Association between blood groups and clinical outcomes in critically ill COVID-19 patients: A retrospective study

Abstract

Introduction: A small proportion of patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) become critically ill. Individuals’ blood group may influence their susceptibility to infection. However, the relationship between blood groups and clinical outcomes in severe Coronavirus disease 2019 (COVID-19) is not well established. Therefore, we conducted a study to investigate the association between blood groups and clinical outcomes in critically ill COVID-19 patients. Methods: We retrospectively analyzed electronic health records of COVID-19 patients admitted to intensive care units (ICUs) at Hazm Mebaireek General Hospital, Qatar, from March 7th, 2020, to July 15th, 2020. The study population was divided based on their blood groups into types A, B, AB, O, Rhesus (Rh)-positive, and Rh-negative. The primary outcome studied in each blood group was all-cause ICU mortality. Secondary outcomes evaluated were the requirement and duration of mechanical ventilation, ICU days, hospitalization days, and C-reactive protein (CRP) value on admission. Results: Eight hundred forty-eight patients were admitted to ICUs with severe COVID-19 during the study period. All-cause ICU mortality in the study population was 19.8% (168/848), and that in individuals with blood groups A, B, AB, O, Rh-positive, and Rh-negative was 22.6% (52/230), 18.1% (44/243), 22% (18/82), 18.4% (54/293), 20.4% (165/810), and 7.9% (3/38). Although the highest mortality was noted in blood group A, followed by AB, these observations failed to achieve statistical significance. Rh-negative blood type had lower odds of death compared to the Rh-positive one (odds ratio = 0.27; 95% confidence interval 0.08–0.99, P = 0.049). None of the blood groups showed an association with the need for mechanical ventilation, duration of mechanical ventilation, duration of ICU and hospital stay, and CRP value on admission. Conclusion: This study revealed no association between ABO blood groups and unfavorable clinical outcomes in critically ill COVID-19 patients. The Rh-negative blood type was associated with slightly lower odds of death compared to the Rh-positive one.

Association Between Rhesus and ABO Blood Group Types and Their Impact on Clinical Outcomes in Critically Ill Patients with COVID-19: A Multi-Center Investigation

“… 21–25 Previous studies have observed a protective effect among Rh-negative blood patients for intubation and mortality and a 2.7% lower risk of initial infection. 12 , 13 , 21 , 26–28 The results from our study have provided insight into the neutral effect of the Rh-blood group on ICU mortality, duration of mechanical ventilation, ICU length of stay, and complications during ICU stay in critically ill patients with COVID‐19.…”

“…Several existing risk factors can increase the susceptibility to COVID-19 infection and worsen clinical impacts in critically ill patients. 11 , 13 Evidence that supports the association between the Rh blood group and COVID‐19 infection in critically ill patients is not well established. The magnitude of the COVID-19 predisposition between two phenotype groups was reported inconsistently in earlier studies.…”

“…Previously reported studies did not show any association between Rh-blood groups and hospital length of stay. 11 , 13 , 24 , 27 …”

“…The author reported no association between ABO blood types and adverse clinical outcomes in critically ill patients with COVID-19. 13 However, Rh-negative blood type patients were associated with a lower incidence of death compared to the Rh-positive blood type, who were more prone to COVID-19 complications. 13 The aforementioned study did not investigate other ICU complications such as thrombosis, acute kidney injury (AKI), liver injury, and the development of new-onset atrial fibrillation.…”

“… 13 However, Rh-negative blood type patients were associated with a lower incidence of death compared to the Rh-positive blood type, who were more prone to COVID-19 complications. 13 The aforementioned study did not investigate other ICU complications such as thrombosis, acute kidney injury (AKI), liver injury, and the development of new-onset atrial fibrillation. Although few studies assessed the associations between blood type and clinical outcomes in patients with COVID-19, some of these studies did not investigate the association between the Rh blood factor and the clinical outcomes of critically ill COVID-19 patients.…”