ABO and RhD blood group are not associated with mortality and morbidity in critically ill patients; a multicentre observational study of 29 512 patients

Impact of ABO blood group on mortality in trauma patients: A systematic review

BACKGROUND

Haemorrhage is a significant cause of death in trauma patients. There is evidence that individuals with blood group O have higher rates of non-traumatic haemorrhage. It has been suggested that blood group O may be associated with higher mortality in trauma, however existing evidence is limited and conflicting.

OBJECTIVE

A systematic review was conducted to evaluate the impact of ABO blood group on mortality in trauma patients.

METHODS

MEDLINE via OVID, the Cochrane library and grey literature were searched to identify studies investigating the effect of ABO blood group on mortality of trauma patients admitted to hospital. PRISMA guidelines were followed throughout, study quality was assessed using CASP checklists and certainty of evidence was evaluated using GRADE. Meta-analysis was precluded by significant study heterogeneity.

RESULTS

180 relevant records were screened and seven studies met inclusion criteria, representing 12,240 patients. Two studies found that there was a higher mortality in blood group O compared to other ABO groups. Included studies had substantial variability in methods and population. Study quality was variable with certainty of evidence rated as very low.

CONCLUSIONS

There is insufficient evidence to definitively establish an association between mortality and ABO group in trauma patients. In an age of increasingly individualised care, there is a need to determine the existence and cause for any association through further studies across multiple settings, trauma mechanisms and populations.

Modeling and predicting individual variation in COVID-19 vaccine-elicited antibody response in the general population

As we learned during the COVID-19 pandemic, vaccines are one of the most important tools in infectious disease control. To date, an unprecedentedly large volume of high-quality data on COVID-19 vaccinations have been accumulated. For preparedness in future pandemics beyond COVID-19, these valuable datasets should be analyzed to best shape an effective vaccination strategy. We are collecting longitudinal data from a community-based cohort in Fukushima, Japan, that consists of 2,407 individuals who underwent serum sampling two or three times after a two-dose vaccination with either BNT162b2 or mRNA-1273. Using the individually reconstructed time courses of the vaccine-elicited antibody response based on mathematical modeling, we first identified basic demographic and health information that contributed to the main features of the antibody dynamics, i.e., the peak, the duration, and the area under the curve. We showed that these three features of antibody dynamics were partially explained by underlying medical conditions, adverse reactions to vaccinations, and medications, consistent with the findings of previous studies. We then applied to these factors a recently proposed computational method to optimally fit an "antibody score", which resulted in an integer-based score that can be used as a basis for identifying individuals with higher or lower antibody titers from basic demographic and health information. The score can be easily calculated by individuals themselves or by medical practitioners. Although the sensitivity of this score is currently not very high, in the future, as more data become available, it has the potential to identify vulnerable populations and encourage them to get booster vaccinations. Our mathematical model can be extended to any kind of vaccination and therefore can form a basis for policy decisions regarding the distribution of booster vaccines to strengthen immunity in future pandemics.

Type-O Blood Is Not Associated With Elevated Mortality After Trauma: A North American Cohort Study

BACKGROUND

Recent studies have presented contradictory findings on the relationship between blood type and mortality in trauma patients. Using the largest population in a study of this type to date, we hypothesized that ABO genotype and Rhesus status would influence trauma-related mortality and morbidity given the relationship between blood type and hemostasis.

METHODS

Data from all trauma patients admitted to level I and level II trauma centers in one city over a five-year period was retrospectively analyzed. Patients were stratified by ABO type. Patient demographics and outcomes were then assessed. Chi-squared and Fisher's exact tests were used to analyze categorical variables. Continuous variables were analyzed using ANOVA or Kruskal-Wallis tests as appropriate. Logistic regression was used to determine independent associations for 28-day mortality and complications.

