Elecsys® IL-6

Immunoassay to assist in identifying severe inflammatory response
For use under the Emergency Use Authorization (EUA) only

Elecsys IL-6

Using Elecsys IL-6, with other clinical findings, can help clinicians quickly identify COVID-19 patients with severe inflammatory response who need mechanical ventilation.

Elecsys IL 6 immunoassay is an in vitro diagnostic test for the quantitative determination of IL 6 (interleukin 6) in human serum or plasma. This assay is used to assist in identifying severe inflammatory response in patients with confirmed COVID 19 illness to aid in determining the risk of intubation with mechanical ventilation, in conjunction with clinical findings and the results of other laboratory testing.

The Elecsys IL-6 immunoassay is an electrochemiluminescence immunoassay “ECLIA” and is intended for use on cobas e immunoassay analyzers.

The Elecsys IL‑6 immunoassay is only for use under the Food and Drug Administration’s Emergency Use Authorization. For use by health care providers. For prescription use only. For in vitro diagnostic use only. Testing is limited to laboratories certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, to perform moderate and high complexity tests.

IL-6 in COVID-19 induced Cytokine Storms1,2,3,4

COVID-19 illness can manifest as viral induced hyperinflammation with multi-organ involvement due to a cytokine cascade. Overproduction of early response proinflammatory cytokines results in a “cytokine storm” that leads to severe downstream effects that include development and progression of Acute Respiratory Distress Syndrome (ARDS).  Elevated circulating concentrations of IL-6, a key mediator of inflammation, can serve as an early alarm signal of SARS-CoV-2 infection-triggered hyperinflammation, helping clinicians identify this hyperinflammatory process in severely ill COVID-19 patients.

IL-6 Role in Assessing the Risk of Intubation5

A subset of severely ill COVID-19 patients experience rapid deterioration and need for mechanical ventilation due to development of ARDS. The following clinical data are from Munich, Germany from polymerase chain reaction (PCR) confirmed symptomatic COVID‑19 patients presenting in the Emergency Department (ED).

  • In this validation data set of 49 hospitalized patients, 19 patients required intubation for respiratory support subsequent to ED presentation. The Elecsys IL‑6 assay, using a cutoff of 35 pg/mL at presentation, correctly identified 16 of the 19 patients that required intubation.

Mechanical Ventilation Patients (n=19) cutoff > 35pg/mL


Percent (%)

95% Confidence Interval

Positive Predictive Value 59 47-71%
Negative Predictive Value 86 68-95%
Prevalence of Mechanical Ventilation in COVID-19 Confirmed, hospitalized patients 39 25-54%

  • The cutoff was established retrospectively (n = 37) and validated prospectively (n = 49) based on the need for mechanical ventilation during the hospitalization. 

The receiver operator curve was calculated for the first assessment value of Elecsys IL‑6 at presentation to the ED.

Using an IL-6 cutoff of 35 pg/mL for PCR confirmed COVID-19 patients at presentation, in conjunction with clinical findings, may prove IL-6 to be a useful tool for clinicians to identify the risk for mechanical ventilation during hospitalization. This helps to provide an objective decision for ventilator resource allocation.


Elecsys IL-6

Elecsys® IL-6

  • Assay time

    18 min

  • Sample material

    Serum, Li-heparin and K2- and K3-EDTA plasma

  • Sample volume

    30 µL for e411, e601, and e602
    18µL for e801

  • Measuring range

    1.5 – 5,000 pg/mL

  • Analytical sensitivity

    1.5 pg/mL

  • Functional sensitivity

    5 pg/mL

  • Traceability

    WHO Standard NIBSC 1st IS 89/548


▪ This test has not been FDA cleared or approved

▪ This test has been authorized by FDA under an EUA for use by authorized laboratories

▪ This test has been authorized only to assist in identifying severe inflammatory response, when used as an aid in determining the risk of intubation with mechanical ventilation in confirmed COVID‑19 patients

▪ This test is only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of medical devices under Section 564(b)(1) of the Act, 21 U.S.C. § 360bbb‑3(b)(1), unless the authorization is terminated or revoked sooner



  1. Jose RJ. (2020). Lancet Resp Med. doi: 10.1016/S2213-2600(20)30216-2
  2. Mehta P, et al. Lancet. (2020). 395:1033-4
  3. Herold T et al. J Allerg and Clin Immunol (2020), doi: https://doi.org/10.1016/j.jaci.2020.05.008
  4. Ye Q et al J Infect (2020) doi:10.1016/j.jinf.2020.03.037
  5. Elecsys IL-6 Package Insert 2020-06, V1.0; Material Numbers 05109442190 and 07027532190

cobas e 801 module

  • Throughput of up to 300 tests/hour
  • 48 reagent positions

Part of the cobas 8000 modular analyzer series and cobas pro integrated solutions.

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cobas e 602 module

  • Throughput of up to 170 tests/hour
  • 25 reagent positions

Part of the cobas 8000 modular analyzer series.

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cobas e 601 module

  • Throughput of up to 170 tests/hour
  • 25 reagent positions

Part of the cobas 6000 modular analyzer series.

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cobas e 411 analyzer

  • Up to 86 tests/hour
  • Benchtop 

Part of the cobas 4000 modular analyzer series.

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