Role of HLA class I and II alleles in susceptibility to ankylosing spondylitis in Chinese Han

OBJECTIVE: The objective of the study was to clarify the associations of HLA class I and II alleles with ankylosing spondylitis (AS) among Chinese Han. METHODS: We performed HLA genotyping and Sanger sequencing for 68 HLA‐B*27(−), 62 HLA‐B*27(+) AS patients, and 70 controls. Case–control analyses and separate analyses of HLA‐B*27(−) patients were performed. One‐way ANOVA and Kruskal–Wallis multiple comparisons test were used to analyze the effects of HLA‐A\B\C\DRB1\DQB1 alleles on clinical characteristics of HLA‐B*27(−) and HLA‐B*27(+) patients. RESULTS: In the HLA‐B*27(+) group, positive associations were seen with A*11:02, B*27:04, B*27:05, C*02:02, C*12:02, and DRB1*04:01 and negative associations were seen with A*33:03, B*07:02, B*57:01, and C*07:02. The age at onset was greater in HLA‐B*27(−) patients than in HLA‐B*27(+) patients (30.03 ± 15.15 vs. 23.08 ± 7.79 years). In the HLA‐B*27(−) group, those with A*01:01, B*13:01, B*13:02, C*01:02, C*04:01, DQB1*02:01, DQB1*06:01, and DRB1*03:01 had an earlier onset than those without these alleles, while patients carrying B*40:02, C*07:02, C*12:02, C*15:02, DQB1*05:02, and DQB1*05:03 had a delayed onset. In the HLA‐B*27(−) group, A*32:01(+), C*08:01(+), and DRB1*04:05(−) women were likely to develop AS. In the HLA‐B*27(+) group, DQB1*03:02(+) women may be more likely to develop AS. DRB1*12:02 and HLA‐B*27 interacted with the distribution of AS‐affected sites. In the HLA‐B*27(+) group, DRB1*12:02(+) patients were likely to have peripheral joint involvement. CONCLUSION: HLA class I and II alleles other than HLA‐B*27 contribute to AS predisposition and characteristics among Chinese Han patients.