False Positives in Thyroglobulin Determinations Due to the Presence of Heterophile Antibodies: An Underrecognized and Consequential Clinical Problem
| Autor: | Alicia Algeciras-Schimnich, Joshua A. Bornhorst, Giuseppe Barbesino |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
endocrine system
endocrine system diseases Heterophile Endocrinology Diabetes and Metabolism medicine.medical_treatment Antibodies Heterophile 030209 endocrinology & metabolism Thyroglobulin 03 medical and health sciences 0302 clinical medicine Endocrinology Thyroid-stimulating hormone medicine False positive paradox Humans Thyroid Neoplasms 030212 general & internal medicine Thyroid cancer biology business.industry General Medicine medicine.disease Immunology biology.protein Antibody business hormones hormone substitutes and hormone antagonists Human anti-mouse antibody Hormone |
| Zdroj: | Endocrine Practice. 27:396-400 |
| ISSN: | 1530-891X |
| Popis: | Objective To report a case series of thyroid cancer patients in whom false positive results in immunometric assays for thyroglobulin (TgIMA) were caused by heterophilic antibody interference, describe the clinical scenario in which this interference should be suspected, and recommend methods to demonstrate the interference. Methods Three patients with unexpectedly elevated thyroglobulin results (range, 1.6-75 ng/mL) were studied. In the first patient, thyroglobulin was elevated despite the presence of Tg antibody. In the second patient, suppressed thyroglobulin was higher than a recent stimulated thyroglobulin. In the third patient, thyroglobulin became detectable years after treatment and did not change after thyroid-stimulating hormone stimulation. TgIMA concentration determination was compared to determination by a mass spectrometry method (TgMS). Thyroglobulin was also remeasured after preabsorption with heterophile antibody blocking reagents and after serial dilutions. Results In all cases, thyroglobulin was undetectable by TgMS. In 2 of 3 patients, dilutions provided nonlinear thyroglobulin results. After blocking agent preabsorption, thyroglobulin dropped by 35%, 45%, and 91% in the 3 samples. Conclusion False positive thyroglobulin concentrations from heterophilic antibody interference have significant impact on the management of thyroid cancer. Here we show that TgMS assays can be used to rule out heterophilic antibody interference. This interference should be suspected when a detectable thyroglobulin by TgIMA does not respond to thyroid-stimulating hormone or is discordant from the clinical assessment. |
| Databáze: | OpenAIRE |
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