In some COVID-19 positive people, the ill conditions improve for some time and then worsen suddenly. Commonly, such people face severe respiratory problems called acute respiratory distress syndrome.
Experts say that after infection is controlled, still it can cause a hyper-inflammation of lungs and other organs.
Studies find inflammation to be a cause of response of receptors in immune cells called macrophage, against the genetic material of viruses such as SARS-CoV-2. Immune cells respond in such a way that they release a lot of immune-signalling molecules called cytokines.
The “cytokine storm” causes inflammation which damages lungs and other organs. Until now, there is no treatment for the damage.
The cause of cytokine storm is an enzyme named Bruton’s tyrosine kinase (BTK), present in macrophages.
A drug is used in treatment for blood cancer which inhibits activity of BTK. It is called acalabrutinib.
Damping down inflammation:
Researchers at the National Cancer Institute, in the United States, realized that since acalabrutinib can inhibit BTK, it should be useful to reduce inflammation due to COVID-19.
To prove this, they collaborated with scientists at the National Institute of Allergy and Infectious Diseases, the Walter Reed National Military Medical Center, and other four hospitals in the US.
The results of the studies are published in journal Science Immunology.
The study examined the patients for about 10-14 days. 19 COVID-19 patients were given the drug. When the research started, patients had serious respiratory problems. 11 were breathing with the help of oxygen masks. Other eight were on ventilators.
By the end of 14 days, eight of the patients who were breathing with masks, were discharged and had no need of masks anymore. Two of the patients had died. However, the drug was not the cause, it was harmless.
The researchers also monitored two markers of inflammation in the blood — levels of a cytokine called interleukin 6 (IL-6) and C-reactive protein (CRP).
Out of the 11 patients supported on supplemental oxygen, ten had returned to normal and one was recovering. Five patients who had had IL-6 levels measured, three had returned to normal and level of two had fallen.
“The oxygenation and clinical status of most patients on supplemental oxygen improved relatively rapidly following acalabrutinib initiation,” the researchers write.
“Although the patients on mechanical ventilation had a more variable clinical response to acalabrutinib, improved oxygenation in half of these patients allowed them to be extubated.”
White blood cells are responsible for protection of the body and are a part of our immune system. Number of lymphocytes, a type of white blood cell, was also increased in patient’s bodies. This is also helpful as COVID-19 patients with low white blood cells are at higher risk.
The research team also observed that many factors causing coronavirus such as obesity, hypertension, atherosclerosis, and diabetes type 2 are linked with inflammation.
Inflammation already existing can be the cause of making these people particularly vulnerable to severe SARS-CoV-2 infections.
There are other ways to damping down immune response of patients such as monoclonal antibodies that target IL-6.
However, the researchers of this study say that the way they had discovered it the best among all the known. The reason is that it solves the problem from its base, in macrophages.
There are different cytokine storms. In COVID-19 patients, several cytokines levels are elevated. If we target one of them, this would not be enough. It can only reduce the inflammation partially.
Researches did this study at very small scale and it had no control group. However, its results are very promising. A much larger, randomized controlled clinical trial been launched. It will have international involvement.