{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T15:20:12Z","timestamp":1783956012109,"version":"3.55.0"},"reference-count":12,"publisher":"The Endocrine Society","issue":"8","license":[{"start":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T00:00:00Z","timestamp":1751414400000},"content-version":"vor","delay-in-days":19,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,6,13]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>Testosterone is commonly measured using immunoassays in clinical practice; however, these methods are subject to analytical interference in both men and women. In women, due to physiologically lower testosterone levels, even modest elevations may appear pathologic and complicate the diagnostic process. We report a case of a 43-year-old female patient with persistently elevated serum testosterone levels documented across multiple institutions. Despite comprehensive endocrine evaluations and imaging studies, no underlying cause could be identified. Ultimately, liquid chromatography\u2013tandem mass spectrometry (LC-MS\/MS) confirmed normal testosterone levels, indicating that the falsely elevated testosterone was due to assay interference. Further analysis using a protein precipitation assay revealed the presence of heterophilic antibodies, which were responsible for the assay interference. This case highlights the importance of considering immunoassay artifacts in the differential diagnosis of unexplained biochemical hyperandrogenism, particularly in the absence of clinical signs of androgen excess.<\/jats:p>","DOI":"10.1210\/jcemcr\/luaf140","type":"journal-article","created":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T06:05:38Z","timestamp":1751436338000},"source":"Crossref","is-referenced-by-count":1,"title":["Apparent Hyperandrogenemia Due to Immunoassay Interference Resolved by Liquid Chromatography\u2013Tandem Mass Spectrometry"],"prefix":"10.1210","volume":"3","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-0919-2832","authenticated-orcid":false,"given":"Dongni","family":"Huang","sequence":"first","affiliation":[{"name":"Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences , Beijing 100730 ,","place":["China"]},{"name":"Chinese Academy of Medical Sciences , Graduate School of Peking Union Medical College, Beijing 100730 ,","place":["China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"ZhiXuan","family":"Guo","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences , Beijing 100730 ,","place":["China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"JingWen","family":"Fan","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences , Beijing 100730 ,","place":["China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences , Beijing 100730 ,","place":["China"]},{"name":"Chinese Academy of Medical Sciences , Graduate School of Peking Union Medical College, Beijing 100730 ,","place":["China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"Pan","sequence":"additional","affiliation":[{"name":"Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences , Beijing 100730 ,","place":["China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6863-1798","authenticated-orcid":false,"given":"Lixin","family":"Guo","sequence":"additional","affiliation":[{"name":"Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences , Beijing 100730 ,","place":["China"]},{"name":"Chinese Academy of Medical Sciences , Graduate School of Peking Union 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Analytical performance of five automated testosterone immunoassays","volume":"58","author":"La\u2019ulu","year":"2018","journal-title":"Clin Biochem"},{"issue":"3","key":"2025070204071738100_luaf140-B8","doi-asserted-by":"crossref","first-page":"928","DOI":"10.1007\/s12020-020-02497-w","article-title":"Hyperprolactinemia: still an insidious diagnosis","volume":"72","author":"Aliberti","year":"2021","journal-title":"Endocrine"},{"issue":"3","key":"2025070204071738100_luaf140-B9","doi-asserted-by":"crossref","first-page":"706","DOI":"10.1007\/s12020-025-04191-1","article-title":"Intricate diagnosis due to falsely elevated testosterone levels by immunoassay","volume":"88","author":"Gardini","year":"2025","journal-title":"Endocrine"},{"issue":"5","key":"2025070204071738100_luaf140-B10","doi-asserted-by":"crossref","first-page":"830","DOI":"10.1210\/er.2018-00119","article-title":"Interferences with thyroid function immunoassays: clinical implications and detection algorithm","volume":"39","author":"Favresse","year":"2018","journal-title":"Endocr Rev"},{"issue":"6","key":"2025070204071738100_luaf140-B11","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1507\/endocrj.EJ19-0023","article-title":"Falsely elevated plasma ACTH levels measured by the Elecsys assay related to heterophilic antibody in a case of secondary adrenocortical insufficiency","volume":"66","author":"Morita","year":"2019","journal-title":"Endocr J"},{"issue":"1","key":"2025070204071738100_luaf140-B12","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1258\/000456307779595896","article-title":"Measurement of serum testosterone in women; what should we do?","volume":"44","author":"Kane","year":"2007","journal-title":"Ann Clin Biochem"}],"container-title":["JCEM Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jcemcr\/article-pdf\/3\/8\/luaf140\/63639404\/luaf140.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jcemcr\/article-pdf\/3\/8\/luaf140\/63639404\/luaf140.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T08:07:28Z","timestamp":1751443648000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jcemcr\/article\/doi\/10.1210\/jcemcr\/luaf140\/8180761"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,13]]},"references-count":12,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2025,6,13]]}},"URL":"https:\/\/doi.org\/10.1210\/jcemcr\/luaf140","relation":{},"ISSN":["2755-1520"],"issn-type":[{"value":"2755-1520","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2025,8]]},"published":{"date-parts":[[2025,6,13]]},"article-number":"luaf140"}}