Thyroid autoantibody testing in practice: an audit of TPO antibody measurement requests in a tertiary hospital

Kevin Veerasamy; Laura Ryan; Erum Rashed; Eoin Noctor; Mohammad Bin Mahfooz; Audrey Melvin; Anne-Marie Hannon

doi:10.1530/endoabs.115.P45

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Endocrine Abstracts (2026) 115 P45 | DOI: 10.1530/endoabs.115.P45

IES2025 Research, Audit and Quality Improvement Projects Physical Posters (55 abstracts)

Thyroid autoantibody testing in practice: an audit of TPO antibody measurement requests in a tertiary hospital

Kevin Veerasamy ¹ , Laura Ryan ¹ , Erum Rashed ² , Eoin Noctor ¹ , Mohammad Bin Mahfooz ¹ , Audrey Melvin ¹ & Anne-Marie Hannon ¹

Author affiliations

¹Department of Endocrinology, University Hospital Limerick; ²Department of Chemical Pathology, University Hospital Limerick

Thyroid peroxidase (TPO) antibodies are commonly present in individuals with Hashimoto’s thyroiditis and, less frequently, in those with Graves’ disease. The National Institute for Health and Care Excellence (NICE) recommends measuring TPO antibodies once in adults with elevated thyroid-stimulating hormone (TSH) levels and advises against repeat testing due to their limited diagnostic value. This audit was undertaken to evaluate TPO antibody testing practices in the Midwest region and assess compliance with established guidelines. A retrospective review was conducted of all TPO antibody tests performed in 2023 and 2024, including corresponding thyroid function tests. Individuals under 18 years were excluded. Laboratory-specific reference ranges were used to define normal TSH and TPO values. A total of 9,960 TPO antibody tests were performed on 7,425 individuals with 1,279 (17.2%) having repeat TPO testing. On average, TPO testing was repeated 2.6 times, with the frequency of duplicates ranging between 2 to 11 times. The majority (77%) were female, with a median age of 47 years. Most requests originated from primary care (76.3%), followed by obstetrics and gynaecology (13.8%) and secondary care (3.1%). Only 14.9% (n = 1,482) of tests were associated with a TSH above 4.2 mU/l, the threshold that justifies testing. Among these, 866 had subclinical hypothyroidism and 166 had overt hypothyroidism. While appropriate TPO testing can support the diagnosis of autoimmune thyroid disease, this audit highlights a high volume of potentially unnecessary testing. These findings support the need for improved adherence to clinical guidelines to ensure appropriate and cost-effective use of thyroid antibody testing.