Insulin-like growth factor-1 and insulin-like growth factor binding protein-3: impact on early haematopoietic reconstitution following allogeneic haematopoietic stem cell transplantation.

Objectives: The aim of the study was to investigate whether high endogenous levels of insulin-like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3) were related to a faster reconstitution of different blood cell populations in the early phase after allogeneic myeloablative haematopoietic stem cell transplantation (HSCT).

Methods: We measured IGF-1 and IGFBP-3 by chemiluminescence during the first three weeks after transplantation in 35 adult patients undergoing myeloablative HSCT and calculated area under the curve divided by time (AUC/t) for each patient.

Results: Circulating levels of IGF-1 and IGFBP-3 correlated with counts of reticulocytes (r = 0.44, p = .011 and r = 0.41, p = .017, respectively) and thrombocytes (r  = 0.38, p = .030 and r  = 0.56, p = .0008) three weeks post-transplant. Furthermore, high IGFBP-3 levels correlated with absolute lymphocyte counts 3 weeks post-HSCT (r  = 0.54, p = .012) and were associated with shorter time to neutrophil engraftment (r  = -0.35, p = .043). Both IGF-1 and IGFBP-3 levels were associated with the number of circulating natural killer cells one month after HSCT (r  = 0.42, p = .032 and r  = 0.57, p = .0026).

Conclusion: These data indicate that high levels of IGF-1 and IGFBP-3 relate to a faster haematopoietic reconstitution after HSCT and suggest a biological influence of these mediators in haematopoietic homeostasis in these patients.