The effect of N-acetylcysteine on nuclear factor-kappa B activation, interleukin-6, interleukin-8, and intercellular adhesion molecule-1 expression in patients with sepsis

Objective: Expression of inflammatory mediators is controlled in part at the transcriptional level via nuclear factor-kappaB. Inhibition of nuclear factor-kappaB activation may be beneficial in critically ill patients. N-acetylcysteine is an antioxidant that inhibits nuclear factor-kappaB activation in vitro. In this pilot study we investigated the effect of N-acetylcysteine on nuclear factor-kappaB activation and circulating cytokine and adhesion molecules in patients with sepsis.

Design: Prospective, randomized, double blind, placebo-controlled pilot trial.

Setting: Eight-bed intensive care unit in a university teaching hospital.

Patients: Twenty consecutive patients within 12 hrs of fulfilling the consensus criteria for sepsis.

Interventions: A bolus of 150 mg/kg N-acetylcysteine in 100 mL of 0.9% saline over 15 mins, then 50 mg/kg in 100 mL of 0.9% saline over 4 hrs as a loading dose, and then a maintenance infusion of 50 mg/kg in 200 mL of 0.9% saline over each 24-hr period for a total of 72 hrs, or an equivalent volume of saline.

Measurements and Main Results: Nuclear factor-kappaB activation was measured in mononuclear leukocytes using electrophoretic mobility shift assay, at baseline and 24, 48, 72, and 96 hrs later.

Activation decreased significantly in patients treated with N-acetylcysteine (p = .016) but not placebo and was significantly reduced at 72 hrs compared with both preinfusion values (p = .028) and patients receiving placebo (p = .01). Plasma interleukin-6, interleukin-8, and soluble intercellular adhesion molecule-1 concentrations were measured using enzyme immunoassay. Interieukin-6 concentrations were high initially and then decreased in all patients, regardless of whether they received N-acetylcysteine or placebo. Interleukin-8 decreased significantly only in those who received N-acetylcysteine (p = .0081). Soluble intercellular adhesion molecule-1 concentrations remained unchanged in all patients.

Conclusions: Administration of N-acetylcysteine results in decreased nuclear factor-kappaB activation in patients with sepsis, associated with decreases in interleukin-8 but not interieukin-6 or soluble intercellular adhesion molecule-1. These pilot data suggest that antioxidant therapy with N-acetylcysteine may be useful in blunting the inflammatory response to sepsis. Further studies are warranted.