RESULTS

Of 5249 patients, severe injury (ISS >15) was present in 1469. Approximately one-quarter of patients with severe injury received blood products within the first 24 hours. There were no significant variations in demographics or complications between patients of different blood types. Univariate and multivariable regression analysis showed no association between blood type and mortality. However, penetrating injury, lower GCS, higher ISS, blood transfusion within 24 hours, and Asian descent were associated with higher overall mortality.

CONCLUSIONS

In contrast to previous studies, we found no evidence of an association between blood type and mortality. However, our findings suggest that patients of Asian descent may be at higher risk for mortality following trauma. Further research is warranted to explore this observation.

Impact of COVID status and blood group on complications in patients in hemorrhagic shock

Objective

Among critically injured patients of various blood groups, we sought to compare survival and complication rates between COVID-19-positive and COVID-19-negative cohorts.

Background

SARS-CoV-2 infections have been shown to cause endothelial injury and dysfunctional coagulation. We hypothesized that, among patients with trauma in hemorrhagic shock, COVID-19-positive status would be associated with increased mortality and inpatient complications. As a secondary hypothesis, we suspected group O patients with COVID-19 would experience fewer complications than non-group O patients with COVID-19.

Methods

We evaluated all trauma patients admitted 4/2020-7/2020. Patients 16 years or older were included if they presented in hemorrhagic shock and received emergency release blood products. Patients were dichotomized by COVID-19 testing and then divided by blood groups.

Results

3281 patients with trauma were evaluated, and 417 met criteria for analysis. Seven percent (29) of patients were COVID-19 positive; 388 were COVID-19 negative. COVID-19-positive patients experienced higher complication rates than the COVID-19-negative cohort, including acute kidney injury, pneumonia, sepsis, venous thromboembolism, and systemic inflammatory response syndrome. Univariate analysis by blood groups demonstrated that survival for COVID-19-positive group O patients was similar to that of COVID-19-negative patients (79 vs 78%). However, COVID-19-positive non-group O patients had a significantly lower survival (38%). Controlling for age, sex and Injury Severity Score, COVID-19-positive patients had a greater than 70% decreased odds of survival (OR 0.28, 95% CI 0.09 to 0.81; p=0.019).

Conclusions

COVID-19 status is associated with increased major complications and 70% decreased odds of survival in this group of patients with trauma. However, among patients with COVID-19, blood group O was associated with twofold increased survival over other blood groups. This survival rate was similar to that of patients without COVID-19.

Mortality and outcomes by blood group in trauma patients: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Blood group O contains lower levels of factor VIII and von Willebrand factor. Higher incidence of bleeding among group O is reported in multiple contexts. Results of studies vary regarding outcomes stratified by blood group in trauma. We systematically reviewed the literature for outcomes related to blood group in trauma patients. Meta-analysis of studies evaluating mortality related to blood group was performed.

MATERIALS AND METHODS

The PubMed and Embase databases were searched for studies analysing relationships between blood group and outcomes in trauma patients. Preferred Reporting Items in Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. We synthesized outcomes data related to blood group. Meta-analysis compared mortality rates between group O and non-O patients.

RESULTS

Inclusion criteria were met by 13 studies. Statistically significant differences by blood group were reported in 3 of 10 (30%) studies evaluating mortality, 2 of 3 (66.7%) evaluating mortality from haemorrhage and 2 of 9 (22.2%) evaluating transfusion requirement. Meta-analysis was performed on seven studies evaluating mortality (total n = 11,835). There was significant heterogeneity among studies (I²  = 86%, p < 0.00001). No difference was found in mortality between group O and non-O patients (relative risk = 1.21, 95% confidence interval = 0.89-1.64, p = 0.23).

CONCLUSION

Existing literature does not consistently demonstrate a mortality difference between trauma patients with O and non-O blood groups. High variability in the methods and results among studies limits this conclusion, and further research is needed to delineate under what circumstances blood group may influence outcomes.

