Production of interleukin-1-alpha and interleukin-2 by mononuclear cells in healthy adults in relation to different experimental conditions and to the presence of growth hormone

Several reports support the view that the growth hormone (GH) possesses a number of important immunomodulatory properties. This study was undertaken to determine in vitro the role of the GH on interleukin (IL) production. Cultures of blood peripheral lymphocytes obtained from human normal adults were performed in RPMI medium in the presence or absence of phytohemagglutinin (PHA), heated normal serum (NHS) 1% and GH 12.5-500 microgram/l. After incubation from 15 h to 4 days at 37 degrees C in a humidified atmosphere containing 5% CO2, cells were discarded and the supernatants were tested for their contents of IL-1 alpha and IL-2 measured using the Amersham radioimmunoassay system. The results of these in vitro experiments show that: (1) the bulk cultures from peripheral lymphocytes are suitable to study the IL-1 and IL-2 production; (2) in optimal conditions for IL production (incubation during 48 h in the presence of PHA and NHS) no effect of GH was observed on IL production; (3) in the absence of PHA GH acts at physiological doses (less than 100 ng/ml) by increasing the IL production. This effect of GH was optimized with a short time of incubation (16 h) and in the simplest conditions of cultures, that is to say in the absence of serum and of PHA: thus in the presence of GH 100 ng/ml the IL-1 production increases from 0.53 to 3.86 fmol (tubes) and IL-2 increases from 0.18 to 3.22 fmol (tubes). These differences are significant (p less than 0.001). We conclude that GH acts in vitro on mononuclear cells to induce IL production.     

Factors influencing the growth hormone response to growth hormone-releasing hormone in children with idiopathic growth hormone deficiency

OBJECTIVE: To evaluate the factors influencing the growth hormone (GH) response to GH-releasing hormone (GHRH) test in idiopathic GH deficiency. METHODS: 28 patients aged 4.9 +/- 0.7 years with certain GH deficiency were given GHRH (2 microg/kg). RESULTS: The GH peak after GHRH was correlated negatively with age at evaluation (r = -0.37, p < 0.05) and body mass index (r = -0.44, p = 0.02), and positively with anterior pituitary height (r = 0.47, p = 0.02), GH peak after non-GHRH stimulation (r = 0.78, p < 0.0001) and spontaneous GH peak (r = 0.82, p = 0.007). It was lower in the patients aged >5 years than in the youngest (p = 0.04), but it was similar in the patients with and without features suggesting a hypothalamic origin. CONCLUSION: The GH response to GHRH test cannot be used to differentiate between hypothalamic and pituitary forms of idiopathic GH deficiency, probably because the GH response decreases after the first 5 years of life, whatever the origin of the deficiency.     

Bone markers and bone mineral density during growth hormone treatment in children with growth hormone deficiency

Growth hormone (GH) has a positive impact on muscle mass, growth and bone formation. It is known to interact with the bone-forming unit, with well-documented increases in markers of bone formation and bone resorption within weeks of the start of GH therapy. These changes relate significantly to short-term growth rate, but it is not evident that they predict long-term response to GH therapy. The consequences of GH deficiency (GHD) and GH replacement therapy on bone mineral density (BMD) have been difficult to interpret in children because of the dependency of areal BMD on height and weight. Some studies have tried to overcome this problem by calculating volumetric BMD, but results are conflicting. The attainment of a normal peak bone mass in an individual is considered important for the future prevention of osteoporosis. From the limited data available, it appears difficult to normalize bone mass totally in GH-deficient individuals, despite GH treatment for long periods. Studies to date examining the interaction between GH and bone have included only small numbers of individuals, making it difficult to interpret the study findings. It is hoped that these issues can be clarified in future research by the direct measurement of bone density (using quantitative computer tomography). Mineralization is only one facet of bone strength, however; other important components (e.g. bone structure and geometry) should be addressed in future paediatric studies. Future studies could also address the importance of the degree of GHD in childhood; how GH dose and insulin-like growth factor-I levels achieved during therapy relate to the final outcome; whether or not the continuation of GH therapy after the attainment of final height may further enhance bone mass; whether the timing and dose of other treatments (e.g. sex hormone replacement therapy) are critical to the outcome; and whether GHD in childhood is associated with an increased risk of fracture.     

