Association of ABO blood group with in-hospital adverse outcome and long term persistent symptoms of COVID-19 infection: A single-center longitudinal observational study.

Background and Aims: There are gaps in knowledge regarding the association between the ABO blood group and coronavirus disease 2019 (COVID-19) immediate and long-term outcomes. We aimed to investigate the association of ABO blood group with COVID-19 in-hospital adverse outcomes and to determine whether ABO blood group is associated with post-COVID-19 persistent symptoms. Methods: This was a single-center longitudinal observational study that included patients who presented with symptoms suggestive of COVID-19 infection and a positive test for COVID-19 and were able to attend the out-patient clinic after 6 months following acute COVID-19. The main outcomes were intensive care unit admission, the requirement for respiratory support, in-hospital death, and persistent symptoms. Results: A total of 169 patients were enrolled for the assessment of in-hospital adverse outcomes of whom 86 patients were included for the assessment of persistent symptoms after the exclusion of deceased patients or patients not attended the out-patient clinic. Patients with blood group B had higher prevalence of in-hospital death compared to blood group O (39% vs. 13%, Conclusions: Blood groups AB and B are significantly associated with respiratory support use and in-hospital death, respectively, compared to blood group O. Blood group AB is significantly associated with persistent palpitation and dizziness compared to other blood groups.