Effects of interleukin-3 on hematopoietic recovery after 5-fluorouracil or cyclophosphamide treatment of cynomolgus primates.
Interleukin-3 (IL-3) is a hematopoietic growth factor that supports the growth of early hematopoietic progenitors in vitro. In vivo administration of recombinant human interleukin-3 (rhIL-3) to normal primates results in a modest and delayed leukocytosis secondary to increases in neutrophils, basophils, and eosinophils. We postulated that the effects of rhIL-3 might be more pronounced in hematologically stressed primates, and therefore administered rhIL-3 to primates after intensive myelosuppressive therapy. Primates received either cyclophosphamide (CPM) at 60 mg/kg or 5-fluorouracil (5-FU) at 75 mg/kg i.v. on two consecutive days. Subsequently, rhIL-3 was administered intravenously or subcutaneously at 20 micrograms/kg per d for 14 d. Compared to controls, all rhIL-3 treated primates experienced higher absolute neutrophil count (ANC) nadirs and dramatic decreases in the period of severe neutropenia (ANC less than 500) after myelosuppressive therapy. RhIL-3 administration resulted in a significant basophilia and eosinophilia, which resolved after discontinuation of the drug. RhIL-3 did not enhance erythroid recovery. Platelet recovery was earlier in rhIL-3-treated animals. However, variations in the platelet recovery observed in control animals, precluded accurate estimation of this effect or its significance. Our results indicate that the administration of rhIL-3 following intensive myelosuppressive therapy dramatically enhances myeloid recovery and ablates the predicted period of prolonged severe neutropenia.
Gillio
A P
AP
Department of Pediatrics and Bone Marrow Transplantation, Memorial Sloan-Kettering Cancer Center, New York 10021.
Gasparetto
C
C
Laver
J
J
Abboud
M
M
Bonilla
M A
MA
Garnick
M B
MB
O'Reilly
R J
RJ
D000818:Animals; D003114:Colony-Forming Units Assay; D003520:Cyclophosphamide / Q000633:toxicity*; D005472:Fluorouracil / Q000633:toxicity*; D006098:Granulocytes / Q000166:cytology / Q000187:drug effects; D006410:Hematopoiesis / Q000187:drug effects*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D007377:Interleukin-3 / Q000494:pharmacology*; D007700:Kinetics; D007958:Leukocyte Count / Q000187:drug effects*; D008252:Macaca fascicularis; D008264:Macrophages / Q000166:cytology / Q000187:drug effects; D008297:Male; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology
D007377:Interleukin-3; D011994:Recombinant Proteins; D003520:Cyclophosphamide; D005472:Fluorouracil