Effect of recombinant human GH on circulating granulocyte colony-stimulating factor and neutrophils in patients with adult GH deficiency

Acute Effects of Growth Hormone on the Cellular Immunologic Landscape in Pediatric Patients

INTRODUCTION

Growth hormone (GH) and the immune system have multiple bidirectional interactions. Data about the acute effects of GH on the immune system are lacking. The objective of our study was to evaluate the acute effects of GH on the immune system using time-of-flight mass cytometry.

METHODS

This was a prospective study of pediatric patients who were being evaluated for short stature and underwent a GH stimulation test at a tertiary care center. Blood samples for immunologic markers, i.e., complete blood count (CBC) and time of flight mass cytometry (CyTOF), were collected at baseline (T0) and over the course of three hours (T3) of the test. Differences in immune profiling in patients by timepoint (T0, T3) and GH response (growth hormone sufficient (GHS) versus growth hormone deficient (GHD)) were calculated using a two-way ANOVA test.  Results: A total of 54 patients (39 boys and 15 girls) aged five to 18 years were recruited. Twenty-two participants tested GHD (peak GH <10 ng/ml). The CyTOF analysis showed a significant increase from T0 to T3 in granulocyte percentage, monocyte count, and dendritic cell (DC) count; in contrast, a significant decrease was seen in T lymphocytes (helper and cytotoxic) and IgD+ B lymphocytes. The CBC analysis supported these findings: an increase in total white blood cell count, absolute neutrophil count, and neutrophil percentage; a decrease in absolute lymphocyte count, lymphocyte percentage, absolute eosinophil count, and absolute monocyte count. No significant differences were found between CBC/CyTOF measurements and GH status at either time.

CONCLUSIONS

This study provides the first high-resolution map of acute changes in the immune system with GH stimulation. This implies a key role for GH in immunomodulatory function.

The immune microenviroment in somatotropinomas: from biology to personalized and target therapy

Pituitary tumors are rare neoplasms, with a heterogeneous biological and clinical behavior, due to their clinical course, local invasive growth, resistance to conventional therapies and the risk of disease progression. Recent studies on tumor microenvironment (TME) provided new knowledge on the biology of these neoplasia, that may explain the different phenotypes of these tumors and suggest new biomarkers able to predict the prognosis and the treatment outcome. The identification of molecular markers that act as targets for biological therapies may open new perspectives in the medical treatments of aggressive pituitary tumors.In this paper, we will review data of TME and target therapies in somatotropinomas.

Neutrophil-to-Lymphocyte, Platelet-to-Lymphocyte Ratios, and Systemic Immune-Inflammation Index as Potential Biomarkers of Chronic Inflammation in Patients with Newly Diagnosed Acromegaly: A Single-Centre Study

Acromegaly is a rare disease caused by overproduction of growth hormone (GH) by a pituitary adenoma, and consequently increased insulin-like growth factor 1 (IGF-1) concentration. The GH/IGF-1 axis and immune cells interactions are hypothesized to be involved in subclinical inflammation. This retrospective study aimed to investigate the differences in neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR) ratios, and systemic immune-inflammation index (SII) in GH-secreting adenomas compared with non-functioning pituitary adenomas (NFPAs) concerning clinical and radiological findings. After evaluation of 665 patients with pituitary tumors, 62 individuals with newly diagnosed acromegaly and 134 with NFPAs were enrolled in the analysis. The control group consisted of 120 healthy individuals. Fifty-eight patients with acromegaly were re-evaluated after medical or surgical therapies. NLR, PLR, SII values, and neutrophil count were significantly higher (p ≤ 0.001), whereas lymphocyte count was lower in acromegaly than in NFPAs (p = 0.001). No significant differences between NFPAs and controls were observed in analyzed ratios. Higher preoperative NLR, PLR, SII values were found in patients who failed to achieve a cure with surgery (p < 0.05). Although NLR, PLR, and SII values were significantly higher in acromegaly, these indices cannot be used to discriminate GH-secreting pituitary tumors from NFPAs. Treatment of acromegaly decreased the value of NLR and SII, but it requires further studies to consolidate the real clinical role of these inflammation-related ratios.

