title: High-sensitivity chemiluminescence immunoassays for detection of growth hormone doping in sports.
abstract: BACKGROUND
  Recombinant human growth hormone (rhGH) is abused in sports, but adequate routine doping tests are lacking. Analysis of serum hGH isoform composition has been shown to be effective in detecting rhGH doping. We developed and validated selective immunoassays for isoform analysis with potential utility for screening and confirmation in doping tests.
  
  
  METHODS
  Monoclonal antibodies with preference for pituitary hGH (phGH) or rhGH were used to establish 2 pairs of sandwich-type chemiluminescence assays with differential recognition of rhGH (recA and recB) and phGH (pitA and pitB). We analyzed specimens from volunteers before and after administration of rhGH and calculated ratios between the respective rec- and pit-assay results.
  
  
  RESULTS
  Functional sensitivities were <0.05 microg/L, with intra- and interassay imprecision < or =8.4% and < or =13.7%, respectively. In 2 independent cohorts of healthy subjects, rec/pit ratios (median range) were 0.84 (0.09-1.32)/0.81 (0.27-1.21) (recA/pitA) and 0.68 (0.08-1.20)/0.80 (0.25-1.36) (recB/pitB), with no sex difference. In 20 recreational athletes, ratios (median SD) increased after a single injection of rhGH, reaching 350% (73%) (recA/pitA) and 400% (93%) (recB/pitB) of baseline ratios. At a moderate dose (0.033 mg/kg), mean recA/pitA and recB/pitB ratios remained significantly increased for 18 h (men) and 26 h (women). After high-dose rhGH (0.083 mg/kg), mean rec/pit ratios remained increased for 32 h (recA/pitA) and 34 h (recB/pitB) in men and were still increased after 36 h in women.
  
  
  CONCLUSIONS
  Using sensitive chemiluminescence assays with preferential recognition of phGH or rhGH, detection of a single injection of rhGH was possible for up to 36 h.
authors.affiliation: Medizinische Klinik-Innenstadt, Ludwig-Maximilians-University, Munich, Germany. martin.bidlingmaier@med.unimuenchen.de
authors.forename: Martin
authors.initials: M
authors.lastname: Bidlingmaier
authors.forename: Jennifer
authors.initials: J
authors.lastname: Suhr
authors.forename: Andrea
authors.initials: A
authors.lastname: Ernst
authors.forename: Zida
authors.initials: Z
authors.lastname: Wu
authors.forename: Alexandra
authors.initials: A
authors.lastname: Keller
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Strasburger
authors.forename: Andreas
authors.initials: A
authors.lastname: Bergmann
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004300:Doping in Sports; D000939:Epitopes / Q000276:immunology; D005260:Female; D019382:Human Growth Hormone / Q000097:blood* / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000097:blood / Q000276:immunology; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D000906:Antibodies; D000939:Epitopes; D011994:Recombinant Proteins; D019382:Human Growth Hormone