Immunomodulation in Septic Shock: Hydrocortisone Differentially Regulates Cytokine Responses

Abstract

Abstract. Cortisol is known to be an immunomodulatory hormone that exerts suppressive and permissive effects on the immune response. Little is known regarding the evolution of the cytokine response in human septic shock in the presence of hypercortisolemia induced by infusion of stress doses of hydrocortisone. Twenty-four consecutive patients with high-out-put circulatory failure (cardiac index, >4 liters/min per m2) who met the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee criteria for septic shock were enrolled in a prospective, double-blind study. The severity of illness at the time of enrollment was graded using the Acute Physiology and Chronic Health Evaluation II system, and the evolution of sepsis-induced organ dysfunction syndrome was assessed using Sepsis-Related Organ Failure Assessment scores. After randomization, hyper-cortisolemia was induced in 12 patients by infusion of 100 mg of hydrocortisone, followed by continuous infusion of 0.18 mg/kg per h. Levels of the circulating cytokines tumor necrosis factor α (TNF), interleukin 6 (IL-6), IL-8, and IL-10 were serially measured at prospectively defined time points during the first 5 d after randomization. The infusion of hydrocortisone was associated with significant reductions in serum IL-6 and IL-8 levels and with earlier resolution of the sepsis-induced organ dysfunction syndrome. IL-6 levels started to differ between the groups on day 5. The TNF and IL-10 responses were not altered by hydrocortisone infusion. Hydrocortisone infusion in septic shock differentially regulated the cytokine responses. IL-6 and IL-8 levels decreased significantly and IL-6 levels differed between the groups, whereas TNF and IL-10 levels were not affected by hydrocortisone. Stress doses of hydrocortisone may be a valuable immunomodulatory therapy for septic shock.