Interferon-alpha therapy increases type I insulin-like growth factor receptors expression on lymphoid cells from patients with chronic myelogenous leukemia

Aiming to verify if insulin-like growth factor type I and its receptor (IGF-IR) are implicated on pathofisiology of chronic myelogenous leukemia (CML), we studied 35 patients with CML in chronic phase at diagnosis or during interferon-alpha (IFN-A) or hydroxyurea treatments. Cytometry flow analysis and reverse transcription PCR (RT-PCR) molecular assay for IGF-IR expression on peripheral blood cells from CML patients diagnosed didn't show statistical differences from the control group. Hydroxyurea treated patients had lower expression of IGF-IR in granulocytes, lymphocytes and monocytes (P < 0.01). We found statistical higher percentage of T and B lymphocytes positive for IGF-IR on IFN-A treated patients (P < 0.001). Also an increase of IGF-IR mRNA expression could be detected in this group when compared with patients in hydroxyurea therapy (P < 0.05). Our study suggest that IGF-IR is not directly implicated on CML installation and that the increased expression of IGF-IR on lymphoid cells of IFN-A treated patients could contribute to the immune recognition of malignant cell clone by enhancing immunecompetent cell proliferation and action. (C) 2001 Elsevier Science Ltd. All rights reserved.