Growth hormone--dependent growth failure.

Growth failure may be associated with low serum somatomedin concentrations despite normal to increased concentrations of serum growth hormone. We have recognized five patients who responded to GH administration with an increase in serum Sm and an acceleration in skeletal growth, and have characterized the circulating GH in an homologous human GH radioreceptor assay employing the IM-9 lymphocyte as a source of human GH receptor. These five prepubertal children, who had a mean height 7.8 SD below the mean for age, had a mean RIA-GH of 34.2 +/- 3.5 ng/ml in response to stimulation, a basal Sm activity by hypophysectomized rat cartilage bioassay of less than 0.3 IU/ml, and a mean peak Sm of 0.9 +/- 0.1 IU/ml in response to 48 hours of GH therapy. During a one-year trial of GH therapy, four of these children significantly increased their growth velocity as compared to their growth rate before GH therapy. These children had a mean RIA-GH/RRA-GH ratio of 2.f. The fifth patient had a low RIA-GH/RRA-GH ratio and had no increase in growth rate. These studies suggest that growth in certain growth retarded children may be dependent on exogenous GH, even though they are not GH deficient by standard criteria.

Angiomatous lymphoid hamartoma: inhibitory effects on erythropoiesis, growth, and primary hemostasis.

An 11-year-old boy was noted to have microcytic anemia, growth retardation, polyclonal hypergammaglobulinemia, and abnormal platelet function. An angiomatous lymphoid hamartoma was removed from the retroperitoneal space. Postoperatively the child exhibited a dramatic growth spurt and complete resolution of the abnormal laboratory measurements. Studies were performed before and after tumor removal to investigate the nature of the associated anemia, growth retardation, and altered hemostasis. There was no evidence of iron deficiency, thalassemia, or an antierythropoietin factor. Prolonged bleeding time and impaired ristocetin-induced platelet aggregation normalized following tumor resection. Serum obtained before surgery inhibited lymphocyte proliferation in mixed lymphocyte culture as well as fibroblast growth in vitro. Detailed study of growth regulatory hormones failed to reveal significant alterations except for significantly reduced somatomedin which normalized after surgery. The factor(s) which inhibit in vitro cellular growth and lower in vivo plasma somatomedin concentration remain unknown.