Diagnosing growth hormone deficiency: the value of short-term hypocaloric diet.

In the attempt to define possible causes of false positive GH deficiency, the role of caloric intake on GH determination was explored. The serum GH responses to insulin-induced hypoglycemia or arginine were assessed before and after 3 days of a hypocaloric diet in 23 prepubertal children of normal weight, aged 6.7-11.9 yr. Seventeen had short stature and a GH response to insulin and arginine below 10 micrograms/L, and 6 controls had normal stature and a GH peak above 10 micrograms/L in response to arginine. After diet, the serum peak GH and the area under the curve increased in both the patients (P < 0.0005 and P < 0.0005) and the controls (P < 0.005 and P < 0.025) with a GH peak greater than 10 micrograms/L in 11 of 17 patients. The patients with a persistent GH response below 10 micrograms/L also had lower mean 12-h overnight GH levels (P < 0.0005), whereas those with a normal GH response after diet had an overnight GH level greater than 3 micrograms/L. In the patients, the mean nighttime GH concentrations correlated with the serum GH peak (r = 0.85; P < 0.005) and with the area under the curve after the diet (r = 0.65; P < 0.025). The diet induced changes in plasma insulin-like growth factor-I, GH-releasing hormone levels, basal blood sugar and the nadir level obtained during insulin stimulation, total T3, and rT3. Height increased significantly during 1 and 2 yr (P < 0.005) of GH treatment only in patients with a GH response below 10 micrograms/L after the diet. These data are consistent with the hypothesis that the GH response to stimulation is strongly calorie dependent and that 3 days of a hypocaloric diet can increase the number and height of GH peaks and the total GH responses to insulin and arginine. The clear correlation of the GH response to stimulation after a hypocaloric diet with the mean nighttime GH and also with the growth response to GH treatment indicates that GH deficiency may be overdiagnosed in many children with short stature.

Growth hormone response to growth hormone-releasing hormone varies with the hypothalamic-pituitary abnormalities.

We determined growth hormone (GH) and insulin-like growth factor I (IGF-I) levels after a 3 h infusion of escalating doses of growth hormone-releasing hormone (GHRH(1-29)) followed by a bolus injection in hypopituitary patients with marked differences in pituitary features at magnetic resonance imaging (MRI) in order to evaluate further the contribution of MRI in the definition of pituitary GH reserve in GH-deficient patients. Twenty-nine patients (mean age 14.5 +/- 4.0 years) were studied. Group I comprised 13 patients: seven with isolated GH deficiency (IGHD) (group Ia) and six with multiple pituitary hormone deficiency (MPHD) (group Ib) who had anterior pituitary hypoplasia, unidentified pituitary stalk and ectopic posterior pituitary at MRI, Group II consisted of eight patients with IGHD and small anterior pituitary/empty sella, while in group III eight had IGHD and normal morphology of the pituitary gland. Growth hormone and IGF-I levels were measured during saline infusion at 08.30-09.00 h, as well as after infusion of GHRH (1-29) at escalating doses for 3h: 0.2 micrograms/kg at 09.00-10.00 h, 0.4 micrograms/kg at 10.00-11.00 h, 0.6 micrograms/kg at 11.00-12.00 h and an intravenous bolus of 2 micrograms/ kg at 12.00 h. In the group I patients, the peak GH response to GHRH(1-29) was delayed (135-180 min) and extremely low (median 2mU/l). In group II it was delayed (135-180 min), high (median 34.8 mU/l) and persistent (median 37.4 mU/l at 185-210 min). In group III the peak response was high (median 30.8 mU/l) and relatively early (75-120 min) but it declined rapidly (median 14.4 mU/l at 185-210 min). In one group I patient, GH response increased to 34.6 mU/l. The mean basal value of IGF-I levels was significantly lower in group I (0.23 +/- 0.05 U/ml) than in groups II (0.39 +/- 0.13U/ ml, p < 0.01) and III (1.54 +/- 0.46 U/ml, p < 0.001) and did not vary significantly during the GHRH(1-29) infusion. The present study demonstrates that the impaired GH response to 3 h of continuous infusion of escalating doses of GHRH(1-29) was strikingly indicative for pituitary stalk abnormality, strengthening the case for use of GHRH in the differential diagnosis of GH deficiency. The low GH response, more severe in MPHD patients, might be dependent on the residual somatotrope cells, while the better response (34.6 mU/l) in the group Ia patients might suggest that prolonged GHRH infusion could help in evaluating the amount of residual GH pituitary tissue. Pituitary GH reserve, given the GH response to GHRH infusion in GH-deficient patients with small anterior pituitary/empty sella, seems to be maintained.

