Comparison Of T-SPOT.TB Assay, Excretion Smears Test And Tuberculin Skin Test In The Diagnosis Of Pediatric Tuberculosis

Objective: To evaluate the value of T-SPOT.TB assay(T-SPOT.TB),excretion smears test and tuberculin skin test(TST)in the diagnosis of pediatric tuberculosis.Methods: A retrospective analysis of 306 cases of suspected tuberculosis patients hospitalized in Children’s Hospital Affiliated to Chongqing Medical University from January 2015 to December 2015 was conducted to calculate the sensitivity,the specificity,the positive predictive value and the negative predictive value of the three detection methods respectively.Results: According to the diagnosis and grouping criteria,135patients(including 52 confirmed cases and 83 clinical diagnosed cases)were finally identified.164 cases was regard as control group with non-tuberculosis and the diagnoses of remaining 7 cases are unsure.The positive rate of T-SPOT.TB assay(T-SPOT.TB),excretion smears test and tuberculin skin test(TST)in the tuberculosis group were 78.20%,24.24%,42.98% respectively;the specificity in the control group were 97.56%,100% and 97.22% respectively.In the phthisis group(Including tuberculosis only and multi-organ tuberculosis with tuberculosis at the same time),the positive rate of were respectively: 86.02%,27.96%,44.71%.Among them,the sensitivity of tuberculosis only group was83.87%,27.41% and 53.45% and the sensitivity of multi-organ tuberculosis with tuberculosis was 90.32%,29.03% and 25.93% respectively.The sensitivity of the three detection methods was 60%,18.42%,37.93% in 42 cases of children with definite extrapulmonary tuberculosis.In addition,positive rate of T-SPOT.TB assay in sputum/gastric juice "smear-negative" tuberculosis was 79.17%.The sensitivity of T-SPOT.TB in children with TST-negative tuberculosis was 78.46%.Positive predictive value and negative predictive value of T-SPOT.TB assay were 96.30%,88.66%.Conclusion: Comparing this three methods,T-SPOT.TB has the highest sensitivity,significantly reduced the missed diagnosis of TB.It also has high specificity at the same time,which may reduce the misdiagnosis rate of TB.According our study,we believe that T-SPOT.TB assay can be an effective means of examination in the early diagnosis of TB.