We investigated the cause of thrombocytosis in 14 patients with tumors producing colony-stimulating factor (CSF). Of the 14 patients, 10 had tumors producing granulocyte-CSF (G-CSF) and 4 had tumors producing granulocyte- macrophage-CSF (GM-CSF). Thrombocytosis of greater than 400 x 109/L was noted in 8 of 10 patients with G-CSF-producing tumors and all 4 patients with GM-CSF-producing tumors. Median peak platelet counts were, respectively, 511 x 109/L (range, 384 to 694 x 109/L) and 579 x 109/L (range, 526 to 910 x 109/L) in patients with tumors producing G-CSF and GM-CSF. In most patients, thrombocytosis declined towards the terminal stage. High interleukin-1 (IL-1) and IL-6 levels were found in addition to CSFs in the plasma or culture supernatants of tumor cells obtained from most patients. In patients with GM- CSF-producing tumors, these specimens had megakaryocyte-CSF (Meg-CSF) activity, which was abolished by anti-GM-CSF antibody. These specimens also had megakaryocyte potentiating (Meg-Pot) activity attributable to both GM-CSF and IL-6. In patients with G-CSF-producing tumors, only Meg-Pot activity due to IL-6 was detected. These results indicate that the thrombocytosis in GM- CSF-producing tumors was caused by both the Meg-CSF activity of GM-CSF and the Meg-Pot activity of IL-6 plus GM-CSF, while that in G-CSF-producing tumors was due to the Meg-Pot activity of IL-6.
|Number of pages||8|
|Publication status||Published - 1992|
ASJC Scopus subject areas
- Cell Biology