Endotoxin, interleukin-6 and phospholipase-A2 as markers of sepsis in patients with hematological malignancies.

The concentrations of endotoxin, interleukin-6 (IL-6) and group II phospholipase-A2 (PLA2-II) were measured in serum or plasma during cytotoxic chemotherapy, fever of unknown origin and sepsis in 56 patients with hematological malignancies and during sepsis and viral infections in 22 non-hematological patients. High concentrations of IL-6, PLA2-II and endotoxin were detected in sepsis, the levels being similarly elevated in hematological and non-hematological patients. The levels of IL-6 and PLA2-II correlated closely with that of C-reactive protein (CRP). The levels of PLA2-II and IL-6 declined earlier than the level of CRP during the course of antimicrobial treatment. The levels of IL-6 also rose earlier than the level of CRP. The ability of IL-6 and PLA2-II and endotoxin to discriminate between sepsis and other causes of fever was comparable to that of CRP. IL-6 and PLA2-II are, together with CRP, valuable tools for the detection of sepsis in patients with hematological malignancies who undergo cytotoxic medication. Endotoxin is not suitable for routine laboratory diagnosis of sepsis.