Platelet-Neutrophil interactions in Klebsiella pneumoniae invasive syndrome: The role of aspirin.

Klebsiella pneumoniae invasive syndrome (KPIS), often arising from pyogenic liver abscesses, is characterized by metastatic infections and thrombotic complications. Diabetes mellitus (DM) is the most important risk factor for KPIS, as hyperglycemia promotes resistance of hypervirulent K. pneumoniae ;(hvKp) strains to phagocytosis and impairs neutrophil function. Given the interplay between platelet activation, inflammation, and thrombosis, aspirin, a well-established antiplatelet agent, has been associated with reduced incidence and recurrence of pyogenic liver abscesses in cohort studies. Platelets interact with neutrophils to form platelet - neutrophil aggregates (PNAs), which may contribute to KPIS pathogenesis. This study examined platelet - neutrophil interactions under hyperglycemic conditions using in vitro assays and in vivo models of diabetic mice infected with hvKp. High glucose concentrations significantly increased platelet activation, PNA formation, and bacterial survival. Salicylic acid, the bioactive metabolite of aspirin, reduced platelet activation and bacterial burden but did not impede PNA formation. Aspirin pre-treatment improved survival, reduced organ abscesses, and preserved tissue integrity in diabetic mice infected with hvKp. These results highlight the relationship between hyperglycemia, platelet activation, and immune dysregulation in KPIS, and support aspirin as a potential adjunctive therapy to mitigate thromboinflammatory complications of hvKp infection.