Calcitonin Screening – Consideration of Heterophilic Antibody Interference in a Case of Obscure HypercalcitoninemiaCalcitonin-Screening – Heterophile Antikörperinterferenz als Ursache unklarer HypercalcitoninämieThis study was funded exclusively with intramural grants from the Jena University Hospital.
20 January 2020 (online)
Medullary thyroid carcinomas (MTCs) are rare tumors originating from the parafollicular C-cells and accounting for up to 10 % of all malignant thyroid neoplasms . Because an early diagnosis is crucial for the prognosis, single calcitonin screening is recommended in nodular thyroid disease by German and European guidelines while the American guidelines are more restrained . However, a large German cohort study based on health-insurance data revealed that calcitonin screening has only been performed in 9 % among patients who underwent surgery . Reasons for the missing establishment in clinical practice are manifold containing uncertain upper limits, diagnostic ambiguities in case of slightly or mildly elevated calcitonin values, the rareness of MTCs, and the low test specificity in case of renal failure, proton-pump inhibitor medication, other malignancies, hypercalcemia, hypergastrinemia, various gastrointestinal and pulmonary diseases and non-medullary benign and malignant thyroid nodules . Nonetheless, in our experience the method is gaining in acceptance as normal calcitonin levels can preclude the presence of MTCs. On the other hand, MTCs are highly probable at basal calcitonin levels of > 30 pg/ml in women and > 60 pg/ml in men, leading to the recommendation of consecutive thyroidectomy .
However, the automated immunometric assays used for calcitonin measurements are at risk of false results due to methodological specifics. Unintended metabolites such as heterophilic antibodies or macrocalcitonin may cause false results . We report a clinically important case of obscure hypercalcitoninemia due to heterophilic antibody interference.
- 1 Kim JM, Chung KW, Kim SW. et al. Spurious hypercalcitoninemia in patients with nodular thyroid disease induced by heterophilic antibodies. Head Neck 2010; 32 (01) 68-75
- 2 Frank-Raue K, Schott M, Raue F. Recommendation for Calcitonin Screening in Nodular Goiter. Dtsch Med Wochenschr 2018; 143 (15) 1065-1069
- 3 Wienhold R, Scholz M, Adler JR. et al. The management of thyroid nodules: a retrospective analysis of health insurance data. Dtsch Arztebl Int 2013; 110 (49) 827-834
- 4 Giovanella L, Giordani I, Imperiali M. et al. Measuring procalcitonin to overcome heterophilic-antibody-induced spurious hypercalcitoninemia. Clin Chem Lab Med 2018; 56 (08) e191-e193
- 5 Censi S, Cavedon E, Fernando SW. et al. Calcitonin measurement and immunoassay interference: a case report and literature review. Clin Chem Lab Med 2016; 54 (12) 1861-1870