Insulin-like growth factors in childhood-onset Gaucher disease

Abstract

There is a high prevalence of growth retardation in children with type 1 Gaucher disease. The cause of this poor growth is not yet known; however, studies have shown acceleration of growth with enzyme replacement therapy (ERT). IGF are recognized as important determinants of somatic growth. It has been proven that chronic diseases with liver involvement might cause IGF deficiency. The aim of this study was to assess the IGF system in patients with childhood-onset Gaucher disease, before and after ERT, and its association with other clinical and analytical parameters. Twenty-two patients with type I Gaucher disease were included. The diagnosis was established before 14 y of age in all patients. Baseline determinations of total IGF-I, free IGF-I, and IGF binding protein 3 (IGFBP-3) were obtained in 19 patients before starting ERT at a mean age of 13.8 ± 11.2 y. A Spearman test was performed to establish the association with other clinical and analytical parameters. In a group of 13 patients receiving IGF, changes were evaluated during the initial 2 y of treatment. A Wilcoxon test was performed for the statistical analysis. Total IGF-I, free IGF-I, and IGFBP-3 were expressed as SD scores (SDS). We found low levels of IGF and its binding proteins before ERT. A significant association was found between the total IGF-I SDS before treatment and the age-adjusted severity score index: r = -0.62, p < 0.05. Total IGF-I and IGFBP-3 SDS correlated negatively with the presence of the L444P mutation (r = -0.53 and -0.5, respectively, p < 0.05). Height SDS correlated with total IGF-I and IGFBP-3 SDS in eight children (r = 0.84 and 0.78, respectively, p < 0.05). Total IGF-I SDS increased from -1.8 ± 0.8 to -0.8 ± 1.4 (p = 0.005) and free IGF-I increased from - 1.2 ± 1 to 1.1 ± 2.1 after 12 ± 6.8 mo (p = 0.011) of ERT. IGFBP-3 SDS increased from -1.3 ± 0.6 to -0.2 ± 1.2 (p = 0.012) after 12 ± 4.5 mo of ERT. Type 1 Gaucher disease is associated with low levels of IGF and its binding proteins, which could be a consequence of liver involvement. Total IGF-I deficiency is associated with the severity of the illness. Growth retardation in pediatric patients with Gaucher disease is related to the alterations in IGF axis. Total IGF-I and IGFBP-3 are the two parameters that better correlate with height before treatment. ERT results in significant increase of total IGF-I, free IGF-I, and IG-FBP-3 during the first year of treatment.