Cytotoxic activity in children with insulin-dependent diabetes mellitus.

We determined the percentage of circulating natural killer (NK) cells, using the monoclonal antibodies anti-CD57 and anti-CD16, NK cytotoxic activity (lytic units/10(6)) and lymphokine-activated killer (LAK) activity in 25 IDDM patients aged 3-23 years, 12 with disease for < 1 year (Group I) and 13 with disease for > 3 years (Group II). Nine age-matched healthy subjects served as controls. The percentage of CD57+ cells was similar in IDDM patients and controls, while the percentage of CD16+ cells was lower in IDDM patients (P < 0.05) than in controls. NK cell cytotoxic activity was lower in IDDM patients than in controls (P < 0.01), in Group I and II compared with controls (P < 0.005). LAK activity was similar in IDDM patients and in controls. No correlation was found between NK cytotoxic activity and metabolic control, HLA typing, while a negative correlation was found between NK cytotoxic activity and insulin requirement (P < 0.05). The decreased NK cytotoxic activity observed in our patients, in particular in long-standing diabetics, with normal NK cell number, could be due to a qualitative defect of the NK cells, or to a deficient IL-2 and/or TNF-alpha production, or to a immunomodulatory or immunosuppressing effect of insulin.

[Current role of echography, of PSA and of PSAD in the diagnosis of prostatic carcinoma]. / Ruolo attuale dell'ecografia, del PSA e della PSAD nella diagnosi del carcinoma prostatico.

The Authors report their experience in the diagnosis of prostatic carcinoma by means of DRE, TRUS and PSA. They emphasize the improvement of diagnosis given by these exams when used in association, despite a high rate of false positives. In the years 92-93, 182 patients underwent ecoguided prostatic biopsy after DRE and PSA evaluation. PSA density value was calculated as proposed by Benson (PSAD = PSA/V); this parameter should screen between PSA elevation due to BPH and those due to prostatic carcinoma. After their experience, even if limited, they conclude that TRUS should not be used as a "first-line test" but only in patients with abnormal findings in DRE and/or PSA. PSAD may be useful to improve specificity of PSA even if a precise cut-off can not be determined.

[Lymphoproliferation stimulating activity in serum]. / Un'attività sierica che stimola la linfoproliferazione.

To characterize the serum growth promoting activity estimated by means of bioassay (Thymidine Activity), the gel filtration chromatographic profile of sera obtained from 10 normal adults and from 10 normal infants was performed. For each serum fraction we evaluated the capacity to stimulate the tritiated thymidine (3H-TdR) uptake into lectin-activated lymphocytes. This capacity was expressed as percent increase in 3H-TdR uptake in presence and in absence of the optimal dose (1.25%) of the fraction. The highest percent increase in 3H-TdR uptake was obtained in the same three fractions (1500-2500 Kd, 28-42 Kd, 1.3-1.9 Kd) in the sera of adults as well as infants. The values observed in infants were higher than in adults, suggesting that the serum growth-promoting activity could be higher in rapidly growing subjects.

[Efficacy of GH-releasing hormone and biosynthetic GH in a group of children with growth hormone deficiency]. / Efficacia del GH-releasing hormone e del GH-biosintetico in un gruppo di bambini con deficit di ormone della crescita.

Eight GH-deficient children were treated with GHRH (1-44), once daily s.c. for 6-18 months. At the 6th month of therapy, 3 patients showed a catch-up growth ("responders"), while the remaining 5 did not ("non-responders"). In all patients treatment was discontinued after 6-18 months, when its effect on growth rate failed. After a wash out period of at least 6 months, patients were submitted to biosynthetic GH therapy. After 6 months of GH treatment a significant catch-up growth was found in both responder and non-responder children. GHRH therapy is found to be less effective than GH treatment. Other methods of GHRH administration are worth investigating.

