Antiplatelet therapies have been proposed for the treatment of sepsis, a syndrome resulting from a dysregulated immune response and inappropriate activation of coagulation. Acetylsalicylic acid (ASA) may serve as a potential therapeutic strategy to prevent infection-induced coagulopathy and associated tissue damage. Using intravital microscopy, we found that Staphylococcus aureus infection induced neutrophil recruitment, platelet aggregation, and neutrophil extracellular trap (NET) release in the liver. Mice pretreated with ASA, or animals receiving ASA 3 hours postinfection, had significantly reduced platelet aggregation and NET release. Additionally, ASA-treated mice had reduced intravascular thrombin activity and microvascular occlusion as compared with untreated S aureus–infected mice. This inhibition of coagulation was accompanied by decreased levels of alanine aminotransferase and aspartate aminotransferase in the plasma, indicating less liver damage. Finally, bacterial loads (colony-forming units per milliliter) in liver, lung, and spleen were not different between groups, and the phagocytic capacity of Kupffer cells was preserved following ASA treatment. These results suggest that ASA may serve as a therapeutic approach to sepsis through its ability to reduce the deleterious action of immunothrombi while maintaining innate immune functions.

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The influenza A virus (IAV) causes a respiratory tract infection with approximately 10% of the population infected by the virus each year. Severe IAV infection is characterized by excessive inflammation and tissue pathology in the lungs. Platelet and neutrophil recruitment to the lung are involved in the pathogenesis of IAV, but the specific mechanisms involved have not been clarified. Using confocal intravital microscopy in a mouse model of IAV infection, we observed profound neutrophil recruitment, platelet aggregation, neutrophil extracellular trap (NET) production and thrombin activation within the lung microvasculature in vivo. Importantly, deficiency or antagonism of the protease-activated receptor 4 (PAR4) reduced platelet aggregation, NET production, and neutrophil recruitment. Critically, inhibition of thrombin or PAR4 protected mice from virus-induced lung tissue damage and edema. Together, these data imply thrombin-stimulated platelets play a critical role in the activation/recruitment of neutrophils, NET release and directly contribute to IAV pathogenesis in the lung.

The emergence of immunotherapy revolutionized the treatment of non-small-cell-lung cancer (NSCLC), with multiple landmark clinical trials establishing the efficacy of these agents. However, many patients who receive immunotherapy in clinical practice would be considered clinical trial ineligible. One such population that is often under-represented in clinical trials is older adults. In the current study, we evaluated clinical and safety outcomes in this population. Overall, older adults (>70 years of age) and younger adults had comparable clinical outcomes with an equivalent objective response rate (ORR), time to treatment failure (TTF), and median overall survival (p = 0.67, p = 0.98, and p = 0.91, respectively). Furthermore, the safety outcomes were equivalent between the cohorts with similar rates of immune-related adverse events (irAEs), irAE-related hospitalizations, and all-cause hospitalization (p = 0.99, p = 0.63, and p = 0.74, respectively). While older age was not found to impact overall survival, multivariant analysis revealed that a poor Eastern Cooperative Oncology Group (ECOG) status, low body-mass-index (BMI), and poor/intermediate lung immune prognostic index (LIPI) were all associated with worse survival. In conclusion, age does not impact the efficacy or safety of pembrolizumab in NSCLC, and therefore advanced age should not be a deterrent for treating these patients with pembrolizumab. Physicians and care providers can thus focus on other factors that may influence therapeutic outcomes.

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