Genetically Determined ABO Blood Group and its Associations With Health and Disease

Association of ABO blood group with risk of coronary stent thrombosis

BACKGROUND

ABO blood group's influence on cardiovascular risk, particularly in venous thromboembolism and coronary artery disease (CAD), is well-studied, with non-O blood groups associated with heightened CAD risk. However, its impact on stent thrombosis remains an unexplored area, prompting the question of whether ABO blood groups are also associated with risk of early stent thrombosis.

OBJECTIVES

The primary objective of this study was to analyze the impact of ABO blood groups on the occurrence of early (≤30 days) stent thrombosis.

METHODS

The study included 10,714 consecutive patients who underwent percutaneous coronary intervention (PCI) with implantation of drug-eluting stents (DES) at a tertiary care hospital. Among these, 78 patients (0.73 %) experienced early stent thrombosis. Propensity score matching was conducted using cardiovascular risk factors and predictors of stent thrombosis, including age, sex, diabetes, hypertension, smoking, hypercholesterinemia, and clinical presentation.

RESULTS

The presence of non-0 blood groups (blood groups A, B and AB; OR 1.48; 95 % CI 0.74-2.97; p = 0.27) and of A-antigen (blood groups A, AB; OR 0.93; 95 % CI 0.51-1.84; p = 0.89) was not associated early stent thrombosis, respectively. In contrast, patients with B-antigen (blood groups B, AB) were at higher risk of early stent thrombosis as compared to patients with blood group 0 (OR 2.48; 95 % CI 1.08-5.69; p = 0.019).

CONCLUSION

The presence of blood group antigen B (blood groups B and AB) emerged as a significant factor associated with early stent thrombosis. Further investigations are warranted to elucidate the specific biological mechanisms through which ABO blood group antigens could influence stent thrombosis.

Blood group is a long-term cardiovascular risk factor after carotid endarterectomy

BACKGROUND

ABO blood group system has been clinically related to an increased incidence of cardiovascular diseases. Preliminary data relating Rhesus (Rh) factor and these outcomes also have been published. Our aim was to analyse the impact of blood group on the short and long-term outcomes after carotid endarterectomy (CEA).

MATERIALS AND METHODS

From 2012 to 2019, patients from a referral centre who underwent CEA for atherosclerotic carotid stenosis were prospectively followed. Our primary outcomes were long-term major adverse cardiovascular events (MACEs) and all-cause mortality. Secondary outcomes were perioperative complications and myocardial injury after non-cardiac surgery (MINS). Median follow-up was 50 months (interquartile range 21-69). Time-to-event analysis was used to determine the effect of ABO and Rh groups in long-term outcomes.

RESULTS

One hundred and eighty-four patients were included, with a mean age of 70.1 ± 9.1 years. Eighteen (25.7%) patients with O type and 48 (42.1%) patients with non-O type presented coronary artery disease (odds ratio [OR]: 2.313, 5-95% confidence interval (CI) 1.245-4.297, p = .008). Patients Rh+ presented significantly more congestive heart failure, 23 (14.7%), p = .03. The incidence of MACE in the long-term was higher in non-O patients (adjusted hazard ratio: 2.034; CI: 1.032-4.010, p = .040). Rh- patients, presented a higher incidence of perioperative MINS. However, there was no statistically significant association with long-term risk of MACE.

CONCLUSION

The incidence of MACE in long-term analysis was higher in non-O blood type and 30-day MINS was significantly more common amongst Rh- patients. The benefit from a more complete preoperative cardiac study in these patients should be performed.

ABO and RhD blood groups as contributors to dyslipidaemia - a cross-sectional study

BACKGROUND

The ABO blood group system has shown an association with cardiovascular disease. The susceptibility to CVD is proposed to be partly mediated by dyslipidaemia in non-O individuals. Previous studies are scarce for the RhD blood group, but we recently showed that RhD - young individuals are associated with subclinical atherosclerosis. Hence, we sought to examine whether the ABO blood groups and RhD factor are associated with dyslipidaemia.

