Work

BAL cells analysis and lung function parameters in fibrotic hypersensitivity pneumonitis at baseline and in relation to survival

Year: 2025

Type: article

Abstract: In fibrotic hypersensitivity pneumonitis, the relevance of bronchoalveolar lavage (BAL) lymphocytosis remains unclear. We investigated the relationship between BAL %lymphocytes, baseline pulmonary function tests (PFTs) and transplant-free survival. We retrospectively analysed 162 treatment-naïve patients (median age 64 years; 43 % male; 39 % ever-smokers) undergoing BAL within three months of PFTs. Mean FVC 79 %, DLCO 43 %, composite physiologic index (CPI) 48. Median BAL lymphocytes were 24 %(IQR 21–28). BAL %lymphocytes were associated with less severe disease, FVC [coefficient 0.28 (95 %C.I. 0.06–0.48), p = 0.01], FEV 1 [0.20(0.0002–0.41), p = 0.05], and CPI [-0.11(-0.21 to −0.01, p = 0.04]. Although BAL% lymphocytes were not correlated with DLCO, significant opposite correlations were observed for its two components: positive with VA% [0.32 (0.18–0.45), p < 0.0005]; negative with KCO% [-0.37(-0.51 to −0.23), p < 0.0005 ]. In adjusted Cox regression models, BAL %lymphocytes, lower CPI, higher %FVC, %FEV 1 and %DLCO were significantly associated with increased survival. These findings suggest BAL lymphocytosis reflects a pathophysiological pattern linked to better outcomes.

Source: Respiratory Investigation

DOI: 10.1016/j.resinv.2025.101359