ABSTRACT
OBJECTIVE: The role of ABO types and RhD antigen in coronavirus disease 2019 (COVID-19) severity has been investigated in several recent studies. Thus, the objective of this study was to identify the relationship of ABO and RhD types with symptomatic COVID-19 disease and determine the groups associated with an increased risk of hospitalization. METHODS: This observational case-control study was performed in 530 Iraqi-Kurdish patients with COVID-19. Among them, 184 were severe cases that required hospitalization, while 346 were mild to moderate cases that were treated at home. ABO and RhD antigen groups were compared between cases and 1698 control records from 1 year before the pandemic. The diagnosis of COVID-19 was based on real-time polymerase chain reaction tests and high-resolution chest computed tomography scans with the typical clinical presentation. RESULTS: There were no significant differences in ABO and RhD antigen distributions between the COVID-19 cases and non-COVID controls. No ABO group was associated with the risk of hospitalization as a marker of the severity of infection. CONCLUSIONS: There was no significant association between symptomatic COVID-19 disease and any ABO group or RhD antigen type. No impact of ABO groups on hospitalization was documented.