Study On The Diagnostic Value Of TSPOT.TB In Tuberculosis

Research Background Tuberculosis is one of the most important diseases that endanger human health,and Tibet is a high prevalence area of tuberculosis in China.In recent years,For its high sensitivity and specificity,and can identify latent tuberculosis and active tuberculosis to a certain extent,the diagnosis of tuberculosis has made great progress,thus it is widely used in clinic,Therefore,a prospective study of early detection of latent tuberculosis by TSPOT.TB and prevention of this part of patients developing active tuberculosis is of great significance for tuberculosis control in our district.Methods and Objectives 322 cases of suspected active tuberculosis infection in People's Hospital of Tibet Autonomous Region from June2016 to November 2017 were included in this study.all of which were detected by peripheral blood TSPOT.TB,Genexpert and acid-resistant staining,Patients with pleural effusion underwent ADA detection.Criteria for diagnosis of active tuberculosis:(1)GeneXpert positive;(2)acid fast staining positive;(3)pleural effusion ADA>45U/L and excluding other diseases,then compared TSPOT.TB results with other three diagnosis results in sensitivity,specific,positive predictive value,negative predictive value,positive likelihood ratio and negative likelihood ratio,coincidence rate and antigen(ESAT-6),and antigen B(CFP-10)spot number as evaluation indexes.To explore the diagnostic value of Tspot.TB in patients with tuberculosis infection in Tibet.Results 78 patients were diagnosed as active tuberculosis,149 cases eventually excluded active TB,and the sensitivity and specificity of peripheral blood TSPOT.TB in diagnosing active TB infection were94.9%and 63.8%respectively.The positive and negative predictive value of the patients with active pulmonary tuberculosis were 57.8%,96%,the coincidence rate was 74.4%,and the positive and negative relieved ratio was 2.62 and 0.08 respectively.The number of antigen A and B spots in the diagnosis of active TB infection is statistically significant,with median number is 168/2.5*10~5PBMC vs 0/2.5*10~5PBMC(p<0.05),81/2.5*10~5PBMC vs 0/2.5*10~5PBMC(p<0.05)respectively,And ROC curve analysis indicated that the sensitivity and specificity of the diagnosis of active tuberculosis were the highest when antigen A was valued at 11.5 and or the antigen B was at 19.5.The total number of spots in antigen A and B is statistically significant in diagnosing active TB infection,The median number was 212/2.5*10~5PBMC,The four-point spacing is(96/2.5*10~5PBMC,366/2.5*10~5PBMC),and ROC work curve analysis suggests that the sensitivity and specificity of the diagnosis of active TB are the highest when the total number of antigen spots was46.5/2.5*10~5PBMC.In the diagnosis of tuberculous pleurisy,the number of antigen A and B spots is statistically significant,the median number is156/2.5*10~5PBMC vs 0/2.5*10~5PBMC(p<0.05),68/2.5*10~5PBMC vs 0/2.5*10~5PBMC(p<0.05)respectively,ROC curve analysis indicated that the sensitivity and specificity of the diagnosis of tuberculous pleurisy were the highest when antigen A was valued at 11.5 and or the antigen B was 12.5,The total number of spots in antigen A and B is statistically significant in the diagnosis of tuberculous pleurisy infection,The median Numberwas212/2.5*10~5PBMC,Thefour-pointspacingis(81/2.5*10~5PBMC,364/2.5*10~5PBMC),and the ROC curve analysis indicated that the sensitivity and specificity of the diagnosis of tuberculous pleurisy were highest when the total number of antigens was40.5/2.5*10~5PBMC.Conclusion 1.Currently,it is not possible to accurately identify active TB infection and latent TB infection based on the number of TSPOT.TB antigen A and antigen B spots,as the number of spots in both is largely overlapping.2.The total spot value of antigen A,Antigen B or antigen a+b is helpful for the clinical diagnosis of active TB or tuberculous pleurisy.