METHODS

All participants were part of the VIPVIZA study, including 3532 individuals with available plasma lipid levels. Lipids were assessed as total, LDL, HDL, remnant, non-HDL cholesterol and triglycerides. Information about ABO and RhD was retrieved by linking VIPVIZA with the SCANDAT-3 database, where 85% of VIPVIZA participants were registered.

RESULTS

For the ABO blood groups, no significant differences in lipid levels between non-O and O individuals were seen. In 40-year-old males, RhD - individuals compared to RhD + had higher levels of non-HDL cholesterol, LDL cholesterol, and remnant cholesterol, with ratios of geometric means of 1.21 (CI95% 1.03; 1.43), 1.20 (1.02; 1.41) and 1.38 (1.00; 1.92), respectively. No differences in lipid levels depending on the RhD blood group were seen in women or the older age groups.

CONCLUSION

Our study indicates that younger RhD - men have increased non-HDL, LDL, and remnant cholesterol levels. Thus, the RhD blood group, but not ABO, seems to be associated with dyslipidaemia and may act as a future possible risk marker of cardiovascular disease.

Platelet indicators do not influence the impact of ABO blood groups on lung adenocarcinoma susceptibility

The aim of this study was to investigate the role of platelet indicators in the susceptibility of ABO blood groups to lung adenocarcinoma. This was a multicenter retrospective cohort analysis. The study included 528 patients diagnosed with primary lung adenocarcinoma and 528 randomly selected control group patients who were admitted to the Chengdu Fifth People's Hospital from January 2021 to September 2023. Additionally, it included 1452 patients diagnosed with primary lung adenocarcinoma and 1452 control group patients who were admitted to the Sichuan Cancer Hospital from November 2013 to May 2021. Platelet indicators were studied using an automated blood counter. ABO blood groups were determined by the gel column method using agglutination techniques. Statistical analysis was performed using Chi-square tests, independent-samples T-tests, ANOVA, and logistic regression. Chi-square analysis showed that there was a difference in ABO blood group composition between the lung adenocarcinoma group and the control group (p < 0.001). Independent-samples T-tests showed that MPV was significantly higher in lung adenocarcinoma than in control group (p = 0.025). The ANOVA of ABO blood groups and platelet indicators in lung adenocarcinoma showed that the average platelet count (PLT) of O group blood was higher than that of B group blood (p = 0.037), while the mean platelet volume (MPV) was significantly lower than that of A group, B group and AB group blood (p = 0.009). After adjusting for gender and age, logistic regression analysis showed that the risk of lung adenocarcinoma in blood groups O and B was higher than that in blood group A (p < 0.05 for each) and blood group AB (p < 0.05 for each), regardless of whether platelet indicators were added. Meanwhile, logistic regression showed that high platelet volume (MPV) was a risk factor for lung adenocarcinoma (p = 0.029). Our findings suggest that platelet indicators are respectively associated with ABO blood groups and lung adenocarcinoma. However, platelet indicators may not influence the ABO blood groups related susceptibility to Lung Adenocarcinoma.

Relationship Between ABO Blood Groups and Mental Disorders

Previous research has unveiled an intriguing positive association between the AB blood group and mental disorders in general. In this study, we compared ABO blood groups with five major groups of mental disorders to attain a higher level of specificity. The analyses were conducted using data from the CoLaus|PsyCoLaus study (N=5111). They revealed that the AB blood group exhibited a positive association with both neurodevelopmental disorders (RR 2.29, CI 1.38-3.82) and substance use disorders (RR 2.25, CI 1.38-3.65) after adjusting for sex and childhood adversities. These associations could be replicated with respect to the familial aggregation of neurodevelopmental and substance use disorders. Large databases are needed to achieve more detailed results related to specific disorders.

Disparities in ABO blood type determination across diverse ancestries: a systematic review and validation in the All of Us Research Program

OBJECTIVES

ABO blood types have widespread clinical use and robust associations with disease. The purpose of this study is to evaluate the portability and suitability of tag single-nucleotide polymorphisms (tSNPs) used to determine ABO alleles and blood types across diverse populations in published literature.

