Association of interleukin-2 therapy with staphylococcal bacteremia

The authors prospectively monitored patients undergoing leukapheresis for peripheral stem cell harvesting (PSCH) or lymphokine activated killer (LAK) cell generation for 3 weeks after catheter placement for evidence of local or systemic infections. Over a 1-year period, 16 patients underwent leukapheresis for PSCH in preparation for autologous bone marrow transplantation (ABMT). The original catheters remained in place an average of 20 days without any documented infections. Seventeen patients underwent leukapheresis as part of a low-dose interleukin-2 (IL-2) treatment for LAK cell generation, and their catheters remained in place an average of 20.2 days with three documented episodes of bacteremia (18%). Eight patients treated with high-dose IL-2 also underwent leukapheresis for LAK cell generation and their catheters remained in place an average of 12 days with three documented episodes of bacteremia (38%). In all cases of bacteremia, Staphylococcus species were isolated from the blood. The IL-2 exposure level was associated with the risk of bacteremia (P = 0.01). Other potential risk factors (e.g., number of pheresis procedures, complement level, serum immunoglobulin levels, absolute neutrophil count) were not related to this risk.