Anti‐A and SARS‐CoV‐2: an intriguing association

Abstract

Background Blood groups and anti‐A isohemagglutinin may be involved in susceptibility to SARS‐CoV‐2 infection. Materials and Methods We retrospectively studied 268 COVID‐19 convalescent plasma donors and 162 COVID‐19 inpatients (total 430 subjects, confirmed by RT‐PCR) and 2,212 healthy volunteer first‐time blood donors as a control group. These were further divided into two groups: those with anti‐A (blood types O and B) and those without it (types A and AB). Titres of nucleoproteins, and neutralizing SARS‐CoV‐2 antibody were measured in the convalescent plasma donors and inpatients. Multivariate logistic regression and non‐parametric tests were applied. Results Persons having types O or B showed less infection prevalence than those of types A or AB (OR = 0·62, 95% CI 0·50–0·78; P < 0·001), but there was no difference when COVID‐19 inpatients were analysed. Immunoglobulins M, G and A were lower in COVID‐19 subjects of types O or B group than those of A or AB (0·16 vs. 0·19; P = 0·03, 2·11 vs. 2·55; P = 0·02, 0·23 vs. 0·32; P = 0·03, respectively). Conclusion In this retrospective cohort, COVID‐19 individuals were less likely to belong to blood types O and B, and also had lower SARS‐CoV‐2 antibody titres than A and AB individuals. COVID‐19 severity did not associate with the blood groups.

ABO blood group does not influence the level of anti‐SARS‐CoV‐2 antibodies in convalescent plasma donors

“…Our results do not confirm the previous reports that the ABO blood group type affects the anti‐SARS‐CoV‐2 antibody concentration in COVID‐19 convalescents 19–22 . In our cohort, we found no statistically significant differences between the SARS‐CoV‐2 antibody levels in different ABO‐types regardless of which serological method was used.…”

“…Therefore, it was logical that the following research would focus on the impact of ABO blood group type on the quantity of anti‐SARS‐CoV‐2 antibodies produced in convalescents since the CCP represents a valuable resource for prevention and therapy. Since the resulting studies led to conflicting results, 16–22 we analyzed a larger cohort of 3187 COVID‐19 convalescent plasma donors.…”

“…On the other hand, Madariaga et al found in 103 CCP donors that AB‐type donors had higher anti‐RBD and anti‐spike Ab levels compared to O‐type donors 19 . De Freitas Dutra et al reported that in 268 donors and 162 patients, O‐type individuals had lower SARS‐CoV‐2 Ab titers than A and AB individuals 20 . Bloch et al reported that in 202 CCP donors, there were no significant differences in anti‐spike IgA or anti‐spike IgG Ab titers by ABO blood group, but that significantly more B‐type individuals presented with a high neutralization Ab titer (≥1:160) compared to O‐type and A‐type donors 21 .…”

Blood group O convalescent plasma donations have significantly lower levels of SARS‐CoV‐2 IgG antibodies compared to blood group A donations

“…Madariaga et al reported lower anti‐receptor binding domain (RBD) and anti‐spike antibodies in blood group O CCP donors compared to blood group AB donors 11 . Additionally, de Freitas Dutra et al describe lower titers of neutralizing antibodies and lower levels of anti‐nucleocapsid antibodies in blood groups O and B COVID‐19 individuals compared to blood groups A and AB COVID‐19 individuals 12 . However, additional studies found no correlation between ABO blood type and anti‐nucleocapsid level, anti‐spike‐RBD level, 13 or maintenance of neutralizing antibody titer, 14 in convalescent individuals.…”

Lower Levels of ABO Anti-A and Anti-B of IgM, IgG and IgA Isotypes in the Serum but Not the Saliva of COVID-19 Convalescents

“…A possible association between SARS-CoV-2-specific antibodies and ABO blood types was previously investigated. It was found that patients with blood types O and B had lower SARS-CoV-2 antibody titres than patients with blood types A and AB [ 26 , 27 ]. A dataset of the ABO blood type distribution in COVID-19 patients published by Zhao et al [ 28 ] was re-analysed by Gerard et al from the perspective of ABO antibodies instead of ABO blood group antigens [ 29 ].…”