title: Recombinant human interleukin-3 induces extramedullary hematopoiesis at subcutaneous injection sites in cynomolgus monkeys.
abstract: Parenteral administration of recombinant hematopoietic growth factors has been sporadically associated with cutaneous complications, including injection site reactions in humans and nonhuman primates. In this study, subcutaneous injection sites were evaluated from 12 cynomolgus monkeys administered a recombinant human interleukin-3 (rhIL-3) at dose levels of 0, 70, or 700 micrograms/kg daily for 18 days. Monkeys administered rhIL-3 developed small (0.5-1-cm-diameter), firm nodules at the subcutaneous injection sites. Histologically, these nodules from 4 of 8 rhIL-3-treated monkeys contained trilineage extramedullary hematopoiesis (EMH) represented by precursors of myeloid, erythroid, and megakaryocytic series cells. The lineage of hematopoietic cells was confirmed by histochemical and immunohistochemical methods. Hematopoietic cells of myeloid and megakaryocytic lineages were more common than erythroid cells. Of myeloid cells, immature eosinophils were more common, which usually formed small sheets or clusters in the panniculus and deep dermis. This report describes, for the first time, the occurrence of cutaneous EMH at the injection sites of recombinant hematopoietic growth factors, which should be differentiated from inflammation. We believe the cutaneous EMH was the exaggerated pharmacologic effect of rhIL-3.
authors.affiliation: Department of Product Safety Assessment, G. D. Searle and Co., Skokie, Illinois 60077, USA.
authors.forename: K N
authors.initials: KN
authors.lastname: Khan
authors.forename: A A
authors.initials: AA
authors.lastname: Kats
authors.forename: M M
authors.initials: MM
authors.lastname: Fouant
authors.forename: S S
authors.initials: SS
authors.lastname: Snook
authors.forename: J P
authors.initials: JP
authors.lastname: Mckearn
authors.forename: C L
authors.initials: CL
authors.lastname: Alden
authors.forename: P F
authors.initials: PF
authors.lastname: Smith
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D019070:Cell Lineage; D004890:Erythema / Q000139:chemically induced / Q000473:pathology; D005260:Female; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D007150:Immunohistochemistry; D007279:Injections, Subcutaneous; D007377:Interleukin-3 / Q000008:administration & dosage / Q000009:adverse effects*; D008252:Macaca fascicularis; D008297:Male; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000009:adverse effects; D012867:Skin / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D007377:Interleukin-3; D011994:Recombinant Proteins