Objective To explore the value of tuberculosis infected T cells spot test(T-SPOT.TB),heated mycobacterium tuberculosis nucleic acid amplification testing(TB-SAT),and adenosine deaminase(ADA)in diagnosing tuberculous pleural effusion.Methods A total of 135 patients with pleural effusion treated at the First Affiliated Hospital of Xinxiang Medical University from January 2021 to December 2021 were selected as the research subjects,including 83 patients with tuberculous pleural effusion and 52 patients with non-tuberculous pleural effusion.All these patients received peripheral blood T-SPOT.TB,chest water TB-SAT and chest water ADA tests,and the sensitivity and specificity of the above three methods in detecting tuberculous pleural effusion alone and in combination were compared.Results In terms of sensitivity and specificity,there was no statistically significant difference among the T-SPOT.TB,TB-SAT and ADA tests in detecting tuberculous pleural effusion alone(P＞0.05).The sensitivity of the T-SPOT.TB+TB-SAT combined test in detecting tuberculous pleural effusion was significantly higher than that of the T-SPOT.TB,TB-SAT and ADA tests alone(x2=4.990,13.410,14.590;P＜0.05),while the specificity of the T-SPOT.TB+TB-SAT combined test in detecting tuberculous pleural effusion showed no significant difference with that of the T-SPOT.TB,TB-SAT and ADA tests alone(x2=0.000,2.420,0.060;P＞0.05).The sensitivity of the T-SPOT.TB+ADA combined test in detecting tuberculous pleural effusion was significantly higher than that of the ADA test alone(x2=4.069,P＜0.05),but showed no significant difference with that of the T-SPOT.TB and TB-SAT tests alone(x2=0.055,3.384;P＞0.05).The specificity of the T-SPOT.TB+ADA combined test in detecting tuberculous pleural effusion was significantly lower than that of the T-SPOT.TB,TB-SAT and ADA tests alone(x2=4.370,12.511,5.371;P＜0.05).The sensitivity of the TB-SAT+ADA combined test in detecting tuberculous pleural effusion showed no significant difference with that of the T-SPOT.TB,TB-SAT and ADA tests alone(x2=0.000,2.604,3.213;P＞0.05).The specificity of the TB-SAT+ADA combined test in detecting tuberculous pleural effusion was significantly lower than that of the TB-SAT test alone(x2=5.765,P＜0.05),but showed no significant difference with that of the T-SPOT.TB and ADA tests alone(x2=0.782,1.251;P＞0.05).The sensitivity of the T-SPOT.TB+TB-SAT+ADA combined test in detecting tuberculous pleural effusion was significantly higher than that of the T-SPOT.TB,TB-SAT and ADA tests alone(x2=6.760,15.755,16.966;P＜0.05),while the specificity of the T-SPOT.TB+TB-SAT+ADA combined test in detecting tuberculous pleural effusion was significantly lower than that of the T-SPOT.TB,TB-SAT and ADA tests alone(x2=4.370,12.511,5.371;P＜0.05).The sensitivity of the T-SPOT.TB+TB-SAT combined test in detecting tuberculous pleural effusion was significantly higher than that of the T-SPOT.TB+ADA and TB-SAT+ADA combined tests(x2=4.090,4.990;P＜0.05);there was no statistically significant difference in the sensitivity in detecting tuberculous pleural effusion between the T-SPOT.TB+ADA combined test and the TB-SAT+ADA combined test(x2=0.060,P＞0.05).The specificity of the T-SPOT.TB+TB-SAT combined test in detecting tuberculous pleural effusion was significantly higher than that of the T-SPOT.TB+ADA combined test(x2=4.371,P＜0.05);the specificity of the TB-SAT+ADA combined test showed no significant difference with that of the T-SPOT.TB+TB-SAT and T-SPOT.TB+ADA combined tests(x2=0.780,1.490;P＞0.05).There was no statistically significant difference in the sensitivity in detecting tuberculous pleural effusion between the T-SPOT.TB+TB-SAT+ADA combined test and the T-SPOT.TB+TB-SAT combined test(x2=0.210,P＞0.05);the sensitivity of the T-SPOT.TB+TB-SAT+ADA combined test in detecting tuberculous pleural effusion was significantly higher than that of the T-SPOT.TB+ADA and TB-SAT+ADA combined tests(x2=5.750,6.760;P＜0.05).The specificity of the T-SPOT.TB+TB-SAT+ADA combined test in detecting tuberculous pleural effusion was significantly lower than that of the T-SPOT.TB+TB-SAT combined test(x2=4.370,P＜0.05);the specificity of the T-SPOT.TB+TB-SAT+ADA combined test in detecting tuberculous pleural effusion showed no significant difference with that of the T-SPOT.TB+ADA and TB-SAT+ADA combined tests(x2=0.000,1.490;P＞0.05).Conclusion The combined detection performs better than the single detection in diagnosing tuberculous pleural effusion,and the peripheral blood T-SPOT.TB combined with chest water TB-SAT performs the best in detecting tuberculous pleural effusion.The combined detection can effectively reduce the missed diagnosis rate and the misdiagnosis rate,and has high clinical application value for diagnosing tuberculous pleural effusion.