To be, or not to be immunocompetent

Several data support the view that impairment of the inflammatory-immune responseis a hallmark of severe sepsis and the level and time of recovery toimmunocompetence has a major impact on the clinical outcome of ICU patients.Recent studies demonstrate that improvement of anti-tumour immune response bytargeting negative regulatory molecules, such as CD25, chronic T-lymphocyteactivation antigen 4, and programmed death-1 receptor (PD-1)/PD-1 L, offersa novel opportunity to prevent or even reverse progression of tumour growth inexperimental models and patients. Likewise, severe sepsis is associated withenhanced expression of those negative regulatory molecules, suggesting a novelapproach to reverse immunoparalysis in sepsis. Consequently, targeting negativemolecules in sepsis can reverse immunoparalysis and improve survival inexperimental sepsis, as shown by Chang and colleagues in a recent issue ofCritical Care. This opens new opportunities to overcomeoverwhelming downregulation of the adaptive immune response to prevent and/orimprove recovery from sepsis.