Polymorphism of HLA-B27 in ankylosing spondylitis of Chinese Han population: B * 2715 a noteworthy subtype / 中华风湿病学杂志

ABSTRACT

Objective To investigate the distribution of HLA-B27 subtypes in ankylosing spondylitis(AS) patients of Chinese Han population by using the updated HLA-B27 typing data. Methods One hundred AS subjects were randomly selected from spondyloarthritis patients data bank of the third affiliated hospital of Sun Yat-sen university. All subjects were independent individuals, and the duplicated samples in the same family were excluded. Salt fraction method was used to prepare genome DNA. Luminex liquid array combining PCR-SSOP was used to perform the low resolution HLA-B genotyping. PCR-SSP was applied to perform the high resolution HLA-B27 typing for HLA-B27 positive subjects. Results Ninety-eight independent AS patients were recruited randomily, of which, 93 were HLA-B27 positive, with positive rate 94.9%, and covered 96% patients with family history of AS. Three subtypes were detected in this population including B * 2704 (n=76, 81.7%), B * 2705 (n=12, 12.9%) and B * 2715 (n=5, 5.4%). Compared with the two reports about HLA-B27 subtype distribution in healthy HLA-B27 positive Han population there was no significant difference between AS patients and healthy controls. But no B * 2715 case was found in those two reports of healthy population. Three reports (including 1 report in Chinese) could found about B * 2715 subtype, but all positive cases were oriental people. Furthermore, all B * 2715 positive patients were AS patients. Conclusion B * 2704 is the predominant subtype ,in AS patients of Chinese Han population, and followed by B * 2705. We found five cases with positive B * 2715, a considerable rare allele. This may suggest association between B * 2715 and AS.