More Evidence of Blood Group Role in COVID-19

Two retrospective studies continue with additional evidence suggesting that blood types can affect not only COVID-19 susceptibility, but also the severity of infection.

In Denmark, blood group O was associated with a reduced risk of developing COVID-19, based on the proportion of patients with ABO blood group tested positive for SARS-CoV-2 (RR 0.87, 95% CI). 0.83-0.91). The reference group was reported by Dr. Toben Barrington, MD, and his colleagues at Odens University Hospital.

However, the risk of hospitalization and death from blood group-related COVID-19 did not increase, the authors write. Blood Advance..

The data limitation was that ABO blood group information was available only to 62% of individuals, and that the population tested was gender-biased, with 71% negative and 67% positive for women. It is included.

They noted a recent study that blood group is involved in infection and noted that the prevalence of blood group O in COVID-19 patients was lower than expected. Researchers also observed that blood types such as SARS-CoV-1 and norovirus were “more and more recognized to affect susceptibility to certain viruses,” and blood types A, B, and AB. Individuals with “high risk of thrombosis and cardiovascular disease,” he added. It is an important comorbidity of patients hospitalized with COVID-19.

ABO and RhD blood group information is available for 473,654 people who were tested for SARS-CoV-2 from February 27 to July 30, and 2,204,742 who were not tested for SARS-CoV-2 as a reference. I was able to get about.

Of the individuals tested, 7,422 were tested positive for SARS-CoV-2. About one-third of those who tested both positive and negative were male, and those who tested positive were slightly older (52:50 each).

Of the individuals who tested positive for SARS-CoV-2, about 38% (95% CI 37.5-39.5%) belonged to blood group O, compared with about 42% in the reference group. In the positive test group, there were significantly more individuals in groups A and AB compared to the reference population, but the difference in group B was not significant. Deleting individuals in Group O made no difference between the remaining groups.

Blood type associated with the severity of COVID-19?

on the other hand, Second, small studies To Blood Advance We reported the relationship between blood type and the severity of COVID-19.

According to Mypinder Sekhon, MD of the University of British Columbia, blood group A or AB in COVID-19 patients has prolonged mechanical ventilation, continuous renal replacement therapy, and ICU admission compared to patients with blood group O or B. Was associated with increased risk. In Vancouver, and a colleague. However, inflammatory cytokines did not differ between groups.

These authors also cited studies in which blood group is associated with viral susceptibility, but the relationship between the severity of SARS-CoV-2 infection and blood group remains “unresolved.” However, COVID-19 appears to be a polyphyletic disease with renal and liver symptoms.

“When ABO blood groups play a role in determining the severity of the disease, these differences appear within multiple organ systems and consume large amounts of multiple resources such as mechanical ventilation and continuous renal replacement therapy. It is expected to be related to treatment, “Sekhon et al. Wrote.

They collected data from six metropolitan hospitals in Vancouver from February 21st to April 28th and identified 95 COVID-19 patients admitted to the ICU with a known ABO blood group system.

Of these patients, 57 were in group O or B and 38 were in group A or AB. A significantly higher proportion of A / AB patients required mechanical ventilation compared to O / B patients (84% vs. 61%, respectively). P= 0.02). Similar numbers were seen in patients requiring continuous renal replacement therapy (32% vs. 9%). P= 0.04). The median length of stay in the ICU was also longer in patients A or AB compared to patients O or B (13.5 days vs. 9 days, P= 0.03).

There was no difference in the probability of leaving the ICU, with 8 patients dying in the O / B group and 9 patients dying in the A / AB group. Not surprisingly, biomarkers for renal and hepatic dysfunction were also high in the A / AB group.

“A unique part of our study is focusing on the effect of blood group severity on COVID-19. We observed this lung and kidney damage. Future studies will focus on blood group and I would like to clarify the effects of COVID-19. About other important organs. “

The authors admitted that about 25% of patients lack blood group data and, due to the nature of the study, it is impossible to infer a causal relationship. Ethnic ancestry and outcomes of COVID-19 patients may be untreated confounding factors. In addition, anti-A antibody titers can affect the severity of COVID-19, which have not been measured.