Comparison of IL-6 measurement methods with a special emphasis on COVID-19 patients according to equipment and sample type

Yu Jeong Choi, Juhye Roh, Sinyoung Kim, Kyung A. Lee, Younhee Park

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Background: Interleukin-6 (IL-6) is a multifunctional cytokine associated with various diseases, including coronavirus disease (COVID-19). Although IL-6 levels can be assessed using serum samples, use of the AFIAS (Boditech Med Inc.) automated immunoassay analyzer enables quick and simple measurement of IL-6 levels in both serum and whole blood specimens. This study aimed to assess the correlation between IL-6 measurements obtained from the AFIAS IL-6 assay and Elecsys IL-6 assay (Roche Diagnostics). Additionally, utilization of the AFIAS IL-6 assay was evaluated. Methods: The IL-6 levels from 113 serum samples quantified using two assay systems were evaluated for their degree of correlation. Meanwhile, the linearity, analytical sensitivity, and precision/reproducibility of the AFIAS IL-6 assay were also assessed. Results: Quantification of IL-6 with the AFIAS IL-6 and Elecsys IL-6 assays showed excellent agreement (kappa 0.802) and were found to be correlated (y = −0.2781 + 1.068x; 95% confidence interval: 1.007–1.124). AFIAS IL-6 showed good analytical performances. IL-6 levels were significantly higher in deceased patients compared to those with non-complicated disease and those who were intubated (p = 0.002 and p < 0.0001, respectively). Finally, IL-6 levels more accurately predicted poor prognosis in patients, than did C-reactive protein (area under the curve, 0.716 vs. 0.634). Conclusion: The overall analytical performance of the AFIAS assay was comparable to that of the Elecsys IL-6 assay. In light of the ongoing COVID-19 pandemic, the AFIAS may be an attractive tool for measuring IL-6 levels.

Original languageEnglish
Article numbere24182
JournalJournal of Clinical Laboratory Analysis
Issue number1
Publication statusPublished - 2022 Jan

Bibliographical note

Publisher Copyright:
© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.

All Science Journal Classification (ASJC) codes

  • Immunology and Allergy
  • Hematology
  • Public Health, Environmental and Occupational Health
  • Clinical Biochemistry
  • Medical Laboratory Technology
  • Biochemistry, medical
  • Microbiology (medical)


Dive into the research topics of 'Comparison of IL-6 measurement methods with a special emphasis on COVID-19 patients according to equipment and sample type'. Together they form a unique fingerprint.

Cite this