Cytokine responses to Staphylococcus aureus bloodstream infection differ between patient cohorts that have different clinical courses of infection. McNicholasSinead TalentoAlida GormanJoanne O HannanMargaret M. LynchMaureen GreeneCatherine M. HumphreysHilary Fitzgerald-HughesDeirdre 2019 <p>BackgroundThe clinical course of Staphylococcus aureus bloodstream infection is unpredictable and bacterial virulence, host immune response and patient characteristics are among the factors that contribute to the clinical course of infection. To investigate the relationship between cytokine response and clinical outcome, circulating cytokine levels were investigated in response to S. aureus bloodstream infection in patient with different clinical courses of infection.MethodsA prospective study was carried out in 61 patients with S. aureus bloodstream infection and circulating levels of IL-6, GRO-¿, RANTES and leptin were assessed over the course of the infection. Levels were compared in patients with complicated courses of infection (e.g. infective endocarditis) versus uncomplicated courses of S. aureus bloodstream infection and methicillin-resistant S. aureus Vs methicillin-susceptible S. aureus infection.ResultsSignificantly lower leptin levels (p¿</p>