Growth hormone and hematopoiesis: A retrospective analysis on a large cohort of children with growth hormone deficiency

OBJECTIVE

Few large-scale studies regarding the impact of GH deficiency (GHD) on hematopoiesis in children have been reported. Our aim was to investigate hematopoiesis indices in a large cohort of GHD children at diagnosis and during GH treatment (GHT) and any correlation with hormonal parameters.

DESIGN

Clinical and biochemical data of children with idiopathic GHD at diagnosis and annually up to 36 months of GHT were retrospectively evaluated. Overall, 255 children reached 12 months, 140 children 24 months and 86 children 36 months of follow-up during GHT.

RESULTS

At baseline, 18.4% of GHD children and 10.1% of controls showed normocytic anemia. GHD children showed lower hemoglobin (Hb) (p = 0.007), red blood cells (RBC) (p < 0.001) and hematocrit (Ht) (p = 0.001) than controls. During GHT, the percentage of anemic patients decreased from 18.4 to 5.4-3.5 and 4.6% after 12 (p = 0.001), 24 (p < 0.001) and 36 months (p < 0.001) of GHT, respectively. In both anemic and non-anemic patients, a significant increase in Hb (p < 0.001, <0.001 and 0.002), RBC (all p < 0.001) and Ht (all p < 0.001) was found after 12, 24 and 36 months of GHT. The Hb levels were significantly correlated with the GH peak after stimulation test (p < 0.001) at baseline and with IGF-I levels at 36 months of GHT (p = 0.002).

CONCLUSIONS

A significant improvement in erythropoiesis indices occurs during GHT, regardless of any previous presence of anemia.

Effects of treatment of preweaning dairy calves with recombinant bovine somatotropin on immune responses and somatotropic axis

Weaning may be associated with negative energy balance and body weight loss when calves are still immunologically immature, predisposing them to infectious diseases. The aim of the present experiment was to investigate the effects of treatment of preweaning dairy calves with recombinant bovine somatotropin (rbST) on the somatotropic axis, selected immune parameters, and hematology of calves around weaning. Thirty-six Holstein female calves were randomly assigned to receive 1.5 to 1.8 mg of rbST (Posilac, Elanco Animal Health, Greenfield, IN) per kilogram of body weight or to receive injections of saline (saline solution 0.9%, Valley Vet Supply, Marysville, KS) every 7 d from 21 to 63 d of life. Calves were fed milk replacer ad libitum from birth to 38 d of age (d -11), when progressive weaning started, and calves were weaned at 49 d of age (d 0). Calves were weighed at birth and weekly from 21 to 63 d of age, when wither height also was measured. Calves were vaccinated with 0.5 mg of ovalbumin on study d -28 and -7. Blood samples were collected on d -28, -25, -21, -11, 0, 3, 7, and 14. Polymorphonuclear leukocytes were isolated and challenged ex vivo with Escherichia coli to determine phagocytosis and oxidative burst capacity. Additionally, expression of cluster of differentiation (CD)62L and CD18 by granulocyte, lymphocyte, and CD14+ monocyte were determined. Blood samples were also used to determine hematological parameters and concentrations of growth hormone, insulin-like growth factor-1, insulin, glucose, fatty acids, β-hydroxybutyrate, haptoglobin, and anti-ovalbumin IgG. Calves treated with rbST had greater concentrations of growth hormone and insulin-like growth factor-1 from d -25 to 14 than control calves, whereas insulin, fatty acid, and β-hydroxybutyrate concentrations did not differ. On d -11, glucose concentration was greater for rbST-treated calves. Treatment did not affect polymorphonuclear lymphocyte phagocytosis and oxidative burst, but intensity of expression of CD62L and CD18 by granulocytes tended to be increased by rbST treatment. Treatment did not affect the concentration of anti-ovalbumin IgG in serum. Haptoglobin concentration was reduced in rbST treated calves on d 3 and we noted a tendency for hematocrit to be lower in rbST-treated calves. Treatment did not affect body weight, wither height, and average daily gain, despite the fact that rbST-treated calves had lower daily milk replacer intake. The relatively minor improvements in immune responses resulting from rbST treatment of weaning calves may not be sufficient to reduce the incidence of infectious diseases.