Production of multilineage growth factors by hematopoietic stromal cells: an intercellular regulatory network involving mononuclear phagocytes and interleukin-1

In the past 8 years, our group has carried out a series of in-vitro studies designed to characterize the role of mononuclear phagocytes as regulators of human hematopoiesis. The results of this program of investigation, some of which are reviewed below, led to the discovery that mononuclear phagocytes are more efficient recruitors of growth factor release by other cells than they are direct stimulators of progenitor cell growth. Specifically, mononuclear phagocytes release soluble factors (MRA) that stimulate other cells, including vascular endothelial cells, skin fibroblasts, and marrow fibroblasts, to release multilineage hematopoietic growth factors. Experiments designed to purify and characterize these monokines indicated unambiguously that the MRA that stimulates granulocyte/macrophage colony stimulating factor (GM-CSF) release is interleukin-1 (IL-1). Based on these observations and recent observations by other groups on the hematopoietic effects of other monokines including tumor necrosis factor alpha, we argue that mononuclear phagocytes serve as important regulators of hematopoiesis by producing monokines that, in turn, induce the expression of multiple hematopoietic growth factor genes in stromal cells of the hematopoietic microenvironment. Because IL-1 molecules and the mononuclear phagocytes producing them are evolutionarily conserved, and in view of the heterogeneous nonhematopoietic effects of these monokines, studies on their role in hematopoiesis may also provide new understanding of the molecular evolution of multicellular organisms.     

Effect of human growth hormone on adrenal androgens in children with growth hormone deficiency

The effect of human growth hormone (hGH) on adrenal androgen secretion was assessed in 7 patients (5 males, 2 females) with GH deficiency but normal ACTH-cortisol function. Patients ranged in age from 9 5/12 to 14 8/12 years (median 12 years). Plasma concentrations of dehydroepiandrosterone-sulfate (DHEA-S) and urinary excretion of 17-ketosteroids (17-KS) and free cortisol were determined before, during short-term (2 U/day X 3) and after long-term (6 months) treatment with hGH. No significant change was noted in the plasma concentration or urinary excretion of steroids during the short-term administration of hGH. Despite a significant increase in growth velocity during 6 months of hGH therapy (8.2 vs. 4.5 cm/year, p less than 0.01), the plasma concentrations of DHEA-S and the urinary 17-KS and free cortisol levels were unchanged. These results fail to substantiate a role for hGH in the physiologic control of adrenal androgen secretion. Thus, the low plasma levels of adrenal androgens sometimes seen in GH-deficient patients are not due to the absence of GH per se.     

Induction of interleukin-1alpha production in murine Sertoli cells by interleukin-1

In the present study we examined the involvement of interleukin (IL)-1alpha, -1beta, FSH, and lipopolysaccharide (LPS) in the regulation of IL-1alpha and -1beta production by Sertoli cells under in vitro conditions. Sertoli cell cultures from immature mice produced constitutively basal levels of intracellular IL-1alpha. Stimulation of Sertoli cell cultures with LPS (5 microgram/ml) resulted in a maximal production of intracellular IL-1alpha 2 h after the stimulation. Thereafter, these levels decreased but remained significantly higher within 24 h after stimulation than those in control cultures. The effect of LPS on IL-1alpha production was dose dependent. FSH did not show any effect on intracellular IL-1alpha production by Sertoli cells. IL-1alpha could not be detected in supernatants of unstimulated or stimulated Sertoli cell cultures. Sertoli cell cultures stimulated with recombinant IL-1alpha induced optimal intracellular levels of IL-1alpha within 2 h of stimulation. These levels remained high 24 h after stimulation. However, stimulation of Sertoli cell cultures with IL-1beta induced a peak of IL-1alpha production 8 h after stimulation. These levels decreased 24 h after the stimulation but were still found to be significantly higher than those in control cultures. The addition of IL-1 receptor antagonist (IL-1ra) to Sertoli cell cultures did not significantly alter their capacity to produce IL-1alpha. However, the stimulatory effects of recombinant IL-1alpha on IL-1alpha production by Sertoli cell cultures were reversed by the concomitant addition of recombinant IL-1ra. No immunoreactive IL-1beta could be detected in lysates or conditioned media of immature murine Sertoli cells under any of the stimulatory conditions outlined. Our results may suggest the involvement of physiological (IL-1) and pathophysiological factors (LPS) in the regulation of spermatogenesis and spermiogenesis processes and male fertility.     

