One-step quantitative thyrotropin assay for the detection of hypothyroidism in point-of-care conditions

• Published in: Clinical biochemistry Vol. 36; no. 2; pp. 121 - 128
• Main Authors: von Lode, Piia, Hagrén, Virve, Palenius, Tom, Lövgren, Timo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2003
• Subjects: Calibration; Fluorescence Polarization Immunoassay - methods; Fluorescence Polarization Immunoassay - standards; Humans; Hypothyroidism - blood; Hypothyroidism - diagnosis; Kinetics; Linear Models; Microparticle; Particle Size; Point-of-Care Systems; Point-of-care testing; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Thyrotropin; Thyrotropin - blood; Time-resolved fluorescence; Point-of-care testing; Thyrotropin; Microparticle; Time-resolved fluorescence
• ISSN: 0009-9120; 1873-2933
• DOI: 10.1016/S0009-9120(02)00431-9

Different screening strategies for early diagnosis of hypothyroidism have been discussed increasingly. We demonstrate the applicability of a miniaturized microparticle assay format for rapid and quantitative determination of increased thyrotropin (TSH) concentrations in serum. Porous microparticles were used as solid phase for a noncompetitive, one-step, kinetic immunoassay with varying incubation times and time-resolved fluorescence detection. The analytical (mean of zero + 3 SD) and functional (CV <15%) detection limits were 1.5 and 6.0 mIU/L for 2-min, 0.5 and 1.5 mIU/L for 7-min, and 0.2 and 0.5 mIU/L for 15-min assays, respectively. A good correlation was found with the Chiron Diagnostics ACS:180 assay (slopes 0.885–1.051, y-intercepts < ± 0.20 mIU/L, S y⊻x ≤ 0.10 mIU/L, r > 0.98, n = 20). The kinetic TSH assay provides reproducible and quantitative information on thyroid status within minutes and is applicable for the detection of hypothyroidism in point-of-care (POC) conditions.