Analysis Of Numerical Correlation Factors Of Spot Forming Cells In The Diagnosis Of Tuberculosis In Children With Tb Infection By T-cell Spot Test

Background and Objectives:Globally,the incidence of tuberculosis is down by about two per year.To reach the WHO milestone of ending TB Strategy 2020,the rate of decline needs to rise to 4-5 a year.As the ninth leading cause of death in the world,tuberculosis is still a major issue of public health safety in Asian and African countries.China is a country with high tuberculosis prevalence and children are at high risk of tuberculosis.Children are more likely to develop tuberculous meningitis and other serious extrapulmonary tuberculosis,and the younger,the higher the fatality rate,even if lucky survival,but also easy to leave sequelae,such as vision,hearing and motor disorders.Early diagnosis and treatment are especially important in tuberculosis treatment.Mycobacterium tuberculosis culture is the "golden standard" for tuberculosis diagnosis,but it is difficult to be diagnosed in the early stage of the disease because of its long culture cycle.The toxic symptoms of tuberculosis infection in children were not obvious,and the respiratory symptoms were difficult to distinguish from other pulmonary diseases.The manifestations of lung imaging are not typical,and the traditional methods are not easy to diagnose tuberculosis.The T cell spot test for TB infection is a simple,rapid and easily available method for detection.After more than a decade of hard work,more and more countries,such as Europe and the United States and other countries,have written it into the guidelines for diagnosis and treatment of tuberculosis.Instead of tuberculin skin test,it is recommended as laboratory method for the detection of tuberculosis infection.This paper focuses on whether the value of spot forming cells determined by t.spot is affected by the location of tuberculosis infection,the activity of Mycobacterium tuberculosis and age.Methods:This study retrospectively analyzed 110 suspected tuberculosis patients admitted to affiliated Children's Hospital of Chongqing Medical University from January 01 to December 31,2016.The patients were divided into pulmonary tuberculosis group,multi-system involvement group and extrapulmonary tuberculosis group according to the final diagnosis.According to their age,they are divided into groups 0-5 years old or older than 10 years of age,active tuberculosis groups and latent tuberculosis infection groups,tuberculous meningitis group and non-tuberculous meningitis group according to whether they are nodular meningitis,To compare the values of A antigen(ESAT-6)and B antigen(CFP-10)of t.spot between the above groups.Results:A antigen and B antigen in pulmonary tuberculosis group,there was no significant difference between groups in the number of spots of extrapulmonary tuberculosis group and multiple A antigen system,the value is less than non tuberculous meningitis group in tuberculous meningitis group dot value,the difference was statistically significant,B antigen in the two groups had no statistical difference between.A antigen and B there are obvious differences in antigen active tuberculosis group and latent tuberculosis infection group,the area under the ROC curve of A antigen(0.726)is slightly larger than the B antigen(0.715),A was 51.5 in the numerical antigen spot for the best value,Youden index was 0.479,the sensitivity was 52.7%,specificity was 95.2%,there was no correlation between A antigen and B antigen positive spots with age,but the A and B antigens had significantly lower peak at 6-10 year old age group,B antigen showed a significant difference in adolescent group of school-age group,A antigen differences between groups was not statistically significant.Conclusion:Spot is of great value in the diagnosis of tuberculosis in children.The spot value of T.spot B antigen has no significant difference between pulmonary tuberculosis and extrapulmonary tuberculosis,suggesting that t.spot can be used in the diagnosis of pulmonary tuberculosis as well as extrapulmonary tuberculosis.The spot value of A antigen detected by t.spot in peripheral blood was lower in tuberculous meningitis than that in non-tuberculous meningitis,so it was recommended that children suspected of tuberculous meningitis should be tested for cerebrospinal fluid.Reduce false negative results of peripheral blood t.spot examination in children with tuberculous meningitis.There was a significant difference between active tuberculosis and latent tuberculosis infected with A and B antigen spots value.The area under the curve of A antigen is 0.726(95%CI :0.635,0.817);the area under the curve of A antigen is0.715(95%CI:0.623,0.806),The area under the A antigen curve is larger than that under the B antigen curve,and the best value is when the A antigen spot value is 51.5.The Yorden index is 0.479,the sensitivity is 52.7 and the specificity is 95.2%.Although there is a large overlap between active tuberculosis and latent tuberculosis infection spots,it can not be easily distinguished from this boundary point,but it can still reflect the active state of Mycobacterium tuberculosis in subjects to some extent.The value of A and B antigen showed a low peak in school age from 6 to 10 years old,and increased significantly after puberty(> 10 years old).The clinical value of t.spot in school-age children could be down-regulated.This study was a retrospective study with a small sample size and a further prospective large sample study was needed.