PLASMA ENDOTOXIN AND CYTOKINE LEVELS IN NEUTROPENIC AND NON-NEUTROPENIC BACTEREMIC PATIENTS

Plasma endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), interleukin 1 receptor antagonist (IL-1ra), and i nterleukin 6 (IL-6) concentrations in 69 bacteremic patients were comp ared with those in 54 nonbacteremic patients suffering from suspected bacterial infections. Only three (11 %) of the 27 patients with gram-n egative bacteremia showed detectable levels of endotoxin, TNF-alpha wa s detected in 6 % of the bacteremic patients and in none of the nonbac teremic patients. Median IL-6 levels were significantly higher in bact eremic than in nonbacteremic patients (55 vs. 0 pg/ml, p = 0.0008). IL -6 concentrations were similar in neutropenic and non-neutropenic bact eremic patients (median 55 vs. 74 pg/ml). In contrast, neutropenic bac teremic patients had significantly lower concentrations of IL-1ra than non-neutropenic bacteremic patients (250 vs. 1,950 pg/ml, p < 0.0001) . Patients with fatal bacteremia had significantly higher concentratio ns of IL-6 and IL-1ra than the survivors (median, 450 vs, 40, p = 0.01 2 and 7,600 vs. 420 pg/ml, p = 0.0075, respectively). Determinations o f endotoxin or TNF-alpha in patients with suspected bacteremia failed to offer clinically relevant data on the prognosis of these patients, IL-6 levels correlated with both the presence of bacteremia and the ri sk of death. Granulocytopenic patients with bacteremia had lower level s of circulating IL-1ra than patients with normal granulocyte counts, and these levels correlated with poor outcome.