Correlation between the Percentage of Lymphocytes in Bronchioalveolar Lavage and Severity in Hypersensitivity Pneumonitis

Abstract

Introduction: Hypersensitivity Pneumonitis (HP) is a Insterstitial Lung Disease (ILD) characterized by a granulomatous inflammatory process, caused by the inhalation of a wide variety of organic powders, which sometimes progresses to fibrosis. Bonquioalveolar Lavage (BAL) is a diagnostic and prognostic method for ILD. The higher the percentage of lymphocytes in the HP, a better evolution has been reported, due to a lower frequency of fibrosis.
Methodology: A retrolective, longitudinal, observational study was conducted in patients in the INER HP cohort, who will have BAL and Respiratory Function Tests (PFT) at the time of diagnosis and at 6 months of follow-up. According to the percentage (%) of lymphocytes, we studied 5 groups (<20%, 20-30%, 30-40%, 40-50% and >50%). We correlated the % of lymphocytes with baseline PFT and follow-up.
Results: We obtained a low positive correlation between the percentage of lymphocytes with baseline CVF (Rho 0.14, P= 0.04); at 6 months of follow-up this correlation was maintained (Rho 0.39, P <0.001), we also identified a moderate positive correlation between the percentage of lymphocytes with the percentage of DLCO (Rho: 0.45, P< 0.001) and with meters walked (Rho: 0.23, P=0.01).
Conclusions: In this study we confirm exists a relation between a higher percentage of lymphocytes in BAL and better PFR and the meters walked in the 6-minute walk test, at 6 months of follow-up.