A New Test Could Determine COVID-19 Severity

A common test could have uncommon importance for COVID-19 prognosis.

Posted May 12, 2020

Can a simple and inexpensive blood test predict how severe COVID-19 will be, and could this test be used as an early screening tool?

A small Italian study published yesterday in the International Journal of Antimicrobial Agents by Dr. Arturo Ciccullo and colleagues suggests that a blood test measuring two different kinds of white blood cells could do just that.

Ciccullo studied the blood of 74 patients (51 males and 23 females) admitted to a hospital in Rome, Italy in March 2020. The team was especially interested in two kinds of white blood cells, both an important part of the immune system: neutrophil and lymphocyte cells.  

Ciccullo noticed that when the number of neutrophils was four times or more the number of lymphocytes (Neutrophils to Lymphocytes Ratio or NLR), the patients were more likely to have a severe form of COVID-19 and to have to be transferred to the ICU.

The medical team concluded that transfer to the ICU was predicted by a Neutrophils to Lymphocyte Ratio of over four, whereas clinical improvement was predicted by younger age and a Neutrophils to Lymphocyte Ratio below three.

Chuan Qin and colleagues from Wuhan, China had already alerted in their publication in Clinical Infectious Diseases (March 2020) that the novel coronavirus seemed to destroy lymphocytes (especially T-lymphocytes) needed to combat the virus effectively, so patients with a high Neutrophils to Lymphocytes Ratio had a worse prognosis (study done on 452 patients with COVID-19). 

Qin suggested that the Neutrophils to Lymphocytes Ratio be used as an early screening of critical illness. 

Why is this important?

If you or your loved one has to go to the emergency room for COVID-19 symptoms, you may want to ask what the Neutrophils to Lymphocytes Ratio is (The number of neutrophils and lymphocytes is a routine, simple and inexpensive blood test that is systematically done on almost everybody who comes into the ER). 

If your NLR or your loved one’s NLR is higher than four, discuss whether a more aggressive treatment should be given early with your physicians.

That treatment might include oxygen, anticoagulants if you are at risk of having blood clots, and the latest effective antiviral drug or combination of drugs.

A recent study published in The Lancet on May 8, 2020, by Pr. Ivan Fan Ngai Hung and colleagues from Hong Kong University show that a combination of four drugs—Lopinavir, Ritonavir, Ribavirin and Interferon beta—seems to be effective against the novel coronavirus in mild to moderate COVID-19 cases.

But since treatments and guidelines are changing every day, if you or your loved one is hospitalized, check with your doctor what the latest most effective treatment is.

References

https://www.sciencedirect.com/science/article/pii/S0924857920301801

https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa248/5803306

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31042-4/fulltex