An increase in circulating angiotensin-converting enzyme-positive (ACE+) endothelial microparticles (EMPs) may be a prognostic marker for acute respiratory distress syndrome (ARDS) in patients with sepsis, according to study results published in the European Respiratory Journal.
Whole-blood samples from septic patients, mice, and the culture supernatant from human microvascular endothelial cells were analyzed by flow cytometry. Associations were examined between the extent of lung injury and the number of circulating EMPs and ACE+ EMPs.
Of the 82 septic patients, the circulating ACE+ EMPs and ACE+ EMP/EMP ratio on admission significantly increased in those who later developed ARDS compared with septic patients who did not (P <.001). Furthermore, in the cell culture experiments, ACE+ EMPs in the culture supernatant from pulmonary microvascular endothelial cells increased after exposure to an inflammatory stimulus. In the mouse lung injury models, the circulating ACE+ EMPs and ACE+ EMP/EMP ratio were higher than in the controls (P <.001). The ACE+ EMP/EMP ratio was correlated with the wet-to-dry lung ratio (rs = 0.775; P <.001),” the authors wrote.
“[T]he results of our study suggest that ACE+ EMPs from pulmonary microvascular endothelial cells may reflect the injury of pulmonary microvascular endothelial cells, and could be a prognostic marker for developing ARDS in septic patients as well as a diagnostic marker for distinguishing ARDS from hydrostatic pulmonary edema,” the researchers concluded.
Takei Y, Yamada M, Saito K, et al. Increase in circulating ACE-positive endothelial microparticles during acute lung injury [published July 18, 2019]. Eur Respir J. doi:10.1183/13993003.01188-2018