The in vivo effects of interleukin-3 on histamine levels in non-Hodgkin's lymphoma patients.

Recombinant human Interleukin-3 (RhIL-3) is a haemopoietic growth factor with effect both on early and differentiated cells, such as eosinophils and basophils, and it also acts as a histamine-releasing agent. The purpose of the present study was to examine whether in vivo rhIL-3 administration after chemotherapy affected basophil histamine levels and whether a concordance between rhIL-3 induced histamine release and side effects during the treatment could be demonstrated. Thirty patients with non-Hodgkin's lymphoma entered the study. All patients received 6 courses of chemotherapy, rhIL-3 was administered subcutaneously once daily after the second and the fourth course of chemotherapy from cycle day 2-15 at the dose levels 0.5, 1.0, 5.0, 7.5 and 10 micrograms/kg with 6 patients at each dose level. In cycle 6 recombinant human Granulocyte-Macrophage Colony-Stimulating Factor (rhGM-CSF) (3.0 micrograms/kg) was administered sequential/concurrent day 9-15 to rhIL-3 (day 2-15) at all dose levels except 7.5 micrograms/kg, where rhIL-3 was given day 2-8 and rhGM-CSF sequential day 9-15. Cycles 1, 3 and 5 served as control cycles with no cytokine therapy. During rhIL-3 treatment, and after CHOP chemotherapy, the basophil counts increased moderately especially during the recovery period day 15-22, and mainly at the two highest dose levels 7.5 and 10 micrograms/kg, but never exceeded the normal upper limit. Histamine levels in basophils were the same in patients before chemotherapy and healthy volunteers, and except from a trend to increased histamine level at 10 micrograms/kg on day 15, no difference was noted between rhIL-3 cycles and control cycles. Within 3-4 hr after rhIL-3 administration, a drop in histamine level in basophils was noted, which could be due to histamine-releasing properties of rhIL-3 as previously demonstrated by in vitro studies. No serious side effects were noted during the cytokine treatment, and despite that most patients had mild flushing of the face, neck and upper chest, no patients experienced sensitization throughout the study. Although a significant increase in rhIL-3-induced histamine release from basophils was noted in some of the patients, no correlation to the dose of rhL-3 was found, and no correlation was noted between side effects and histamine release or histamine levels in basophils.