ABO blood groups as determinants to patient outcomes in SARS-CoV-2

Background: Blood group antigens are present on the red blood cell surface. O, A, and B are the major blood groups. A, B, AB, and A1 are the antigens. An ample amount of research supports the close association of blood groups with diseases. A new school of thought and finding seems to be indicating that certain blood groups are more susceptible to the COVID-19 infection in comparison to others. Current evidence suggests that SARS-CoV-2 positive cases are more prevalent in individuals with blood group A as compared to those with blood group O. This finding, however, was only relevant for the Rh (+ve) positive blood types. Genetic association reveals that the ABO blood group locus and a chromosome 3 gene cluster are associated with severe acute respiratory syndrome in coronavirus (SARS-CoV-2) respiratory failure patents. This was found in an Italian- Spanish genome-wide association analysis. Various associations between the patients' blood groups when comparing the data with that of physiologically healthy individuals from the same geographical region helped to get a clear comparative picture. Associations that were cross-replicating in nature were determined at chromosome 3p21.31 and chromosome 9q34. The association at chromosome 9q34 was identified at the ABO blood group locus. The difference in the susceptibility could be correlated to the circulating anti‐A antibodies, which inhibit or interfere with the virus-cell adhesion process. Conclusion: It is evident that the research conducted to date is supportive and does suggest that humans of the Blood group O are less likely to be infected in the COVID-19 pandemic as when compared to other blood groups. The SARS-CoV-2 situation is evolving rapidly, discoveries and anomalies are being reported daily. Therefore, it is advised that more definitive and consolidatory research is to be conducted to further elucidate the underlying mechanism of action for the protection in blood group O.

The ABO blood group locus and a chromosome 3 gene cluster associate with SARS-CoV-2 respiratory failure in an Italian-Spanish genome-wide association analysis

ABSTRACTBackgroundRespiratory failure is a key feature of severe Covid-19 and a critical driver of mortality, but for reasons poorly defined affects less than 10% of SARS-CoV-2 infected patients.MethodsWe included 1,980 patients with Covid-19 respiratory failure at seven centers in the Italian and Spanish epicenters of the SARS-CoV-2 pandemic in Europe (Milan, Monza, Madrid, San Sebastian and Barcelona) for a genome-wide association analysis. After quality control and exclusion of population outliers, 835 patients and 1,255 population-derived controls from Italy, and 775 patients and 950 controls from Spain were included in the final analysis. In total we analyzed 8,582,968 single-nucleotide polymorphisms (SNPs) and conducted a meta-analysis of both case-control panels.ResultsWe detected cross-replicating associations with rs11385942 at chromosome 3p21.31 and rs657152 at 9q34, which were genome-wide significant (P<5×10−8) in the meta-analysis of both study panels, odds ratio [OR], 1.77; 95% confidence interval [CI], 1.48 to 2.11; P=1.14×10−10 and OR 1.32 (95% CI, 1.20 to 1.47; P=4.95×10−8), respectively. Among six genes at 3p21.31, SLC6A20 encodes a known interaction partner with angiotensin converting enzyme 2 (ACE2). The association signal at 9q34 was located at the ABO blood group locus and a blood-group-specific analysis showed higher risk for A-positive individuals (OR=1.45, 95% CI, 1.20 to 1.75, P=1.48×10−4) and a protective effect for blood group O (OR=0.65, 95% CI, 0.53 to 0.79, P=1.06×10−5).ConclusionsWe herein report the first robust genetic susceptibility loci for the development of respiratory failure in Covid-19. Identified variants may help guide targeted exploration of severe Covid-19 pathophysiology.