Significance Of Bronchoalveolar Lavage Fluid IL-6,PCT,and Cell Classification In Patients With Fever And Pulmonary Shadow

Objective:The specific etiology and imaging characteristics of patients with fever accompanied by pulmonary shadow were analyzed.The levels of interleukin-6(IL-6)and procalcitonin(PCT)in serum of all patients with bronchoalveolar lavage fluid(BALF)and bronchoscopy on the day of examination as well as cell classification in BALF were detected to explore the levels of IL-6 and PCT in BALF and serum.The significance of BALF cell classification in the differentiation of different diseases with fever and lung shadow,and the superiority of BALF test over serum test in the differentiation of different diseases with fever and lung shadow were compared.Methods:Selection in November 2019-November 2020 in kunming medical university second affiliated hospital of respiratory and critical care medicine ward two tips with fever and chest CT lung shadow in the hospital,at the same time can cooperate with 99 patients with complete bronchoscopy,eliminate the data is not complete case 8 cases.3 patients with treatment midway departure from the hospital,the remaining cases 88 cases.Through the combination of clinical.inspection.imaging and pathological methods,the final diagnosis of 78 cases,10 cases failed to clear diagnosis,detection on line bronchoscopy day all subjects BALF and IL-6,the PCT level in serum and BALF cytological classification(including lymphocytes percentage,the percentage of neutrophils,eosinophils percentage,Percentage of macrophages).This study first analyzed the etiology and imaging characteristics of patients with fever accompanied by pulmonary shadow,and then compared whether there were differences in the levels of IL-6 and PCT in serum and BALF of patients with different diseases,as well as the percentage of cell classification in BALF(diseases with small number of cases and unknown etiology in a single group were not included in this part).The ability of the above indicators to distinguish different diseases was analyzed by ROC curve.Results:1.Fever with pulmonary shadow can be caused by a variety of factors,which can be divided into infectious diseases(54.55%),non-infectious diseases(34.09%)and diseases of unknown etiology(11.36%).Infectious diseases include bacteria,mycobacterium tuberculosis,and fungal infections,while non-infectious diseases include lung cancer,connective tissue diseases,and pulmonary embolism.Imaging manifestations include consolidation shadow,nodular shadow,interstitial change,ground glass shadow,mass shadow,consolidation+nodular shadow,and may also be accompanied by pleural effusion and cavity.2.The levels of IL-6 and PCT in BALF of the fever group with pulmonary shadow infectious disease were higher than those of the non-infectious disease group,and the differences were statistically significant(P<0.05).However,there were no statistically significant differences in cell classification and serum IL-6 and PCT levels in BALF between the two groups(P>0.05).3.The levels of IL-6 and PCT in BALF and serum and the percentage of neutrophils in BALF in the bacterial pneumonia group were higher than those in the tuberculosis group,and the difference was statistically significant(P<0.05).There was no statistical significance in the percentage of lymphocytes,eosinophils and macrophages in BALF between the two groups(P>0.05).4.In non-infectious diseases with fever and lung shadow,the levels of IL-6 in BALF and serum of lung cancer group were higher than those of lung benign disease group,and the differences were statistically significant(P<0.05).There were no statistically significant differences in the levels of PCT in serum and BALF and cell classification in BALF between the two groups(P>0.05).5.The optimal cut-off values of IL-6 and PCT in BALF for the identification of fever with pulmonary shadow infectious etiology and non-infectious etiology were 13.805pg/ml and 0.0825ng/ml,respectively.The areas under the ROC curve were 0.714 and 0.701,respectively.The sensitivity of IL-6 and PCT were 76.1%and 60.9%,respectively.The specificities were 63.3%and 80%,respectively.6.The optimal cut-off values of IL-6,PCT and neutrophils percentage in BALF for the differentiation of bacterial pneumonia and tuberculosis in fever with pulmonary shadow infectious diseases were 119.165pg/ml,0.087ng/ml and 47%,respectively.The areas under the ROC curve were 0.686,0.787 and 0.724,respectively.The sensitivity was 40.7%.81.5%and 77.8%,and the specificity was 94.7%,78.9%and 63.2%,respectively.The optimal cut-off values of serum IL-6 and PCT for the identification of bacterial pneumonia and tuberculosis in fever with pulmonary shadow infection were 35.42pg/mL and 0.075ng/mL.respectively.The areas under the ROC curve were 0.682 and 0.771,respectively.The sensitivities of the two were 48.1%and 74.1%,respectively.The specificity was 94.7%and 78.9%,respectively.Conclusion:1.Fever with pulmonary shadow can be caused by infectious diseases(54.55%),non-infectious diseases(34.09%)and diseases with unknown etiology(11.36%).The imaging manifestations of these diseases are complex,and they should be screened in clinical practice so as to better guide clinical treatment.2.The detection of IL-6 and PCT in BALF plays a certain role in distinguishing infectious and non-infectious causes of fever with pulmonary shadow.3.PCT test in BALF has the best ability to distinguish bacterial pneumonia and tuberculosis with fever and pulmonary shadow,followed by the percentage of neutrophils,and the low ability to distinguish IL-6.4.BALF test is more advantageous than serum test in the identification of the etiology of fever with pulmonary shadow.5.IL-6 has the ability to differentiate between lung cancer and benign lung disease in non-infectious diseases.