[In vitro effects of GH and IGF-1 on natural cytostatic activity]. / Effetto in vitro del GH e dell'IGF1 sull'attività citostatica naturale.

We previously reported that natural cytotoxicity, mediated by Natural Killer (NK) cells, is low in GH-deficient children and increases up to normal levels after a long-term treatment. In order to investigate the role of GH and IGF1 on the restoration of this immune function, we studied the in vitro effect of increasing doses of biosynthetic GH and IGF1 on NK activity of GH-deficient children. No variations of NK activity were observed after incubation of GH-deficient children's cells in the presence of GH as well as IGF1. Our data suggest the effect of GH and IGF1 on NK activity not to be direct, but mediated by unidentified factors.

[Enteroparasitosis in nutrition personnel in a general hospital: incidence and value of the repetition of examination]. / Enteroparasitoses em pessoal de nutrição de um hospital geral: incidência e valor da repetição dos exames.

Four hundred twenty one civil servants of nutritional area of a large hospital were examined by means of three stool specimens, collected at intervals of three days. Positive results increased from 37.14%, when only one of three requested samples was delivered, to 58.38%, when three specimens were examined. About 80% of infected people presented only one or two species of pathologic and/or non-pathologic parasites. Non-pathologic protozoa, mainly Endolimax nana and Entamoeba coli, presented the largest incidence.

X-linked agammaglobulinemia and isolated growth hormone deficiency.

No further reports of associated X-linked hypogammaglobulinemia and isolated growth hormone deficiency have appeared in the literature since the description of the first affected family, two brothers and two maternal uncles, by Fleisher et al. in 1980. We report here a 13-year-old boy with X-linked agammaglobulinemia and isolated growth hormone deficiency, also probably inherited as an X-linked trait. The height of an older agammaglobulinemic brother who died at 6 years of age was below the third percentile.

Influence of growth hormone-releasing hormone (GHRH) on phytohemagglutinin-induced lymphocyte activation: comparison of two synthetic forms. GHRH and PHA-induced lymphocyte activation.

The in vitro effect of synthetic human growth hormone-releasing hormone (GHRH) on mitogen-induced lymphocyte proliferation and lymphokine secretion was investigated. Peripheral blood mononuclear cells (PBMC) of healthy adults were incubated in the presence and absence of increasing concentrations (from 0.006 to 50 micrograms/ml) of two forms of GHRH differing in amino-acid sequence (GHRH 1-44 and GHRH 1-29) or of increasing concentrations (from 0.0012 to 20 U/ml) of recombinant human insulin (rh-insulin). Low concentrations of GHRH 1-29 increased phytoemoagglutinin (PHA)-induced lymphoproliferation, while high concentrations inhibited lymphocyte response, interleukin-2 (IL-2) secretion and IL-2 receptor expression on activated cells. A toxic effect was excluded since no differences in cell viability were observed between cells cultured with and without hormone. GHRH 1-44 did not affect PHA-induced lymphoproliferation, IL-2 production and IL-2 receptor expression. Low concentrations of rh-insulin increased PHA-elicited lymphoproliferation, while high concentrations did not decrease lymphocyte response. The present study suggests that GHRH modulates in vitro human T lymphocyte functions.

Effects of short-term administration of human chorionic gonadotropin on immune functions in cryptorchid children.

To delineate the effects of human chorionic gonadotropin (hCG) administration on immune responsiveness, immunological parameters including serum immunoglobulins, total and differential white blood cell count T and B lymphocyte membrane phenotype, in vitro, proliferative response to phytohaemagglutinin, Concanavalin A (ConA) and pokeweed mitogen were studied in 13 prepubertal cryptorchid boys before, during, and 3 months after hCG therapy. Before treatment, all the immunological parameters were normal except for an unexpected high percentage of T suppressor-cytotoxic cells (CD8+). During therapy, the absolute number of total peripheral blood lymphocytes, and that of total T-cells, T helper-inducer cells and of CD8+ subsets were diminished. The percentage of CD8+ cells and lymphocyte response to ConA decreased significantly and returned to normal after hCG withdrawal. The possible effects of long-term hCG treatment remain to be determined.

