Naevocyte triggering by recombinant human growth hormone

Effects of Growth Hormone (GH) Supplementation on Dermatoscopic Evolution of Pigmentary Lesions in Children with Growth Hormone Deficiency (GHD)

Recent reports have confirmed higher levels of growth hormone (GH) receptor (GHR) transcripts in malignant melanomas (MM), yet the role of GH in the pathogenesis of MM remains controversial. Although melanocytes appear to be hormonally responsive, the effects of GH on MM cells are less clear. A direct correlation between GH administration and the development of melanoma seems possible. Our study aimed to assess whether GH supplementation in children with growth hormone deficiency (GHD) could induce changes in the melanocytic lesions both from a dimensional and dermoscopic point of view. The study population consisted of 14 patients sorted into two groups. The experimental group consisted of seven GHD pediatric patients who underwent dermatological examination with epiluminescence through the use of digital video recording of all melanocytic lesions before and after 12 months of GH supplementation, whilst the control group consisted of seven healthy pediatric patients matched for age, sex and phototype. All patients were evaluated according to auxological and dermatological features. A total of 225 melanocytic lesions were examined in the experimental group and 236 in the control group. Our study shows a significant increase in the mean size values of the lesions in the study group but not in the control group. Increases in the dermoscopic ABCD Score and in BMI correlated to an increase in the size of the melanocytic lesions and the dermoscopic parameters. The increase in SDS Height correlated with ABCD Score changes and with dermoscopic score structures. No differences were found compared to the control group. Dimensional/structural modifications in melanocytic lesions of patients treated with GH were closely related to weight and statural growth and can be considered a normal physiological process induced by GH supplementation.

Hypertrophic scars in a patient with Turner's syndrome treated with recombinant growth hormone

Turner's syndrome is a common genetic disorder of girls and women, for which characteristic clinical symptoms encompass short stature, gonadal dysgenesis, systemic defects, multiple dysmorphic features and skin changes, including an increased number of melanocytic nevi, hypertrophic scars and keloids. The affected girls are treated with recombinant human growth hormone to improve the height. We present a case of a 15-year-old girl with Turner's syndrome, hypertrophic scars and a keloid. At the age of 12 years and 8 months, the girl started recombinant human growth hormone treatment. During the therapy, a surgical excision of 4 out of 42 benign melanocytic nevi was performed. After 2 months the hypertrophic scars as well as a keloid were noted at sites of excision. Parents of girls with Turner's syndrome undertake various attempts to improve not only the height and maturity of their daughters, but also their appearance by commonly performed surgical corrections of the webbed neck and pigmented nevi. The presented case suggests an increased risk of scars hypertrophy and keloid formations after surgical intervention in Turner's syndrome patients who are treated with recombinant human growth hormone at the same time. Due to that it should be advised to postpone all planned surgical procedures until the therapy has been completed.

Streamlining cutaneous melanomas in young women of the Belgian Mosan region

Sporadic cutaneous melanoma (SCM) has shown a dramatic increase in incidence in Caucasian populations over the past few decades. A particular epidemiological increase was reported in women during their childbearing age. In the Belgian Mosan region, a progressive unremitting increase in SCM incidence was noticed in young women for the past 35 years. The vast majority of these SCMs were of the superficial type without any obvious relationship with a large number of melanocytic nevi or with signs of frequent and intense sunlight exposures as disclosed by the extent in the mosaic subclinical melanoderma. A series of investigations pointed to a possible relationship linking the development of some SCM to the women hormonal status including the effect of hormonal disruptors. These aspects remain, however, unsettled and controversial. It is possible to differentiate and clearly quantify the SCM shape, size, scalloped border, and variegated pigmentation using computerized morphometry as well as fractal and multifractal methods.

Adverse effects of growth hormone replacement therapy in children

Human growth hormone (hGH) replacement therapy has been widely available for clinical purposes for more than fifty years. Starting in 1958, hGH was obtained from cadaveric pituitaries, but in 1985 the association between hGH therapy and Creutzfeldt-Jakob disease was reported. In the same year, the use of recombinant hGH (rhGH) was approved. Side effects of rhGH replacement therapy in children and adolescents include rash and pain at injection site, transient fever, prepubertal gynecomastia, arthralgia, edema, benign intracranial hypertension, insulin resistance, progression of scoliosis, and slipped capital femoral epiphysis. Since GH stimulates cell multiplication, development of neoplasms is a concern. We will review the side effects reported in all rhGH indications.