MATERIALS AND METHODS

Bibliographic databases were searched for studies using tSNPs to determine ABO alleles. We calculated linkage between tSNPs and functional variants across inferred continental ancestry groups from 1000 Genomes. We compared r2 across ancestry and assessed real-world consequences by comparing tSNP-derived blood types to serology in a diverse population from the All of Us Research Program.

RESULTS

Linkage between functional variants and O allele tSNPs was significantly lower in African (median r2 = 0.443) compared to East Asian (r2 = 0.946, P = 1.1 × 10-5) and European (r2 = 0.869, P = .023) populations. In All of Us, discordance between tSNP-derived blood types and serology was high across all SNPs in African ancestry individuals and linkage was strongly correlated with discordance across all ancestries (ρ = -0.90, P = 3.08 × 10-23).

DISCUSSION

Many studies determine ABO blood types using tSNPs. However, tSNPs with low linkage disequilibrium promote misinference of ABO blood types, particularly in diverse populations. We observe common use of inappropriate tSNPs to determine ABO blood type, particularly for O alleles and with some tSNPs mistyping up to 58% of individuals.

CONCLUSION

Our results highlight the lack of transferability of tSNPs across ancestries and potential exacerbation of disparities in genomic research for underrepresented populations. This is especially relevant as more diverse cohorts are made publicly available.

ABO Blood Group and Risk Associated With Sepsis-Associated Thrombocytopenia: A Single-Center Retrospective Study

OBJECTIVES

This study aimed to investigate the relationship between ABO blood group and sepsis-associated thrombocytopenia (SAT).

DESIGN AND SETTING

The primary outcome was SAT within the first 72 hours of ICU admission.

PATIENTS

The retrospective study included 9113 patients diagnosed with sepsis from January 2014 to December 2022. A total of 6296 patients eventually were included into the study, who were divided into four groups based on ABO blood group.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 2494 patients (39.6%) were diagnosed with SAT, and 712 (11.3%) of them experiencing severe SAT. The occurrence of SAT among the ABO blood groups was significantly lower in AB blood group compared with the other groups (p = 0.032). Individuals in AB blood group were less likely to experience severe SAT (p = 0.028). In multivariate analysis, B blood group (odds ratio [OR], 1.32; 95% CI, 1.05-1.67) and O (OR, 1.37; 95% CI, 1.09-1.72) were significantly associated with a higher occurrence of SAT compared with AB blood group. In multivariate analyses, A blood group (OR, 1.68; 95% CI, 1.16-2.42), B blood group (OR, 1.74; 95% CI, 1.74-2.50), and O blood group (OR, 1.72; 95% CI, 1.20-2.48) remained significantly risk factors associated with a higher occurrence of severe SAT compared with AB blood group.

CONCLUSIONS

B blood group and O were associated with an increased risk of SAT and severe SAT.

COVID-19 Is a Coronary Artery Disease Risk Equivalent and Exhibits a Genetic Interaction With ABO Blood Type

BACKGROUND

COVID-19 is associated with acute risk of major adverse cardiac events (MACE), including myocardial infarction, stroke, and mortality (all-cause). However, the duration and underlying determinants of heightened risk of cardiovascular disease and MACE post-COVID-19 are not known.

METHODS

Data from the UK Biobank was used to identify COVID-19 cases (n=10 005) who were positive for polymerase chain reaction (PCR+)-based tests for SARS-CoV-2 infection (n=8062) or received hospital-based International Classification of Diseases version-10 (ICD-10) codes for COVID-19 (n=1943) between February 1, 2020 and December 31, 2020. Population controls (n=217 730) and propensity score-matched controls (n=38 860) were also drawn from the UK Biobank during the same period. Proportional hazard models were used to evaluate COVID-19 for association with long-term (>1000 days) risk of MACE and as a coronary artery disease risk equivalent. Additional analyses examined whether COVID-19 interacted with genetic determinants to affect the risk of MACE and its components.

