Two of the genes are linked to the innate immune response, while three are tied to inflammation and lung damage.
There are certain genes that instruct the body to make more ACE2 receptors, which the coronavirus uses to invade cells. The genes are associated with a weaker innate immune response and more aggressive inflammation, Business Insider reports.
NEW STUDY OPENS DOOR FOR FOCUSSED COVID-19 TREATMENTS
The new study compared more than 2,200 coronavirus patients in UK intensive care units to patients of similar ancestry who had not tested positive for COVID-19.
The critically ill patients were found to have a lower expression of IFNAR2.The gene helps code for proteins called interferons and act as an emergency flare to warn the immune system of an intruder.
The patients also displayed a variation in a cluster of genes called OAS which normally helps prevent a virus from replicating.
The critically ill patients had higher expressions of the genes TYK2 and CCR2 which can drive inflammation and potentially lead to lung injury. They displayed a variation in the gene DPP9 which scientists have linked to pulmonary fibrosis, a condition that causes damaged or scarred lung tissue.
STRONG IMMUNE SYSTEM NEEDED
Our immune system dispatches white blood cells when it senses a foreign invader to destroy the threat. The immune response in some people, however, is not strong enough to conquer the coronavirus right away. This can trigger aggressive inflammation that damages healthy tissue or leads to organ failure.
Other factors, including age and underlying health conditions, also play a role in severe COVID-19 cases.
CLUES ON HOW TO TREAT COVID-19 PATIENTS
The Edinburgh researchers also found clues about how to treat patients.
Business Insider quoted a Reuters article in which Kenneth Baillie, an academic consultant in critical care medicine who co-led the research, said: “Our results immediately highlight which drugs should be at the top of the list for clinical testing.”
Drugs that boost the expression of INFAR2 might help patients fight the virus before it wreaks havoc in the body.
One potential treatment, a multiple sclerosis drug called Rebif, is attempting a similar approach by giving patients a boost of interferon. Merck, the company behind the drug, hopes the therapy might prevent the coronavirus from replicating.
DRUGS TARGETING INFLAMMATION PLAY KEY ROLE
The Edinburgh study also suggests drugs targeting inflammation could potentially halt the disease’s progression. The researchers in particular pointed to a class of anti-inflammatory drugs called Janus kinase (JAK) inhibitors, already being used to treat rheumatoid arthritis.
An arthritis drug, Eli Lilly’s baricitinib, was recently authorised by the FDA for use in combination with remdesivir.
Baricitinib targets TYK2 which is one of the highly expressed genes found in critically ill patients. Eli Lilly announced in September that, together, baricitinib and remdesivir reduced patients’ average recovery time by one day compared to patients who only received remdesivir.
The findings shed light on where the immune system goes wrong, which could help identify new treatments and why some develop more severe COVID-19 cases than others.