Bronchoalveolar lavage fluid characteristics and outcomes of invasively mechanically ventilated patients with COVID-19 pneumonia in Genoa, Italy
Chiara Dentone, Antonio Vena, Maurizio Loconte, Federica Grillo, Iole Brunetti, Emanuela Barisione, Elisabetta Tedone, Sara Mora, Antonio Di Biagio, Andrea Orsi, Andrea De Maria, Laura Ambra Nicolini, Lorenzo Ball, Daniele Roberto Giacobbe, Laura Magnasco, Emanuele Delfino, Luca Mastracci, Rosa Mangerini, Lucia Taramasso, Chiara Sepulcri, Rachele Pincino, Martina Bavastro, Matteo Cerchiaro, Małgorzata Mikulska, Bianca Bruzzone, Giancarlo Icardi, Paolo Frisoni, Angelo Gratarola, Nicolò Patroniti, Paolo Pelosi, Matteo Bassetti
Abstract
BACKGROUND: The primary objective of the study is to describe the cellular characteristics of bronchoalveolar lavage fluid (BALF) of COVID-19 patients requiring invasive mechanical ventilation; the secondary outcome is to describe BALF findings between survivors vs non-survivors. MATERIALS AND METHODS: Patients positive for SARS-CoV-2 RT PCR, admitted to ICU between March and April 2020 were enrolled. At ICU admission, BALF were analyzed by flow cytometry. Univariate, multivariate and Spearman correlation analyses were performed. RESULTS: Sixty-four patients were enrolled, median age of 64 years (IQR 58-69). The majority cells in the BALF were neutrophils (70%, IQR 37.5-90.5) and macrophages (27%, IQR 7-49) while a minority were lymphocytes, 1%, TCD3+ 92% (IQR 82-95). The ICU mortality was 32.8%. Non-survivors had a significantly older age (p = 0.033) and peripheral lymphocytes (p = 0.012) were lower compared to the survivors. At multivariate analysis the percentage of macrophages in the BALF correlated with poor outcome (OR 1.336, CI95% 1.014-1.759, p = 0.039). CONCLUSIONS: In critically ill patients, BALF cellularity is mainly composed of neutrophils and macrophages. The macrophages percentage in the BALF at ICU admittance correlated with higher ICU mortality. The lack of lymphocytes in BALF could partly explain a reduced anti-viral response.