People with blood type A may be more at risk of serious forms of the coronavirus, new research has shown. The study, by researchers in Germany and Norway but not yet published in a journal, is the latest to show that people with this particular blood type may be more susceptible to the disease.
The researchers found two points in the human genome which were associated with an increased risk of respiratory failure in patients with COVID-19. One of these points is the gene that determines blood type.
Having type A blood was linked to a 50% increase in the likelihood that a patient would need oxygen or go on a ventilator, the researchers found.
The researchers detected at least a couple of significant “associations”, including one that “located at the ABO blood group locus and a blood-group-specific analysis showed higher risk for A-positive individuals and a protective effect for blood group O”, they said in the paper.
The ABO blood group locus refers to a set of genes that determine which blood group an individual has.
The study could offer scientists more insight into why the disease behaves unpredictably across humans: the symptoms range from being virtually non-existent, resembling a flu, or, in most severe cases, leaving people unable to breathe.
The claims were made in a pre-publication paper by researchers from seven hospitals and universities in Wuhan, Shenzhen and Shanghai, China. The researchers compared the blood group distribution in 2,173 patients with COVID-19 confirmed by SARS-CoV-2 test, from three hospitals in Wuhan and Shenzhen (including 206 who had died), with that of 27,080 people from “recent surveys” of the general population of Wuhan and Shenzhen.
The research reported:
- 37% of patients with COVID-19 (including 85 who had died) were blood type A, compared to 29% of the general population
- 26% of patients with COVID-19 (including 52 who had died) were blood type O, compared to 38% of the general population
“We 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,” the study reads.
“The association signal at 9q34 was located at the ABO blood group locus and a blood-group-specific analysis showedhigher risk for A-positive individuals, and a protective effect for blood group O,” the study states as a result.
According to a study in the US National Centre for Biotechnology Information (NCBI), ‘O’ is the most common blood group (37.12%) in India, closely followed by B at 32.26%, followed by A at 22.88% while AB was the least prevalent group at 7.74%.
Over 6.5 million people worldwide have been infected from the novel coronavirus. In India, the number of cases has crossed 200,000 while the death toll is now upwards of 6,000.