Histo‐blood group A is a risk factor for severe COVID‐19

Garibaldi, Pedro M. M.; Oliveira, Luciana C.; da Fonseca, Benedito A.; Auxiliadora‐Martins, Maria; Miranda, Carlos H.; Almado, Carlos E. L.; Langhi, Dante M.; Gilio, Renato N.; Palma, Leonardo C.; Gomes, Bruno B. M.; Bottura, Camila; Barrientto, Larissa C.; Donadel, Camila D.; Calado, Rodrigo T.; De Santis, Gil C.

OBJECTIVES: Evaluate the impact of ABO histo‐blood group type on COVID‐19 severity. BACKGROUND: ABO histo‐blood type has been associated with different outcomes in infectious diseases. It has also shown a higher proportion of type A patients with SARS‐CoV‐2. In this observational study, extracted from an ongoing clinical trial on the efficacy of convalescent plasma transfused in COVID‐19 patients, we describe the impact of ABO blood type on the risk of developing severe COVID‐19. MATERIALS AND METHODS: Seventy‐two consecutive patients (37 type A, 23 type O, 11 type B, 1 type AB) with severe (respiratory failure) COVID‐19 were included. Control group was composed of 160 individuals randomly selected from the same populational basis. RESULTS: Blood group A was overrepresented (51.39%) in the patient group in relation to the control group (30%), whereas blood group O was less represented (31.94%) in patient than in control group (48%). Odds ratio (A vs. O) was 2.581 (1.381–4.817), CI 95%; p = 0.004. Also, blood group A patients appeared to have more severe disease, given by the scores of the Sequential Organ Failure Assessment and Simplified Acute Physiologic Score 3 (p = 0.036 and p = 0.058, respectively). CONCLUSION: Histo‐blood type A is associated with a higher risk of developing severe COVID‐19 in relation to blood type O.