RESULTS

The risk of MACE was elevated in COVID-19 cases at all levels of severity (HR, 2.09 [95% CI, 1.94-2.25]; P<0.0005) and to a greater extent in cases hospitalized for COVID-19 (HR, 3.85 [95% CI, 3.51-4.24]; P<0.0005). Hospitalization for COVID-19 represented a coronary artery disease risk equivalent since incident MACE risk among cases without history of cardiovascular disease was even higher than that observed in patients with cardiovascular disease without COVID-19 (HR, 1.21 [95% CI, 1.08-1.37]; P<0.005). A significant genetic interaction was observed between the ABO locus and hospitalization for COVID-19 (Pinteraction=0.01), with risk of thrombotic events being increased in subjects with non-O blood types (HR, 1.65 [95% CI, 1.29-2.09]; P=4.8×10-5) to a greater extent than subjects with blood type O (HR, 0.96 [95% CI, 0.66-1.39]; P=0.82).

CONCLUSIONS

Hospitalization for COVID-19 represents a coronary artery disease risk equivalent, with post-acute myocardial infarction and stroke risk particularly heightened in non-O blood types. These results may have important clinical implications and represent, to our knowledge, one of the first examples of a gene-pathogen exposure interaction for thrombotic events.

Shared genetic etiology of vessel diseases: A genome-wide multi-traits association analysis

BACKGROUND

The comorbidity among vascular diseases has been widely reported, however, the contribution of shared genetic components remains ambiguous.

METHODS

Based on genome-wide association study summary statistics, we employed statistical genetics methodologies to explore the shared genetic basis of eight vascular diseases: coronary artery disease, abdominal aortic aneurysm, ischemic stroke, peripheral artery disease, thoracic aortic aneurysm, phlebitis, varicose veins, and venous thromboembolism. We assessed global and local genetic correlations among these disorders by linkage disequilibrium score regression, high-definition likelihood, and local analysis of variant association. Cross-trait analyses conducted with CPASSOC identified pleiotropic variants and loci. Further, biological pathways at the multi-omics level were explored using multimarker analysis of genomic annotation, transcriptome-wide and proteome-wide association studies. Causal associations among the vascular diseases were evaluated by mendelian randomization and latent causal variable to assess vertical pleiotropic effects.

RESULTS

We found significant global genetic associations in 18 pairs of vascular diseases. Additionally, we discovered 317 unique genomic regions where at least one pair of traits demonstrated significant correlation. Multi-trait association analysis identified 19,361 significant potential pleiotropic variants in 274 independent pleiotropic loci. Multi-trait colocalization analysis revealed 56 colocalized loci in specific disease sets. Gene-based analysis identified 700 potential pleiotropic genes, which were subsequently validated at both transcriptome and protein levels. Gene-set enrichment analysis supports the role of biological pathways such as vessel wall structure, coagulation and lipid transport in vascular disease. Additionally, 7 pairs of vascular diseases have a causal relationship.

CONCLUSIONS

Our study indicates a shared genetic basis and the presence of common risk genes among vascular diseases. These findings offer novel insights into potential mechanisms underlying the association between vascular diseases, as well as provide guidance for interventions and treatments of multi-vascular conditions.

Association between ABO genotypes and risk of dementia and neuroimaging markers: roles of sex and APOE status

Background

Whether the relationships between ABO blood genotypes (AA, AO, BB, BO, AB, and OO) and dementia are modified by gender and APOE status has been unclear.

Methods

We used data from the UK Biobank, a population-based cohort study of 487,425 individuals. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) between ABO genotypes and risk of dementia. Multivariable linear regression models were used to estimate the relationship between ABO genotypes and MRI-based brain indices.

