The association of ABO blood type with the risk and severity of COVID-19 infection

There is conflicting data in the literature about the association of ABO blood type and susceptibility to COVID-19 infection. Moreover, very few studies have examined the effect of blood type on severity of COVID-19 infection.

This was a retrospective, single-center analysis of adult patients with COVID-19 infection who were hospitalized between March 8^th to July 31^st, 2020 at a regional tertiary care hospital. All patients who were hospitalized with a diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection and had a documented ABO blood type were enrolled in this analysis. Aims of this study were to examine the prevalence of ABO blood types in patients with COVID-19 infection and to determine the frequency of severe COVID-19 infection among ABO blood types.

A total of 227 cases were identified. Our cohort had a mean age of 63.3 years and 60% were males. The most common blood type was O (49%) followed by A (36%), which was similar to the prevalence of ABO blood types in our regional population. Moreover, there was no significant difference in the frequency of severe COVID-19 infection between ABO blood types (O: 50%, A: 53%, B: 56%, AB: 57%; P=0.93), or any additional outcomes including in-hospital mortality rate (P=0.72), need for ICU admission (P=0.66), ICU free days at day 28 (P=0.51), hospital free days at day 28 (P=0.43), or need for acute renal replacement therapy (P=0.09).

We did not find an increased susceptibility of any blood type to COVID-19 infection, nor was there an increased risk of severe COVID-19 infection in any ABO blood types.