Elecsys^® IL-6

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 prescription use only by healthcare providers. 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.

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.

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.

• 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.