title: Clinical evidence-based cutoff limits for GH stimulation tests in children with a backup of results with reference to mass spectrometry.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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: 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.
authors: I V
authors: IV
authors: Wagner
authors: 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.
authors: C
authors: C
authors: Paetzold
authors: 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.
authors: R
authors: R
authors: Gausche
authors: 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.
authors: M
authors: M
authors: Vogel
authors: 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.
authors: A
authors: A
authors: Koerner
authors: 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.
authors: J
authors: J
authors: Thiery
authors: 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.
authors: C G
authors: CG
authors: Arsene
authors: 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.
authors: A
authors: A
authors: Henrion
authors: 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.
authors: B
authors: B
authors: Guettler
authors: 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.
authors: E
authors: E
authors: Keller
authors: 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.
authors: W
authors: W
authors: Kiess
authors: 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.
authors: R
authors: R
authors: Pfaeffle
authors: 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.
authors: J
authors: J
authors: Kratzsch
mesh_terms: D001827:Body Height / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual / Q000592:standards; D005260:Female; D006130:Growth Disorders / Q000097:blood / Q000175:diagnosis*; D019382:Human Growth Hormone / Q000096:biosynthesis* / Q000097:blood; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000592:standards*; D012189:Retrospective Studies
chemical_list: D019382:Human Growth Hormone