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. χ (2) test and regression analysis were used to analyze the collected data. 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%, p = 0.01) and this persisted after adjusting for sex (odds ratio, OR [confidence interval, CI] = 1.4 [1.1–2.1], p = 0.04), while patients with blood group AB had higher prevalence of requiring respiratory support than blood group O (54% vs. 10%, p = 0.02) and this persisted after adjusting for age (OR [CI] = 1.5 [1.1–2.3], p = 0.02). Concerning the association of ABO blood group and long‐term symptoms, blood group AB showed a higher prevalence of palpitation (p < 0.001) and dizziness (p = 0.02) than other blood groups. 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.