Immunoparalysis and adverse outcomes from critical illness.

Proper immunologic balance between pro- and anti-inflammatory forces is necessary for recovery from critical illness. Persistence of a marked compensatory anti-inflammatory innate immune response after an insult is termed immunoparalysis. Critically ill patients demonstrating prolonged, severe reductions in monocyte HLA-DR expression or ex vivo tumor necrosis factor alpha production are at high risk for nosocomial infection and death. Reversal of immunoparalysis can be accomplished through the administration of immunostimulatory agents or tapering of exogenous immunosuppression. Evidence suggests that this may be associated with improved clinical outcomes. Immune-monitoring protocols are needed to identify patients who may benefit from immunomodulatory trials.