Rapid, automated quantification of total human chorionic gonadotropin in serum by a chemiluminescent enzyme immunometric assay.
Total human chorionic gonadotropin (hCG-hCG beta) in serum was assayed with the immulite system, a fully automated random-access immunoassay analyzer that has a unique centrifugal procedure for solid-phase washing and a chemiluminescent detection system. The broad range of the hCG calibration curve (up to 5000 IU/L) is achieved by using a small serum sample size (5 microL), which provides sufficient volume for low-end sensitivity and prevents the possible high-dose hook effect in the working range of the assay. Within-run imprecision (CV) ranged from 3.9% to 5.9% for hCG between 10.5 and 2908 IU/L. Between-run imprecision ranged from 8.8% to 12.7% for hCG mean concentrations from 11.4 to 88.4 IU/L. The antibodies used in the immulite hCG assay system gave little or no interferences when high amounts of follitropin, lutropin, and thyrotropin were added. A complete recognition of the free beta-subunit of hCG was obtained (+/- 180%). In sera from women with molar pregnancies, we observed no high-dose hook effect at hCG concentrations up to 3000 kIU/L. The broad range of hCG concentrations encountered throughout normal pregnancy (up to 200 kIU/L) requires an extended working range to avoid high dilutions. In early pregnancy, accuracy in the range of 1000-5000 IU/L is enhanced by avoiding dilutions.
Vankrieken
L
L
Department of Obstetrics and Gynecology, Faculty of Medicine, Brussels, Belgium.
De Hertogh
R
R
D001322:Autoanalysis; D006063:Chorionic Gonadotropin / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000295:instrumentation / Q000706:statistics & numerical data; D015592:Immunoradiometric Assay; D008163:Luminescent Measurements; D008297:Male; D008593:Menopause / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D017698:Postmenopause / Q000097:blood; D011247:Pregnancy; D011786:Quality Control; D011933:Reagent Kits, Diagnostic; D012016:Reference Values; D012680:Sensitivity and Specificity
D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments; D011933:Reagent Kits, Diagnostic