Prognostic impact of cytokines and chemokines in bronchoalveolar lavage fluid on acute exacerbation of fibrosing interstitial lung disease

Background and objective: Acute exacerbation of fibrosing interstitial lung disease (AE-FILD) is a serious condition with a high mortality rate. We aimed to comprehensively analyze cytokines in bronchoalveolar lavage fluid and their association with the clinical course of AE-FILD. Methods: We retrospectively enrolled 60 patients with AE-FILD who underwent bronchoalveolar lavage. We comprehensively measured 44 cytokines and chemokines in the obtained bronchoalveolar lavage fluid using a Luminex analyzer. Patients were grouped into those who died within 90 days (non-survival group) and survived beyond 90 days (survival group) to investigate the association of the levels of cytokines and chemokines with mortality. Results: The levels of matrix metalloproteinase 1 (p = 0.003), granulocyte-macrophage colony-stimulating factor (p = 0.040), interleukin 6 (p = 0.047), interleukin 8 (p = 0.050), monocyte chemoattractant protein-1 (p = 0.043), and eotaxin (p = 0.044) were significantly higher in the non-survival group than in the survival group. In the receiver operating characteristic analysis, their areas under the curve were 0.80, 0.68, 0.71, 0.70, 0.70, and 0.72, respectively. Using machine learning with these six cytokines and chemokines, the predictive accuracy for the survival group was 0.94. Conclusions: Our study demonstrated that several cytokines and chemokines in bronchoalveolar lavage fluid could be prognostic predictors in patients with AE-FILD.