Does the presence of HLA-DR B1 shared motif affect progression of the disease in rheumatoid arthritis patients?

The present study was undertaken in order to evaluate role of HLA DR Bl shared motif in prognosis of development of erosions in rheumatoid arthritis (RA). HLA genotyping was carried out in a retrospective analysis of 73 RA patients and 87 healthy controls using polymerase chain reaction. The assessment of disease activity was performed according to Mallya-Mace Index, whereas radiographs of hands were assessed according to the Larsen Index. HLA-DR4 and DR10 were significantly increased among RA patients. Relative risk was 7.540 and 4.646, respectively. Interestingly, the presence of DRl and DR14 did not enhance the relative risk in our group of patients. Determination of HLA-DR B1 alleles showed that among RA patients the most frequent was HLA-DR Bl*0401, *0404, and *0408. They gave a rise to a relative risk of 4.010, 7.540, and 3.686 respectively. For the purpose of analysis the patients were divided into three groups. The first group comprised 14 patients with two high-risk alleles (HLA DR B1 *01, *0401, *0404, *0408, *14). The second group gathered 35 patients with one high-risk allele. Twenty-four patients with no high-risk alleles were designated to the third group. We did not notice any differences in damage score and progression of damage score in rheumatoid arthritis patients with different number of high risk motifs. In conclusion, HLA-DR B1 shared motif was found to be significantly more frequent among analyzed erosive rheumatoid arthritis as compared to matched healthy controls. We did not observe any relation between the presence of shared motifs and outcome of the disease. Therefore, it seems that HLA DR B1 determination may very helpful in diagnosing or in establishing groups of risk but it is not likely to have a role in predicting development aggressive forms of RA.