Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 7 1 2008 03 15 19 24 Mohamad Hossein Nicknam Mahdi Mahmoudi Ali Akbar Amirzargar Mazdak Ganjalikhani Hakemi Farideh Khosravi Ahmad Reza Jamshidi Aref Amirkhani Bita Ansaripour Zahra Pourpak Mostafa Moin Behrooz Nikbin 2015 10 01 The human leukocyte antigen-B27 is one of the class I molecules of the major histocompatibility complex which is strongly associated with ankylosing spondylitis (AS). The strength of the disease association with B27 varies markedly among racial and ethnic populations. It is an allele family, which constitutes about 31 subtypes, with a considerable geographic and ethnic difference in distribution. It is important to know whether certain subtypes show any preferential association with AS. Because there is no report regarding HLA-B27 subtypes in Iranian patients with AS, the factthe main there are rarelystudies (if any); purpose of the present study was to assess the frequency of subtypes of human leukocyte antigen (HLA)-B27 in patients with ankylosing spondylitis in Iranian population One hundred and nineteen AS patients (82 HLA-B27 positive and 37 HLA-B27 negative) were selected for this study. HLA-B27 positive patients were selected screened for B*27 subtyping were performed by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) for B*27 subtyping.. The results of present study revealed that onlythat only two subtypes were detected in Iranian patients, including: B*2705 (52 patients, 63.4%) and B*2702 (30 patients, 36.6%). Our results showed a restricted number of HLA-B27 subtypes associated with AS in Iran and an elevated frequency of the B*2705 allele in these patients similar to other Euro-Caucasoid (Aryan) groups in the world. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/194 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/194/194