Final height in children with idiopathic growth hormone deficiency treated with recombinant human growth hormone: the Belgian experience

BACKGROUND: The growth response to recombinant hGH (rhGH) treatment and final height of 61 Belgian children (32 boys) with idiopathic growth hormone deficiency (GHD) were studied. PATIENTS/METHODS: Two patient groups were compared: Group 1 with spontaneous puberty (n = 49), Group 2 with induced puberty (n = 12). The patients were treated with daily subcutaneous injections of rhGH in a dose of 0.5-0.7 IU/kg/week (0.17-0.23 mg/kg/week) from the mean +/- SD age of 11.9 +/- 3.1 years during 5.1 +/- 2.1 years. RESULTS: rhGH treatment induced a doubling of the height velocity during the first year and resulted in a normalisation of height in 53 (87%) patients. Final height was -0.7 +/- 1.1 SDS, being 170.4 +/- 7.2 cm in boys and 158.0 +/- 6.4 cm in girls. Corrected for mid-parental height, final height was 0.0 +/- 1.1 SDS. Ninety-two percent of the patients attained an adult height within the genetically determined target height range. Although height gain during puberty was smaller in the patients with induced puberty (boys: 17.1 +/- 7.0 cm vs. 27.5 +/- 6.6 cm (p < 0.005); girls: 9.6 +/- 7.4 cm vs. 22.2 +/- 6.1 cm (p < 0.005)), no differences in final height after adjustment for mid-parental height were found between patients with spontaneous or induced puberty. CONCLUSIONS: We conclude that patients with idiopathic GHD treated with rhGH administered as daily subcutaneous injections in a dose of 0.5-0.7 IU/kg/week reach their genetic growth potential, resulting in a normalisation of height in the majority of them, irrespective of spontaneous or induced puberty.     

Plasma growth hormone response to synthetic GH-RH1-44 in 52 children and adults with growth hormone deficiency of various etiologies

52 patients (42 children and 10 adults) with growth hormone deficiency (GHD), grouped into four diagnostic categories, and 6 children with constitutional short stature who served as controls were tested for plasma GH response to synthetic GH-RH1-44 given in an intravenous bolus. The response was classified into three degrees according to the magnitude of the maximal rise: Good, greater than 9 ng/ml; Partial, 3.1-9.0 ng/ml; None, less than or equal to 3 ng/ml. Among the GHD patients the highest response was observed in patients with partial growth hormone deficiency (PGHD), and 60% of the children with isolated GH deficiency (IGHD) showed an increase in plasma GH levels. Nevertheless, the response of the GHD patients was lower than that in the control group. In the children and adolescents with PGHD and IGHD the response was not age related. Among those with multiple pituitary hormone deficiencies-idiopathic (MPHD-ID) there was no response in the adolescents although a hypothalamic disorder had been documented by other tests. Among those with MPHD-organic (MPHD-ORG) the GH-RH stimulated GH secretion in the patients with glioma, who had received only irradiation treatment, and in the youngest of the patients with craniopharyngioma. Of the 10 young adults tested none showed a good response. It is concluded that GH-RH is useful in differentiating between GH deficiency of hypothalamic origin and that of pituitary origin, and in selecting those patients who might benefit from long-term treatment with GH-RH in the future.     

Insulin sensitivity in adults with growth hormone deficiency and effect of growth hormone treatment

Adult growth hormone deficiency (GHD) is a multifactorial disorder in which pituitary dysfunction associated with pituitary adenomas or their treatment plays a major role. The introduction of recombinant growth hormone (GH) for the treatment of GHD has opened up new treatment avenues but has also raised concerns about possible untoward long-term metabolic effects of GH, such as the potential effect of GH on insulin sensitivity and a deterioration in glucose tolerance. Research has shown that GH induces insulin resistance by the stimulation of lipolysis and a concomitant switch from oxidation of glucose to oxidation of lipids, during both acute and chronic treatment. However, although this is a consistent effect of GH therapy, it does not mean per se that it leads to abnormal glucose tolerance and diabetes mellitus. This article discusses this and other potential long-term metabolic effects of GH, and raises a number of questions to be addressed by future research.     

