A patient with a cytokine storm may have an abnormally fast heart rate, fever, and low blood pressure. Besides an increase in interleukin-6, the body may also have high swirling levels of molecules called interleukin-1, interferon-gamma, C-reactive protein, and tumor necrosis factor alpha.
This storm, if it develops, becomes evident a few days after infection. But the sooner doctors dwell on it and treat it, the more likely the patient is to survive. Too late and the storm may be out of control or may have already caused too much damage.
There is a relatively simple, fast, and readily available test that can detect whether a patient’s body has been taken care of by a cytokine storm. He’s looking for high levels of a protein called ferritin.
But if the test suggests that a cytokine storm is underway, then what?
The seemingly obvious solution is to stifle the storm, said Dr. Cron: “If it’s the body’s response to the infection that is killing you, you have to deal with it. “
The reality is more delicate, especially given the lack of reliable data for Covid-19. But noting that drugs like tocilizumab are taken regularly by people with arthritis, Dr. Cron said the benefits would likely outweigh the potential harm if someone were threatened with death.
“We need evidence, but in a pandemic, where we fly near the seat of our pants, we always have to treat the patient in front of us,” he said.
Other drugs may also be useful for cytokine storms. For example, a drug called anakinra cuts interleukin-1, another of the capricious proteins. Clinical trials of anakinra for Covid-19 are also underway. A report released this week suggested that hydroxychloroquine, a high-profile malaria drug that also calms an overactive immune response, may also be effective as a treatment for those with mild coronavirus disease.