I V Wagner1, C Paetzold1, R Gausche1, M Vogel1, A Koerner1, J Thiery1, C G Arsene1, A Henrion1, B Guettler1, E Keller1, W Kiess1, R Pfaeffle1, J Kratzsch2. 1. Centre for Paediatric Research Leipzig (CPL)Hospital for Children and Adolescents, University of Leipzig, Leipzig, GermanyInstitute for Laboratory MedicineClinical Chemistry and Molecular Diagnostics, University of Leipzig, Paul-List-Straße 13-15, 04103 Leipzig, GermanyCrescNet GmbHUniversity of Leipzig, Leipzig, GermanyPhysikalisch-Technische Bundesanstalt (PTB)Braunschweig, Germany. 2. Centre for Paediatric Research Leipzig (CPL)Hospital for Children and Adolescents, University of Leipzig, Leipzig, GermanyInstitute for Laboratory MedicineClinical Chemistry and Molecular Diagnostics, University of Leipzig, Paul-List-Straße 13-15, 04103 Leipzig, GermanyCrescNet GmbHUniversity of Leipzig, Leipzig, GermanyPhysikalisch-Technische Bundesanstalt (PTB)Braunschweig, Germany juergen.kratzsch@medizin.uni-leipzig.de.
Abstract
CONTEXT: Cutoff limits of GH stimulation tests to diagnose GH deficiency (GHD) in children and adolescents are not sufficiently validated by clinical studies due to discrepancies in the performance of GH immunoassays and lack of available study populations. OBJECTIVE: We aimed to establish new cutoff limits for GH stimulation tests based on clinical evidence and compared these immunoassay-based values with an antibody-independent mass spectrometric method. DESIGN AND SETTING: In a retrospective study, GH cutoff limits for eight different immunoassays and isotope dilution mass spectrometry (ID-MS) were calculated from hGH peak concentrations of short-statured children with and without GHD. PATIENTS: We compared the serum GH peak concentrations at GH stimulation test of 52 short-statured children and adolescents, who have normal GH secretion at initial workup and normal growth in the follow-up, with the serum GH peak concentrations of 44 GHD patients in the same age range, in order to optimize the cutoff limit calculation. RESULTS: Discriminant analysis of re-measured GH led to a new cutoff limit of 7.09 μg/l using the iSYS assay (IDS) and the limits for the other seven hGH assays varied between 4.32 and 7.77 μg/l. For ID-MS, cutoffs of 5.48 μg/l (22k GH) and 7.43 μg/l (total GH) were ascertained. CONCLUSION: The establishment of method-specific clinical evidence-based GH cutoff limits is of importance to ensure adequate clinical diagnosis and treatment of children and adolescents with GHD. ID-MS may become an important tool for providing both reliable and sustainable SI traceability of GH measurements in the future.
CONTEXT: Cutoff limits of GH stimulation tests to diagnose GH deficiency (GHD) in children and adolescents are not sufficiently validated by clinical studies due to discrepancies in the performance of GH immunoassays and lack of available study populations. OBJECTIVE: We aimed to establish new cutoff limits for GH stimulation tests based on clinical evidence and compared these immunoassay-based values with an antibody-independent mass spectrometric method. DESIGN AND SETTING: In a retrospective study, GH cutoff limits for eight different immunoassays and isotope dilution mass spectrometry (ID-MS) were calculated from hGH peak concentrations of short-statured children with and without GHD. PATIENTS: We compared the serum GH peak concentrations at GH stimulation test of 52 short-statured children and adolescents, who have normal GH secretion at initial workup and normal growth in the follow-up, with the serum GH peak concentrations of 44 GHD patients in the same age range, in order to optimize the cutoff limit calculation. RESULTS: Discriminant analysis of re-measured GH led to a new cutoff limit of 7.09 μg/l using the iSYS assay (IDS) and the limits for the other seven hGH assays varied between 4.32 and 7.77 μg/l. For ID-MS, cutoffs of 5.48 μg/l (22k GH) and 7.43 μg/l (total GH) were ascertained. CONCLUSION: The establishment of method-specific clinical evidence-based GH cutoff limits is of importance to ensure adequate clinical diagnosis and treatment of children and adolescents with GHD. ID-MS may become an important tool for providing both reliable and sustainable SI traceability of GH measurements in the future.
Authors: Helen L Storr; Sumana Chatterjee; Louise A Metherell; Corinne Foley; Ron G Rosenfeld; Philippe F Backeljauw; Andrew Dauber; Martin O Savage; Vivian Hwa Journal: Endocr Rev Date: 2019-04-01 Impact factor: 19.871
Authors: Philip G Murray; Adam Stevens; Chiara De Leonibus; Ekaterina Koledova; Pierre Chatelain; Peter E Clayton Journal: JCI Insight Date: 2018-04-05
Authors: Paulo F Collett-Solberg; Geoffrey Ambler; Philippe F Backeljauw; Martin Bidlingmaier; Beverly M K Biller; Margaret C S Boguszewski; Pik To Cheung; Catherine Seut Yhoke Choong; Laurie E Cohen; Pinchas Cohen; Andrew Dauber; Cheri L Deal; Chunxiu Gong; Yukihiro Hasegawa; Andrew R Hoffman; Paul L Hofman; Reiko Horikawa; Alexander A L Jorge; Anders Juul; Peter Kamenický; Vaman Khadilkar; John J Kopchick; Berit Kriström; Maria de Lurdes A Lopes; Xiaoping Luo; Bradley S Miller; Madhusmita Misra; Irene Netchine; Sally Radovick; Michael B Ranke; Alan D Rogol; Ron G Rosenfeld; Paul Saenger; Jan M Wit; Joachim Woelfle Journal: Horm Res Paediatr Date: 2019-09-12 Impact factor: 2.852
Authors: Mohamad Maghnie; José I Labarta; Ekaterina Koledova; Tilman R Rohrer Journal: Front Endocrinol (Lausanne) Date: 2018-01-11 Impact factor: 5.555