Variability in the detection of macro TSH in different immunoassay systems

Autor: Akira Shimatsu, Naoki Hattori, Takashi Ishihara
Rok vydání: 2016
Předmět:
Adult
Male
Thyroid Hormones
endocrine system
medicine.medical_specialty
endocrine system diseases
Normal free thyroxine
Endocrinology
Diabetes and Metabolism
Thyrotropin
030209 endocrinology & metabolism
Sensitivity and Specificity
Polyethylene Glycols
Mice
03 medical and health sciences
0302 clinical medicine
Endocrinology
Hypothyroidism
Internal medicine
medicine
Animals
Chemical Precipitation
Humans
In patient
False Negative Reactions
Aged
Subclinical infection
Aged
80 and over
Immunoassay
medicine.diagnostic_test
Elevated serum tsh
business.industry
General Medicine
Middle Aged
Serum samples
Antibodies
Anti-Idiotypic
Molecular Weight
stomatognathic diseases
Immunoglobulin G
030220 oncology & carcinogenesis
Thyroid hormones
Chromatography
Gel
Female
business
hormones
hormone substitutes
and hormone antagonists
Zdroj: European Journal of Endocrinology. 174:9-15
ISSN: 1479-683X
0804-4643
Popis: DesignMacro TSH is a large molecular-sized TSH that is mostly a complex of TSH and IgG. Patients with macro TSH have elevated serum TSH and normal free thyroxine levels, mimicking subclinical hypothyroidism. The aim of this study was to clarify the degree of cross-reactivity of macro TSH to different commercial immunoassay systems.MethodsScreening for macro TSH was done using a polyethylene glycol (PEG) method and confirmed with gel filtration chromatography in serum samples from 1901 patients with subclinical hypothyroidism. Interference due to human anti-mouse antibodies (HAMA) was examined using HAMA blockers. TSH was measured with an enzyme immunoassay for the analysis of macro TSH. Serum TSH values in patients with macro TSH were also determined with the widely used commercial immunoassay platforms Elecsys, Centaur and Architect, and the detectability of macro TSH was compared among them.ResultsGel filtration chromatography was performed with 174 serum samples with PEG-precipitable TSH ratios >75%. Twenty serum samples were found to contain large molecular-sized TSH, five of which were due to interference by HAMA. The prevalence of macro TSH was eventually 0.79% (15/1901). Commercial immunoassay systems variably recognized macro TSH. The Architect TSH immunoassay platform was the least reactive to macro TSH, but still recognized it in 60% of macro TSH-containing serum samples.ConclusionsThere were no commercial TSH immunoassay platforms that did not cross-react with macro TSH. Screening for macro TSH should be performed before hormone replacement therapy is initiated for subclinical hypothyroidism.
Databáze: OpenAIRE
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