CLINICIANS DILEMMA: FALSELY UNDETECTED TSH LEVELS DUE TO TSH ISOFORM ON POPULAR COMMERCIAL IMMUNOASSAY IN INDIAN SUBJECT AND RETROSPECTIVE ANALYSIS

Main Article Content

PAWAN KUMAR
PARUL SHARMA
MEGHA TOMAR
RAVI TOMAR

Abstract

Introduction: TSH is one of the most routinely measured tests the clinical laboratory to diagnose and monitor thyroid diseases. TSH as the preferred screening test as recommended by The American Thyroid Association and the American Association of Clinical Endocrinologists for diagnosing thyroid dysfunction. Third-generation Ultra serum TSH assays have a functional sensitivity of 0.001 uIU/mL and have been considered highest among biochemical assay for assessing thyroid disorders. However, as observed in many clinical laboratories sometimes results of TSH assays are discordant among different immunoassay platforms.

Case Report: TSH values of a 56 years old male on Siemens Attelica while TSH was found to be elevated on Abbott Architect 1000 and Beckman Coulter DXI800. Retrospective analysis revealed few other cases (8/190) approx. 4.2 % showed discordant TSH values. This was found to be possibly because of mutation in TSH beta region (R55G).

Conclusion: Our present study suggest that these individuals who shows <0.001 values on Siemens Attelica must be tested with other platforms to assure appropriate management of disease. Further, clinicians and laboratory staff need to be aware about TSH variants along with other reported interferences.

Keywords:
TSH, immunoassays, siemens attelica, TFT

Article Details

How to Cite
KUMAR, P., SHARMA, P., TOMAR, M., & TOMAR, R. (2022). CLINICIANS DILEMMA: FALSELY UNDETECTED TSH LEVELS DUE TO TSH ISOFORM ON POPULAR COMMERCIAL IMMUNOASSAY IN INDIAN SUBJECT AND RETROSPECTIVE ANALYSIS. Journal of Case Reports in Medical Science, 8(1), 1-3. Retrieved from https://ikpresse.com/index.php/JOCRIMS/article/view/7572
Section
Case Report

References

Edith T, Starich GH, Mazzaferri EL. Sensitivity, specificity, and cost effectiveness of the sensitive thyrotropin assay in the diagnosis of thyroid disease in ambulatory patients. Arch Intern Med. 1989;149(3):526–532.

Sheehan MT. Biochemical testing of the thyroid: TSH is the best and, oftentimes, only test needed - A review for primary care. Clin Med Res. 2016;14(2):83-92.
DOI: 10.3121/cmr.2016.1309

Demiral M, Kiraz ZK, Alataş IO, Cetin N, Kirel B. Pseudo-hyperthyroidism: Biotin interference in a case with renal failure. Acta Endocrinol (Buchar). 2021;17(3):319-322.
DOI: 10.4183/aeb.2021.319

Piketty ML, Polak M, Flechtner I, Gonzales Briceno L, Souberbielle JC. False biochemichal diagnosis of hyperthyroidism in streptavidin-biotin-based immunoassays: the problem of biotin intake and related interferences. Clin Chem Lab Med. 2017;55(6):780–788.

D'Arcy R, Hunter S, Spence K, McDonnell M. A Case of macro-TSH masquerading as subclinical hypothyroidism. BMJ Case Rep. 2021 Jul 12;14(7):e243436.
DOI: 10.1136/bcr-2021-243436

Mogolu S, Armston AE, Mozley E, Nasruddin A. Heterophilic antibody interference affecting multiple hormone assays: Is it due to rheumatoid factor? Scand J Clin Lab Invest. 2016;76(3):240–242.

Favresse J, Burlacu MC, Maiter D, Gruson D. Interferences with thyroid function immunoassays: Clinical implications and detection algorithm. Endocr Rev. 2018; 39(5):830–850.

Ismail AA, Walker L, Barth H, Lewandowski C, Jones R, Burr A. Wrong biochemistry results: Two case reports and observational study in 5310 patients on potentially misleading thyroid-stimulating hormone and gonadotropin immunoassay results. J Clin Chem. 2002;48(11):2023–2029.

Drees JC, Stone JA, Reamer CR, Arboleda VE, Huang K, Hrynkow J, et al. Falsely undetectable TSH in a cohort of south Asian euthyroid patients. J Clin Endocrinol Metabol. 2014;99(4):1171–1179.