COVID-19 and the ABO blood group connection

Abstract

COVID-19 and the ABO blood group connection Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), causing the current pandemic of COVID-19, is genetically similar to SARS-CoV that caused the SARS outbreak in 2002. Recently, nextgeneration sequencing of SARS-CoV-2 showed a 99•98 % sequence identity across 9 patients. SARS-CoV-2 showed 79 % similarity to SARS-CoV, with a comparable receptor-binding domain (ACE2) on modeling [1]. Susceptibility of certain viral infections has been linked to antigenic determinants of ABO blood groups. Cheng et al. showed linkage of SARS coronavirus infection with ABO blood groups, where individuals with blood group O were less likely to become infected, compared to non-O blood group individuals (OR 0•18) [2]. Data from Wuhan, China, the first epicenter of COVID-19 pandemic, shows ABO blood group linkage with COVID-19 infections [3]. Zhao et al. compared ABO blood groups of controls from the general population with 2173 COVID-19 patients from three hospitals in Wuhan region. Across all three hospitals, blood group A was associated with a higher risk for COVID-19 (OR 1•21; P = 0•027) compared with non-A blood groups, whereas blood group O was associated with a significantly lower risk for the infection (OR 0•67; P < 0•001) compared with non-O blood groups [3]. Another observational study on data from New York Presbyterian hospital system, on 1559 individuals tested for SARS-CoV-2 with known blood type, also showed similar results. In SARS-CoV-2 positive cases, there was a high proportion of blood group A, with a low proportion of blood group O [4]. With regards to the case fatality rate, as mentioned by Zhao et al., blood group A was also linked to higher mortality risk in contrast to blood group O (OR 1•482; P = 0•008), the latter was associated with a lower mortality risk compared with non-O blood groups (OR 0•660; P = 0•014) [3]. Zietz & Tatonetti mentioned the significance of this association in only Rh-positive blood types 4. But what is important to note, is that the association of blood type is not explainable by other risk factors e.g. obesity, diabetes mellitus and other comorbidities [4]. The linkage and effects of blood groups have been hypothesized using different facts: For one, blood groups are dictated by sugars, and coronaviruses in the cattle have surface proteins that bind to sugars. It might be of value to consider the extra sugar N-acetyl galactosamine, on the surface of blood group A cells [5], possibly suggesting more pathogen contact. This sugar is missing on blood group O cells [5]. The association of the spike (S) protein of SARS-CoV-2, a transmembranal protein, has been shown with ACE2 protein that acts as its cellular receptor [6]. As suggested in the past for SARS-CoV [7], the adhesion of Spike protein to the ACE2 receptor on the host cell surface may be inhibited by the presence of anti-A antibody. Although this may be true for blood group B and blood group O, it does not explain blood group AB, that even without anti-A antibody does not have a higher

A pandemic center’s experience of managing pregnant women with COVID‐19 infection in Turkey: A prospective cohort study

“…A Rhesus positive was the most common blood group (48.3%). It has been reported that there was a higher risk for COVID‐19 infection with blood group A compared with non‐A blood groups 12,13 …”

“…It has been reported that there was a higher risk for COVID-19 infection with blood group A compared with non-A blood groups. 12,13 Obstetric and neonatal outcomes of cases positive for SARS-CoV-2 with RT-PCR are shown in Table 3 Table 4.…”

Relationship between blood group phenotypes (ABO, Rh and Kell) and nCOVID-19 susceptibility – A retrospective observational study.

“…Likewise, a retrospective cohort study with 265 patients from the Central Hospital of Wuhan showed there is a higher proportion of patients infected with SARS-CoV-2 that have blood group 'A' than that in healthy controls (39.3 % vs. 32.3 %, p = 0.017), while the proportion of blood group 'O' in patients infected with SARS-CoV-2 was signi cantly lower than that in healthy controls (25.7 % vs. 33.8 %, p < 0.01) [12].In other recent ndings, Ziadi (2020) agreed the decreased e ciency of adhesion of Spike protein to ACE2 receptor by antibody A as suggest by many studies. He argued, that lower susceptibility of blood group 'B' and 'O' is true but it does not explain susceptibility of 'AB' blood group without anti A and anti B in serum [13].…”

COVID-19 Disease Map, a computational knowledge repository of SARS-CoV-2 virus-host interaction mechanisms

“…Groups of increased risk are men, pregnant and postpartum women, and individuals with high occupational viral exposure [229][230][231]. Other susceptibility factors include the ABO blood groups [232][233][234][235][236][237][238][239][240] and respiratory conditions [241][242][243][244][245][246].…”