Serum Growth Hormone Measurements in Clinical Practice: An Audit of Performance from the UK National External Quality Assessment Scheme

Seth, John; Ellis, Andy; Al-Sadie, Ruth

doi:10.1159/000053130

Cited by 41 publications

(36 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One major source of variability is the GH assay itself, as shown by the outcome of multilaboratory external quality-control assessment programs (17,18). First, results depended on the assay standards.…”

Section: Discussionmentioning

confidence: 99%

Central reassessment of GH concentrations measured at local treatment centers in children with impaired growth: consequences for patient management

Hauffa

Lehmann

Bettendorf

et al. 2004

European Journal of Endocrinology

View full text Add to dashboard Cite

Objective: GH deficiency is diagnosed in children if serum GH fails to rise above a predefined cutoff value in response to at least two stimuli. Diagnostic decisions based on this testing are highly variable between centers and depend on the GH assays used. Considering the large spectrum of commercially available GH assays, we wanted to evaluate the agreement between assays, and to test whether assayrelated variability of diagnostic decisions could be reduced by reassessment of peak GH concentrations in a reference center. Design: We reanalysed 699 peak GH serum samples obtained after GH testing of 382 children and adolescents from 19 centers using three reference assays and compared these results with those obtained with the local assays. A subgroup of 132 patients tested with the combination of insulin hypoglycemia test and arginine test was evaluated for changes in the assignment to the diagnostic group of GH deficiency. Results: The mean difference between methods ranged from 5.4 to 10.3 mU/l, slopes of the regression lines from 1.28 to 1.65. Significant non-linearity was detected in five of six assay comparisons, indicating that most assay results cannot be interconverted by the use of a factor. Overall agreement between reference and local assays was only moderate. Significant changes in diagnostic assignment occurred when different assays were used on the same patient (P , 0.0001 -P , 0.0023). Based on GH remeasurement by one reference assay, 36 of 132 patients were categorized differently, with 35 patients changing into the GH-deficient group. Similar findings were obtained with the other reference assays. Conclusions: To decrease variability in GH testing related to assays and cutoff values, we recommend nationwide reassessment of GH peak sera in reference centers. Decisions to treat GH deficiency should incorporate the reference center results.European Journal of Endocrinology 150 291-297

show abstract

Section: Discussionmentioning

confidence: 99%

Central reassessment of GH concentrations measured at local treatment centers in children with impaired growth: consequences for patient management

Hauffa

Lehmann

Bettendorf

et al. 2004

European Journal of Endocrinology

View full text Add to dashboard Cite

show abstract

“…F ü r viele in der klinischen Routinediagnostik eingesetzte Methoden ist das Spektrum der von den jeweiligen Antik ö rpern erkannten GH-Isoformen nicht bekannt. Es konnte gezeigt werden, dass die Vergleichbarkeit zwischen den Ergebnissen verschiedener kommerziell verf ü gbarer GH-Assays mit dem zunehmenden Einsatz von sehr spezifi schen monoklonalen Antik ö rpern in Sandwichassays eher schlechter wurde als zu Zeiten, in denen haupts ä chlich polyklonale Antiseren in kompetitiven Assays zum Einsatz kamen [28] . Es sei hier erw ä hnt, dass die unterschiedliche Spezifi t ä t der Antik ö rper nat ü rlich auch zum Tragen kommt, wenn " ungew ö hnliche " Isoformen von Wachstumshormon in einer Probe vorhanden sind.…”

Section: Wachstumshormon (Growth Hormone Gh)unclassified

Labordiagnostik bei Wachstumshormon-assoziierten Erkrankungen/Biochemical diagnosis of growth hormone related diseases