[Effects of chorionic gonadotropin (hCG) therapy on the immune system]. / Effetto della terapia con gonadotropina corionica (hCG) sul sistema immunitario.

Humoral and cellular immunologic parameters were evaluated in 13 prepuberal cryptorchid boys before, during and 3 months after hCG therapy. Before treatment, all the immunologic parameters were normal except for a higher percentage of T suppressor-cytotoxic cells (CD8+). During therapy, the percentage of CD8+ cells and lymphocyte response to ConA significantly decreased, and returned to the control level after hCG withdrawal. The possible effects of long-term hCG treatment on the immune system remains to be determined.

Modulating effect of growth hormone (GH) on PHA-induced lymphocyte proliferation.

In order to investigate the ability of growth hormone (GH) to modulate lymphoproliferation, peripheral blood mononuclear cells (PBMC) from healthy adults were stimulated with phytohaemagglutinin (PHA) in the presence of increasing concentrations of pituitary (Crescormon) and biosynthetic (Somatonorm and Genotropin) GH (from 0.425 x 10(3) to 501.5 x 10(3) ng/ml) as well as biosynthetic insulin (rhinsulin, Humulin 1 Eli Lilly: from 0.0012 to 20 U/ml). The results obtained show that low doses of GHs and insulin increase lymphoproliferation. In contrast, high concentrations of GHs (8.5 x 10(3) ng/ml) induce a progressive decrease of PHA-induced lymphoproliferation, while insulin does not. No differences in cell viability were observed with and without GHs. Comparable percentages of lymphocytes bearing interleukin-2 receptor (CD25) and comparable values of interleukin-2 (IL-2) pr oduction were found in all conditions tested. Nevertheless, when exogenous recombinant IL-2 (R IL-2) was added to PHA-induced PBMC cultures with high doses of GH, a reconstitution of lymphoproliferation was observed. Further experiments seem to exclude the presence of suppressor T lymphocyte induction by GH. The present results suggest that hypothesis that high concentrations of GH may interfere with the binding between IL-2 and its membrane receptor on activated lymphocytes.

Effectiveness of growth hormone (GH) therapy in GH-deficient children and non-GH-deficient short children.

The growth response during short-term growth hormone (GH) treatment was evaluated in eight prepubertal non-GH-deficient (non-GHD) children and compared with six prepubertal GH-deficient (GHD) patients. Standard doses of GH can improve growth rate in GHD and in some non-GHD patients. In neither group the growth response can be predicted by the acute increase in Thymidine Activity or Somatomedin-C levels. A diagnostic trial of GH treatment may be the only certain method of selecting the short non-GHD patients who may benefit from long-term GH therapy.

Effect of corticoid therapy on growth hormone secretion.

Exogenous corticoids are known to be potent inhibitors of linear growth in children. We investigated the mechanisms underlying growth failure by evaluating growth hormone (GH) release during short-term high-dose prednisone treatment (40 mg/m2/day given orally in 3 divided doses) and 7 days after steroid withdrawal in 7 prepubertal children (4 males, 3 females, age range 3-12 years), affected by acute lymphoblastic leukemia. Patients also received weekly administrations of vincristine (1.5 mg/m2 i.v.), daunomycin (20 mg/m2 i.v.) and L-asparaginase (6,000 IU/m2 i.m.). Corticoid therapy suppressed GH secretion during deep sleep as well as in response to arginine, insulin and GH-releasing hormone (GHRH) administration. A significant recovery of GH responsiveness after drug discontinuation was observed during deep sleep (14.03 +/- 3.47 vs. 1.49 +/- 0.43 ng/ml, p less than 0.025) as well as in response to arginine (13.63 +/- 2.73 vs. 4.95 +/- 1.54 ng/ml, p less than 0.025) and GHRH (32.62 +/- 4.59 vs. 7.27 +/- 3.52 ng/ml, p less than 0.005) but not to insulin (7.12 +/- 0.88 vs. 4.47 +/- 0.96 ng/ml, p = NS). Insulin-like growth factor 1 levels during deep sleep (0.61 +/- 0.13 IU/ml/min) were found to be low in the course of steroid therapy and did not increase after drug withdrawal (0.41 +/- 0.07 IU/ml/min). Our preliminary data suggest that recovery of adrenergic response to insulin does not immediately follow corticosteroid discontinuation.