Results

Overall, 487,425 participants were included at baseline. After 34 million person-years follow up, 7,548 patients developed all-cause dementia. Before stratifying by sex and APOE status, compared to OO genotype, BB genotype was associated with increased risk of all-cause dementia (1.36, 1.03-1.80) and other types dementia (1.65, 1.20-2.28). After stratifying by sex, only in males, BB genotype was associated with higher risk of all-cause dementia (1.44, 1.02-2.09) and other types of dementia (1.95, 1.30-2.93). AB genotype in males was also associated with increased AD (1.34, 1.04-1.72). After further stratifying by APOE e4 status, BB genotype with two APOE e4 alleles showed even stronger association with all-cause dementia 4.29 (1.57, 11.72) and other types dementia (5.49, 1.70-17.69) in males. Also in males, AA genotype with one APOE e4 was associated with increased risks of all-cause dementia (1.27, 1.04-1.55), AD (1.45, 1.09-1.94) and other types dementia (1.40, 1.08-1.81). Linear regression models showed that in both sexes with APOE e4, AA genotype was associated with reduced total grey matter volume.

Conclusion

Sex and APOE e4 carrier status modified the association between ABO genotypes and risk of dementia. In males, BB genotype was consistently associated with increased risk of dementia, especially in those with two APOE e4 alleles. Also, in males with one APOE e4, AA genotype might be linked to higher risk of dementia.

Blood groups and Rhesus status as potential predictors of outcomes in patients with cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) improves prognosis in patients with heart failure (HF) however the role of ABO blood groups and Rhesus factor are poorly understood. We hypothesise that blood groups may influence clinical and survival outcomes in HF patients undergoing CRT. A total of 499 patients with HF who fulfilled the criteria for CRT implantation were included. Primary outcome of all-cause mortality and/or heart transplant/left ventricular assist device was assessed over a median follow-up of 4.6 years (IQR 2.3-7.5). Online repositories were searched to provide biological context to the identified associations. Patients were divided into blood (O, A, B, and AB) and Rhesus factor (Rh-positive and Rh-negative) groups. Mean patient age was 66.4 ± 12.8 years with a left ventricular ejection fraction of 29 ± 11%. There were no baseline differences in age, gender, and cardioprotective medication. In a Cox proportional hazard multivariate model, only Rh-negative blood group was associated with a significant survival benefit (HR 0.68 [0.47-0.98], p = 0.040). No association was observed for the ABO blood group (HR 0.97 [0.76-1.23], p = 0.778). No significant interaction was observed with prevention, disease aetiology, and presence of defibrillator. Rhesus-related genes were associated with erythrocyte and platelet function, and cholesterol and glycated haemoglobin levels. Four drugs under development targeting RHD were identified (Rozrolimupab, Roledumab, Atorolimumab, and Morolimumab). Rhesus blood type was associated with better survival in HF patients with CRT. Further research into Rhesus-associated pathways and related drugs, namely whether there is a cardiac signal, is required.

Group B or not group B? An association between ABO, early mortality, and organ dysfunction in major trauma patients with shock

BACKGROUND

ABO blood group alters coagulation profiles in the general population and may influence outcomes after trauma. The relationship between trauma-induced coagulopathy, severe injury with hemorrhagic shock, and survival with respect to ABO group is unknown.

OBJECTIVES

In severe hemorrhagic trauma, we aimed to characterize the association of ABO group with admission coagulation profiles, mortality, and immune-mediated complications.

METHODS

Clinical and laboratory variables were examined from severely injured adult patients enrolled in a perpetual observational cohort study at a UK Major Trauma Center. Univariate and multivariate analyses were performed to determine differences in clinical outcomes (mortality, organ dysfunction, and critical care support). In a shock subgroup, we performed an exploratory analysis of rotational thromboelastometry parameters and coagulation biomarkers.

RESULTS

In 1119 trauma patients, we found no difference in mortality between ABO groups. In patients with shock, 24-hour mortality was significantly lower in group B vs non-B groups (7% vs 16%, adjusted odds ratio [aOR], 0.19; P = .030), but there were increased rates of invasive ventilation (aOR, 3.34; P = .033), renal replacement therapy (aOR, 2.55; P = .037), and a trend for infection (aOR, 1.85; P = .067). Comparing patients with shock, group B vs non-B patients had 40% higher fibrinogen, 65% higher factor (F) VIII, 36% higher FIX, 20% higher FXIII, and 19% higher von Willebrand factor.

