Growth hormone replacement therapy in growth hormone deficient children and adults : effects on hemochrome

Several lines of evidence have suggested a role of the GH/IGF-I axis in the regulation of hemochrome. Many studies have been carried out in GH deficient children and adults about this topic, reporting predominantly a positive effect of recombinant human GH (rhGH) on red series, with no action on serum leucocytes and platelets counts. The aim of this study was to assess the impact of GH deficiency (GHD) and of rhGH replacement on blood cells count in 17 pre-pubertal children with idiopathic isolated GHD (11 males and 6 females, aged 9.1±0.8 yr) and in 18 patients with adult-onset GHD (12 males and 6 females, aged 47.9±3.0 yr). Evaluation of absolute and SD score (SDS) values of red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets and white blood cells was performed at baseline and after 12 months of rhGH treatment (0.045±0.001 mg/kg bw/day and 4.2±0.5 μg/kg bw/day for children and adults, respectively). At baseline, all patients showed low IGF-I levels. Effectiveness of rhGH therapy was documented by significant increase in height SDS, height velocity and serum IGF-I levels in children. In adults, adequacy of rhGH was demonstrated by significant increase in serum IGF-I and significant decrease in body fat. At baseline, about 25% of patients (4 of 17 children and 4 of 18 adults) showed normochromic normocytic anemia, while the other indices were normal. In 7 of the 8 anemic patients, normal levels of hemoglobin were restored on rhGH, while no change in all the other indices was observed. In conclusion, rhGH therapy at physiological doses has no effect on erythropoiesis in GHD children and adults with normal blood cells count, while in patients with normochromic normocytic anemia rhGH is able to restore normal hemoglobin levels.