Interferon-alpha inhibits CFU-GM mobilization following chemotherapy and G-CSF administration.

Changes in routine hematologic data and in circulating granulocyte-macrophage colony-forming units (CFU-GM) during granulocyte colony-stimulating factor (G-CSF) administration were evaluated in non-small cell lung carcinoma (NSCLC) patients treated with a combination of 5-fluorouracil (5-FU) and cisplatin (DDP) with and without the addition of interferon-alpha (IFN-alpha). The patterns of leukocyte changes following chemotherapy plus G-CSF were similar in both the IFN-alpha-inclusive and the IFN-alpha-devoid courses. However, the twofold increase in CFU-GM observed in patients receiving chemotherapy plus G-CSF was completely absent following the course including IFN-alpha. The activity of G-CSF on the hematologic pattern is seemingly affected by its combination with IFN-alpha treatment. Mechanisms of the possible in vivo interaction among IFNs and hematopoietic growth factors remain to be elucidated.