Turner's syndrome in dermatology

Turner's syndrome (TS) is a common genetic disorder of girls and women, for which the defining clinical triad is short stature, impaired sexual development, and infertility. Although classically known as monosomy X, genetic heterogeneity is frequent in TS, with mosaicism conferring a survival advantage. Several genetic loci have been implicated in TS including the short stature homeobox gene. TS effects many organs, with cutaneous stigmata providing critical clues for early detection of TS. The presence of lymphedema and its cutaneous sequelae are predictive of other systemic disorders, such as cardiac disease. Although an increased number of benign nevi have been reported in TS, the decreased melanoma rate in this population suggests some protective factor is active. Keloids were thought to be prevalent in TS, but recent data suggest otherwise. Autoimmune diseases are common in TS, with a possible increased prevalence of alopecia areata and vitiligo. The following review discusses new insights into the genetics and pathogenesis of this complex disorder, summarizes the major systemic effects, and reviews skin manifestations of TS and their implications.

Epidermal homeostasis: the role of the growth hormone and insulin-like growth factor systems

GH and IGF-I and -II were first identified by their endocrine activity. Specifically, IGF-I was found to mediate the linear growth-promoting actions of GH. It is now evident that these two growth factor systems also exert widespread activity throughout the body and that their actions are not always interconnected. The literature highlights the importance of the GH and IGF systems in normal skin homeostasis, including dermal/epidermal cross-talk. GH activity, sometimes mediated via IGF-I, is primarily evident in the dermis, particularly affecting collagen synthesis. In contrast, IGF action is an important feature of the dermal and epidermal compartments, predominantly enhancing cell proliferation, survival, and migration. The locally expressed IGF binding proteins play significant and complex roles, primarily via modulation of IGF actions. Disturbances in GH and IGF signaling pathways are implicated in the pathophysiology of several skin perturbations, particularly those exhibiting epidermal hyperplasia (e.g., psoriasis, carcinomas). Additionally, many studies emphasize the potential use of both growth factors in the treatment of skin wounds; for example, burn patients. This overview concerns the role and mechanisms of action of the GH and IGF systems in skin and maintenance of epidermal integrity in both health and disease.

Problems with GH doping in sports

Human hGH is listed as a prohibited class E substance by the International Olympic Committee (IOC), and its use is considered as doping. However, until today the likelihood of being punished for using recombinant hGH is very limited: once injected, it is believed to be undetectable by laboratories. No official test is implemented in the doping control procedures, and the only situation when athletes were found guilty of doping with hGH arose from actions of customs officers or policemen arresting athletes carrying ampoules with them. The primary reason for the lack of an accepted test method is the amino acid sequence identity between the main fraction of pituitary derived hGH and recombinant hGH, which makes it difficult to discriminate between endogenous and exogenous hGH. In addition, hGH is known to have a very short half-life time in circulation of around 15 min. Recent efforts of endocrine researchers led to the identification of two main strategies promising to be useful for the detection of recombinant hGH application, which are reviewed in this article: on the one hand, changes in GH-dependent parameters after administration of recombinant GH have been shown to be possible indicators of GH abuse, because the increase in various parameters following recombinant hGH administration exceeds the variability commonly observed in normal, healthy subjects. More directly, another approach focuses on changes in the hGH isoform pattern in serum occurring after injection of recombinant hGH. Because of the negative feedback on pituitary hGH secretion, the relative abundance of isoforms other than 22 kD are greatly reduced after administration of recombinant hGH, which only consists of the 22 kD hGH isoform.

Metabolic effects of growth hormone in the child and adolescent

During the year 2000, several original studies were published regarding the metabolic effects of growth hormone therapy in pediatric patients. Pharmacologic doses of growth hormone were rarely associated with abnormalities in glucose tolerance in children with intrauterine growth retardation and Turner syndrome; however, serum insulin levels were elevated. A report from the Pharmacia International Growth Study database suggested a possible increase in type 2 diabetes in growth hormone-treated patients, indicating the need for continued surveillance for this condition. Growth hormone therapy increased markers of bone turnover and bone mineral density in children with chronic renal failure and Prader-Willi syndrome. In Prader-Willi syndrome, 2 years of growth hormone therapy also induced a sustained decrease in body fat, improvement in strength and physical skills, and increased lean body mass. Serum leptin, a reflection of body fat, declined with growth hormone therapy in a dose-dependent manner in intrauterine growth retardation children; the magnitude of the decline correlated with linear growth response. Skin is a target organ for growth hormone in children; growth hormone increased dermal thickness and reduced skin stiffness in growth hormone-deficient children. Reassuring data were published regarding the risk of tumor recurrence and mortality in children with brain tumors treated with growth hormone. Growth hormone administered to short children prior to kidney transplantation did not have adverse effects on subsequent graft survival or number of rejection episodes.

