IL-6 testing as a standard for COVID-19 patients

Lab Directors know that physicians quickly learn which test results are helpful and end up only running those tests to help care for their patients.

At Norton Healthcare in Louisville, Kentucky, Dr. Joshua Hayden saw this with interleukin-6  (IL-6) testing for COVID-19 patients. 

“There was a wake-up call when physicians saw how helpful IL-6 was; they asked us to move the testing period from 24 to 12 hours. Now, the testing period is during presentation without waiting for a diagnosis. The clinical uptick is the most telling sign that the IL-6 laboratory results are impacting patient care and management,” said Dr. Joshua Hayden, Ph.D., DABCC, Chief of Chemistry, Norton Healthcare.


IL-6 and COVID-19

Acute respiratory distress syndrome (ARDS) and multiple organ dysfunction are among the leading causes of death in critically ill patients with COVID-19 . Elevated interleukin-6 (IL-6) is a hallmark inflammatory signature seen in the serum of patients with severe COVID-19 acute respiratory distress ii .

Before the COVID-19 pandemic, Norton Healthcare did not offer in-house IL-6 testing, as they did not have an appreciable send-out volume. However, in mid-to-late March, as COVID-19 started to progress, Dr. Joshua Hayden and his team discussed standard COVID-19 laboratory tests with the Norton Healthcare leadership team. 

Based on data and literature from China, albeit preliminary and not peer-reviewed, the Norton Healthcare team saw strong support of elevated levels of IL-6 as a portent of poor outcomes for COVID-19 patients. IL-6 was seen as a way to stratify patients under intensive therapy.

Bringing IL-6 to Norton Healthcare

Once Norton Healthcare decided to bring IL-6 in-house, they wanted rapid deployment to support COVID-19 patient care as the need was urgent.

“Initially, IL-6 tests were done every 24 hours on confirmed COVID-19 patients to monitor which patients may need more intensive monitoring and treatment and to make decisions on which level of care they needed, in-patient versus ICU,” said Dr. Hayden.

IL-6 gained even more traction at Norton Healthcare when the system’s research team initiated several clinical trials around the world showing promise with regard to patient disposition and management. “We saw that IL-6 really jumped up in severe COVID-19 patients within 24 hours and this was exactly consistent with how the patient progressed clinically,” said Dr. Hayden. “Once the providers saw this, they started to request we test COVID-19 patients every 12 hours.”

The Norton Healthcare team relies on IL-6 because of the cytokine’s kinetics. Unlike c-reactive protein (CRP) levels where physicians had to wait to see the differentiation, IL-6 levels can rise very quickly in a patient, allowing for rapid detection of patients who need the most care.

“We have now expanded IL-6 use and patients are assessed upon presentation. This is helpful as we’re experiencing a delay in PCR testing. The IL-6 data provides an additional data point for providers as they make decisions about patients presenting with symptoms to determine the potential severity of the infection,” said Dr. Hayden.

IL-6 was also included as a lab marker of assessment of inflammation in Norton Children’s Hospital for children presenting Multisystem Inflammatory Syndrome (MIS-C) associated with COVID-19.

Improving COVID-19 patient care with IL-6

Norton Healthcare has been fortunate to have enough ICU beds and capacity during these challenging times; and has used IL-6 to monitor patients to see if they may benefit from additional levels of care. Some of the data seen by the Norton team gave them confidence that IL-6 was helpful in predicting which patents were going to get worse so physicians could recognize and respond before the actual symptoms adversely impacted the patient.

However, one of the key aspects of using IL-6 as a marker was to help keep patients off ventilators. According to a study that analyzed data from 5,700 patients hospitalized in a large health system in New York from March 1 to April 4, nearly 88% of patients with COVID-19 who were put on a ventilator died iii.

“Our goal is to keep patients off the ventilator as that’s the best way to help COVID-19 patients. IL-6 can help us treat the patient before they need a ventilator. The side effect of this is that we are able to reduce the number of patients on ventilators to preserve capacity if needed in a hospital,” said Dr. Hayden. 

“Any time you can have more objective measures, such as testing with IL-6 to predict which patients are going to get worse, it is helpful. I highly encourage places that have to make rationing decisions to use markers such as IL-6 to assist them.”

Disclaimer: For Use Under the Emergency Use Authorization (EUA) Only. For In Vitro Diagnostic Use. Access IL-6 is available in the U.S. under the FDA Emergency Use Authorization program as an aid in identifying COVID-19 patients at risk of intubation with mechanical ventilation.

Liu B, Li M, Zhou Z, Guan X, Xiang Y. Can we use interleukin-6 (IL-6) blockade for coronavirus disease 2019 (COVID-19)-induced cytokine release syndrome (CRS)? Journal of Autoimmunity. 2020 Jul;111:102452. DOI: 10.1016/j.jaut.2020.102452.
ii Wang Z , Yang B , Li Q , et al . Clinical features of 69 cases with coronavirus disease 2019 in Wuhan, China. Clin Infect Dis.doi:10.1093/cid/ciaa272 Google Scholar

iii Richardson S, Hirsch JS, Narasimhan M, et al. Presenting Characteristics, Comorbidities, and Outcomes Among 5700 Patients Hospitalized With COVID-19 in the New York City Area. JAMA. 2020;323(20):2052–2059. doi:10.1001/jama.2020.6775