title: Steroid profiling for congenital adrenal hyperplasia by tandem mass spectrometry as a second-tier test reduces follow-up burdens in a tertiary care hospital: a retrospective and prospective evaluation.
abstract: BACKGROUND
  Newborn screening for congenital adrenal hyperplasia (CAH) based on measuring 17-hydroxyprogesterone (17-OHP) by immunoassay generates a number of false-positive results, especially in preterm neonates. We applied steroid profiling by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a second-tier test in newborns with positive CAH screening and evaluated its clinical utility in a tertiary care hospital setting.
  
  
  METHODS
  By performing a 4-year retrospective data review, we were able to test 121 dried blood spots from newborns with positive CAH screening for 17-OHP, androstenedione and cortisol levels by LC-MS/MS. We prospectively evaluated the clinical utility of steroid profiling after the implementation of steroid profiling as a second-tier test in our routine clinical practice. During the 2-year prospective study period, 104 cases with positive initial screening by FIA were tested by LC-MS/MS. Clinical and laboratory follow-up were performed for at least 6 months.
  
  
  RESULTS
  The preterm neonates accounted for 50.7% (76/150) and 70.4% (88/125) of screening-positive cases in retrospective and prospective cohorts, respectively. By applying steroid profiling as a second-tier test for positive CAH screening, we eliminated all false-positive results and decreased the median follow-up time from 75 to 8 days.
  
  
  CONCLUSIONS
  Our data showed that steroid profiling reduced the burden of follow-up exams by improving the positive predictive value of the CAH screening program. The use of steroid profiling as a second-tier test for positive CAH screening will improve clinical practice particularly in a tertiary care hospital setting where positive CAH screening from preterm neonates is frequently encountered.
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Seo
authors.forename: Hyung-Doo
authors.initials: HD
authors.lastname: Park
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Hyeon Ju
authors.initials: HJ
authors.lastname: Oh
authors.forename: Jeong Soo
authors.initials: JS
authors.lastname: Yang
authors.forename: Yun Sil
authors.initials: YS
authors.lastname: Chang
authors.forename: Won Soon
authors.initials: WS
authors.lastname: Park
authors.forename: Soo-Youn
authors.initials: SY
authors.lastname: Lee
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood / Q000175:diagnosis*; D000735:Androstenedione / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002853:Chromatography, Liquid; D059788:Dried Blood Spot Testing; D005189:False Positive Reactions; D005500:Follow-Up Studies; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000175:diagnosis; D015997:Neonatal Screening / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D053719:Tandem Mass Spectrometry; D062606:Tertiary Care Centers
chemical_list: D015415:Biomarkers; D000735:Androstenedione; D019326:17-alpha-Hydroxyprogesterone; D006854:Hydrocortisone