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.

Standardization with Synthetic 22-KDa Monomer Human Growth Hormone Reduces Discrepancies Between Two Monoclonal Immunoradiometric Assay Kits

1992 ◽  
Vol 38 (10) ◽  
pp. 2107-2110 ◽  
Author(s):  
G Banfi ◽  
M Marinelli ◽  
M Pontillo ◽  
P Bonini
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Immunoradiometric Assay ◽  
Serum Samples

Abstract Discrepancies among different methods for assaying human growth hormone have been described in various studies. The two major sources of discordant results are the heterogeneity of the antibodies and the different standardization bases used by the assay manufacturers. We propose standardizing assays with 22-kDa biosynthetic monomer human growth hormone diluted with the diluents supplied by the kit manufacturers. In a study of two monoclonal immunoradiometric assays (Hybritech, specific for the 22-kDa monomer; Sorin, recognizing also a 20-kDa variant hormone), standardization with 22-kDa monomer human growth hormone reduced by 63% the differences in results for 44 serum samples from children. The use of 22-kDa human growth hormone as a common standard, highly pure and easily available in large quantities, could help limit the interpretative problems in growth diagnostics.

Performance of Proficiency Survey Samples in Two Immunoradiometric Assays of Human Growth Hormone and Comparison with Patients' Samples

1992 ◽  
Vol 38 (4) ◽  
pp. 553-557 ◽  
Author(s):  
P J Pringle ◽  
J Jones ◽  
P C Hindmarsh ◽  
M A Preece ◽  
C G Brook
Keyword(s):  
Growth Hormone ◽  
Quality Assessment ◽  
Human Growth Hormone ◽  
Matrix Effect ◽  
External Quality Assessment ◽  
Human Growth ◽  
Immunoradiometric Assay ◽  
Serum Samples ◽  
External Quality ◽  
External Quality Assessment Scheme

Abstract The immunoradiometric assay (IRMA) used in our laboratory for the measurement of growth hormone (hGH; somatotropin) performed badly in the national proficiency survey program, the U.K. External Quality Assessment Scheme (EQAS). We compared our assay with another IRMA, which gave similar results for patients' samples and performed adequately in EQAS. The samples from EQAS are collected from patients with polycythemia and fall into two categories: those containing endogenous hGH and those supplemented with pituitary-derived hGH. Analysis of the two groups separately showed that the differences between the two IRMAS were in the measurement of the endogenous hormone. The reason for this appears to be a matrix effect related to the fact that the EQAS serum samples are collected from polycythemic patients.

Somatotropin as measured by a two-site time-resolved immunofluorometric assay.

1989 ◽  
Vol 35 (6) ◽  
pp. 913-917 ◽  
Author(s):  
C Strasburger ◽  
G Barnard ◽  
L Toldo ◽  
B Zarmi ◽  
Z Zadik ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Gh Deficiency ◽  
Polyclonal Antibodies ◽  
Immunoradiometric Assay ◽  
Time Resolved ◽  
Epitope Specificity ◽  
Accuracy And Precision ◽  
Hybridoma Technology ◽  
Criteria For Diagnosis ◽  
Serum Gh

Abstract To date, many of the current criteria for diagnosis of somatotropin (growth hormone, GH) deficiency have been based upon measurement of this hormone by competitive radioimmunoassay (RIA) with use of polyclonal antibodies. In recent years, however, the development of hybridoma technology has led to the generation of various monoclonal antibodies (Mabs) to GH with different affinities and epitope specificities. Subsequently, these reagents have been used in the development of noncompetitive two-site immunometric assays (e.g., immunoradiometric assay; IRMA). In general, the values obtained for serum GH by IRMA have been lower than those obtained by RIA, because of the epitope-specificity profile of the Mabs in the IRMA. Attempting to obtain GH values numerically similar to those by RIA, we used a combination of Mabs to GH in developing and evaluating a two-site time-resolved immunofluorometric assay (IFMA) based on the streptavidin-biotin interaction. Fluorescence is proportional to concentration of analyte and is linearly related to concentration over the range 0.3 to 40 micrograms/L. The assay was satisfactory with respect to sensitivity, accuracy, and precision (CV less than 10% over the entire working range). In addition, the concentration of GH was determined by the IFMA and a competitive RIA in serum obtained from GH deficient and acromegalic patients. The pairing of antibodies in the IFMA gave numerical values that agreed well with those by RIA (r = 0.97; n = 100).

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 (>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.

Isotopic and nonisotopic assays for measuring somatotropin compared: re-evaluation of cutoff value in provocative tests

1991 ◽  
Vol 37 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Gluseppe Banfi ◽  
Marcello Marinelli ◽  
Ermlnla Casari ◽  
Michelangelo Murone ◽  
Plerangel Bonini
Keyword(s):  
Growth Hormone ◽  
Monoclonal Antibodies ◽  
Human Growth Hormone ◽  
Reference Values ◽  
Polyclonal Antibodies ◽  
Human Growth ◽  
Complete Agreement ◽  
Cutoff Value ◽  
Short Children ◽  
Wide Range

Abstract Measurement of human growth hormone (hGH; somatotropin) concentrations in serum after provocative tests is crucial for diagnosing deficiencies in production of this hormone. Serum hGH can be measured by various immunoassays, isotopic and nonisotopic, with monoclonal or polyclonal antibodies: a cutoff value of 10 micrograms/L after provocative testing is usually used to distinguish normal from hGH-deficient children. Previous studies demonstrated discrepancies in hGH measurement by different radioisotopic immunoassays. Here we evaluated the responses of six different commercial assays, radioisotopic and nonisotopic, with monoclonal or polyclonal antibodies in a series of 16 provocative tests (stimulation with clonidine) in short children. A wide range of discrepant values was obtained with the different kits. A cutoff of 10 micrograms/L produced discordance of diagnosis among assays for two children, whereas complete agreement was reached for a cutoff value of 7 micrograms/L. Parallelism tests performed with hGH international standard, pure recombinant hGH, and a serum with high hGH content suggest that heterogeneity of the antibodies used by the manufacturers, even among monoclonal antibodies, is the main source of discordant results. Cutoff values and reference values must be established separately for each method proposed for routine use.

Time-Resolved fluorometric sandwich immunoassay for human growth hormone in serum and urine

1991 ◽  
Vol 5 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Seiichi Hashida ◽  
Koichiro Tanaka ◽  
Eiji Ishikawa ◽  
Shinobu Inoue ◽  
Kunio Hayakawa
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Sandwich Immunoassay ◽  
Time Resolved ◽  
Serum And Urine

Applicability of short-lived radiometallic nuclide for high sensitivity two-site “sandwich” immunoradiometric assay: Human growth hormone assay

1996 ◽  
Vol 10 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Kazuko Horiuchi ◽  
Lin H. Lin ◽  
Yasuhisa Fujibayashi ◽  
Vania C. Borghi ◽  
Akira Yokoyama
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
High Sensitivity ◽  
Immunoradiometric Assay ◽  
Hormone Assay

IMMUNORADIOMETRIC ASSAY OF HUMAN GROWTH HORMONE

The Lancet ◽  
1968 ◽  
Vol 292 (7566) ◽  
pp. 492-493 ◽  
Author(s):  
L.E.M. Miles ◽  
C.N. Hales
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Immunoradiometric Assay

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.

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