Nosocomial sepsis associated with interleukin-2

To determine the incidence, clinical magnitude, and risk factors for nosocomial bacteremia in patients given interleukin-2 with or without (+/-) lymphokine activated killer (LAK) cells for cancer immunotherapy.

Cohort study.

Clinical study unit of tertiary medical center.

All patients entering the interleukin-2 +/- LAK cancer immunotherapy protocol during a 28-month period. Control groups were patients in a surgical intensive care unit, patients receiving total parenteral nutrition, and patients with solid tumors.

Twenty of 107 (19%) interleukin-2-treated patients developed sepsis; in 12 of these patients, sepsis was intravenous catheter-associated. The bacteremia rate among patients receiving total parenteral nutrition, in the surgical intensive care unit, or having solid tumors was 2.8%, 4.1%, and 1.9%, respectively. Staphylococcus aureus was the pathogen in 13 courses; Staphylococcus epidermidis, in 5; and Escherichia coli, in 2. Two patients died; three developed suppurative thrombophlebitis; one developed septic arthritis; one, septic arterial aneurysm; and one, peritonitis with probable meningitis. Colonization with S. aureus increased the risk of S. aureus bacteremia 6.3-fold (95% CI, 2.8 to 14.5; P less than 0.001); skin desquamation at the catheter site increased the relative risk 2.0-fold (95% CI, 1.3 to 3.1; P = 0.031). Both colonization with S. aureus and skin desquamation increased the relative risk of S. aureus bacteremia 14.5-fold (95% CI, 4.1 to 50.9; P less than 0.0001).

Staphylococcal bacteremia is more frequent in patients receiving interleukin-2 therapy and is associated with substantial morbidity and toxic skin reactions.