Medium-term cardiovascular effects of high-dose growth hormone treatment in growth hormone-deficient children

AIM: To investigate the possible cardiac morphofunctional alterations inducd by prolonged and high-dose GH therapy in a group of 14 children with isolated GH deficiency. PATIENTS AND METHODS: Patients were evaluated at phase 1, after 1.1 +/- 0.6 years of treatment with GH 0.93 +/- 0.13 U/kg/week, and at phase 2, after 5.5 +/- 2.1 years of therapy 0.89 +/- 0.11 U/kg/week. At each phase left ventricular volume, mass and systolic function were evaluated by two-dimensional guided M-mode echocardiography; left ventricular diastolic function was assessed by PW-Doppler sampling of transmitral flow. RESULTS: Phase 1: diastolic blood pressure was lower (p < 0.05) and fractional shortening was not adequate for the level of afterload (stress shortening index p < 0.05) in patients compared to controls. Phase 2: diastolic blood pressure was lower (p < 0.01) and mass and mass/volume ratio were increased (mass index p < 0.05, mass/ volume ratio p < 0.05) in patients compared to controls. The increased mass/volume ratio, together with the normal systolic blood pressure, explains the reduction in peak systolic stress (p < 0.005). Among the parameters of left ventricular diastolic function, the peak E velocity/total area under mitral valve tracing and the area under E velocity/total area under mitral value tracing ratios were significantly decreased (p < 0.05). CONCLUSION: After a mean period of 5 years on high-dose GH treatment in GH-deficient children, subclinical morphofunctional alterations in the left ventricle were found.     

Short-term effect on growth of two doses of GRF 1-44 in children with growth hormone deficiency: comparison with growth induced by methionyl-GH administration

In a double-blind study 12 prepubertal children with idiopathic growth hormone (GH) deficiency were treated with growth hormone releasing factor (GRF) 1-44 in a dosage of 7.5 or 15 micrograms/kg body weight, administered once a day subcutaneously. With 7.5 micrograms/kg the average growth velocity increased from 2.5 to 4.6 cm/year, an insufficient response. With the higher dosage the average growth velocity increased from 2.7 to 7.0 cm/year, a similar increase as observed with GH therapy in subsequent periods. In 3 of the 6 children treated with the higher dose appropriate catch-up growth was observed. The growth response of the lower leg length was not always consistent with the statural growth response.     

The effects of growth hormone treatment in patients with somatotropin deficiency during their developmental age

INTRODUCTION: In Poland treatment with growth hormone of adolescent patients dates back to 1964. Till 1993 the therapy was conducted in an interrupted manner, depending on the periodic availability of the drug. The data form such forms of therapy suggested that the end height within 3rd centile was achieved only by a portion of treated patients. Since 1995 the growth hormone is used in continuous therapy, which allows to sum up the effects of the therapy, including the growth rate and end height. MATERIAL AND METHODS: A total of 117 children and adolescent of both sexes, aged 4.6 to 18.1 years, with diagnosed somatotropic or multihormonal pituitary insufficiency were included in the study. All of them were treated with growth hormone and had an analysis of growth rate and end height. RESULTS: In the first 6 months of growth hormone treatment the growth rate achieved 10.4 cm/year in boys and 10.0 in girls and showed no correlation with maturation status. In the second half of the year the growth rate declined slightly. During the remainder of the therapy the growth rate markedly declined, and this effect was most notable in girls. In 93% of patients after the end of therapy the final height was no different than the expected height. CONCLUSIONS: 1. The growth rate in first half a year of the treatment was 3 times higher than before the beginning of therapy. 2. In the second half of the first year the growth rate slightly declined. 3. In following years the growth rate declined notably. 4. The final achieved height in most of the patients does not differ from the prognosed height.     

Cytomegalovirus infection of peripheral blood mononuclear cells: effects on interleukin-1 and -2 production and responsiveness.

Cytomegalovirus suppresses the proliferative response of peripheral blood mononuclear cells to phytohemagglutinin. In these experiments, we identified which mononuclear cell subpopulation might be responsible for the suppression. We found that prior infection of either lymphocytes or monocytes followed by reconstitution with monocytes or lymphocytes, respectively, would abrogate the proliferative response in a subsequent culture with phytohemagglutinin. Infection of either cell type also reduced both the production of interleukin-1 (IL-1) and IL-2 and the proliferative response to exogenously supplied IL-1 or IL-2. We did not find evidence for an IL-2 antagonist. These experiments suggest that cytomegalovirus causes a metabolic derangement in lymphocytes and monocytes and impairs their ability both to produce and to respond to physiological mediators of the immune response.     

