title: Monitoring steroid replacement therapy in children with congenital adrenal hyperplasia.
abstract: BACKGROUND
  The objective of this study was to compare the analysis of 17-hydroxyprogesterone (17-OHP) by radio-immunoassay (RIA) in serum with analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) on dried blood spot samples (DBSS) for monitoring therapy in children with congenital adrenal hyperplasia (CAH), and to investigate differences in 17-OHP values during the day.
  
  
  METHODS
  Fourteen children (8 females), median age 4.2 (0.3-16.0) years, were studied. Serum samples and DBSS were drawn before hydrocortisone dosing.
  
  
  RESULTS
  17-OHP by LC-MS/MS in DBSS were highly correlated to 17-OHP by RIA in serum, r=0.956, p<0.01. A total of 26 three-time-point series were investigated. Using only the afternoon 17-OHP values to determine the hydrocortisone doses would have led to overdosing seven times and underdosing six times.
  
  
  CONCLUSIONS
  Good agreement was demonstrated between 17-OHP determination by RIA in serum and LC-MS/MS on DBSS. Multiple 17-OHP measurements per day are required to ensure sufficient hydrocortisone dose adjustment.
authors.forename: Niels H
authors.initials: NH
authors.lastname: Birkebaek
authors.forename: David M
authors.initials: DM
authors.lastname: Hougaard
authors.forename: Arieh S
authors.initials: AS
authors.lastname: Cohen
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D000293:Adolescent; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood* / Q000188:drug therapy*; D015415:Biomarkers / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D002853:Chromatography, Liquid / Q000379:methods; D002940:Circadian Rhythm; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy; D006801:Humans; D007223:Infant; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D011379:Prognosis; D011863:Radioimmunoassay / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D015415:Biomarkers; D019326:17-alpha-Hydroxyprogesterone