Related Experiment Video
Updated: Jan 11, 2026

Generation of a Mouse Spontaneous Autoimmune Thyroiditis Model
Published on: March 17, 2023
Variation in Thyroid Function Tests in Acute Scrub Typhus Infection
Sai N Gogineni1, Adlyne R Asirvatham1, Vasireddy N Tara1
1Department of Endocrinology and Metabolism, SRMC, Porur, Chennai, Tamil Nadu, India.
Introduction:
Immunoassays used to measure thyroid function tests (TFTs) are prone to interference due to several factors that could potentially affect clinical decisions. With increased awareness and frequency of testing TFT, even 1% prevalence of assay interferences would possibly increase the occurrence of deranged TFT significantly. In this study, we report six cases of thyroid hormone assay interference in acute scrub typhus infection.
Methods:
A prospective observational study was conducted in patients admitted with acute scrub typhus infection. TFT was done for some indication that showed discordance with clinical suspicion. Initial assay was performed by electrochemiluminescence immunoassay (ECLIA) using a Roche Cobas e411 analyzer, which was verified by Chemiluminescent Microparticle Immuno Assay (CMIA) with an ARCHITECT i1000SR analyzer.
Results:
Initial TFT done by ECLIA showed elevated FT4 and FT3(FT4>> FT3) with a normal or low-normal TSH in all cases. Samples were re-analyzed in the CMIA platform within 24 hours, which showed normal TFT, raising the suspicion of assay interference. TFT performed by ECLIA 6 weeks after recovery was normal in all patients.
Conclusion:
Assay interference with TFT should always be considered when there is a discrepancy between clinical suspicion and biochemical values. It is prudent to confirm abnormal values on another platform to avoid misdiagnosis and unwarranted therapeutic decisions.
Related Concept Videos
Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...
Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
Myocarditis II: Clinical Features and Diagnostic Tests
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test
Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
Acute Pharyngitis
Acute pharyngitis is the inflammation of the back of the throat (pharynx), commonly resulting in a sore throat. It is a frequently encountered condition that prompts individuals to seek medical advice.
Classification
Acute pharyngitis can be categorized based on its underlying cause:

