Characteristics Of Cell Types And Their Clinical Significance Of Bronchoalveolar Lavage Fluid In Patients With Idiopathic Interstitial Pneumonia

Object: To study the characteristics of cell profiles and their clinical significance of bronchoalveolar lavage fluid (BALF) in patients with idiopathic interstitial pneumonia (IIP), and to investigate the relationship between the BALF differential cell counts and survival.Methods: Patients with HP (n=88) through clinical-radiological-histological diagnosis were classified into three groups: 38 patients with idiopathic pulmonary fibrosis (IPF), 27 patients with nonspecific interstitial pneumonia (NSIP), and 23 patients with cryptogenic organizing pneumonia (COP). One-Way ANOVA was used for comparing means of BAL fluid cell counts between groups, Bivariate Correlation was used for investigating the relationship between BALF cellularity and pulmonary function test, Kaplan-Meiter was used for comparing survival between groups, and Cox Regression was used for estimating the relationship between percentages of differential cell counts in BALF and survival.Result:1. The percentage of macrophages in BALF from patients with IPF was significantly higher than those in the other two groups, and the percentage of lymphocytes in BALF from patients with COP was higher than those in the others (P<0. 05). The percentage of neutrophils of the patients with IPF was significantly higher than that in BALF from patients with COP (P<0. 05).2. The percentage of eosinophils in BALF from patients with IPF had a negative correlation with diffusion capacity for carbon monoxide (DLco). In NSIP group, there was a negative correlation between the percentage of neutrophils and DLco, there were positive correlations between the percentage of CD4+T cells and FEV1, FVC and TLC, and there was a negative correlation between the percentage of CD8+T cells and DLco. The absolute cell number of lymphocytes of patients with COP had a negative correlation with VC%, the absolute cell number per milliliter of eosinophils had a negative correlation with FEF75, and CD4+/CD8+T lymphocyte ratio had positive correlations with DLco and TLC. (P<0. 05).3. Higher percentage of lymphocytes in patients with IIP predicted better prognosis. Taking histo-pathological difference into account, the mortality had a probable 8% decrease when the percentage of lymphocytes increased 1%.Conclusion: Although this study has restrictions, these findings suggest a positive relationship between the percentage of lymphocytes in BALF samples and survival in patients with IIP, and a possible negative relationship between the percentage of neutrophils and survival in patients with IIP.