Diagnostic value of T-cell enzyme-linked immunosorbent spot assay in pleural effusion and peripheral blood from patients with tuberculous pleurisy / 中华传染病杂志

ABSTRACT

Objective To evaluate the diagnostic value of T-cell enzyme-linked immunosorbent spot assay (T-SPOT.TB) using both pleural effusion and peripheral blood in tuberculous pleurisy.Methods One hundred and two cases of in patients with pleural effusion treated in Anhui Chest Hospital from January 2014 to October 2015 were enrolled in this study.T-SPOT.TB was performed using both serous effusion mononuclear cells (SEMC) and peripheral blood mononuclear cells (PBMC),and the diagnostic sensitivity and specificity were calculated.Chi square test was used for categorical variables and MannWhitney U test was used for continuous variables in non-normal distribution.Results Of the 102 participants,71 (69.61 ％) were microbiologically or clinically diagnosed with tuberculous pleurisy and 31 (30.39 ％) were diagnosed with other diseases.In tuberculous pleurisy group,the median spot forming cells (SFC) of T-SPOT.TB for early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) using SEMC were 159/2.5 × 105 (120/2.5 × 105-200/2.5× 105) and 160/2.5 × 105 (110/2.5 × 105-210/2.5 × 105),respectively;and the median SFC of T-SPOT.TB using PBMC were 30/2.5×105 (15/2.5×105-55/2.5×105) and 40/2.5×105(8/2.5×105-87/2.5 ×105),respectively.The SFC counts of SEMC were obviously higher than those of PBMC,and differences were statistically significant (for ESAT-6,Z=-7.818;for CFP-10,Z=-7.120,both P＜0.05).The ROC curve analysis showed that using a cut-off value of 38 SFC per 2.5 × 105 SEMC,the area under the curve is 0.969.The sensitivity and specificity of T-SPOT.TB using PBMC were 90.14％ and 77.42％,respectively;and those of T-SPOT.TB using SEMC were 95.77％ and 93.55％,respectively.When combined the T-SPOT.TB assay using both PBMC (≥6 spots) and SEMC (≥38 spots),the sensitivity and specificity were 90.14％ and 96.77％,respectively.Conclusion The joint detection of T-SPOT.TB using both PBMC and SEMC can be an effective diagnostic method for tuberculous pleurisy.