Bidlingmaier

2012

LaboratoriumsMedizin

View full text Add to dashboard Cite

ZusammenfassungDie Krankheitsbilder des Wachstumshormonmangels und des Wachstumshormonexzesses imponieren klinisch unterschiedlich vor und nach dem Abschluss des Längenwachstums. Stets jedoch bilden die Messung der zirkulierenden Konzentrationen von Wachstumshormon und Insulinartigem Wachstumsfaktor I (Insulin-like growth-factor I, IGF-I) die Basis der laborchemischen Diagnostik. Mit den Immunoassays stehen praktikable, sensitive und meist auch spezifische Methoden zur Messung beider Hormone zur Verfügung. Trotzdem bestehen nach wie vor gravierende Diskrepanzen zwischen den Messergebnissen verschiedener Assays. Diese Diskrepanzen sind vor allem bedingt durch Unterschiede in der Isoformspezifität der Assays, die Verwendung unterschiedlicher Standardpräparationen sowie die Interferenz von Bindungsproteinen. Die methodenbedingten Unterschiede in den Messergebnissen erschweren die allgemeine Anwendung publizierter diagnostischer Entscheidungsgrenzen. Auf einer interdisziplinären Konsensuskonferenz unter Beteiligung der Growth Hormone Research Society, der IGF Society, und der International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) wurden die bestehenden Probleme analysiert und mögliche Strategien zu einer Verbesserung der Vergleichbarkeit der Messergebnisse verschiedener GH- und IGF-I-Assays aufgezeigt. Derzeit bleibt jedoch in der klinischen Praxis die Anwendung methodenspezifischer, an gut charakterisierten Kollektiven gewonnener Referenzbereiche unabdingbar.

show abstract

“…Através desse ensaio, várias formas moleculares de GH poderiam ser reconhecidas e medidas (6,11,12).…”

Section: Anticorposunclassified

“…Como a distribuição dessas isoformas varia entre um individuo e outro, os resultados dependerão do anticorpo utilizado no ensaio (5)(6)(7)17,21,(23)(24)(25)(26)(27)(28).…”

Section: Anticorposunclassified

See 1 more Smart Citation

Ensaios para a medida de hormônio do crescimento (GH) e IGF-I: aspectos metodológicos e suas implicações no diagnóstico e seguimento da acromegalia

Casagrande

Czepielewski

2007

Arq Bras Endocrinol Metab

View full text Add to dashboard Cite

RESUMOA dosagem do GH no soro é essencial para confirmar ou excluir o seu excesso. Na acromegalia, a ausência de critérios clínicos suficientemente sensíveis para monitorizar o sucesso do tratamento faz com que o GH sérico seja o procedimento de escolha e, para isso, é essencial que a sua dosagem seja realizada de forma confiável, capaz de permitir interpretações uniformes. Vários critérios hormonais têm sido propostos para caracterizar remissão da acromegalia, incluindo níveis séricos de GH randômico inferior a 2,5 µg/l, nadir de GH durante o teste de tolerância oral a glicose inferior a 1,0 µg/l e IGF-I normal para sexo e idade. A importância do tratamento adequado consiste na possibilidade de reverter a mortalidade prematura da acromegalia através da diminuição dos níveis de GH para valores menores que 2,5 µg/l. Com o surgimento de ensaios ultra-sensíveis para medida do GH, tornaram-se necessários critérios mais estritos para determinar cura ou remissão da doença. Nesta revisão, descreveremos aqui as modificações decorrentes da evolução dos ensaios, as conseqüências nos resultados de GH e os pontos de corte propostos na literatura para caracterização da atividade e remissão da acromegalia. ABSTRACT Growth Hormone (GH) and IGF-I Assays: Methodological Aspects and its Implications in Acromegaly Diagnosis and Follow-Up.Growth hormone quantification in serum is essential for confirming or ruling out its excess. The absence of clinical criteria sufficiently sensitive to evaluate the treatment success enables GH as the key diagnostic procedure and for that, its measurements must be done in a reliable way and must allow uniform interpretation. Several different biochemical criteria for remission have been suggested in the past, including a random GH measurement less than 2.5 µg/l, mean GH value from a day curve less than 2.5 µg/l, nadir GH value after an oral glucose tolerance test (OGGT) less than 1.0 µg/l and a normal age-related IGF-I level. The importance of adequate treatment is highlighted by data indicating that lowering GH levels to less than 2.5 µg/l reverses the premature mortality of acromegaly. With the advances of ultrasensitive assays for GH measurement, strictest remission criteria to determine remission or cure were necessary. In this review, we describe the changes of assay methodology and its consequences in serum GH results and cut off point values to define activity and remission of acromegaly.

show abstract

Serum Growth Hormone Measurements in Clinical Practice: An Audit of Performance from the UK National External Quality Assessment Scheme

Cited by 41 publications

References 5 publications

Central reassessment of GH concentrations measured at local treatment centers in children with impaired growth: consequences for patient management

Central reassessment of GH concentrations measured at local treatment centers in children with impaired growth: consequences for patient management

Labordiagnostik bei Wachstumshormon-assoziierten Erkrankungen/Biochemical diagnosis of growth hormone related diseases

Ensaios para a medida de hormônio do crescimento (GH) e IGF-I: aspectos metodológicos e suas implicações no diagnóstico e seguimento da acromegalia

Contact Info

Product

Resources

About