Growth Hormone (GH) and Cardiovascular System

This review describes the positive effects of growth hormone (GH) on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on vessels improving oxidative stress imbalance and endothelial dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease, inducing a neovascularization process that finally increases flow in ischemic tissues. We include some preliminary data from a trial in which GH or placebo is given to elderly people suffering from critical limb ischemia, showing some of the benefits of the hormone on plasma markers of inflammation, and the safety of GH administration during short periods of time, even in diabetic patients. We also analyze how Klotho is strongly related to GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH, most likely to repair the injury in the ischemic tissues. We also show how GH can help during wound healing by increasing the blood flow and some neurotrophic and growth factors. In summary, we postulate that short-term GH administration could be useful to treat cardiovascular diseases.

The Impact of Growth Hormone Therapy on the Apoptosis Assessment in CD34+ Hematopoietic Cells from Children with Growth Hormone Deficiency

Growth hormone (GH) modulates hematopoietic cell homeostasis and is associated with apoptosis control, but with limited mechanistic insights. Aim of the study was to determine whether GH therapeutic supplementation (GH-TS) could affect apoptosis of CD34+ cells enriched in hematopoietic progenitor cells of GH deficient (GHD) children. CD34+ cells from peripheral blood of 40 GHD children were collected before and in 3rd and 6th month of GH-TS and compared to 60 controls adjusted for bone age, sex, and pubertal development. Next, apoptosis assessment via different molecular techniques was performed. Finally, to comprehensively characterize apoptosis process, global gene expression profile was determined using genome-wide RNA microarray technology. Results showed that GH-TS significantly reduced spontaneous apoptosis in CD34+ cells (p < 0.01) and results obtained using different methods to detect early and late apoptosis in analyzed cells population were consistent. GH-TS was also associated with significant downregulation of several members of TNF-alpha superfamily and other genes associated with apoptosis and stress response. Moreover, the significant overexpression of cyto-protective and cell cycle-associated genes was detected. These findings suggest that recombinant human GH has a direct anti-apoptotic activity in hematopoietic CD34+ cells derived from GHD subjects in course of GH-TS.

Multiple Effects of Growth Hormone in the Body: Is it Really the Hormone for Growth?

In this review, we analyze the effects of growth hormone on a number of tissues and organs and its putative role in the longitudinal growth of an organism. We conclude that the hormone plays a very important role in maintaining the homogeneity of tissues and organs during the normal development of the human body or after an injury. Its effects on growth do not seem to take place during the fetal period or during the early infancy and are mediated by insulin-like growth factor I (IGF-I) during childhood and puberty. In turn, IGF-I transcription is dependent on an adequate GH secretion, and in many tissues, it occurs independent of GH. We propose that GH may be a prohormone, rather than a hormone, since in many tissues and organs, it is proteolytically cleaved in a tissue-specific manner giving origin to shorter GH forms whose activity is still unknown.

Long-term effects of growth hormone (GH) replacement therapy on hematopoiesis in a large cohort of children with GH deficiency

