Degree of apoptosis in bronchoalveolar lavage fluid correspond to the severity of brain injury

Abstract Objectives: The mechanism of acute brain injury initiates a cascade of consequences which can directly cause lung damage, and this can contribute to poor neurological outcomes. The aim of this study was to evaluate activation of different apoptotic pathways in the bronchoalveolar lavage fluid (BALF) in patients after severe brain injury and to correlate them with selected clinical variables and mortality.Methods: Patients with brain injury undergoing BALF were included in the study. BALF samples were collected within the first 6-8 hours after traumatic brain injury (A) and at days 3 (B) and 7 (C) after admission to the ICU. Changes in the BALF nuclear-encoded protein (Bax), apoptotic regulatory protein (Bcl-2), pro-apoptotic protein (p53) and its upregulated modulator (PUMA), apoptotic protease factor 1 (APAF-1), Bcl-2 associated agonist of cell death (BAD) and caspase-activated DNase (CAD) were analysed to assess the degree of apoptosis. These values were correlated with the Rotterdam computed tomography (CT) score, the Glasgow Coma Score and 28-day mortality. Results: We found a significant increase in the concentration of selected apoptotic factors at admission (A), at days 3 (B) and 7 (C) after brain injury compared to baseline level A (p<0.001 respectively). That activation of selected apoptotic factors was significantly correlated with the severity of the injury and mortality.Conclusions: Activation of different apoptotic pathways seems to be an important process occurring in the lungs of patients in the early phases after severe brain trauma. Activation of apoptosis in the lungs correlates with the severity of brain injury.