Urs Wilgen1, Carel J Pretorius2, Rehna S Gous3, Cameron Martin3, Vincent J Hale3, Jacobus P J Ungerer3. 1. Pathology Queensland, Department of Chemical Pathology, Royal Brisbane and Women's Hospital, Herston Road, Herston 4029, Queensland, Australia; University of Queensland, School of Medicine, Brisbane, St. Lucia, 4072 Queensland, Australia. Electronic address: Urs.Wilgen@health.qld.gov.au. 2. Pathology Queensland, Department of Chemical Pathology, Royal Brisbane and Women's Hospital, Herston Road, Herston 4029, Queensland, Australia; University of Queensland, School of Medicine, Brisbane, St. Lucia, 4072 Queensland, Australia. 3. Pathology Queensland, Department of Chemical Pathology, Royal Brisbane and Women's Hospital, Herston Road, Herston 4029, Queensland, Australia.
Abstract
UNLABELLED: Point-of-care testing for β-hCG has been widely advocated to allow rapid diagnosis/exclusion of pregnancy in the emergency department. A quantitative blood β-hCG assay has the additional benefit of being able to monitor the viability of pregnancy, using serial measurements, to determine the appropriate expected increase in β-hCG levels over time (e.g. ectopic pregnancy), and aiding in determining if an intrauterine gestational sac should be visible on sonographic imaging. OBJECTIVES: Evaluation of the newly released Abbott i-STAT β-hCG point-of-care assay with the Beckman Coulter β-hCG laboratory assay in use. DESIGN AND METHODS: Whole blood, plasma and serum samples with a wide range of β-hCG concentrations were analysed by both methods. RESULTS: The Abbott I-STAT β-hCG compares favourably, can be performed on heparinised whole blood, plasma and serum, and shows acceptable accuracy and precision. However a hook effect at elevated β-hCG was shown in gestational trophoblastic disease as well as normal pregnancies. CONCLUSIONS: The i-STAT β-hCG performs acceptably in its intended use in the early detection of pregnancy, but results should always be interpreted within the clinical context, as a hook effect may occur. Crown
UNLABELLED: Point-of-care testing for β-hCG has been widely advocated to allow rapid diagnosis/exclusion of pregnancy in the emergency department. A quantitative blood β-hCG assay has the additional benefit of being able to monitor the viability of pregnancy, using serial measurements, to determine the appropriate expected increase in β-hCG levels over time (e.g. ectopic pregnancy), and aiding in determining if an intrauterine gestational sac should be visible on sonographic imaging. OBJECTIVES: Evaluation of the newly released Abbott i-STAT β-hCG point-of-care assay with the Beckman Coulter β-hCG laboratory assay in use. DESIGN AND METHODS: Whole blood, plasma and serum samples with a wide range of β-hCG concentrations were analysed by both methods. RESULTS: The Abbott I-STAT β-hCG compares favourably, can be performed on heparinised whole blood, plasma and serum, and shows acceptable accuracy and precision. However a hook effect at elevated β-hCG was shown in gestational trophoblastic disease as well as normal pregnancies. CONCLUSIONS: The i-STAT β-hCG performs acceptably in its intended use in the early detection of pregnancy, but results should always be interpreted within the clinical context, as a hook effect may occur. Crown
Authors: Miranda M Brun; Laura Holloway; Amanda Oleksy; Jan Dayton; Mathew P Estey; Bobbi-Lynn Goudreau; Anna K Füzéry Journal: Pract Lab Med Date: 2019-01-11