Immunoparalysis in Pediatric Critical Care

Abstract

Although many forms of critical illness are initiated by a proinflammatory stimulus, a compensatory anti-inflammatory response can occur with systemic inflammation. Immunoparalysis, an important form of acquired immunodeficiency, affects the innate and adaptive arms of the immune system. Immunoparalysis has been associated with increased risks for nosocomial infection and death in a variety of pediatric critical illnesses. Evidence suggests that immunoparalysis is reversible with immunostimulants. Highly standardized, prospective immune monitoring regimens are needed to better understand the immunologic effects of critical care treatment regimens and to enrich clinical trials with subjects most likely to benefit from immunostimulatory therapies.

Keywords: Cardiopulmonary bypass; Critical care; Immune; Immunoparalysis; Pediatric; Sepsis; Trauma.

Figure 1. The dynamic nature of the immune response to critical illness

Severe and persistent inflammation is associated with the classic symptoms of SIRS with fever, capillary leak, and organ dysfunction. A compensatory anti-inflammatory response syndrome (CARS) can occur concurrently with systemic inflammation. This can also be pathogenic when severe and prolonged, with associated increases in risk of nosocomial infection and death. More modest and transient deviations from immunologic homeostasis are typically associated with uncomplicated recovery. Both SIRS and CARS can be quantified through specific laboratory testing.