Expression Of Serum TLR4 In Patients With Idiopathic Pulmonary Fibrosis And Its Clinical Significance

Objective:The purpose of this study is to analyze the expression of TLR4 in patients with idiopathic pulmonary fibrosis(IPF),connective tissue-related interstitial lung disease(CTD-ILD)and healthy controls,and to further investigate the correlation between TLR4 level and clinical data in patients with IPF,so as to explore the diagnostic and therapeutic value of TLR4 as a biomarker of IPF,as well as its role in pathogenesis and severity assessment.It may provide new ideas and theoretical basis for the diagnosis and treatment of IPF in clinical work.Methods:15 patients with IPF and 20 patients with CTD-ILD were collected in the respiratory department of the Second Affiliated Hospital of Kunming Medical University from January 2019 to December 2019.At the same time,15 health controls who received physical examination in the health examination center of the Second Affiliated Hospital of Kunming Medical University were selected as the control group.The patients in these three groups were recorded the general data and the clinical indicators,such as blood gas analysis,pulmonary function and so on.The severity of pulmonary fibrosis of patients with IPF and CTD-ILD was assessed by high-resolution computed tomography(HRCT).The elbow vein blood of the three groups was collected when they were fasting.Serum levels of TLR4 were measured by enzyme linked immunosorbent assay(ELISA).Results:1.The serum levels of TLR4 in patients with IPF were significantly higher than those in patients with CTD-ILD and healthy controls(P<0.05).And the serum levels of TLR4 in patients with CTD-ILD also were significantly higher than those in healthy controls(P<0.05).2.FVC/pre(%)in patients with IPF was significantly lower than that in patients with CTD-ILD and healthy controls(P<0.05).FEV1/pre(%)in patients with IPF was also significantly lower than that of healthy controls(P<0.05).But compared to patients with CTD-ILD,there was no statistically significant differences(P>0.05).And in FEV1/FVC(%),there were no statistically significant differences among IPF patients,CTD-ILD patients and healthy controls(P>0.05).3.The PaO2 of patients with IPF was significantly lower than that in patients with CTD-ILD and healthy controls(P<0.05).Compared pH,PaCO2 of patients with IPF to patients with CTD-ILD and healthy controls,there were no statistically significant differences(P>0.05).4.The HRCT scores of patients with IPF were significantly higher than those of patients with CTD-ILD(P<0.05).5.Correlation analysis showed that the serum levels of TLR4 in patients with IPF were negatively correlated with FVC/pre(%),PaO2 and pH(P<0.05);positively correlated with HRCT scores(P<0.05);and there were no significant correlations with age,gender,smoking history,FEV1/pre(%),FEV1/FVC(%)and PaCO2(P>0.05).6.The ROC curve showed that AUC was 0.914,And when the diagnostic threshold was 6.34ng/ml,the sensitivity,specificity,positive predictive value and negative predictive value of TLR4 were 86.7%,82.9%,68.4%and 93.5%.Conclusion:1.the serum levels of TLR4 in patients with IPF were significantly higher than those in patients with CTD-ILD and healthy controls,suggesting that TLR4 may be involved in the pathogenesis of IPF,and can be used in the diagnosis and differential diagnosis of IPF.2.It was found that there were significant differences in PaO2,FVC/pre(%)and HRCT scores among IPF patients,CTD-ILD patients and healthy controls,and in patients with IPF,they were certainly correlated with the serum levels of TLR4,suggesting that TLR4 can be used as a reference index to replace the above indicators to evaluate the severity of disease in patients with IPF.3.TLR4 can be used as a diagnostic index of IPF in clinic.