Platelets Key To Acute Lung Injury

Acute lung injury (ALI) is a relatively common life-threatening condition that can be caused by sepsis, trauma, and acid aspiration, which can be a complication of general anaesthesia. Currently there are no good therapies for the treatment of ALI, but a study appearing in the December issue of the Journal of Clinical Investigation has identified new potential therapeutic targets for the treatment of individuals with ALI.

Klaus Ley and colleagues from the University of Virginia show that platelet-neutrophil interactions have a key role in the development of disease in a mouse model of acid aspiration-induced ALI. Reducing the number of platelets in the mice or inhibiting the platelet-neutrophil interaction reduced the recruitment of neutrophils to the lungs, reduced lung permeability, improved gas exchange in the lungs, and prolonged survival. Mechanistically, expression of a molecule known as P-selectin by the platelets was crucial for mediating the platelet-neutrophil interaction, which induced platelets to produce proinflammatory factors such as TXA2. The authors therefore suggest that disrupting the platelet-neutrophil interaction or blocking the proinflammatory factors produced as a result of this interaction might provide new therapeutic targets for the treatment of individuals with ALI. In an accompanying commentary, Wolfgang Kuebler suggests that although this study highlights the importance of platelets in ALI, they might also have an important role in the development of other 'lung inflammatory disorders, including asthma, chronic obstructive pulmonary disease, and cystic fibrosis.'(Source: Journal of Clinical Investigation : University of Virginia : December 2006.)