Comparison of Six Automated Immunoassays With Isotope-Diluted Liquid Chromatography–Tandem Mass Spectrometry for Total Thyroxine Measurement

Abstract

Background Accurate serum total thyroxine (TT4) measurement is important for thyroid disorder diagnosis and management. We compared the performance of six automated immunoassays with that of isotope-diluted liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) as the reference method. We also evaluated the correlation of thyroid stimulating hormone (TSH) with TT4 measured by ID-LC-MS/MS and immunoassays. Methods Serum was collected from 156 patients between October 2015 and January 2016. TT4 was measured by immunoassays from Abbott (Architect), Siemens (ADVIA Centaur XP), Roche (E601), Beckman-Coulter (Dxi800), Autobio (Autolumo A2000), and Mindray (CL-1000i), and by ID-LC-MS/MS. Results were analyzed using Passing-Bablok regression and Bland-Altman plots. Minimum requirements based on biological variation were as follows: a mean bias of ≤4.5% and total imprecision (CV) of ≤3.7%. Results All immunoassays showed a correlation >0.945 with ID-LC-MS/MS; however, the slope of the Passing-Bablok regression line varied from 0.886 (Mindray) to 1.23 (Siemens) and the intercept from −12.8 (Siemens) to 4.61 (Mindray). Only Autobio, Beckman-Coulter, and Roche included the value of one in the 95% confidence interval for slope. The mean bias ranged from −10.8% (Abbott) to 9.0% (Siemens), with the lowest value noted for Roche (3.5%) and the highest for Abbott (−10.8%). Only Abbott and Roche showed within-run and total CV ≤3.7%. Conclusions Though all immunoassays correlated strongly with ID-LC-MS/MS, most did not meet the minimum clinical requirement. Laboratories and immunoassay manufacturers must be aware of these limitations.

Endocrine, Metabolic and Pharmacological Effects of Thyronamines (TAM), Thyroacetic Acids (TA) and Thyroid Hormone Metabolites (THM) – Evidence from in vitro, Cellular, Experimental Animal and Human Studies

“…Thus, new approaches are required, such as liquid chromatography -mass spectrometry (LC-MS/MS) of THM, which might allow simultaneous quantification of several THM from one single human serum sample without the need to establish compound-specific monoclonal antibody-based immunoassays. Such attempts have been made and meanwhile led to significant progress over the last decade [5][6][7][8][9][10][11][12][13][14][15].…”

Thyroid Hormone Abuse Among Elite Athletes

“…The pivotal serum TSH screening immunoassays, despite lacking a pure gravimetric standard, have achieved significant harmonization [ 65 ], although without universal acceptance [ 66-69 ]. By contrast, despite availability of a pure gravimetric T4 standard, the diversity and incongruence of commercial T4 immunoassays remains suboptimal even for clinical care [ 70 , 71 ], with analogous or greater problems arising for T3 immunoassays [ 70 , 72 , 73 ]. Still more serious limitations arise for harmonization of FT4 and FT3 immunoassays, which inherently lack any certified reference standard and have achieved only limited standardization [ 73-76 ].…”

Mass Spectrometry-Based Determination of Thyroid Hormones and Their Metabolites in Endocrine Diagnostics and Biomedical Research – Implications for Human Serum Diagnostics

“…In the meantime, quantification of free T4 and T3 concentrations is achievable using online sample preparation and sophisticated column switching methods. Such techniques have been developed, validated, and applied (and patented) successfully to determine free T4 and free T3 concentrations in specific populations, experimental and clinical conditions, and have even meanwhile conquered routine analysis with specialized laboratories using high throughput facilities [32,[70][71][72]. A general lesson initially learned from these experiences has been that, as with the determination of total T4 and T3 concentrations, MS and commercially available IA methods when validated give reasonably comparable data within the respective reference ranges, and under "normal physiological conditions", whilst at the lower or upper limits of detection or at the edge of reference ranges, agreement between the two techniques is unconvincing or even poor.…”