Cross-reactivity of monomeric and dimeric biosynthetic human growth hormone in commercial immunoassays

1990 ◽  
Vol 36 (2) ◽  
pp. 362-366 ◽  
Author(s):  
R R Bowsher ◽  
J M Apathy ◽  
A L Ferguson ◽  
R M Riggin ◽  
D P Henry
Keyword(s):  
Growth Hormone ◽  
Model Compound ◽  
Rank Order ◽  
Polyclonal Antibodies ◽  
Human Growth ◽  
Cross Reactivity ◽  
Serum Samples ◽  
The Mean ◽  
Commercial Kits ◽  
Normal Adults

Abstract Commercial kits give different measurements for concentrations of growth hormone (GH, somatotropin) in serum. Most notably, a two-site monoclonal-antibody-based immunoradiometric assay (IRMA) from Hybritech routinely yields lower values than do conventional RIAs in which polyclonal antibodies are used. We used purified dimeric biosynthetic human GH as a model compound to investigate the specificity of five commercial immunoassays for size variants of GH. In all five assays, biosynthetic monomeric GH was significantly more potent than pituitary-derived standard GH supplied with the kits. Dimeric GH was significantly less potent than monomer in four of the five assays, and cross-reactivities varied more than fivefold, from 15% to 84%. Using three commercial kits selected for their specificity for dimeric GH, we measured GH in serum samples from 18 normal adults. The mean GH concentrations in serum--0.7 (Hybritech, IRMA), 1.8 (Diagnostic Products, RIA), and 3.1 (Cambridge, RIA) micrograms/L--differed significantly, but in the same rank order as that obtained in the experiments on dimer cross-reactivity.

Time-resolved immunofluorometric assay of human growth hormone

1993 ◽  
Vol 39 (8) ◽  
pp. 1620-1625 ◽  
Author(s):  
K Albertsson-Wikland ◽  
C Jansson ◽  
S Rosberg ◽  
A Novamo
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Polyclonal Antibodies ◽  
Human Growth ◽  
Immunoradiometric Assay ◽  
Serum Samples ◽  
Time Resolved ◽  
Counting Time ◽  
Pediatric Use ◽  
The Eu

Abstract We describe a time-resolved immunofluorometric assay (trIFMA) for human growth hormone (hGH), in which monoclonal antibody (mAb)-coated microtiter strip wells and a europium (Eu) chelate-labeled mAb are used. We compare the new trIFMA, in which two mAbs are used, with an immunoradiometric assay (IRMA) in which polyclonal antibodies are used. Serum samples (n = 185) from 36 children with various diagnoses were analyzed. In addition, 24-h profile samples (72 per child) from 39 children were analyzed. The trIFMA was more sensitive (detection limit, 0.03 mIU/L) than existing IRMAs. Both the intra- and interassay CVs were < or = 10.6% for hGH concentrations between 1 and 100 mIU/L. The trIFMA is technically simple and rapid, requires no centrifugation or separation reagent, and has a counting time of only 1 s per sample. In addition, the Eu label is nontoxic, presents no waste-disposal problems, and has a long shelf-life. Finally, the assay requires only small volumes of serum (25 muL), which is of considerable importance in pediatric use. The mAbs used for the trIFMA selectively bind the 22-kDa form of hGH, with the result that the assay detects about 80% of the amount detected by the polyclonal IRMA.

scholarly journals Inter-Laboratory Agreement of Insulin-like Growth Factor 1 Concentrations Measured Intact by Mass Spectrometry

2020 ◽  
Vol 66 (4) ◽  
pp. 579-586 ◽  
Author(s):  
Danielle Moncrieffe ◽  
Holly D Cox ◽  
Samantha Carletta ◽  
Jessica O Becker ◽  
Andreas Thomas ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Human Growth ◽  
Trypsin Digestion ◽  
Insulin Like Growth Factor ◽  
Serum Samples ◽  
Hormone Administration ◽  
Commercial Kits ◽  
Single Laboratory ◽  
Digestion Methods

