Multiple immunoassay interference in a patient with falsely elevated calcitonin
SUMMARY Calcitonin (CT) is a diagnostic and follow-up marker of medullary thyroid carcinoma. Heterophile antibodies (HAbs) may interfere during immunometric assay measurements and result in falsely high CT levels and different markers. A 50-year-old female patient was referred to our institution for...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Brazilian Society of Endocrinology and Metabolism
2024-02-01
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| Series: | Archives of Endocrinology and Metabolism |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2359-39972024000101603&lng=en&tlng=en |
| _version_ | 1797323539818217472 |
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| author | Mehmet Cagri Unal Aslihan Cavunt Bayraktar Tevfik Uslu Serkan Yener |
| author_facet | Mehmet Cagri Unal Aslihan Cavunt Bayraktar Tevfik Uslu Serkan Yener |
| author_sort | Mehmet Cagri Unal |
| collection | DOAJ |
| description | SUMMARY Calcitonin (CT) is a diagnostic and follow-up marker of medullary thyroid carcinoma. Heterophile antibodies (HAbs) may interfere during immunometric assay measurements and result in falsely high CT levels and different markers. A 50-year-old female patient was referred to our institution for elevated CT levels (3,199 pg/mL [0-11,5]). Physical examination and thyroid ultrasonography show no thyroid nodules. Because of the discrepancy between the clinical picture and the laboratory results, various markers and hormones were examined to determine whether there was any interference in the immunometric assay. Thyroglobulin (Tg) and Adrenocorticotropic hormone (ACTH) levels were also found inaccurately elevated. After precipitation with polyethylene glycol, CT, Tg, and ACTH levels markedly decreased, showing macro-aggregates. Also, serial dilutions showed non-linearity in plasma concentrations. Additionally, CT samples were pretreated with a heterophilic blocking tube before measuring, and the CT level decreased to < 0.1 pg/mL, suggesting a HAb presence. Immunoassay interference should be considered when conflicting laboratory data are observed. This may help reduce the amount of unnecessary laboratory and imaging studies and prevent patients from complex diagnostic procedures. |
| first_indexed | 2024-03-08T05:30:04Z |
| format | Article |
| id | doaj.art-8cf2a3a95b484cdf92f4f6bb983cd6fc |
| institution | Directory Open Access Journal |
| issn | 2359-4292 |
| language | English |
| last_indexed | 2024-03-08T05:30:04Z |
| publishDate | 2024-02-01 |
| publisher | Brazilian Society of Endocrinology and Metabolism |
| record_format | Article |
| series | Archives of Endocrinology and Metabolism |
| spelling | doaj.art-8cf2a3a95b484cdf92f4f6bb983cd6fc2024-02-06T07:43:11ZengBrazilian Society of Endocrinology and MetabolismArchives of Endocrinology and Metabolism2359-42922024-02-016810.20945/2359-4292-2023-0074Multiple immunoassay interference in a patient with falsely elevated calcitoninMehmet Cagri Unalhttps://orcid.org/0000-0001-8000-5220Aslihan Cavunt Bayraktarhttps://orcid.org/0000-0001-9966-5122Tevfik Usluhttps://orcid.org/0009-0008-5431-4263Serkan Yenerhttps://orcid.org/0000-0003-0427-735XSUMMARY Calcitonin (CT) is a diagnostic and follow-up marker of medullary thyroid carcinoma. Heterophile antibodies (HAbs) may interfere during immunometric assay measurements and result in falsely high CT levels and different markers. A 50-year-old female patient was referred to our institution for elevated CT levels (3,199 pg/mL [0-11,5]). Physical examination and thyroid ultrasonography show no thyroid nodules. Because of the discrepancy between the clinical picture and the laboratory results, various markers and hormones were examined to determine whether there was any interference in the immunometric assay. Thyroglobulin (Tg) and Adrenocorticotropic hormone (ACTH) levels were also found inaccurately elevated. After precipitation with polyethylene glycol, CT, Tg, and ACTH levels markedly decreased, showing macro-aggregates. Also, serial dilutions showed non-linearity in plasma concentrations. Additionally, CT samples were pretreated with a heterophilic blocking tube before measuring, and the CT level decreased to < 0.1 pg/mL, suggesting a HAb presence. Immunoassay interference should be considered when conflicting laboratory data are observed. This may help reduce the amount of unnecessary laboratory and imaging studies and prevent patients from complex diagnostic procedures.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2359-39972024000101603&lng=en&tlng=en |
| spellingShingle | Mehmet Cagri Unal Aslihan Cavunt Bayraktar Tevfik Uslu Serkan Yener Multiple immunoassay interference in a patient with falsely elevated calcitonin Archives of Endocrinology and Metabolism |
| title | Multiple immunoassay interference in a patient with falsely elevated calcitonin |
| title_full | Multiple immunoassay interference in a patient with falsely elevated calcitonin |
| title_fullStr | Multiple immunoassay interference in a patient with falsely elevated calcitonin |
| title_full_unstemmed | Multiple immunoassay interference in a patient with falsely elevated calcitonin |
| title_short | Multiple immunoassay interference in a patient with falsely elevated calcitonin |
| title_sort | multiple immunoassay interference in a patient with falsely elevated calcitonin |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2359-39972024000101603&lng=en&tlng=en |
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