Objectives The objective was to assess the distribution and possible associations of HLA-DRB1 alleles in the Russian population with long standing rheumatoid arthritis.

Methods Forty four patients (pts) with RA (2 males, 42 females, mean age 53.3 ± 10.85 yr. and mean disease duration 12.9 ± 7.71 yr. and 135 controls were typed for HLA-DRB1 alleles using PCR based molecular techniques. Radiological outcome was measured by scoring X-rays of the hands and feet using the standard radiographs of Larsen (Larsen score). Patients were stratified by RF status and the results were analysed using the Fisher exact test.

Results The frequency of individuals with DRB1*04 (p < 0.00001) was significantly higher, DRB1*05 (p < 0.04) and *07 (p < 0.006) were lower in the pts in compare with the controls. HLA-DRB1*04 proved to be significantly increased in seropositive pts (p < 0.038). RF(+) pts with homozygous status for HLA-DRB1*04 (p < 0.04) had significantly higher radiological score (p < 0.05).

Conclusion Protracted RA in the Russian population is characterised by high frequency HLA-DRB1*04 and low distribution DRB1*05 and DRB1*07. In RF(+) RA pts there was association between the presence DR4 and radiological severity.