Objective:Human leukocyte antigen(HLA)B27 is a susceptibility allele of ankylosing spondylitis(AS),and HLA-B27 antigen typing is an important indicator for clinical diagnosis of AS,but current typing methods such as sequence specific primer polymerase chain reaction(PCR-SSP)still possess limitation.Therefore,this study aims to analyze the correlation between B27 subtypes and susceptibility to AS in Hunan Province by applying high-resolution polymerase chain reaction-sequence-based typing(PCR-SBT). Methods:Peripheral blood of 116 patients with suspected AS(suspected AS group)and 121 healthy volunteers(control group)admitted to the Second Xiangya Hospital from January 2020 to December 2020 were collected for HLA-B genotyping by PCR-SBT.Among the patients in the suspected AS group,23 patients were finally diagnosed with AS(confirmed AS group),and the remaining 93 undiagnosed patients served as the non-confirmed AS group.PCR-SBT and PCR-SSP were used to detect HLA-B27 typing in 116 patients with suspected AS,and the results of the 2 methods were compared. Results:The HLA-B27 allele frequency in the suspected AS group was significantly higher than that in the control group[11.63%vs 2.48%;P<0.001,odds ratio(OR)=5.18,95%confidence interval(CI)2.097 to 12.795].B*27:04,B*27:05,B*27:06,and B*27:07 were detected in the suspected AS group and the control group.The frequency of the B*27:04 allele in the suspected AS group was significantly higher than that in the control group(9.48%vs 1.24%;P<0.001,OR=8.346,95%CI 2.463 to 28.282).The positive rate of B27 in the suspected AS group and the confirmed AS group(B27+/+ and B27+/-)was significantly higher than that in the control group(χ2=16.579,P<0.001;χ2=94.582,P<0.001,respectively).Among the confirmed AS group,21 were HLA-B27 carriers,and the B27 positive rate in the confirmed AS group was 91.3%.PCR-SBT could achieve high resolution typing of the HLA-B gene locus,with higher sensitivity,specificity,positive predictive value,negative predictive value,and accuracy than PCR-SSP. Conclusion:PCR-SBT typing analysis shows a strong correlation between HLA-B * 27:04 and AS in Hunan province.The PCR-SBT method can be used as the preferred option for the auxiliary diagnosis of clinical AS.