Positivity and genotype distribution of HLA-B27 antigen in 7 829 patients with suspected ankylosing spondylitis

Abstract

Objective To analyze the positivity of human leukocyte surface antigen-B27 (HLA-B27) in patients with suspected ankylosing spondylitis (AS) and their relatives in Chongqing to understand the gender-specific distribution of HLA-B27 genotypes in the patients. Methods We retrospectively analyzed the clinical data of 7 829 patients with suspected AS and some of their relatives, who were diagnosed in Chongqing between January 1, 2018 and November 29, 2019. HLA-B27 genotypes were determined using a sequence-specific primer polymerase chain reaction (PCR-SSP). Results Of the 7 829 patients, 2 112 were positive for HLA-B27 antigen, with a positive rate of 26. 98%. The positive rate of HLA-B27 antigen was significantly higher in the male than in the female patients (33.87% vs 18.58%, P < 0.01). A total of 1 655 (78. 36%) patients had a B* 2704 genotype and 358 (16.95%) had a B* 2705/07 genotype of HLA-B27 antigen. Forty-six of the HLA-B27-positive patients were found to have ocular diseases, among whom 36 (78.26%) patients had a B* 2704 genotype; uveitis was the most frequent ocular disease in these patients (34/46). Conclusion The patients with suspected AS in Chongqing have a significantly higher rate HLA- B27 antigen positivity than the normal population, and the positive rate is significantly higher in male than in female patients. The HLA-B27 genotypes are predominantly B * 2704 and B * 2705/07, and the former is associated with AS susceptibility. Uveitis is common in HLA-B27-positive AS patients with ocular diseases, who have a predominant B * 2704 genotype.

Keywords

• hla-b27
• subtype
• ankylosing spondylitis