Platelets in the pathogenesis of acute respiratory distress syndrome

Abstract

Platelets have an emerging and incompletely understood role in a myriad of host immune responses, extending their role well beyond regulating thrombosis. Acute respiratory distress syndrome is a complex disease process characterized by a range of pathophysiologic processes including oxidative stress, lung deformation, inflammation, and intravascular coagulation. The objective of this review is to summarize existing knowledge on platelets and their putative role in the development and resolution of lung injury.

Immunothrombosis in Acute Respiratory Distress Syndrome: Cross Talks between Inflammation and Coagulation

“…There are several reports on the role of activated platelets and their interaction with leucocytes during infection [2,19] . Gando and Otomo [39] have recently described the role of immunothrombosis in acute coagulopathy of trauma shock; they concluded that in trauma patients the mechanism of immunothrombosis and hemostasis is dysregulated and the endothelial injury leads to fibrinogenolysis and subsequent diffuse oozing.…”

What’s in a Number? Platelet Count Dynamics as a Novel Mediator of Acute Respiratory Distress Syndrome Survival

“…Elegantly, the use of a genetic variant as the exposure of interest in mediation analysis obviates the typical requirement for a control of possible exposure-outcome confounding, because the exposure (e.g., possessing a variant in LRRC16A) clearly preceded the studied outcome (e.g., ARDS) (6). The investigators focused on platelet abundance as a potential mediator, because platelets influence both impaired coagulation and the excessive inflammatory response observed in ARDS (7,8). Beyond their classic role in the regulation of hemostasis, platelet activation in ARDS influences host immune responses, resulting in the release of immunomodulatory mediators, increased neutrophil migration, and decreased endothelial membrane integrity (8,9).…”

“…Furthermore, the platelet count does not fully characterize the variety of platelet functions that may influence ARDS outcome. Platelet activation plays a crucial role in ARDS pathogenesis, including contributions to hemostasis, angiogenesis, microvascular coagulopathy, increased capillary permeability, and recruitment of inflammatory cells (7,9,16). Additional studies are necessary to further clarify the mechanisms in which platelets serve as causal agents.…”

“…1362-1372) present a well-designed pragmatic trial in which they address the question of the type of intravenous crystalloid therapy in the medical ICU in regard to adverse effects (7). The SALT (Isotonic Solution Administration Logistical Testing) randomized trial was designed as a cluster-randomized, multiple-crossover study of 974 critically ill patients treated in a tertiary care medical ICU during a 4-month period.…”

Pharmacotherapy in acute respiratory distress syndrome—the long and winding road

“…ARDS affects the alveolar space, the interstitium, and the pulmonary vasculature. When platelets are activated in the pulmonary circulation, they increase production of thromboxane A2 and expression of P selectin, propagating platelet-neutrophil aggregation and extravasation into the interstitium and alveolar space (12). Animal studies have repeatedly shown that disruption of platelet signaling decreases neutrophil chemotaxis and platelet-neutrophil aggregation (13)(14)(15).…”