One year growth hormone replacement therapy does not alter colonic epithelial cell proliferation in growth hormone deficient adults

OBJECTIVE

Increased colonic epithelial cell proliferation has been found in various conditions associated with increased risk of colorectal cancer including acromegaly. In a placebo-controlled study we determined the effect of growth hormone (GH) replacement therapy in GH deficient adults on the colonic epithelial proliferation rate.

PATIENTS AND DESIGN

Sixteen GH deficient adults were randomised to low dose GH therapy (1 U (0.5 mg) subcutaneously per day, n = 5), high dose GH therapy (2 U daily, n = 5) or placebo (n = 6) during 6 months. Thereafter, all patients were treated with 2 U of GH daily during a 6-months open extension period.

MEASUREMENTS

Plasma Insulin-like growth hormone I (IGF-I) and IGF binding protein 3 (IGF BP3) concentrations were measured using commercial RIA kits. The colonic epithelial proliferation rate, expressed as overall crypt labelling index (LI) using 5-bromo-2'-deoxyuridine (BrdU) immunostaining, was determined at baseline, after 6 months treatment and at the end of the 6 months open extension period.

RESULTS

IGF-I rose from 8.9 +/- 6.7 to 34.6 +/- 20.0 nmol/l after 6 months in 8 GH treated patients (P < 0.01 from baseline; P < 0.01 from change with placebo). In the extension study, plasma IGF-I was also increased in the patients who previously received placebo (P < 0.02, n = 5). LI was evaluable in 14 biopsies at baseline, in 16 after 6 months and in 14 after 12 months. Overall crypt LI did not change in 8 GH treated patients after 6 months (P > 0.40 from baseline; P > 0.80 from change with placebo). In the extension study, overall crypt LI was also unchanged in those patients who received GH after placebo (n = 5, P > 0.40) and in those who continued GH replacement (n = 9, P > 0.60; P > 0.80 from change in initially placebo treated patients). Separate evaluation of the LI at the basal, mid and luminal portions of the colonic crypts also did not reveal any effect of GH treatment on BrdU labelling.

CONCLUSIONS

Six to 12 months of GH replacement therapy, aimed to increase plasma IGF-I into the (high) physiological range, does not adversely affect colonic epithelial cell proliferation as a biomarker for the risk of development of colorectal cancer.

Growth hormone abuse

Doping with growth hormone (GH) has become an increasing problem in sports during the last 10 years. GH has a reputation of being fairly effective among GH users, although the effectiveness is not undisputed, and the few controlled studies that have been performed with supraphysiological GH doses to athletes have shown no significant positive effects of GH in the aspect of a doping agent. There is no method yet to discover GH doping, but current intensive research in this matter will hopefully produce a method in the years to come. This article describes the GH physiology, the clinical use of GH, the athlete's view, administration regimens and side effects.

Interactions between growth hormone, insulin-like growth factor I, and basic fibroblast growth factor in melanocyte growth

Melanocytes, highly differentiated neural crest-derived cells, are located in the basal layer of the epidermis, where they play a role in protecting against UV damage in the skin. Previous studies suggest that both growth hormone (GH) and the insulin-like growth factor I (GH/IGF-I) system may be important for melanocyte growth and function. We have therefore characterized the role of the GH/IGF system in melanocyte growth in vitro and its interaction with the local growth factor basic fibroblast growth factor (bFGF). Analysis of the effects of GH, IGF-I, and bFGF and combinations of these growth factors on melanocyte growth in vitro revealed that 1) GH stimulates the growth of melanocytes when combined with IGF-I, des(1-3)IGF-I [an analog of IGF-I that has a reduced binding affinity for IGF-binding proteins (IGFBPs)], or bFGF, either separately or in combination; 2) in contrast to the lack of effect of GH or bFGF alone, both IGF-I and des(1-3)IGF-I enhance melanocyte growth in a dose-dependent manner; and 3) IGF-I is more efficacious in eliciting a growth response at low concentrations compared to des(1-3)IGF-I. Using Western ligand blotting, affinity cross-linking, immunoprecipitation, RIA, and Northern analysis, we show that cultured human melanocytes synthesize and secrete minimal amounts of IGFBP. IGFBP-4 is the major IGFBP produced by these cells when cultured in complete growth medium or in the presence of either IGF-I or des(1-3)IGF-I alone. In conclusion, these studies provide support for a role for both GH and IGF-I in the growth of human melanocytes in vitro, involving synergy with bFGF. Low levels of melanocyte-derived IGFBP-4 may play a role in enhancing the modulation of IGF action.