Diagnostic Accuracy Of Interleukin-27 In Bronchoalveolar Lavage Fluids For Sputum-negative Pulmonary Tuberculosis

Objective: To evaluate the diagnostic significance of interleukin-27 in bronchoalveolar lavage fluids for sputum-negative tuberculosis.Methods: A total of 248 bronchoalveolar lavage fluids from patients with active pulmonary tuberculosis,previous pulmonary tuberculosis and lung cancer were collected from November 2017 to November 2018.141 patients who did not meet the inclusion criteria or whose diagnosis was not clear were excluded.The concentrations of interleukin-27 and adenosine deaminase were determined in bronchoalveolar lavage fluids from 25 patients with sputum-negative pulmonary tuberculosis,23 sputumpositive pulmonary tuberculosis,35 lung cancer and 24 previous pulmonary tuberculosis by enzyme-linked immunosorbent assay.Results: It was found that the concentrations of interleukin-27 in bronchoalveolar lavage fluids of sputum-positive pulmonary tuberculosis group were significantly higher than those in sputum-negative pulmonary tuberculosis,lung cancer,and previous pulmonary tuberculosis groups,respectively(all P<0.001).The concentrations of adenosine deaminase in bronchoalveolar lavage fluids was significantly lower in the previous pulmonary tuberculosis group than those in sputumnegative pulmonary tuberculosis,sputum-negative pulmonary tuberculosis and lung cancer groups,respectively(all P<0.001),and there was no significant difference between sputum-positive pulmonary tuberculosis,sputum-negative pulmonary tuberculosis and lung cancer groups(all P>0.05).Interleukin-27 levels in bronchoalveolar lavage fluids could be used for diagnostic purpose for pulmonary tuberculosis,with the cut off value of 7.845 pg/ml,interleukin-27 had a sensitivity of 68.75% and specificity of 100% for differential diagnosing pulmonary tuberculosis from non-pulmonary tuberculosis.In the differential diagnosis of sputum-positive pulmonary tuberculosis and sputum-negative pulmonary tuberculosis,with the cut off value of 8.222 pg/ml,interleukin-27 had a sensitivity of 88% and specificity of 100%.The concentrations of adenosine deaminase in bronchoalveolar lavage fluids had a sensitivity of 75% and specificity of 67.8% for differential diagnosing pulmonary tuberculosis from non-pulmonary tuberculosis with the cut off value of 0.917 U/L,and had a sensitivity of 64% and specificity of 60.87% for differential diagnosing sputumpositive pulmonary tuberculosis from sputum-negative pulmonary tuberculosis with the cut off value of 1.109 U/L.Combinations of interleukin-27 and adenosine deaminase had a sensitivity of 70.8% and specificity of 98.3% for differential diagnosing pulmonary tuberculosis from non-pulmonary tuberculosis.The risk of pulmonary tuberculosis was positively correlated with the concentrations of interleukin-27 and adenosine deaminase in bronchoalveolar lavage fluids.Conclusions: 1.Interleukin-27 in bronchoalveolar lavage fluids is a sensitive and specific biomarker for differential diagnosing pulmonary tuberculosis from non-pulmonary tuberculosis,and sputum-negative pulmonary tuberculosis from sputum-positive pulmonary tuberculosis;2.The concentrations of adenosine deaminase in bronchoalveolar lavage fluids had limited diagnostic value in pulmonary tuberculosis.