HLA DRB1 POLYMORPHISM IN POLYMYALGIA-RHEU MATICA AND GIANT-CELL ARTERITIS

Some studies have suggested that distribution of HLA DRB1 alleles in p olymyalgia rheumatica (PMR) resembles that found in giant cell arterit is (GCA). However these data are controversial. Objective.- To evaluat e in French native patients whether PMR immunogenetically resembles GC A in determining HLA DRB1 alleles. Patients and methods.- Fourty-five patients were included in the study. Twenty-one patients with PMR alon e (Bird's criteria) and 24 with GCA (ACR criteria). In 11 patients, GC A was associated with PMR. HLA DRB1 genotype was determined by PCR-RFL P analysis. Statistical analysis was performed by the chi(2) test and determination of the odds ratio (OR). Two hundred and thirty-three uns elected normal healthy subjects served as controls. Results.- A signif icant increased prevalence of HLA DR1 was observed in patient with PMR alone and an absence of DR7 (0% vs 10.3%, p = 0.02, OR = 0.1). An inc reased incidence of DR4 and particularly 0401 allele was only found i n patients with GCA (OR = 2.4). No patients with isolated PMR had DR7 genotype compared with 25% in GCA (p<0.001, OR = 0.03). A comparative study between isolated PMR versus GCA showed a significant increased i n DR1 and DR3 alleles in isolated PMR and a significant increased prev alence of DR4 and DRB1 0701 allele in GCA. Conclusion.- The present s tudy empahsizes the absence od similarity in HLA DRB1 allele distribut ion between PMR and GCA. The association of DR7 in patient with GCA se ems characteristic in French native patients.