ORIGINAL ARTICLE Study on association of human leukocyte antigen-DRB1 alleles in rheumatoid arthritis within Bangladeshi population Maksuma BEGUM, 1 Humayun SATTAR, 2 Syed A. HAQ, 3 Md. Nazrul ISLAM, 3 Sushanta K. SAHA, 3 M. Masudul HASSAN, 3 Ritu SAHA 4 and Md. Shahriar KABIR 5 1 Department of Microbiology, Shaheed Monsur Ali Medical College, Departments of 2 Microbiology, 3 Rheumatology, Bangabandhu Sheikh Mujib Medical University, 4 Department of Microbiology, BashundharaAd-din Medical College, and 5 Medical Oncology, National Institute of Cancer Research and Hospital, Dhaka, Bangladesh Abstract Introduction: 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 develop- ment of RA. Different human leukocyte antigen (HLA)-DRB1 alleles have major pathogenic effects to the devel- opment of RA. Objective: To determine the HLA-DRB1 allelic frequency of RA in one Bangladeshi tertiary care center. Methods: This case–control study was conducted at the Microbiology and Rheumatology Department of Banga- bandhu 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 immunosor- bent assay method. Statistical associations of HLA antigen between the groups were determined by chi-square test. Results: 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 sig- nificant association was found. Conclusions: 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. Key words: rheumatoid arthritis, shared epitope, human leukocyte antigen-DRB1 typing, human leukocyte antigen-DR04, human leukocyte antigen-DR10, human leukocyte antigen-DR15. INTRODUCTION Rheumatoid arthritis (RA) is a common systemic rheumatological disease with autoimmune associations. It causes progressive destruction of synovial joints and Correspondence: Maksuma Begum Assistant Professor, Depart- ment of Microbiology Shaheed Monsur Ali Medical College, Plot # 26/26A, Road # 10, Sector # 11, Uttara, Dhaka-1230, Bangladesh. Email: maksuma.begum@gmail.com © 2018 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd International Journal of Rheumatic Diseases 2018