Objective: The HLA-DRB1 alleles play an important role in the genetic predisposition to rheumatoid arthritis (RA). The relationship between HLA-DRB1 and rheumatoid arthritis show differences according to various ethnic groups and geographical distributions. The aim of this study was to determine the distribution of HLA-DRB1 among the Turkish RA patient population in the Southeastern Anatolia Region.

Materials and Methods: 96 patients diagnosed with RA and a control group consisting of 84 healthy individuals were enrolled in the study. The HLA-DRB1 type and subtypes were specified using the polymerase chain reaction with sequence specific primers (PCR-SSP) method. The betweengroup HLA-DRB1 type and certain subtype frequencies were compared.

Results: The DRB1*10 alleles were found to be statistically significantly higher in patients with RA compared to the control group (p=0.001). However, the DRB1*07 and DRB1*11 alleles were statistically significantly lower in patients with RA (p<0.001 and p=0.02, respectively). In the RA patient group, the DRB1*0401, DRB1*0408 and DRB1*1001 subtypes were found to be statistically significantly higher (p=0.04, p=0.01, p=0.005, respectively), while the DRB1*0402, DRB1*0403 and DRB1*0701 subtypes were statistically significantly lower (p=0.01, p=0.02, p<0.001, respectively).

Conclusion: This study has revealed the HLA-DRB1 distribution in the Southeastern Anatolia Region of Turkey. DRB1*10 type and DRB1*0401, DRB1*0408, DRB1*1001 subtypes were observed to be related with RA. DRB1*07, BRB1*11 types and DRB1 *0402, DRB1*0403, DRB1*0701 subtypes were accepted as protective alleles and subtypes.