Aim: To investigate the distribution of human leucocyte antigen (HLA) class I antigens and B27 subtypings in a group of B27(+) ankylosing spondylitis (AS) patients and a group of B27(+) control individuals, and to compare differences in their clinical features using subtyping.
Methods: A total of 143 B27(+) AS samples and 32 B27(+) control samples were collected consecutively from two rheumatology centres in South Korea. All patients were diagnosed according to the modified New York criteria for AS. Medical records of the patients were retrospectively reviewed for demographic information, Bath disease activity index (BASDAI) scores, laboratory parameters at diagnosis and extra-articular manifestations. Polymerase chain reaction-sequence-specific primer typing for the B27 subtypes was performed using the Dynal HLA-B27 high resolution kit.
Results: Whereas subtypes in Korean AS patients include B*2704 (n = 11, 7.7%) B*2705 (n = 130, 90.9%), and B*2710 (n = 2, 1.4%), those of the control groups include B*2704 (n = 11, 34.4%), B*2705 (n = 19, 59.4%), B*2710 (n = 1, 3.1%), and B*2715 (n = 1, 3.1%). The proportion of B*2705 subtypes were significantly higher in the AS group than the control group (P < 0.01). There were no differences in clinical features (peripheral arthritis, uveitis, BASDAI scores) or laboratory parameters between the two groups.
Conclusion: In Korean AS patients, not in the control group, the HLA-B*2705 subtype was higher than other subtypes, in contrast to AS patients from Japan and China. B27 subtypes in AS patients were not associated with clinical features or laboratory parameters.