Abstract Background Insulin-like growth factor-I (IGF-1) is measured mainly by immunoassay for the diagnosis and treatment of growth hormone (GH) disorders, and to detect misuse of GH in sport. Immunoassays often have insufficient inter-laboratory agreement, especially between commercial kits. Over the expected range of IGF-1 in blood (∼50–500 ng/mL), in an inter-laboratory study we previously established a measurement imprecision of 11% (%CV) for the digested protein analyzed by LC-MS. Measuring intact IGF-1 by LC-MS should be simpler. However, no inter-laboratory agreement has been published. Methods Intact and trypsin-digested IGF-1 in 32 serum samples from healthy volunteers and human growth hormone administration studies were analyzed by LC-MS using different instruments in five laboratories, as well as by immunoassay in a single laboratory. Another 100 samples were analyzed for IGF-1, both intact and after trypsin-digestion, in each laboratory by LC-MS. The statistical relationship between measurements and the imprecision of each assay group was assessed. Results An intra-laboratory variability of 2-4% CV was obtained. Inter-laboratory variability was greater at 14.5% CV. Orthogonal regression of intact versus trypsin-digestion methods (n = 646) gave a slope of 1.01 and intercept of 2.05 ng/mL. Conclusions LC-MS measurements of IGF-1 by intact and trypsin-digestion methods are not statistically different and each is similar to immunoassay. The two LC-MS approaches may be used interchangeably or together to eliminate concerns regarding an immunoassay IGF-1 measurement. Because intact and digested IGF-1 measurements generally agreed within 20% of each other, we propose this as a criterion of assay acceptability.

scholarly journals Intact transferrin receptors in human plasma and their relation to erythropoiesis

Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 102-107 ◽  
Author(s):  
HA Huebers ◽  
Y Beguin ◽  
P Pootrakul ◽  
D Einspahr ◽  
CA Finch
Keyword(s):  
Human Plasma ◽  
Polyclonal Antibodies ◽  
Close Correlation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transferrin Receptors ◽  
Erythroid Hyperplasia ◽  
The Mean ◽  
Tissue Receptors ◽  
Mean Concentration ◽  
Normal Adults

Abstract Intact transferrin receptor molecules complexed with transferrin were found in human plasma. The concentration of receptors was determined by an enzyme-linked immunosorbent assay that uses polyclonal antibodies. The mean concentration of 8,279 micrograms/L in 56 normal adults appears to be unrelated to age or sex. Additional receptor measurements were performed on plasmas from 260 subjects with erythropoietic disorders. Decreased concentration of plasma receptors was found in patients with erythroid hypoplasia and increased numbers in those with erythroid hyperplasia. Ferrokinetic measurements of erythropoiesis were compared with numbers of receptors in 148 subjects, and a close correlation was found (r = .86). Both sets of values, measured in different conditions and expressed in relation to normal, were consistent with expected values. Receptor values were unproportionally increased only in conditions of iron deficiency. It is concluded that plasma receptors have a constant relationship to tissue receptors, and their number in most instances reflects the rate of erythropoiesis.

scholarly journals ELISA for Determination of Human Growth Hormone: Recognition of Helix 4 Epitopes

2004 ◽  
Vol 2004 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Juliana F. Moura ◽  
Luiz DeLacerda ◽  
Romolo Sandrini ◽  
Fernanda M. Borba ◽  
Denise N. Castelo ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Synthetic Peptide ◽  
Human Growth ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunoaffinity Column ◽  
Receptor Dimerization ◽  
Human Prolactin

Human growth hormone (hGH) signal transduction initiates with a receptor dimerization in which one molecule binds to the receptor through sites 1 and 2. A sandwich enzyme-linked immunosorbent assay was developed for quantifying hGH molecules that present helix 4 from binding site 1. For this, horse anti-rhGH antibodies were eluted by an immunoaffinity column constituted by sepharose-rhGH. These antibodies were purified through a second column with synthetic peptide correspondent tohGH helix 4, immobilized to sepharose, and used as capture antibodies. Those that did not recognize synthetic peptide were used as a marker antibody. The working range was of 1.95 to 31.25 ng/mL of hGH. The intra-assay coefficient of variation (CV) was between 4.53% and 6.33%, while the interassay CV was between 6.00% and 8.27%. The recovery range was between 96.0% to 103.8%. There was no cross-reactivity with human prolactin. These features show that our assay is an efficient method for the determination of hGH.

Human growth hormone blunts Na2EDTA-induced hypocalcaemia in hyposomatotrophic children

1983 ◽  
Vol 102 (1) ◽  
pp. 11-15
Author(s):  
Allen W. Root ◽  
Gregory E. Duckett ◽  
Margaret Sweetland ◽  
Catherine Livingston ◽  
Edward O. Reiter
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Ionized Calcium ◽  
Total Calcium ◽  
The Mean ◽  
Pre Treatment ◽  
Basal Concentration ◽  
Immunoreactive Parathyroid Hormone ◽  
Ethylenediamine Tetraacetate

