Regulated plasma levels of colony-stimulating factors,interleukin-6 and interleukin-10 in patients with acute leukaemia and non-Hodgkin's lymphoma undergoing cytoreductive chemotherapy

Endogenous plasma levels of granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6 and IL-10 were measured in a total of 70 patients undergoing cytoreductive chemotherapy for treatment of acute leukaemia or non-Hodgkin’s lymphomas. The diagnoses were acute myeloid leukaemia (AML; n = 30), acute lymphoblastic leukaemia (ALL; n = 6), non-Hodgkin’s lymphomas (NHL; n = 11) and other malignant haematological disorders including myelodysplastic syndromes (n = 23). After chemotherapy, plasma G-CSF was elevated (mean 5.6 ng/ml; range 1.2–10 ng/ml), and was inversely correlated with white blood cell counts (WBC) (r = ?0.7, P < 0.001). Occurrence of fever (T>38.0°C) during severe myelosuppression (WBC<1 × 10⁹/l) was associated with an additional increase of G-CSF levels (P < 0.001). Plasma IL-6 correlated significantly with fever (range <1 to 1100 pg/ml, mean 130 pg/ml; r = 0.5, P < 0.001) but revealed only a weak association with WBC or platelet counts. In patients treated with recombinant G-CSF (n = 9), an association between IL-6 and fever was still observed after chemotherapy. During the nonfebrile status (total n = 242; AML n = 124), IL-6 levels remained <9 pg/ml in 90% of cases, whereas G-CSF increased with leucopenia (r = ?0.72; P < 0.001). In contrast, endogenous GM-CSF remained normal and IL-10 showed only a slight increase (21% of samples; maximum 22 pg/ml) in severe leucopenia. In particular, IL-10 levels did not correlate with G-CSF or IL-6 levels. We conclude that systemic release of G-CSF and IL-6 is obviously not abrogated by cytoreductive chemotherapy in acute leukaemia and NHL and may add to the therapeutic efficacy of recombinant cytokines. Also, plasma levels of G-, GM-CSF or IL-6 appear to be regulated by separate mechanisms.