Peer-reviewed veterinary case report
Point-of-care test accuracy for cat thyroid hormone levels
By Spada, Eva et al.·Published in Journal of feline medicine and surgery·2025·Department of Veterinary Medicine and Animal Sciences (DIVAS), Italy·View original on PubMed →
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Original publication title: Evaluation of a point-of-care test for quantitative determination of total thyroxine in feline serum.
- Species:
- cat
Plain-English summary
A study evaluated a new test called Vcheck T4 for measuring thyroid hormone levels in cats, which is important for diagnosing hyperthyroidism. The test showed good accuracy and reliability when compared to a standard method, with a high ability to correctly identify cats that do not have the disease. However, while it can effectively rule out hyperthyroidism, it may not be as reliable for confirming the condition if the results are high. This means that if a cat's thyroid levels are elevated, further testing may be necessary to confirm the diagnosis.
People also search for: cat hyperthyroidism test · feline thyroid hormone levels · Vcheck T4 for cats
Abstract
OBJECTIVES: Total thyroxine (TT4) evaluation is the most commonly used first-line test for the diagnosis and monitoring of cats with hyperthyroidism. Vcheck T4 is a point-of-care immunoassay that measures TT4 using a Vcheck V200 analyser. This study aimed to evaluate the analytic performance of the Vcheck T4 assay in feline sera and the agreement in the classification of normal, high and low TT4 concentrations of Vcheck T4 with those measured by an enzyme immunoassay (EIA). METHODS: Assay precision, reproducibility and linearity were evaluated for the Vcheck T4. For method comparison, TT4 concentrations in 73 serum samples were analysed by both methods. RESULTS: Vcheck T4 demonstrated good precision, reproducibility (intra- and inter-assay coefficients of variation between 3% and 13.5%) and linearity in the diagnostic range of <0.5 and >8 μg/dl. The correlation coefficient was 0.87, Passing-Bablok regression showed a proportional, but not constant bias, Bland-Altman plots revealed a mean difference of +0.5 μg/dl. The overall inter-rater agreement () between TT4 EIA and Vcheck results was substantial ( = 0.69), with 82.2% of concordant results. As a diagnostic test for hyperthyroidism, Vcheck T4 showed a sensitivity and specificity of 88.9% and 84.4%, and a positive predictive value (PPV) and negative predictive value (NPV) of 44.5% and 98.2%, respectively. CONCLUSIONS AND RELEVANCE: Vcheck T4 assay provided precise and reproducible results in substantial agreement with the EIA. Given the high NPV, Vcheck T4 is useful in ruling out hyperthyroidism when screening cats, but, based on low PPV, samples with results with high TT4 need to be analysed by another reference method. Further analysis with haemolytic, icteric and lipaemic samples is needed to assess the test performance. Finally, the reference intervals provided by the manufacturer require verification, and TT4 intervals specific to this method must be established in future studies.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/39781578/