SALT LAKE CITY: Your blood type does not take into account the risk of contracting COVID-19 or developing a serious case, according to researchers from Intermountain Healthcare and other institutions.
Their findings, published in the Journal of the American Medical Association earlier this month, contrast previous global studies and research suggesting that blood type was a factor in why some people suffered from COVID-19 symptoms more than others.
“I think it’s important because it’s been, for us, really one of our main goals to identify patients at higher risk and to get risk scores,” said Dr. Jeffrey Anderson, a cardiologist and researcher at Intermountain Medical. Center Heart Institute, and the study’s lead researcher.
Hospitals use all sorts of possible risks to determine if someone should be hospitalized or not, or what other care they should receive. The results of the study indicate that the ABO blood group is not a necessary factor in assessing risk.
Anderson explained that the study was motivated by the many unknowns of COVID-19. Medical professionals around the world had little or no answers as to why some people got sicker than others. If they could solve the puzzle, they could help provide better treatment to patients.
The data identified the elderly as well as people with high obesity, diabetes, high blood pressure, and pre-existing lung or heart disease. But since COVID-19 ravaged China and Europe before the United States, global researchers gained an advantage over other potential factors.
A study that emerged in China early last year sparked Anderson’s interest. He suggested that the blood group played a role in the recruitment of COVID-19. More specifically, it was suggested that those with blood group A had a higher risk of contracting COVID-19 and blood group O had a lower risk of becoming infected.
Researchers in Italy and Spain then published a study that suggested that the blood group did not influence the contraction of COVID-19, but rather affected the severity of a new case. In a somewhat similar result, research suggested that blood group A caused more severe cases and type O resulted in less severe ones. It is unclear to what extent medical professionals relied on these studies to treat treatment with COVID-19.
“We started to get interested in that and wondered if we should look at it as well, especially when other reports came out that had variable results,” Anderson said. “There was one in Denmark who, on the other hand, said it was infectious, but it didn’t affect the severity of the disease, and then here in the United States from New York and Boston … where there there was no risk association “.
Thus, researchers from Intermountain Healthcare, the University of Utah School of Medicine, and Stanford University tried to confirm the results of the first studies.
They examined the results of 107,796 people tested for COVID-19 in Utah, Idaho and Nevada between March 3, 2020 and November 2, 2020. Anderson said the health care database provided a mine of ‘gold for researchers, as it provided them with patients. ‘Results of COVID-19 tests and their blood groups. He also provided information on the severity of a case if someone ended up hospitalized.
According to the data, approximately 10.6% of the nearly 108,000 people involved in the study tested positive for COVID-19. Disaggregated by blood groups, the researchers found that the percentage of people who tested positive for COVID-19 essentially reflected the percentage of negatives.
Blood group A, for example, accounted for 39.6% of positive results, but also 40.4% of negative results. Type B accounted for 9% positive and 9.3% negative. Type AB accounted for 3.2% positive and 3.3% negative, while Type O accounted for 48.1% positive and 47.1% negative.
“There was no relationship between the ABO type and the risk of being infected,” Anderson said.
Similar patterns were presented in cases of hospitalizations and intensive care units. Of the 11,468 positive cases, 2,326 ended up admitted; and 706 of those hospitalized ended up in the ICU.
Again, blood type accounted for 38.6% of hospitalizations and 39.9% of outpatients. It accounted for 36.4% of ICU stays and 39.5% of outpatient hospitalizations.
Type B accounted for 8.8% of hospitalizations and 9.1% of those not hospitalized, as well as 8.6% of ICU cases and 8.9% of non-ICU cases. . Type AB accounted for 3.4% of hospitalizations and 3.1% of cases that did not require hospitalization; accounted for 2.8% of ICU cases and 3.6% of cases where ICU was not necessary.
Finally, 49.2% of hospitalizations affected people with type O blood compared with 47.9% of cases where no hospitalization was needed; it also accounted for 52.1% of all ICU cases in the data, compared with 48% of non-hospitalization.
The results came as a bit of a surprise to researchers, especially because studies over the years have found connections between type A blood and the risk of heart attack, Anderson said.
“We had entered this study thinking we would probably validate or verify the reports of a relationship, but we didn’t find any,” he said.
This is not to say that research does not find other connections. The data confirmed theories that older people, men, and minority communities were at higher risk of contracting COVID-19 or developing serious illness.
I think it’s extremely important that we learn all we can about this virus to fight it better.
–Dr. Jeffrey Anderson, cardiologist and researcher at the Intermountain Medical Center Heart Institute
Anderson added that the findings may also be regional. There is the potential for other factors to lead other regions of the world to find different results.
“Blood type varies in terms of frequency between different populations and so on,” he said. “There may be different associations with the blood group that explain some of the other results, differentiating the results from other areas.
“In other words, blood groups could be related to some other characteristics that cause disease or put people at risk,” he continued. “This is called association and this is different from what we would call a causal risk factor.”
For researchers like Anderson, not finding any correlation between blood group and COVID-19 risks is something closer to solving the COVID-19 puzzle.
It is added to the growing list of items learned since SARS-CoV-2 and COVID-19 were first identified in late 2019. Because SARS-CoV-2 was a new coronavirus, it meant that medical experts began with the same knowledge as any other how it spread and how it affects humans.
“I think it’s extremely important that we learn everything we can about this virus to fight it better,” Anderson said. “We’re not done yet. It’s wonderful to see the light at the end of the tunnel, to see our numbers go down, but that will continue with us at some level, I think, for the next few months and maybe years.
“The more we can learn from it, the better off we are.”