Final height in children with idiopathic growth hormone deficiency treated with a fixed dose of recombinant growth hormone

There is no consensus regarding the optimal dosing of recombinant human growth hormone (rhGH) for children with growth hormone deficiency (GHD). Our objective was to evaluate the final adult height (FAH) in children with idiopathic GHD treated with a fixed rhGH dose of 0.18 mg/kg/week. We reviewed all charts of patients with idiopathic GHD treated with rhGH since 1985 who reached FAH. Ninety-six patients were treated for an average of 5.4 years. The mean age was 11.9 years, the mean height -2.87 standard deviation score (SDS) and the mean FAH was -1.04 SDS. Females had a lower predicted adult height than males at the initiation of therapy (-2.0 vs. -1.01 SDS; p = 0.0087) but a higher FAH - predicted adult height (1.08 vs. 0.04 SDS; p = 0.0026). In multiple regression analysis, the FAH SDS was positively related to the midparental height SDS, the height SDS at GH initiation and growth velocity during the first year of therapy, and negatively correlated with peak GH and bone age at initiation (r(2) = 0.51; p < 0.005). Treatment of children with idiopathic GHD with a fixed dose of 0.18 mg/kg/week rhGH is sufficient to reach FAH within 2 SDS of the normal population range (84%) with an average FAH within -0.5 SDS of midparental height.     

Secretion of IGF-1 by ovine granulosa cells: effects of growth hormone and follicle stimulating hormone

Insulin-like growth factor-1 (IGF-1) is implicated in follicle development and is considered to mediate the actions of growth hormone (GH) and gonadotrophins at the ovarian level. However, the expression and secretion of IGF-1 by the ovary are controversial, partly because of species and cell-type specificity. The present study investigated whether IGF-1 is produced by ovine granulosa cells and whether its production is regulated by GH and follicle stimulating hormone (FSH). Follicles (>/=4.0 mm) were obtained from ewes during seasonal anoestrus. Granulosa cells were cultured for a total period of 96 h in Dulbecco's modified Eagle's medium (DMEM)/Ham's F-12 medium supplemented with BSA (0.1%, w:v), transferrin (0.5 microg/ml) and testosterone (100 ng/ml). In the first set of experiments, cells were incubated in the presence of bovine calf serum (BCS) (2.5%) for the initial 48 h of culture. The cells were then cultured for the next 48 h in medium without BCS, but containing either GH (0, 2, 20, and 200 ng/ml) or FSH (0, 20, 200, and 2000 ng/ml). The medium was assayed for oestradiol (E), progesterone (P) and IGF-1. There were six wells per treatment and the experiment was carried out four times. Control granulosa cells maintained both IGF-1 and E secretion, with only low levels of progesterone output. In all experiments, both GH and FSH produced significant (P<0.001) dose-related increases in E, IGF-1 and P secretion into the medium. The maximum responses to GH (20 or 200 ng/ml) were 402% for E and 528% for IGF-1 compared with controls. The maximum responses to FSH (200 or 2000 ng/ml) were 460% for E and 514% for IGF-1. The objective of the second set of experiments was to determine the effect of the progestogenic status of cells on IGF-1 production. Granulosa cells were cultured both in the presence and absence of BCS (2.5% in the medium) during the initial 48 h of culture. For the next 48 h, cells were cultured in serum-free medium. Addition of BCS to the medium during the initial 48 h of culture stimulated progesterone production. However, it did not affect either IGF-1 or oestradiol secretion between 49 and 96 h of culture, or the cell numbers at the end of culture. In conclusion, (1) IGF-1 is secreted by granulosa cells irrespective of their progestogenic status and (2) concomitant increases in E and IGF-1 production by granulosa cells as a result of GH and/or FSH treatment suggest a role for GH and FSH in the regulation of ovarian function.     

Synthetic hpGRF 1–40 stimulates growth hormone and inhibits prolactin secretion in normal children and children with isolated growth hormone deficiency

Intravenously administered synthetic hpGRF 1–40 at doses of 0.1, 0.33 and 1.0 μg/kg increased plasma GH in a dose-dependent fashion in 4 normal prepubertal children. hpGRF 1–40 at the dose of 1.0 μg/kg stimulated GH release, though to a lesser extent than in normals, in 7 children with isolated GH-deficiency (IGHD) but failed to do so in a patient with craniopharyngioma. In all normal children and 6/7 patients with IGHD, hpGRF 1–40 at all doses used induced a clear and sustained lowering of plasma prolactin levels; this effect was lacking in the patient with craniopharyngioma. hpGRF 1–40 had no effect on plasma FSH, LH, TSH or glucose levels nor did it influence pulse rate, blood pressure, or body temperature. These results indicate that hpGRF 1–40 is a potent stimulus to GH release in normal prepubertal children and holds promise for treatment of GH-deficient children. In addition, in both normal children and children with IGHD, hpGRF 1–40 is a potent suppressor of prolactin levels.