Rheumatoid arthritis (RA) is a chronic, systemic and autoimmune disease affecting 0.5-1% of the world population. Genetic and environmental factors are already established as being involved in the development of RA. Different human leukocyte antigen (HLA)-DRB1 alleles have major pathogenic effects to the development of RA.
To determine the HLA-DRB1 allelic frequency of RA in one Bangladeshi tertiary care center.
This case-control study was conducted at the Microbiology and Rheumatology Department of Bangabandhu Sheikh Mujib Medical University (BSMMU). Fifty-two patients diagnosed as having RA and 52 healthy controls were enrolled. Buccal swabs were collected from all subjects and HLA-DRB1 typing was carried out with polymerase chain reaction with sequence-specific primers (PCR-SSP) of low resolution. Blood was also collected for auto-antibodies (rheumatoid factor [RF] and anti-cyclic citrullinated peptide [anti-CCP]) detection from all subjects. RF was detected by nephelometry and anti-CCP was detected by using the enzyme-linked immunosorbent assay method. Statistical associations of HLA antigen between the groups were determined by chi-square test.
In RA patients DR*04 and DR*10 were found at the DRB1 locus at higher frequencies (20.5%, P = 0.0035 and 18.3%, P = 0.0045, respectively). However, the frequency of DR*15 was significantly lower (P = 0.005) in RA cases (18.3%) than the control group (35.6%). The frequencies of autoantibodies (anti-CCP and RF) were compared between approximate shared epitope (SE) positive and SE negative patients, and no significant association was found.
In this study DRB1*04 and DRB1*10 alleles were significantly associated with RA patients while DRB1*15 was found more in the control group.