more »

... se criteria using Disease Activity Score-28 (DAS28) activity measure. SE determinations have been undertaken by polymerase chain reaction and sequence-specific oligonucleotide genotyping methods. Results. The mean (S.D.) Disease Activity Score-28 (DAS28) was 5.1 (1.3) before the treatment, which was significantly decreased after 16 weeks [3.0 (1.1), P < 0.001]. According to the EULAR response criteria, 55 patients (59.1%) were classified as good responders. SE was positive in 51 (54.8%) of the patients, with 13 (13.9%) having SE homozygosity or carrying any two SE alleles. Among SE-positive patients, 68.6% (35/51) were good responders, compared with 47.6% (20/42) in SE negatives (P ¼ 0.04). No difference was present according to SE hetero-or homozygosity (68.4 vs 69.2%). RF was also present significantly more frequently in the SE-positive group compared with negatives (78.4 vs 57.1%, P ¼ 0.03). However, no significant difference was observed in the prevalence of RF positivity in patients with a good clinical response (72.7 vs 63.2%, P ¼ 0.32). Conclusions. The results suggest that HLA-DRB1 SE presence may favourably affect the outcome of leflunomide monotherapy in an unselected group of RA patients with an active disease and naive to leflunomide. KEY WORDS: Leflunomide, Rheumatoid arthritis, Shared epitope. Results Eighty-two percent of our patient group were female. The mean age (S.D.) of the patients was 45.8 (11.5) yrs and the mean disease duration was 5.3 (2.8) yrs. RF was positive in 68.8% (64/93).