key: cord-0921680-tz86f55y
authors: Gérard, Christiane; Maggipinto, Gianni; Minon, Jean‐Marc
title: COVID‐19 and ABO blood group: another viewpoint
date: 2020-06-08
journal: Br J Haematol
DOI: 10.1111/bjh.16884
sha: dbc2053c20c1631ff2fb4b2e6284ed28ce766cba
doc_id: 921680
cord_uid: tz86f55y

Juyi Li et al. [1] have recently published "an association between ABO blood groups and risk of SARS-CoV-2 pneumonia", an observation already reported a few weeks ago as a MedRxiv preprint by Jiao Zhao et al. [2] and which had a certain impact in the press.

whatever the group: A and AB (P < 0Á001), A (P < 0Á001) or AB (P = 0Á0323), whereas there was no significant difference versus circulating anti-B (data not shown).

We then wondered if there was a difference between anti-A from O and anti-A from B, and then we compared the supposed protective effect of anti-A from O and from B (Table II) .

Whereas both blood group O and B patients possess circulating seric anti-A, it appears and it is statistically highly significant (P < 0Á001) that O group patients are underrepresented (49Á4 % vs. 57Á6%), whereas B group patients are, on the contrary, overrepresented (50Á6% vs. 42Á4%), meaning that anti-A from O is more protective than anti-A from B. This latter observation is probably related to the fact that the immunoglobulin predominant isotype of anti-B/anti-A is IgM in serum from group A and B individuals, but IgG in O group serum, an already known notion, 5 which has been well documented by flow cytometry. 6 In conclusion, this way of analysing the data strongly suggests that the presence of anti-A antibodies in serum and more specifically IgG anti-A, should be considered as a factor more significant than the blood group itself, as far as the relationship between COVID-19 susceptibility and ABO blood groups is concerned.

Far from intending to corroborate the authors' conclusions as such, we wanted to show that the resources of immuno-haematology allow several approaches that could perhaps be useful for the disease follow-up. 

Association between ABO blood groups and risk of SARS-CoV-2 pneumonia

Relationship between the ABO Blood Group and the COVID-19 Susceptibility. MedRxiv 2020

Que penser des donn ees sur la susceptibilit e moindre des individus O a l

Inhibition of the interaction between the SARS-CoV Spike protein and its cellular receptor by anti-histo-blood group antibodies

American Association of Blood Banks (AABB) Technical Manual, 18th edn

Isotypespecific detection of ABO blood group antibodies using a novel flow cytometric method