Serum interleukin-6 and fever at diagnosis in children with acute leukemia

We examined serum interleukin (IL)-6 and tumor necrosis factor (TNF) alpha levels at initial diagnosis in acute leukemic children in order to clarify the roles of these cytokines on the febrile and hematological responses in the disease.

IL-6 levels were significantly higher in 34 leukemic children than in 18 healthy controls and 15 patients with various malignant diseases in long remission (p < 0.0001). Three patients with apparent bacterial infections showed especially high IL-6 levels of > 100 pg/ml. In all the leukemic children, the high IL-6 levels at initial diagnosis had decreased to a low range at the time of complete remission, regardless of the use of antibiotics. In 10 of 14 leukemic children, TNF levels were high at diagnosis and then decreased to undetectable levels at remission. The relationship between IL-6/TNF levels and clinical/laboratory findings in leukemic children at diagnosis was also examined. Serum IL-6 significantly correlated with elevated body temperature (BT) (p < 0.001) and C-reactive protein (CRP) levels (p < 0.001), but not with other parameters such as leukocyte and platelet counts, hemoglobin levels, lactate dehydrogenase, and serum immunoglobulin. On the other hand, serum TNF did not show any statistical linkage with these parameters.

These data provide evidence for the role of IL-6 in the pathogenesis of tumor-related fever and other acute phase responses in acute leukemia.