High neutrophils and low lymphocytes percentages in bronchoalveolar lavage fluid are prognostic factors of higher in-hospital mortality in diffuse alveolar hemorrhage

BACKGROUND: Diffuse alveolar hemorrhage (DAH) is a syndrome resulting from bleeding in the microcirculation of the lung, with a poor prognosis. The study aim was to identify prognostic factors of DAH, especially bronchoalveolar lavage fluids (BALF) cell pattern. METHODS: We conducted a single-center retrospective cohort study of patients diagnosed as having DAH and hospitalized at our hospital between October 2008 and July 2020. We performed univariate logistic regressions to identify variables associated with in-hospital death. RESULTS: Sixty-eight patients were included in our analysis. In-hospital mortality was 26.5%. Variables associated with in-hospital death were neutrophils percentage in BALF ≥ 44.5% [Odds Ratio (OR) 16.0, 95% confidence interval (CI) 4.33-58.9)], lymphocytes percentage in BALF < 14% (OR 7.44, 95% CI 2.11-26.2), idiopathic DAH (OR 0.31, 95% CI 0.10-0.95), oxygen flow ≥ 4L/min (OR 3.90, 95% CI 1.20-12.6), and estimated glomerular filtration rate < 60 mL/min (OR 5.00, 95%CI 1.29-19.4). CONCLUSIONS: High neutrophils and low lymphocytes percentages in BALF were associated with poor prognosis.