Lymphocyte subpopulations in preterm infants: high percentage of cells expressing P55 chain of interleukin-2 receptor.

Surface phenotype of peripheral blood lymphocytes (PBL) from preterm infants was evaluated using monoclonal antibodies which define T cell membrane antigens associated with processes of maturation and activation of these cells. In the majority of preterm infants born during the 25th and 26th week of gestation, PBL included higher percentages of cells bearing an immature/activated surface phenotype characterized by the presence of CD1, CD38, and CD71 surface antigens than in term newborns. In these gestational age groups, PBL included, in particular, very high percentages of lymphocytes (range: 22-60) expressing the p55 chain of interleukin-2 receptor (IL-2R). After the 26th week of gestation, PBL of some preterm neonates included, as well, high percentages of lymphocytes bearing immature/activated phenotype; their median values, however, were not significantly different from those observed in term newborns. Our data suggest that the presence of the p55 chain of IL-2R on the surface of neonatal lymphocytes could be correlated with the immaturity of these cells.

Synthetic growth hormone-releasing hormone (GHRH 1-44) in the differential diagnosis between hypothalamic and pituitary GH deficiency.

GH response to an iv bolus of growth-hormone-releasing hormone (GHRH 1-44, 2 micrograms/kg iv) was evaluated in 17 prepubertal children with total GH deficiency (GHD), 6 with partial GHD and in 7 prepubertal normal but short children tested as control. GH response to conventional pharmacological (insulin and arginine or L-Dopa) and physiological stimuli (sleep test) and to GHRH test was also compared. GHRH-induced GH peak occurred at variable times and marked heterogeneity in magnitude of the individual responses to this peptide was observed in GHD patients and in controls. GH increases after GHRH with a peak greater than 10 ng/ml suggested an hypothalamic origin of the GHD in 12 patients (8 with total GHD and 4 with partial GHD). A significant difference (p less than 0.025) of GH peak mean following GHRH administration between total GHD children and normal short children was found. GH response to GHRH injection was usually higher than to conventional stimuli. Nevertheless GH peak following GHRH administration was lower than GH peak following conventional stimuli in 6 children (2 partial GHD children and 4 normal ones). A normal short child failed to respond to GHRH test performed twice. GHRH test is an important diagnostic tool in order to point out hypothalamic GHD.

Immunological and endocrinological response to growth hormone therapy in short children.

We investigated the influence of human growth hormone (hGH) on mitogen-stimulated lymphoproliferation, in vitro IgM production, serum levels of immunoglobulins, somatomedin-C (Sm-C) values and serum growth-promoting activity (Thymidine Activity, TA) in 18 short children, aged between 6.6-14.5 years, undergoing a 3-month course of hGH therapy. Blood was collected the day before treatment (Group A), on the 5th day after patients were administered hGH daily (0.1 U/kg) i.m. for 4 days (Group B), after a 3-month course of hGH injected three times weekly, and finally before (Group C) and 24 h after an extra injection (Group D). In vitro IgM production from the patients' unstimulated lymphocytes decreased from 277 +/- 41 (Group A) to 168 +/- 38 (Group B), to 119 +/- 43 (Group C) and then to 119 +/- 28 ng/ml (Group D) (p less than 0.05). Using PWM-stimulated lymphocytes in vitro IgM production decreased from 2,015 +/- 464 (Group A) to 1,116 +/- 316 (Group B), then to 511 +/- 170 (Group C) and 968 +/- 295 ng/ml (Group D) (p less than 0.02). The variation of this decrease could be correlated with the variation of growth velocity during treatment (r = 0.619, p less than 0.05). In contrast, no significant changes were found following therapy either in serum levels of IgA, IgE, IgG, IgM, Sm-C and TA, or in phytohemagglutinin, concanavalin A and pokeweed mitogen-stimulated lymphoproliferation. Our data suggest that there is some relationship between growth hormone, growth and immunity.