Clinical application of T-SPOT.TB assay in tuberculosis diagnosis / 中国医师杂志

ABSTRACT

Objective To investigate the diagnostic value of enzyme-linked immunospot assay for tuberculosis (T-SPOT.TB) in pulmonary tuberculosis and non-pulmonary tuberculosis,and evaluate the clinical application value of T-SPOT.TB's spot forming cell frequencies in the diagnosis of tuberculosis.Methods T-SPOT.TB,tuberculin test (PPD) assay,and tuberculosis antibody test (TB.AB) were used in the diagnosis of tuberculosis among 78 active pulmonary tuberculosis patients,58 active non-pulmonary tuberculosis patients,27 old pulmonary tuberculosis patients,and 76 non-tuberculosis patients.Results (1) The sensibility and specificity if T-SPOT.TB assay were 71.17％ and 78.95％,the highest among 3 methods.Three trials's joint detection obviously increased the sensitivity of tuberculosis diagnosis.(2) The positive rate of T-SPOT.TB and spot forming cell frequencies in active pulmonary tuberculosis and active non-pulmonary tuberculosis were not statistically significant (P ＞ 0.05).The positive rate of T-SPOT.TB in active pulmonary tuberculosis and old pulmonary tuberculosis were not statistically significant (P ＞ 0.05).However,spot forming cell frequencies of T-SPOT.TB in active pulmonary tuberculosis were significantly higher than old pulmonary tuberculosis (P ＜ 0.05).(3) When spot forming cell frequencies of T-SPOT.TB.of peripheral blood mononuclear cell (PBMC) was set to 11.5 spots-forming cell (SFC)/106 PBMC,it had the best cut-off value to diagnose the tuberculosis as a diagnostic criteria.(4) When spot forming cell frequencies of T-SPOT.TB of PBMC was set to 17 SFC/106pBMC,it had the best cut-off value to distinguish the active pulmonary tuberculosis from old pulmonary tuberculosis.Conclusions The joint detection of TSPOT.TB assay,PPD assay and TB.AB assay,could obviously improve the positive rate of TB infection.TSPOT.TB assay has useful diagnostic value for pulmonary tuberculosis and non-pulmonary uberculosis.Reasonable application of spot forming cell frequencies contributes to the early diagnosis and treatment of tuberculosis.