The aim of our prospective case-control study was to evaluate long-term effects of GH replacement therapy on erythrocytes parameters, leukocytes, and platelets numbers in a large cohort of children with isolated GH deficiency (GHD). Hemoglobin (Hb) concentration, hematocrit (Hct), mean corpuscular volume, mean corpuscular hemoglobin, red cell distribution width, number of erythrocytes, leukocytes, neutrophils, lymphocytes, monocytes and platelets, ferritin, and C-reactive protein were evaluated in 85 children with isolated GHD (10.20 ± 3.50 years) before and annually during the first 5 years of GH replacement therapy and in 85 healthy children age and sex comparable to patients during 5 years of follow-up. Compared with controls, GHD children at study entry showed lower Hb (-1.18 ± 0.87 vs. -0.40 ± 0.90 SDS, p < 0.0001), red cells number (-0.24 ± 0.81 vs. 0.25 ± 1.14 SDS, p < 0.0001), and Hct (-1.18 ± 0.86 vs. -0.68 ± 0.99 SDS, p < 0.0001). Twelve GHD patients (14 %) showed a normocytic anemia. GH therapy was associated with a significant increase in Hb, Hct, and red cells number which became all comparable to controls within the first 2 years of treatment. Moreover, hemoglobin levels normalized in all anemic GHD patients after 5 years of therapy. No difference between patients and controls was found in leukocytes and platelets numbers neither at baseline nor during the study. GHD in childhood is associated with an impairment of erythropoiesis which causes a normocytic anemia in a considerable percentage of patients. GH replacement therapy exerts a beneficial effect leading to a significant increase of erythrocytes parameters and recovery from anemia. Neither GHD nor GH replacement treatment exerts effects on leukocytes or platelets numbers.

Effects of recombinant bovine somatotropin during the periparturient period on innate and adaptive immune responses, systemic inflammation, and metabolism of dairy cows

The aim of this experiment was to determine effects of treating peripartum dairy cows with body condition score ≥3.75 with recombinant bovine somatotropin (rbST) on immune, inflammatory, and metabolic responses. Holstein cows (253±1d of gestation) were assigned randomly to 1 of 3 treatments: untreated control (n=53), rbST87.5 (n=56; 87.5mg of rbST), and rbST125 (n=57; 125mg of rbST). Cows in the rbST87.5 and rbST125 treatments received rbST weekly from -21 to 28d relative to calving. Growth hormone, insulin-like growth factor 1, haptoglobin, tumor necrosis factor α, nonesterified fatty acids, β-hydroxybutyrate, glucose, and cortisol concentrations were determined weekly from -21 to 21d relative to calving. Blood sampled weekly from -14 to 21d relative to calving was used for hemogram and polymorphonuclear leukocyte (PMNL) expression of adhesion molecules, phagocytosis, and oxidative burst. Cows were vaccinated with ovalbumin at -21, -7, and 7d relative to calving, and blood was collected weekly from -21 to 21d relative to calving to determine IgG anti-ovalbumin concentrations. A subsample of cows had liver biopsied -21, -7, and 7d relative to calving to determine total lipids, triglycerides, and glycogen content. Growth hormone concentrations prepartum (control=11.0±1.2, rbST87.5=14.1±1.2, rbST125=15.1±1.3ng/mL) and postpartum (control=14.4±1.1, rbST87.5=17.8±1.2, rbST125=21.8±1.1ng/mL) were highest for rbST125 cows. Cows treated with rbST had higher insulin-like growth factor 1 concentrations than control cows (control=110.5±4.5, rbST87.5=126.2±4.5, rbST125=127.2±4.5ng/mL) only prepartum. Intensity of L-selectin expression was higher for rbST125 than for control and rbST87.5 cows [control=3,590±270, rbST87.5=3,279±271, rbST125=4,371±279 geometric mean fluorescence intensity (GMFI)] in the prepartum period. The PMNL intensities of phagocytosis (control=3,131±130, rbST87.5=3,391±133, rbST125=3,673±137 GMFI) and oxidative burst (control=9,588±746, rbST87.5=11,238±761, rbST125=12,724±781 GMFI) were higher for rbST125 cows than for control cows during the prepartum period. Concentrations of serum IgG anti-ovalbumin tended to be higher for rbST125 cows than for control cows (control=0.75±0.11, rbST87.5=0.94±0.10, rbST125=1.11±0.11 optical density) in the prepartum period. Haptoglobin concentration was significantly reduced 7d postpartum for rbST125 treatment compared with control and rbST87.5 treatments (control=2.74±0.28, rbST87.5=2.81±0.28, rbST125=1.87±0.28 optical density). Although treatment tended to affect postpartum β-hydroxybutyrate (control=747.5±40.2, rbST87.5=753.2±40.1, rbST125=648.8±39.7 µmol/L), it did not affect liver contents of total lipids, triglycerides, or glycogen. Incidence of metritis among rbST125 cows was reduced compared with that in control cows (control=23.1, rbST87.5=18.0, rbST125=7.8%). Treatment of dairy cows with 125mg of rbST improved innate immune responses and IgG concentration, with limited effects on metabolism.

