Prognostic value of lymphocyte counts in bronchoalveolar lavage fluid in patients with acute respiratory failure: a retrospective cohort study

Abstract

Background Cellular patterns in bronchoalveolar lavage fluid (BALF) are used to distinguish or rule out particular diseases in patients with acute respiratory failure (ARF). However, whether BALF cellular patterns can predict mortality or not is unknown. We test the hypothesis that BALF cellular patterns have predictive value for mortality in patients with ARF. Methods This was a retrospective single-center observational study conducted in a Japanese University Hospital. Consecutive patients (n = 78) with both pulmonary infiltrates and ARF who were examined by bronchoalveolar lavage (BAL) between April 2015 and May 2018 with at least 1 year of follow-up were analyzed. Primary analysis was receiver operating characteristic curve—area under the curve (ROC-AUC) analysis for 1-year mortality. Results Among the final sample size of 78 patients, survivors (n = 56) had significantly increased lymphocyte and eosinophil counts and decreased neutrophil counts in BALF compared with non-survivors (n = 22). Among the fractions, lymphocyte count was the most significantly different (30 [12-50] vs. 7.0 [2.9-13]%, P <0.0001). In the ROC curve analysis of the association of BALF lymphocytes with 1-year mortality, the AUC was 0.787 (P <0.0001, cut-off value [Youden index] 19.0%). Furthermore, ≥20% BALF lymphocytes were significantly associated with increased survival with adjustment for baseline imbalances (1-year adjusted hazard ratio, 0.0929; 95% confidence interval, 0.0147–0.323, P <0.0001; 90-day P =0.0012). Increased survival was significantly associated with ≥20% BALF lymphocytes in both interstitial lung disease (ILD) and non-ILD subgroups (P =0.0052 and P =0.0033, respectively). In secondary outcome analysis, patients with ≥20% BALF lymphocytes had significantly increased ventilator-free days, which represents less respiratory dysfunction than those with <20% BALF lymphocytes. Conclusions In the patients with ARF, ≥20% lymphocytes in BALF was associated with significantly less ventilatory support, lower mortality at both 90-day and 1-year follow-ups.

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

“…These diseases are usually responsive to glucocorticoids and administration of glucocorticoids was recommended [21]. Additionally, a high lymphocytes percentage in BALF was correlated with good prognosis in interstitial pneumonia or acute respiratory failure in the studies that most of cases had been administered glucocorticoids [22,23]. We speculate that enriched lymphocytes in BALF is associated with good responsiveness to glucocorticoids and, as a result, with good prognosis in DAH.…”

An improved Yolov5s based on transformer backbone network for detection and classification of bronchoalveolar lavage cells

“…Patients with BALF lymphocytes ≥ 20% had significantly higher 1-year survival compared to patients with BALF lymphocytes< 20% [52] . In studies related to acute exacerbations of chronic progressive interstitial pneumonia, mortality was significantly lower in patients with BALF lymphocytes ≥ 15% compared to those with BALF lymphocytes< 15% [53] . In addition, a BALF total leukocyte count ≥ 510/µL was considered an independent predictor of bacterial pneumonia [54] .…”

Clinical course and prognostic factors of Pneumocystis pneumonia with respiratory failure in non-HIV patients

“…Hirasawa et al. reported that BALF-lymphocyte percentage ≥20% was significantly associated with increased 90-day and 1-year survival in patients with acute respiratory failure (ARF) caused by interstitial lung disease or non-interstitial lung disease ( Hirasawa et al., 2021 ). These findings suggested that BALF-lymphocytes may play a vital role in the prognosis of PCP patients with RF, and the usefulness of BALF-lymphocytes warrants further investigation.…”