Health & Wellbeing

Simple blood test predicts patients most likely to die from COVID-19

Simple blood test predicts pat...
New research has found a biomarker commonly measured in routine blood tests can predict mortality risk from COVID-19
New research has found a biomarker commonly measured in routine blood tests can predict mortality risk from COVID-19
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New research has found a biomarker commonly measured in routine blood tests can predict mortality risk from COVID-19
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New research has found a biomarker commonly measured in routine blood tests can predict mortality risk from COVID-19

One of the big challenges healthcare workers are facing in this global pandemic is identifying those COVID-19 patients most at risk of severe illness and death. COVID-19 certainly is more dangerous, on average, in the elderly or those with pre-existing health problems, but that doesn’t preclude a 96-year-old from presenting with no symptoms, or a healthy 21-year-old losing her life. A team of researchers from Massachusetts General Hospital have been trawling through hospital admission data to find some way to help doctors better assess those patients most at risk of suffering the worst effects of the disease.

The researchers analyzed blood samples from 1,641 patients admitted to Boston hospitals with COVID-19 earlier this year. The plan was to closely study the samples to identify any particular molecular patterns that could predict disease severity. Before looking at more complicated blood-based biomarkers the researchers first looked at biomarkers gathered in the most routine blood tests.

"We were surprised to find that one standard test that quantifies the variation in size of red blood cells – called red cell distribution width, or RDW – was highly correlated with patient mortality, and the correlation persisted when controlling for other identified risk factors like patient age, some other lab tests, and some pre-existing illnesses," says co-author on the new study, Jonathan Carlson.

RDW is a very common metric gathered in most standard blood count tests. The new study found patients displaying an elevated RDW at time of admission were 2.7 times more likely to die from COVID-19. Elevated RDW was also more significantly associated with mortality in younger COVID-19 patients.

The study also notes that patients whose RDW was seen to increase during hospitalization were more likely to suffer worse outcomes from the disease. The researchers suggest this indicates RDW may be a useful biomarker to track the progress of a patient while admitted in hospital.

RDW has been previously determined to be an effective non-specific biomarker of illness, and the researchers do note it is unlikely there is a direct causal relationship at play. But, what is important here is the routine nature of RDW measurements gathered in common blood testing.

A number of similar studies have been published over the past few months exploring blood-based biomarkers to identify patients most as risk of death or severe illness from COVID-19. Many researchers have homed in on particular blood biomarker patterns that can be associated with the worst outcomes, however, not many of those blood measurements are as simple and routine to collect as RDW measurements.

The finding needs further validation in broader cohorts of patients, but if confirmed, this simple laboratory test may be a useful way to detect those COVID-19 patients most in need of clinical care.

The new research was published in the journal JAMA Network Open.

Source: Massachusetts General Hospital

4 comments
Nobody
Most of the studies that I have read indicate the vitamin D level was a major factor in the severity of the virus. Vitamins C and zinc also seem to play a role.
drBill
I had not known RDW changed with age (from reading the linked article in JAMA), Interesting.
see3d
Yes vitamin D3 blood status below a certain number seems to be a much stronger indicator then this RDW factor. However, vitamin D3 status is not routinely measured, otherwise they would have found this correlation. A few small studies have found as much as a "15 Fold Higher Risk of Death due to COVID-19 with Vitamin D Level Below 12 ng/ml". Since most of the world's population (especially the elderly and darker skinned), are deficient in vitamin D, this is a real danger. The answer is literally under our noses, and few are taking notice. A large scale study needs to be done, though there is nothing stopping people from taking a D3 supplement on their own. US RDA is 2,000 IU/day. Seems this would make a good research article for New Atlas.
Brian Artzberger
MCV is an indirect test for a patients B-vitamin status. An elevated MCV usually relates to a deficiency of one or more B-vitamins. It would be interesting to see the B-vitamin levels of those most severely affected by the CCP virus. Of note a HCQ deficiency increases death rate by 51-75%.