By Molly Walker
A recent study found no association between blood type and susceptibility to COVID-19 infection or disease severity in a large cohort study.
Among 11,000 patients, blood type A was not associated with increased viral positivity, hospitalization, or ICU admission compared with type O, and there were no associations with worse outcomes among type B or AB patients, reported Jeffrey Anderson, MD, of the University of Utah School of Medicine in Salt Lake City and colleagues.
Because each set was subjected to nine comparisons, the significance for individual comparisons was set at P = 0.006, meaning that none of these associations were significant, they wrote in JAMA Network Open .
They pointed to conflicting research on blood types and COVID, with studies around the world finding links between the two, in particular, greater susceptibility in people with type A and/or lower risk with type O, while others found no links.
"The smaller sample sizes and retrospective observational nature of many previous studies, in addition to their surprising heterogeneity of ABO associations with disease susceptibility and severity, could be due to random variations, publication bias, differences in genetic background, geography, and environment."
Anderson's group examined data from Intermountain Healthcare, an integrated system of 24 hospitals and 215 clinics in Utah, Idaho, and Nevada. They looked at patients from March 3 to November 2, 2020, who were tested for SARS-CoV-2 and had a recorded blood type, comparing positive tests with negative tests, hospitalized and non-hospitalized patients, and ICU patients with non-ICU patients.
Of the 107,796 people tested for COVID-19, 11,468 patients tested positive. The average age of the patients was 42 years, 77% were women, and the majority were white.
Among those with COVID-19, hospitalization and ICU admission were associated with male sex and age. They also found that non-white race, defined as African American, American Indian/Alaska Native, Native Hawaiian, or Pacific Islander, was associated with viral positivity (13.9% vs. 6.9%, respectively) and hospitalization (23.9% vs. 11.3%).
While Anderson and his colleagues noted that their sample was mostly white, with a minor contribution from other ethnicities, they added that their results were similar when restricted to the white race only.
"Given the scope and prospective nature of the study, based on its results, we believe that significant associations of SARS-CoV-2 and COVID-19 with ABO blood groups are unlikely and will not be useful factors associated with susceptibility or severity of the disease in either case, at the individual or population level for similar environments and ancestry."
From: https://www.medpagetoday.com/infectiousdisease/covid19/91939