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Updated: May 5, 2026
Electrochemiluminescence Assays for Human Islet Autoantibodies
Published on: March 23, 2018
Analytical evaluation of the automated interleukin-6 assay on the Roche cobas e602 analyzer
Anastasia Gant Kanegusuku1, Timothy Carll1,2, Kiang-Teck J Yeo1,2
1Department of Pathology, University of Chicago, Chicago, IL, US.
Insights
This study validates the Roche Elecsys IL-6 assay, finding good analytical performance but a significant bias compared to other methods. This bias limits using multiple assays for monitoring interleukin-6 (IL-6) levels.
Area of Science:
- Clinical chemistry
- Immunology
- Biomarker validation
Background:
- Interleukin-6 (IL-6) is a key proinflammatory cytokine implicated in various inflammatory diseases.
- Accurate IL-6 measurement is crucial for disease monitoring and management.
- The Roche Elecsys IL-6 assay is an automated immunoassay with emergency use authorization.
Purpose of the Study:
- To evaluate the analytical performance of the automated Roche Elecsys IL-6 immunoassay.
- To assess the clinical performance of the Elecsys IL-6 assay by comparing it to a reference method.
- To determine the suitability of the assay for routine clinical use.
Main Methods:
- Precision, linearity, and interference studies were conducted for the Elecsys IL-6 assay.
- Analytical interference was assessed using hemoglobin, bilirubin, triglycerides, and biotin.
- Clinical performance was evaluated by comparing patient sample results with the V-PLEX Human IL-6 immunoassay.
Main Results:
- The Elecsys IL-6 assay demonstrated excellent precision (intra-assay CV <3%, interassay CV <5%) and a wide analytical range (1.5–4790 pg/mL).
- The assay showed tolerance to significant levels of common interferents.
- A systematic bias (slope bias of 2.95, mean difference of 152 pg/mL or 73%) was observed when compared to the V-PLEX assay.
Conclusions:
- The Roche Elecsys IL-6 assay exhibits robust analytical performance.
- A significant systematic bias between the Elecsys IL-6 and reference methods prevents interchangeable use for IL-6 monitoring.
- The automated, random-access nature of the Roche platform ensures IL-6 testing availability on demand.
Background:
Interleukin-6 (IL-6) is a proinflammatory cytokine that is associated with many inflammatory diseases. This validation study evaluates the automated Roche Elecsys IL-6 electrochemiluminescent immunoassay that has been granted emergency use authorization by the US Food and Drug Administration.
Methods:
The Elecsys IL-6 assay was evaluated for precision, linearity, interference (by hemoglobin, bilirubin, triglycerides, and biotin) and clinical performance was compared to the V-PLEX Human IL-6 immunoassay (Meso Scale Discovery), performed by a reference laboratory.
Results:
The Elecsys IL-6 assay is precise (intra-assay <3% coefficient of variation [CV], interassay <5% CV), exhibits an analytical measurable range of 1.5-4790 pg/mL, and is tolerant of significant interferences (H < 2522, I <62, L<2101, biotin <50 ng/mL). Comparison with the V-PLEX assay revealed a 2.95 slope bias in patient samples evaluated for IL-6 concentration (n = 43, range = 1.5-1891 pg/mL, y = 2.95x - 32.7, r2 = 0.84). Bland-Altman analysis revealed an absolute mean bias of 152 pg/mL (SD = 254 pg/mL), or a mean percentage difference of 73%.
Conclusion:
The Roche IL-6 assay showed good analytical performance. The large systematic bias compared with another reference method precludes using multiple methods to monitor IL-6 response. The random-access nature of an automated IL-6 assay on the Roche platform makes the test available on demand.
