scholarly journals Interference Due to Heterophilic Antibody, Biotin and Thyroid Hormone Autoantibody

2021 ◽  
Author(s):  
jiajia ni ◽  
long yu ◽  
jingyi li ◽  
li zhang ◽  
qingqing yang ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Function ◽  
Diagnostic Strategy ◽  
Thyroid Function Testing ◽  
Other Substances ◽  
Polyethylene Glycol Precipitation ◽  
Radioimmunoprecipitation Assay ◽  
New Generation ◽  
Function Testing ◽  
Heterophilic Antibody

Abstract Purpose: Immunoassay is susceptible to interference by other substances in the serum. The main substances interfering with thyroid function testing include heterophilic antibody, biotin, thyroid hormone autoantibody, and Macro-TSH. We reported a patient with fraudulently elevated FT4 and TSH and described various common experimental methods used to explore the existence of substances interfering with thyroid function testing.Methods and Results: FT4 and TSH were significantly lower when measured on the Architect platform (FT4: 7.09 pmol/L, TSH: 58.94 µIU/ml). Polyethylene glycol precipitation showed lower FT4 and TSH, suggesting the presence of a high molecular weight interfering substance. Heterophile blocking tube study showed heterophilic antibody interfered with TSH detection. 125I-hTSH binding study and radioimmunoprecipitation assay indicated that the patient didn’t contain anti-TSH autoantibody. The new generation of Elecsys immunoassay kit indicated that biotin interfered with TSH detection. Radioimmunoprecipitation assay showed that all four kinds of thyroid hormone autoantibodies were positive. After reviewing 24 literatures, we provided the diagnostic strategy for investigation of interferences with thyroid function immunoassays.Conclusion: We reported a case with falsely elevated TSH due to the combined action of heterophilic antibody and biotin and fraudulently elevated FT4 caused by thyroid hormone autoantibody. When there is a discrepancy between thyroid function and clinical manifestation, the presence of immunoassay interference with one or more indicators needs to be considered.

scholarly journals Alternative Sequences of Thyrotropin and Free Thyroxine Assays for Routine Thyroid Function Testing

1998 ◽  
Vol 158 (3) ◽  
pp. 266 ◽  
Author(s):  
Robert A. Nordyke ◽  
Thomas S. Reppun ◽  
Lynn D. Madanay ◽  
Joseph C. Woods ◽  
Alan P. Goldstein ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Free Thyroxine ◽  
Thyroid Function Testing ◽  
Function Testing

scholarly journals Case Report: De Quervain’s Thyroiditis as a Long-Term Sequelae Complication to SARS-CoV-2 Infection

2021 ◽  
pp. 64-70
Author(s):  
Mark Kong ◽  
Sarah La Porte
Keyword(s):  
Case Report ◽  
Thyroid Function ◽  
Elevated Serum ◽  
Subacute Thyroiditis ◽  
Thyroid Function Tests ◽  
Thyroid Function Testing ◽  
Neck Lump ◽  
Function Testing

A 44-year-old man presented with an enlarged painful lower anterior neck lump with elevated serum concentrations of free thyroxine (T4) and tri-iodothyronine (T3), alongside the presence of antithyroid peroxidase antibodies. Prior to presentation, the patient was demonstrating recovery from a SARS-CoV-2 infection that required sedation, intubation, and invasive ventilation in the intensive care unit (ICU) for 11 days. Ultrasound examination of the thyroid demonstrated features of De Quervain’s (subacute) thyroiditis. This corresponded to the clinical picture, and continuous thyroid function tests were arranged. Emerging evidence throughout the SARS-CoV-2 pandemic describes the long-term sequelae of the infection, including developing atypical effects on the thyroid gland. This case report emphasises the association of painful subacute thyroiditis with post-viral infection and its manifestation during recovery from severe SARS-CoV-2, suggesting that follow-up thyroid function testing should be considered in patients discharged from the ICU who develop neck discomfort.

scholarly journals Rationalizing Thyroid Function Testing: Which TSH Cutoffs Are Optimal for Testing Free T4?

2017 ◽  
Vol 102 (11) ◽  
pp. 4235-4241 ◽  
Author(s):  
Meg Henze ◽  
Suzanne J Brown ◽  
Narelle C Hadlow ◽  
John P Walsh
Keyword(s):  
Thyroid Function ◽  
Reference Range ◽  
Health Study ◽  
Free T4 ◽  
Clinical Cohort ◽  
Thyroid Function Testing ◽  
Reflex Testing ◽  
Study Participants ◽  
Function Testing ◽  
Tsh Levels

Abstract Context Thyroid function testing often uses thyrotropin (TSH) measurement first, followed by reflex testing for free thyroxine (T4) if TSH is outside the reference range. The utility of different TSH cutoffs for reflex testing is unknown. Objective To examine different TSH cutoffs for reflex free T4 testing. Design, Setting, and Patients We analyzed concurrent TSH and free T4 results from 120,403 individuals from a single laboratory in Western Australia (clinical cohort) and 4568 Busselton Health Study participants (community cohort). Results In the clinical cohort, restricting free T4 measurement to individuals with TSH <0.3 or >5.0 mU/L resulted in a 22% reduction in free T4 testing compared with a TSH reference range of 0.4 to 4.0 mU/L; using TSH cutoffs of 0.2 and 6.0 mU/L resulted in a 34% reduction in free T4 testing. In the community cohort, the corresponding effect was less: 3.3% and 4.8% reduction in free T4 testing. In the clinical cohort, using TSH cutoffs of 0.2 and 6.0 mU/L, elevated free T4 would go undetected in 4.2% of individuals with TSH levels of 0.2 to 0.4 mU/L. In most, free T4 was marginally elevated and unlikely to indicate clinically relevant hyperthyroidism. Low free T4 would go undetected in 2.5% of individuals with TSH levels of 4 to 6 mU/L; in 94%, free T4 was marginally reduced and unlikely to indicate clinically relevant hypothyroidism. Conclusions Setting TSH cutoffs at 0.1 to 0.2 mU/L less than and 1 to 2 mU/L greater than the reference range for reflex testing of free T4 would reduce the need for free T4 testing, with minimal effect on case finding.

Sign in / Sign up

Export Citation Format

Share Document