Levels of insulin-like growth factor after stem cell transplantation

Some cytokines, i.e. tumor necrosis factor-, interleukin-6 and soluble interleukin-2 receptors are associated with complications of stem cell transplantation. Insulin-like growth factors (IGFs) are a family of peptides essential for the proliferation of normal and malignant cells. Recently increased levels of IGFs have been associated with the development of malignant tumors. In this communication we report on 96 measurements of insulin-like growth factor-I (IGF-1), insulin-like growth factor-II (IGF-2), and insulin-like growth factor-binding protein-3 (IGFBP-3) performed in 19 patients following stem cell transplants. Seventeen patients had allogeneic and 2 patients autologous transplants. Most IGF determinations were made at days 0, 7, 14, 21 and 28, some at other time points. The baseline values (day 0) of IGF-1 and IGFBP-3 were not different from controls. IGF-2 values were slightly lower than controls. Following transplantation, a consistent increase of IGF-1 was observed in 9/16 patients at days 7 and 14. Later the values decreased again. IGF-2 and IGFBP-3 did not change significantly after transplantation. No direct correlation could be established with the severity of graft-versus-host disease, levels of interleukin-6 and the time to hematopoietic recovery. A potential relevance of IGFs following stem cell transplantation may be the early diagnosis of liver damage and the development of second malignancies. More studies are necessary to investigate the pathophysiology and the clinical relevance of the increase of IGF-1 following stem cell transplantation.