POLYMYALGIA-RHEUMATICA IS ASSOCIATED WITH BOTH HLA-DRB1-ASTERISK-0401AND DRB1-ASTERISK-0404

The frequency of HLA-DRB1 alleles was determined in 68 Caucasoid patie nts with polymyalgia rheumatica (PMR) and 140 controls using polymeras e chain reaction (PCR) sequence-specific oligonucleotide typing. In ke eping with previous studies, an increased frequency of DRB104 was obs erved in patients [55.9% vs 35.0%, odds ratio (OR) 2.4, 95% confidence interval (CI) 1.3-4.4]. HLA-DRB10101 frequency was also increased in patients, although less confidence could be placed on this associatio n (19.1% vs 14.3%, OR 1.4, 95% CI 0.6-3.3). HLA-DRB104 subtyping indi cated that the frequencies of both DRB10401 (38.2% vs 22.1%, OR 2.2, 95% CI 1.0-4.3) and DRB10404 (16.2% vs 5.0%, OR 3.7, 95% CI 1.2-11.1) were specifically raised. An increased frequency of the RA shared epi tope (QKRAA/QRRAA) was also observed in this group (75.0% vs 44.2%, OR 3.8, 95% CI 1.9-7.6). When the analysis was restricted to only DRB10 4-negative patients and controls, the frequencies of DRB10301, *11 an d 08 were marginally raised. However, no obvious relationship appeare d to exist between PMR susceptibility and DRB1 alleles carrying the DY F conserved epitope in the second hypervariable region. Autoantibodies to thyroid antigens were present in 23% of patients. An increased fre quency of DRB10301 was observed in patients with thyroid microsomal a ntibodies compared to those without (54.5% vs 24.6%, OR 3.7, 95% CI 0. 8-17.0). This increase was not observed in patients with thyroglobulin autoantibodies. These data indicate that both DRB10401 and *0404 are associated with PMR, and that this may extend to include DRB10101. T he immunogenetic profile of susceptibility markers in this condition a ppears to be similar to that in rheumatoid arthritis.