Treatment of Cancer Patients with Endotoxin Induces Release of Endogenous Cytokines

Abstract

This study sought to determine whether endogenous tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and granulocyte-colony-stimulating factor (G-CSF) were detectable in sera of lipopolysaccharide (LPS)-treated cancer patients. Twenty patients received an intravenous bolus of purified LPS from Salmonella abortus-equi (4.0 ng/kg). Patients were pretreated with ibuprofen (1,600 mg) to prevent constitutional side effects like fever and chills. Serum TNF-alpha levels increased from less than 0.01 ng/ml before treatment up to maximal levels of 21 ng/ml, peaking 1.5 h after LPS injection. Similarly, serum IL-6 concentrations increased from less than 0.01 to 11 ng/ml, but peak levels were obtained 30 min later than TNF-alpha. Circulating G-CSF appeared still later than TNF-alpha and IL-6. It was detectable within 3 h and peaked 6 h after LPS injection. Parallel to the release of the above cytokines a marked increase in granulocyte counts was observed. In all patients administration of LPS led to an acute-phase response as measured by C-reactive protein.