Evaluation Of HLA-B27 In Diagnosis Of Ankylosing Spondylitis In Various Ethnic Groups In Xinjiang

Objective: To analyze the distribution of the positive rates of HLA-B27 among the Han,Uygur,Hui,Kazak and Mongolian patients with suspected ankylosing spondylitis(AS)in Xinjiang and to study the HLA-B27 critical value setting difference of ROC curve between Uygur and Han ankylosing spondylitis patients.Methods: A total of 1909 patients were recruited in our study who were suspected with ankylosing spondylitis(AS).Flow cytometry was used to detect the expression of HLA-B27 antigen in peripheral blood T lymphocytes and the positive rates of different ethnic groups,gender and age were compared.In the Han and Uygur cases,AS group consisted of the gold standard confirmed in197 cases and 682 cases control group.By studying the 197 cases of AS group and 682 cases of non-AS control group(206 cases of sacroiliac arthritis,160 cases of rheumatoid arthritis,146 cases of systemic lupus erythematosus,90 cases of psoriatic arthritis and 80 healthy subjects)HLA-B27,the author is trying to map the ROC curve so that to establish flow cytometry HLA-B27 screening AS threshold,and tocompare the distinction between Uygur and Han.Results:1.According to the results,we can knew that the positive rate in males(37.6%)was higher than that of females(21.4%),with a significantly difference between them(P=0.000).The positive rate in Han was statistically higher than that of other nationalities(P<0.05).Among other ethnic groups,the positive rates were statistically significant except for the comparison between Kazak and Hui,Kazak and Mongolian,Hui and Mongolian.The positive rates in the group of 20~39 years old(34%)was significantly higher than that of other groups(P<0.05).2.The sensitivity of AS group was 62.4%,and the sensitivity was 91.9%,87.7% respectively.The sensitivity of the new group was 26.7% and the new threshold of Uygur was 37.9% The specificity was 88.1%,87.5% and Jorden index were 0.8,0.75 respectively.The data is based on the critical value set by Beckman-Coulter original kit in the United States.Conclusion: 1.The positive rates of HLA-B27 in patients who were suspected with AS have significant difference between different nationalities,gender and age in XinJiang.2.If the threshold value of the original kit is too high,it exists the possiblity of missing some of the patients.To adjust the critical value for the Uygur and Han can improve the sensitivity and specificity of diagnosis,contribute to the early diagnosis of AS and also be instructive to the clinical.