<abstract xmlns="http://www.w3.org/1999/xhtml">

<bold>Introduction</bold>: Anti-thyroid peroxidase autoantibodies (TPO) is an essential diagnostic tool for autoimmune disorders of the thyroid gland. However, TPO results are not always comparable due to differences between methods. Here, we aimed to investigate the differences between two modern laboratory methods for TPO measurement: electrochemiluminescence (ECLIA) and chemiluminescence microparticle (CMIA) immunoassays.
<bold>Methods</bold>: A total of 234 serum samples were tested on two methods: Cobas-e601 (ECLIA) and Alinity i (CMIA). TPO results were compared statistically both quantitatively and qualitatively (results were coded as positive/negative, according to ECLIA/CMIA reference ranges.
<bold>Results</bold>: The precisions of both methods were acceptable compared with the claims of the manufacturer. There was a very strong, but unsatisfactory correlation between the two methods (Pearson r=0.85). Passing-Bablok regression revealed a significant deviation from linearity (Cusum p&lt;0.01) and an unacceptable quantitative relationship: intercept −7.61, slope 1.10. Moreover, a visual analysis of overall and medical decision level-focused Bland-Altman plots confirmed the lack of quantitative agreement. As for the qualitative analysis, the concordance rate between methods was 218/234 (93.1%). The agreement was considered good to very good according to the inter-rater agreement test: weighted Cohen κ = 0.805.
<bold>Conclusions</bold>: The qualitative agreement between Cobas-e601 (ECLIA) and Alinity i (CMIA) was good, therefore the two methods may be used indiscriminately for initial testing of patients suspected of thyroid gland autoimmune diseases. However, due to poor quantitative agreement, the two methods should not be used interchangeably for monitoring as the results may mislead both physicians and patients, possibly leading to medical errors.
</abstract>

Introduction: Anti-thyroid peroxidase autoantibodies (TPO) is an essential diagnostic tool for autoimmune disorders of the thyroid gland. However, TPO results are not always comparable due to differences between methods. Here, we aimed to investigate the differences between two modern laboratory methods for TPO measurement: electrochemiluminescence (ECLIA) and chemiluminescence microparticle (CMIA) immunoassays.
Methods: A total of 234 serum samples were tested on two methods: Cobas-e601 (ECLIA) and Alinity i (CMIA). TPO results were compared statistically both quantitatively and qualitatively (results were coded as positive/negative, according to ECLIA/CMIA reference ranges.
Results: The precisions of both methods were acceptable compared with the claims of the manufacturer. There was a very strong, but unsatisfactory correlation between the two methods (Pearson r=0.85). Passing-Bablok regression revealed a significant deviation from linearity (Cusum p<0.01) and an unacceptable quantitative relationship: intercept −7.61, slope 1.10. Moreover, a visual analysis of overall and medical decision level-focused Bland-Altman plots confirmed the lack of quantitative agreement. As for the qualitative analysis, the concordance rate between methods was 218/234 (93.1%). The agreement was considered good to very good according to the inter-rater agreement test: weighted Cohen κ = 0.805.
Conclusions: The qualitative agreement between Cobas-e601 (ECLIA) and Alinity i (CMIA) was good, therefore the two methods may be used indiscriminately for initial testing of patients suspected of thyroid gland autoimmune diseases. However, due to poor quantitative agreement, the two methods should not be used interchangeably for monitoring as the results may mislead both physicians and patients, possibly leading to medical errors.

Anti-thyroid peroxidase (TPO) antibodies – Comparative analysis of two automatic methods, ECLIA and CMIA

George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures

Revista Romana de Medicina de Laborator

This work is licensed under the Creative Commons Attribution 4.0 International License.

Introduction: Anti-thyroid peroxidase autoantibodies (TPO) is an essential diagnostic tool for autoimmune disorders of the thyroid gland. However, TPO results...

Anti-thyroid peroxidase (TPO) antibodies – Comparative analysis of two automatic methods, ECLIA and CMIA

Published Online: Jan 29, 2024

Page range: 33 - 40

Received: Jan 05, 2024

Accepted: Jan 18, 2024

DOI: https://doi.org/10.2478/rrlm-2024-0009

Keywords
CMIA, ECLIA, method comparison, thyroid peroxidase antibodies, TPO

© 2024 Ion Bogdan Manescu et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Anti-thyroid peroxidase (TPO) antibodies – Comparative analysis of two automatic methods, ECLIA and CMIA

Published Online: Jan 29, 2024

Page range: 33 - 40

Received: Jan 05, 2024

Accepted: Jan 18, 2024

DOI: https://doi.org/10.2478/rrlm-2024-0009

KeywordsCMIA, ECLIA, method comparison, thyroid peroxidase antibodies, TPO

© 2024 Ion Bogdan Manescu et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
CMIA, ECLIA, method comparison, thyroid peroxidase antibodies, TPO