Effect of human recombinant growth hormone therapy on circulating levels of erythropoietin and granulocyte-colony stimulating factor in short children

Several reports suggest a role of growth hormone (GH) in the regulation of the haematopoietic system, as regards the normal differentiation and function of blood cells. The aim of this study was to evaluate the influence of rhGH therapy on erythropoietin (Epo) and granulocyte-colony stimulating factor (G-CSF) levels in 18 prepubertal short children with idiopathic GH deficiency (GHD) (n = 8) or without GHD (n = 10), during the first year of treatment. In non-GHD children Epo levels significantly decreased and G-CSF levels increased from basal to 12 months of therapy, whereas in GHD children they did not change significantly. Circulating levels of G-CSF are significantly lower in GHD than in non-GHD children. In non-GHD children the number of red blood cells, haemoglobin and haematocrit values significantly increased after 1 year of rhGH treatment. rhGH therapy influences Epo and G-CSF levels in short non-GHD children, while it shows no effects in GHD children.

Serum resistin concentrations in growth hormone-deficient children during growth hormone replacement therapy

We performed this study to examine whether the serum resistin concentrations in growth hormone (GH)-deficient (GHD) children are influenced by administration of GH and to assess the relationship between serum resistin and free fatty acid levels during GH replacement therapy. The study included 20 prepubertal GHD children (16 boys and 4 girls) who were treated with recombinant human GH (hGH). The serum levels of resistin, insulin-like growth factor I, free fatty acid (FFA), triglyceride, cholesterol and glucose levels, leukocyte counts, and hemoglobin A(1c) were measured at baseline and after 1 month of hGH treatment. The serum resistin levels after hGH therapy were significantly higher than the basal resistin levels (median [range], 6.2 [4.9-11.8] vs 5.6 [4.4-8.3] ng/mL; P < .05), whereas the serum FFA levels were unchanged before and after treatment (0.51 [0.34-0.76] vs 0.37 [0.24-0.60] mEq/L). No significant relationship was found between serum resistin and FFA levels after hGH therapy. Body mass index, serum triglyceride, cholesterol and glucose levels, leukocyte counts, and hemoglobin A(1c) showed no significant differences before and after hGH treatment. Our results suggest that elevated serum resistin levels after 1-month hGH therapy in GHD children are not associated with the GH-induced lipolysis as found in GHD adults during short-time hGH therapy.

Insulin-like growth factor-binding protein 3 and hemoglobin concentration in older persons living in the community

A decreased hemoglobin concentration is a common clinical condition in elderly subjects, and in at least 20% of the cases it is not possible to directly attribute the anemia to specific factors. The aim of the present study was to evaluate the relationship of different levels of insulin-like growth factor-binding protein 3 (IGFBP-3) with the blood concentration of hemoglobin in persons aged 80 years and older. Data are from a baseline evaluation of the Aging and Longevity in the Sirente Geographic Area (ilSIRENTE) study (n=253). Analysis of covariance was used to examine the effect of different IGFBP-3 levels on hemoglobin concentration. After adjustment for potential confounding variables, which included age, sex, number of diseases, renal failure, cancer, gastric ulcer, albumin, and iron concentrations, individuals in the group with higher IGFBP-3 concentrations showed a significantly higher mean hemoglobin concentration than participants in the group with lower IGFBP-3 concentrations (13.4 +/- 1.4 g/dL versus 12.9 +/- 1.9 g/dL, respectively; P=.03). In conclusion, the present study has shown that a higher IGFBP-3 level is associated with a higher hemoglobin concentration among older people living in the community. This finding suggests that the growth hormone/IGF axis may play an important role in hematopoiesis, and it may be implicated in the age-related decline in hemoglobin concentration.