Abstract. An infusion of disodium ethylenediamine tetraacetate (Na2EDTA) (0.13 mmol/kg for 2 h) was administered to 10 hyposomatotrophic children prior to and after 6 and 12 months of treatment with human growth hormone (hGH). Total and ionized calcium and immunoreactive parathyroid hormone (iPTH) concentrations were determined. Mean basal total and ionized calcium concentrations did not change during the year of treatment with hGH. The nadir concentrations of total and ionized calcium increased progressively during hGH administration and after 12 months were significantly increased over pre-treatment values (total calcium: pre-treatment 1.85 ± 0.32 (sd) mmol/l, + 12 months 2.10 ± 0.15, P < 0.01; ionized calcium: pre-treatment 0.55 ± 0.31 mmol/l, + 12 months 0.78 ± 0.14, P < 0.05). The mean basal concentration of iPTH increased slightly after 12 months of hGH administration (pre-treatment 72 ± 18 pg/ml, + 12 months 106 ± 71, P < 0.05), but Na2EDTA-evoked secretion of iPTH was not significant altered by hGH.

EFFECT OF INTRAVENOUS ADMINISTRATION OF HUMAN GROWTH HORMONE ON SULPHATION FACTOR ACTIVITY IN SERUM OF HYPOPITUITARY SUBJECTS

1971 ◽  
Vol 66 (3) ◽  
pp. 491-497 ◽  
Author(s):  
Kerstin Hall
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Intravenous Administration ◽  
Human Growth ◽  
Significant Rise ◽  
Mean Difference ◽  
Factor Activity ◽  
The Mean

ABSTRACT Human growth hormone (HGH) administered as an iv injection of 2–4 mg to hypopituitary patients induced a rise in the levels of sulphation factor (SF) in serum. The low basal levels of SF were not changed during the first hour after HGH injection. Not until three hours after injection, when HGH values approached basal values, there was a significant rise in SF. The mean difference of SF at one and at three hours after HGH injection was 0.52 ± 0.11.

GROWTH HORMONE AND SOMATOMEDIN BEHAVIOUR IN THE NEWBORN

1976 ◽  
Vol 81 (2) ◽  
pp. 449-454 ◽  
Author(s):  
Giulio Giordano ◽  
Edilio Foppiani ◽  
Francesco Minuto ◽  
Davide Perroni
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Normal Adult ◽  
The Difference ◽  
Generating System ◽  
Normal Adults

ABSTRACT Human growth hormone (HGH) and somatomedin (Sm) concentrations have been studied in a group of newborns. Plasma HGH values were 41.17 ± 24.26 (sd) ng/ml (14.00-90.00 ng/ml) and the Sm value was 0.59 ± 0.43 (sd) U/ml (0.18–1.8 U/ml); the difference between these values and the ones observed in normal adults (2.45 ± 2.53 (sd) ng/ml and 1.16 ± 0.28 (sd) U/ml respectively) were statistically significant. While growth hormone values were higher than in normal adult controls, somatomedin was significantly decreased. It is possible that the dissociation between human growth hormone and somatomedin in newborn could reflect a reduced biosynthesis of the somatomedin-generating system and consequently a lack of a feed-back control on GH exerted by somatomedin.

scholarly journals Gaps in the Traceability Chain of Human Growth Hormone Measurements

2013 ◽  
Vol 59 (7) ◽  
pp. 1074-1082 ◽  
Author(s):  
Sébastien Boulo ◽  
Katja Hanisch ◽  
Martin Bidlingmaier ◽  
Cristian-Gabriel Arsene ◽  
Mauro Panteghini ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Higher Order ◽  
Serum Samples ◽  
Traceability Chain ◽  
Eu Directive ◽  
In Vitro Diagnostic ◽  
Relative Differences

BACKGROUND Human growth hormone (hGH) is measured for the diagnosis of secretion disorders. These measurements fall under the EU Directive 98/79/EC on in vitro diagnostic medical devices requiring traceability of commercial calibrator values to higher-order reference materials or procedures (Off J Eur Communities 1998 Dec 7;L 331:1–37). External quality assessment schemes show large discrepancies between results from different methods, even though most methods provide results traceable to the recommended International Standard (IS 98/574). The aim of this study was to investigate possible causes for these discrepancies. METHODS We investigated the commutability and recovery of hGH in reconstituted IS 98/574. We tested different reconstitution protocols and used 4 different serum matrices for spiking. These IS preparations were measured together with serum samples. We quantified hGH by 5 different methods in 4 different laboratories. RESULTS Results from the different methods correlated well for the serum samples. Mean discrepancies between results from different methods were ≤20%. None of the IS preparations was commutable for all the method comparisons. The recovery of hGH in preparations of IS 98/574 depended on the reconstitution protocol (&gt;10-fold differences) and BACKGROUND matrix (relative differences ≤17% for different serum matrices). CONCLUSIONS The use of different protocols for reconstitution and spiking of hGH reference preparations affects quantification by immunoassays, potentially leading to a bias between commercial methods, despite the use of calibrators with values claimed to be traceable to the same higher-order reference material.

