Impact of ABO and Rhesus blood groups on COVID‐19 susceptibility and severity: A case‐control study

Abstract

Early evidence from China suggested that blood groups may be involved in susceptibility to COVID-19. Several subsequent studies reported controversial results.We conducted a retrospective matched case-control study that aims to investigate the association between blood groups and the risk and/or severity of COVID-19.We compared the blood groups distribution of 474 patients admitted to the hospital for COVID-19 between March 2020 and March 2021, to that of a positive control group of outpatients infected with COVID-19 and matched them for sex and age, as well as to the distribution in the general population. Three hundred and eighteen HC + pairs with available blood group information were matched. The proportion of group A Rh+ in hospitalized patients (HC+) was 39.9% (CI 35.2%-44.7%), compared to 44.8% (CI 39.8%-49.9%) and 32.3% in the positive outpatient controls (C+) and the general population (C−), respectively. Both COVID-19-positive groups (HC+ and C+) had significantly higher proportions of group A Rh+ compared to the general population (p = 0.0019 and p < 0.001, respectively), indicating that group A Rh+ increases susceptibility to COVID-19. Although blood group A Rh+ was more frequent in the outpatients C+ compared to the hospitalized group HC+, the association did not reach statistical significance, indicating that blood group A Rh+ is not associated with severity. There was no significant relationship between COVID-19 and other blood groups. Our findings indicate that blood group A Rh+ increases the susceptibility for COVID-19 but is not associated with higher disease severity.

Risk Markers of COVID-19, a Study from South-Lebanon

“…While a recent population-based cohort study from Ontario, Canada, demonstrated that Rh-negative individuals may be linked with a slightly lower risk for SARS-CoV-2 infection and severe COVID-19 illness [19]. In October 2021, a similar study performed in Beirut, Lebanon, with a sample size of 404 patients concluded that A Rh+ blood group is associated with an increased risk of developing COVID-19 [20].…”

A large cohort study of the effects of Lewis, ABO, 13 other blood groups, and secretor status on COVID‐19 susceptibility, severity, and long COVID‐19

“…We did not find any other associations between blood groups and SARS‐CoV‐2. This questions the validity of previous findings of an association to the Rh blood group 11,12,14,15 …”

“…This questions the validity of previous findings of an association to the Rh blood group. 11,12,14,15 Two COVID-19 severity results worth discussing are blood type O vs AB, which was significant (p = .008), and secretor status, which was close to being significant (p = .06). Blood type AB is a rare phenotype (5%), which reduces confidence in that result.…”

“…This questions the validity of previous findings of an association to the Rh blood group. 11 , 12 , 14 , 15 …”

Sex and ABO Blood Differences in SARS-CoV-2 Infection Susceptibility

“… 20 Kerbage et al (2022) indicated that A Rh (+) subjects are more susceptible to SARS-CoV-2 infection; however, ABO blood groups lack any association with the severity of the disease. 21 Supporting the Indian study, Behera et al (2022) emphasized that blood group A was the most sensitive group considering a higher risk severity of the disease with admission to the intensive care unit. 19 In the present study, a total number of 18,639 (297 COVID-19 patients and 18,342 controls) individual's current data were investigated including SARS-CoV-2 RT-PCR results, sex, age, ABO blood groups, and Rh blood types.…”