Relationship between COVID-19 infection and ABO and Rh blood group systems

Purpose: The aim of this study was to determine whether there is a relationship between COVID-19 infection and ABO and Rh blood groups. Materials and Methods: 1360 patients with positive SARS-CoV-2 RNA test between April 2020 and March 2022 and 80219 healthy controls whose blood groups were determined before March 2020 were included in this study. Patients were classified according to disease severity as mild, moderate, severe and critical. Results: Patient and control groups were matched in terms of age and gender using case-control matched method. 1360 patients and 1161 controls were included in the analysis. Of the patients, 42.1% (n=572) had mild, 41.5% (n=564) moderate, 13.8% (n=187) severe and 2.7% (n=37) critical course of infection. It was observed that patients with blood group A were 1.33 times more at risk (OR: 1.33, 95%Cl: 1.12-1.56) for the development of COVID-19 infection compared to patients with other blood groups. No relationship was found between ABO and Rh blood groups and severe-critical COVID-19 disease, need for intensive care and mortality. However, when patients are divided into two groups as mild and non-mild (moderate, severe, critical); the frequency of having O and B blood groups was found to be significantly higher in non-mild cases than in mild cases ( (53.3% and 46.7%), (64.5% and 35.5%, respectively). Conclusion: In our study, while A blood group was found to be at risk for the development of COVID-19 infection, no relationship was found between Rh blood groups and susceptibility to the disease. In addition, the rate of O and B blood groups was found to be higher in patients who did not have mild disease.

Blood phenotype O and indirect bilirubin are associated with lower, early COVID-19-related mortality: A retrospective study

OBJECTIVES

To evaluate the ABO blood type and indirect bilirubin to predict early mortality in adults with severe COVID-19.

METHODS

This retrospective observational study was conducted on 268 adult patients with laboratory-confirmed COVID-19 who had attended the intensive care unit (ICU), Quena general hospital and Luxor International Hospital, and other hospitals or centers for the treatment of COVID-19, during the period from January 2021 till December 2021.

RESULTS

Relation between mortality and ABO group were highly significant, as we found non-O blood group with more risk of early mortality and intensive care unit admission ICU. There were significant differences between dead and alive cases as regards platelets, white blood cells WBCs (neutrophil, lymphocyte), albumin, liver enzymes aspartate transeferase (AST), alanine transferase (ALT), total direct and indirect bilirubin, creatinine, and urea.

CONCLUSION

There was a highly significant relation between dead cases and ABO blood group as between the O and non-O groups; also, group O was associated with less severe manifestations and or ventilation and less mortality in patients with severe COVID-19 infection. Direct bilirubin >0.5 was found to be the best predictor for mortality in cases with COVID-19 so indirect bilirubin may be considered a good protector against complications of the infection.

ABO blood group and link to COVID-19: A comprehensive review of the reported associations and their possible underlying mechanisms

ABO blood group is long known to be an influencing factor for the susceptibility to infectious diseases, and many studies have been describing associations between ABO blood types and COVID-19 infection and severity, with conflicting findings. This narrative review aims to summarize the literature regarding associations between the ABO blood group and COVID-19. Blood type O is mostly associated with lower rates of SARS-CoV-2 infection, while blood type A is frequently described as a risk factor. Although results regarding the risk of severe outcomes are more variable, blood type A is the most associated with COVID-19 severity and mortality, while many studies describe O blood type as a protective factor for the disease progression. Furthermore, genetic associations with both the risk of infection and disease severity have been reported for the ABO locus. Some underlying mechanisms have been hypothesized to explain the reported associations, with incipient experimental data. Three major hypotheses emerge: SARS-CoV-2 could carry ABO(H)-like structures in its envelope glycoproteins and would be asymmetrically transmitted due to a protective effect of the ABO antibodies, ABH antigens could facilitate SARS-CoV-2 interaction with the host’ cells, and the association of non-O blood types with higher risks of thromboembolic events could confer COVID-19 patients with blood type O a lower risk of severe outcomes. The hypothesized mechanisms would affect distinct aspects of the COVID-19 natural history, with distinct potential implications to the disease transmission and its management.