RESUMO
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, main 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 by polymerase chain reaction amplification with sequence-specific primers [PCR-SSP] for B 27 subtyping. The results of present study revealed that 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