Desensitization from long-term intranasal treatment with hexarelin does not interfere with the biological effects of this growth hormone-releasing peptide in short children

1996 ◽  
Vol 134 (6) ◽  
pp. 716-719 ◽  
Author(s):  
Beatrice Klinger ◽  
Aviva Silbergeld ◽  
Romano Deghenghi ◽  
Jenny Frenkel ◽  
Zvi Laron
Keyword(s):  
Growth Hormone ◽  
Growth Velocity ◽  
Biological Effects ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Human Growth ◽  
Pediatric Endocrinology ◽  
Short Children ◽  
The Mean

Klinger B, Silbergeld A, Deghenghi R, Frenkel J, Laron Z. Desensitization from long-term intranasal treatment with hexarelin does not interfere with the biological effects of this growth hormonereleasing peptide in short children. Eur J Endocrinol 1996;134:716–9. ISSN 0804–4643 A clinical, prospective experiment was carried out to determine whether long-term intranasal administration of the growth hormone-releasing peptide hexarelin (His-d-2-methyl-Trp-Ala-Trp-d-Phe-Lys-NH2) affects pituitary growth hormone secretion. Hexarelin (60 μg/kg t.i.d.) was administered to seven prepubertal constitutionally short children (mean age ±sd = 7.6 ± 2.4 years). Serum human growth hormone (hGH) response to an intranasal (20 μg/kg) and intravenous (1 μg/kg) bolus of hexarelin before, during and after 6–10 months of treatment was measured. The mean (±sd) peak rise of hGH to the intranasal bolus before treatment was 70.6 ± mU/I. After 7 days of hexarelin treatment, mean peak values dropped to 34.1 ±15.7 mU/l (p < 0.002) and thereafter remained constant for 6 months of treatment at 37.5 10.3 ±mU/l (p < 0.03). The pretreatment peak to the iv hexarelin bolus was 84.8 52.5 ±mU/l, and at the end of the treatment period it was 19.8 10.9 ±mU/l (p < 0.05). Three months after stopping treatment the mean (±sd) hGH response rose to 42.1 ±4.7 mU/l (p < 0.005). Growth velocity increased from 5.3±0.9 cm/year (before treatment) to 7.4 1.6 cm/year at ±6–10 months of treatment (p < 0.005). In conclusion, the partial suppression of pituitary hGH responsiveness to long-term intranasal hexarelin treatment, probably due to desensitization, does not affect the observed increase in growth velocity. Z Laron, Pediatric Endocrinology, 11 El Al Street, Ramat Efal, 52960, Israel

STIMULATION OF IMMUNOREACTIVE INSULIN AND HUMAN GROWTH HORMONE RELEASE BY ADMINISTRATION OF ARGININE IN PATIENTS WITH DIABETIC RETINOPATHY

1972 ◽  
Vol 70 (4) ◽  
pp. 719-730 ◽  
Author(s):  
W. Waldhäusl
Keyword(s):  
Growth Hormone ◽  
Diabetic Retinopathy ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Immunoreactive Insulin ◽  
Insulinogenic Index ◽  
Hormone Release ◽  
Arginine Hydrochloride ◽  
The Mean ◽  
Secretory Capacity

ABSTRACT The effect of arginine hydrochloride (30 g), given twice at 90 min intervals, on the release of immunoreactive insulin and of human growth hormone was studied in healthy subjects (HS), in diabetics without and with various degrees of retinopathy and in acromegalics. The insulinogenic index estimated by the ratio of μU IRI per ml/mg per 100 ml of blood glucose was maximal in HS after the first administration of arginine. It was highest in acromegalics and diminished in all the diabetic subjects. The release of human growth hormone as estimated by the mean sum of increments above the basal levels (x̄ + sem) during period I and II was 80.2±15 ng/ml and 59.0±18 ng/ml in HS (n = 7), 38±8.6 ng/ml and 36±16.3 ng/ml in diabetics without retinopathy (n = 9), 4.2±0.4 ng/ml and 19±7 ng/ml in insulin treated diabetics with retinopathy (n = 9), and 22.7±10.7 ng/ml and 46±10.5 ng/ml in orally treated diabetics with retinopathy (n = 7). Patients suffering from proliferative retinopathy (n = 9) exhibited values of 32.8±10.6 ng/ml during period I and 43.5±10.6 ng/ml during period II. The secretory response of HGH to arginine in acromegalics (n = 6) was not significant. The data reported suggest an impaired secretory capacity for the release of human growth hormone to the administration of arginine in patients with diabetic retinopathy. The observations do not support the hypothesis that an exaggerated release of HGH plays a role in the development of diabetic retinopathy.

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