Association of ABO blood group with COVID-19 severity, acute phase reactants and mortality

Background and objective The ABO blood group system has been associated with infectious and non-infectious diseases, including dengue, hepatitis B virus (HBV), and severe respiratory syndrome coronavirus (SARS), etc. Coronavirus disease 2019 (COVID-19) is an ongoing pandemic with a multitude of manifestations and the association of ABO blood group in the South-East Asian population needs to be explored. Methods It was a retrospective study of patients with real-time polymerase chain reaction (RT-PCR) diagnosis of COVID-19 at Advanced Diagnostics and Liver Center between April 2020 to January 2021. Blood groups A, B, O, and AB were identified in every participant, irrespective of their RH type and allotted groups 1, 2,3, and 4, respectively. Cox regression and logistic regression were used for inferential statistics. Results The cohort included 1067 patients: 521 (48.8%) of blood group O, 295 (27.6%) of blood group B, 202 (18.9%) of blood group A, and 49 (4.5%) of blood group AB. The majority of the patients were males 712 (66.7%) with an average body mass index (BMI) of 27.45 (3.53). Patients with AB blood group stayed a median (IQR) of 14 (5, 27) days while A blood group cohort stayed 13 (6,27) days and overall 10.6% COVID-19-related mortality was observed at our center, with 13.9% in blood group A as the majority of COVID-19 deaths. Regarding severity of COVID-19 disease, there was a trend towards critical disease in blood group A and O (n=83, 41.1%; n=183, 35.1%; OR, 11.34 (95% CI, 46.79-53.22); p<0.001). Logistic regression demonstrates blood group O and AB as predictors for severe COVID-19 disease (O: OR: 0.438 (95% CI: 0.168-1.139) p=0.090; AB: OR: 0.415 (95% CI: 0.165-1.046) p=0.062) and cause-specific hazards ratio (HR) for survival function was 3.206 (p=0.361) among all blood groups. Conclusion Although the prevalence of blood group O was higher in this cohort, hospital stay, the severity of disease, and mortality were associated with blood group A. Further studies are needed for understanding the underlying mechanism behind the association of blood groups with COVID-19.