ABO Blood Group and RhD Antigen Relationship to COVID-19 Infections in Duhok-Iraq: A Retrospective Study

Background: Since the World Health Organization declared the Coronavirus a pandemic, various studies have suggested that blood group antigens might influence COVID-19 infection susceptibility. This research aims to assess the relationship between the ABO blood group system, RhD factors, and COVID-19 infection symptoms, considering age and gender variables in Duhok province, Iraq.Method: This retrospective study analyzed data from 578 individuals who attended several hospitals and medical centers in Duhok province from September 2023 to February 2024. The cohort comprised 308 males and 270 females.Results: The distribution of blood groups A, B, AB, and O among the participants was 22.1%, 26.3%, 18.5%, and 33.1% respectively. Notably, blood type O was predominant in both mild and severe COVID-19 cases. Statistical analysis revealed no significant differences (p > 0.05) between the observed and expected frequencies of blood groups and RhD antigens. However, significant differences (p < 0.01) were found in the age distribution of COVID-19 symptom severity between the genders, indicating varying symptomatology across different age groups. The comparison between genders did not show significant differences in age distribution (p > 0.05).Conclusion: The study concludes that there are no statistically significant associations between the ABO and RhD antigen groups with the frequency of COVID-19 infections. However, age appears to play a critical role in the severity of symptoms, with significant variations noted between different age groups within both sexes. Further research is recommended to explore the mechanisms behind these variations and to assess potential vulnerabilities among specific demographic groups.