title: Chemiluminescence immunoassay versus radioimmunoassay for the measurement of reproductive hormones.
abstract: OBJECTIVE
  To compare the hormonal values determined by chemiluminescence immunoassay (CIA) and radioimmunoassay (RIA).
  
  
  METHODS
  Blood samples, drawn from eight volunteers during one menstrual cycle, were assayed for estradiol, progesterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin by CIA and RIA methods. The values obtained from these two assay techniques were compared. Statistical analysis were performed using the t-test, Pearson correlation coefficient and simple linear regression analysis.
  
  
  RESULTS
  CIA yielded lower mean values of LH, FSH, progesterone, but higher mean values of prolactin than RIA. Mean estradiol levels assayed by the two methods were similar. There was a good correlation between the hormonal values performed by the two methods. By calculation, the CIA hormonal value could accurately predict the RIA value by 96.6, 93.9, 89.9 and 66.0% for progesterone, LH, FSH and prolactin, respectively.
  
  
  CONCLUSIONS
  The disparity in the hormonal values obtained from different assay methods warrants clinicians to be aware of their clinical interpretation. Using the same reference range for different assay methods is not appropriate. A comparative study between the new and standard assays is essential.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, Ramathibodi Hospital, Bangkok, Thailand.
authors.forename: A
authors.initials: A
authors.lastname: Rojanasakul
authors.forename: U
authors.initials: U
authors.lastname: Udomsubpayakul
authors.forename: S
authors.initials: S
authors.lastname: Chinsomboon
mesh_terms: D000328:Adult; D004958:Estradiol / Q000097:blood*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008163:Luminescent Measurements; D007986:Luteinizing Hormone / Q000097:blood*; D008597:Menstrual Cycle / Q000097:blood*; D011237:Predictive Value of Tests; D011374:Progesterone / Q000097:blood*; D011388:Prolactin / Q000097:blood*; D011863:Radioimmunoassay; D012044:Regression Analysis
chemical_list: D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone