SOLUBLE TUMOR-NECROSIS-FACTOR RECEPTORS, TUMOR-NECROSIS-FACTOR AND INTERLEUKIN-6 IN SERUM IN GRANULOCYTOPENIC PATIENTS WITH FEVER

Serum levels of TNF, IL-6 and soluble TNF receptors p55 and p75 (sTNFR -p55 and sTNFR-p75) were examined in 14 patients with acute myeloid le ukaemia during 43 courses of chemotherapy. The patients experienced 30 episodes of fever which occurred during granulocytopenia (defined as granulocyte counts <0.2x10(9)/l) and six fever episodes when granulocy te counts were > 1.0x10(9)/l. Febrile episodes were classified as micr obiologically defined infection, clinically defined infection, and une xplained fever. Levels of bioactive IL-6 and immunoreactive TNF increa sed in response to fever during granulocytopenia, whereas bioactive TN F was not detected in any sample in this study. During granulocytopeni a, both sTNFR rose significantly in microbiologically defined infectio n (P < 0.01 for sTNER-p55 and P < 0.05 for sTNFR-p75), but not in the other two categories. The ratio of sTNFR-p55 to sTNFR-p75 was higher d uring febrile periods in granulocytopenia than in a non-granulocytopen ic situation with granulocyte counts >1.0x10(9)/l (P<0.01). We conclud e that granulocytopenia affects release of the two sTNFR differently d uring febrile periods, and that release of sTNFR-p75 in response to fe ver is reduced during granulocytopenia, suggesting a role for the gran ulocytes in systemic release of sTNFR-p75.