title: Effects of interleukin 6 administration on platelets and haemopoietic progenitor cells in peripheral blood.
abstract: Platelet numbers and circulating haemopoietic progenitor cells were examined in 12 patients with advanced malignancies who were receiving recombinant human interleukin-6 (rhIL-6) as part of an investigation of its thrombopoietic effects. Patients received recombinant glycosylated IL-6 by daily subcutaneous injection for 7 consecutive days in doses of 1, 3 or 10 micrograms/kg/day. Platelet numbers increased reaching a peak on days 12-15 with a mean on day 15 of 198.1% of pre-treatment values. This was accompanied by a significant fall in the mean platelet volume (mean decrease of 10.6%, P = 0.0044). No significant correlation was seen between the IL-6 dose and the change in platelet number. No significant differences were observed between pre- and post-treatment levels of circulating erythroid burst-forming units (E-BFU) and granulocyte macrophage colony-forming units (GM-CFU) but a small significant increase was seen in circulating primitive progenitor cells measured in a plastic-adherent (P delta) assay (P = 0.025). As positive controls, a group of patients treated with cyclophosphamide/G-CSF showed significant increases in GM-CFU (P = 0.018), E-BFU (P = 0.018) and P delta progenitors (P = 0.028). These data suggest that the thrombopoietic effects of IL-6 are mediated at a relatively late stage via effects on megakaryocyte differentiation, with a relatively small effect on circulating haemopoietic progenitors.
authors.affiliation: Imperial Cancer Research Fund, Cancer Medicine Research Fund, St James's University Hospital, Leeds, UK.
authors.forename: D
authors.initials: D
authors.lastname: Clarke
authors.forename: P W
authors.initials: PW
authors.lastname: Johnson
authors.forename: R E
authors.initials: RE
authors.lastname: Banks
authors.forename: M
authors.initials: M
authors.lastname: Storr
authors.forename: S E
authors.initials: SE
authors.lastname: Kinsey
authors.forename: R
authors.initials: R
authors.lastname: Johnson
authors.forename: G
authors.initials: G
authors.lastname: Morgan
authors.forename: M Y
authors.initials: MY
authors.lastname: Gordon
authors.forename: J M
authors.initials: JM
authors.lastname: Illingworth
authors.forename: T J
authors.initials: TJ
authors.lastname: Perren
authors.forename: P J
authors.initials: PJ
authors.lastname: Selby
mesh_terms: D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects* / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects; D003114:Colony-Forming Units Assay; D003520:Cyclophosphamide / Q000627:therapeutic use; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000473:pathology; D006801:Humans; D007279:Injections, Subcutaneous; D015850:Interleukin-6 / Q000627:therapeutic use*; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood* / Q000628:therapy; D010976:Platelet Count / Q000187:drug effects; D011994:Recombinant Proteins / Q000627:therapeutic use
chemical_list: D000970:Antineoplastic Agents; D015850:Interleukin-6; D011994:Recombinant Proteins; D003520:Cyclophosphamide