CONCLUSION

In this observational study limited by single time-point sampling and subgroup analysis of trauma hemorrhage with shock, group B patients have enhanced hemostatic capability associated with early survival but with increased risk of immune-mediated complications.

ABO Blood Groups, RhD Factor and Their Association with Subclinical Atherosclerosis Assessed by Carotid Ultrasonography

Background: The ABO blood group system has previously been associated with cardiovascular disease (CVD), where non-O blood group individuals have shown an increased risk. Studies assessing early atherosclerotic disease while also including RhD are few. We aimed to determine whether the ABO and RhD blood groups are associated with subclinical atherosclerosis in a healthy population. Methods: We included 3532 participants from the VIPVIZA trial with available carotid ultrasonography results to assess subclinical disease. Information about blood groups was obtained from the SCANDAT-3 database, where 85% of VIPVIZA participants were registered. Results: RhD- individuals aged 40 years showed increased carotid intima-media thickness (B 1.09 CI 95% 1.03; 1.14) compared to RhD+ individuals. For ABO, there were no differences in ultrasonography results when assessing the whole study population. However, 60-year-old individuals with heredity for CVD and a non-O blood group had decreased odds for carotid plaques (OR 0.54 CI 95% 0.33; 0.88). Conclusions: RhD blood group is associated with subclinical atherosclerosis in younger individuals, indicating a role as a mediator in the atherosclerotic process. In addition, a non-O blood group was associated with decreased subclinical atherosclerosis in individuals aged 60 and with heredity (corresponding to the group with the highest atherosclerotic burden).

Genetic examination of hematological parameters in SARS-CoV-2 infection and COVID-19

People hospitalized with COVID-19 often exhibit altered hematological traits associated with disease prognosis (e.g., lower lymphocyte and platelet counts). We investigated whether inter-individual variability in baseline hematological traits influences risk of acute SARS-CoV-2 infection or progression to severe COVID-19. We report inconsistent associations between blood cell traits with incident SARS-CoV-2 infection and severe COVID-19 in UK Biobank and the Vanderbilt University Medical Center Synthetic Derivative (VUMC SD). Since genetically determined blood cell measures better represent cell abundance across the lifecourse, we also assessed the shared genetic architecture of baseline blood cell traits on COVID-19 related outcomes by Mendelian randomization (MR) analyses. We found significant relationships between COVID-19 severity and mean sphered cell volume after adjusting for multiple testing. However, MR results differed significantly across different freezes of COVID-19 summary statistics and genetic correlation between these traits was modest (0.1), decreasing our confidence in these results. We observed overlapping genetic association signals between other hematological and COVID-19 traits at specific loci such as MAPT and TYK2. In conclusion, we did not find convincing evidence of relationships between the genetic architecture of blood cell traits and either SARS-CoV-2 infection or COVID-19 hospitalization, though we do see evidence of shared signals at specific loci.

Polygenic risk scores for prediction of cancer-associated venous thromboembolism in the UK Biobank cohort study

BACKGROUND

Guidelines recommend thromboprophylaxis for patients with cancer at high risk of venous thromboembolism (VTE). Polygenic risk scores may improve VTE prediction but have not yet been evaluated in patients with cancer.

OBJECTIVES

We assessed the performance of the 5-, 37-, 297-, extended 297- (additionally including factor V Leiden and prothrombin G20210A), and 100-single-nucleotide polymorphism (SNP) scores in predicting cancer-associated VTE in the UK Biobank, a population-based, prospective cohort study.

METHODS

The primary outcome was VTE during 12 months after cancer diagnosis. Cancer and VTE diagnosis were based on ICD-10 codes. Discrimination was evaluated by c-indices and subdistribution hazard ratios in the upper vs 3 lower quartiles of the scores in a competing risk model. As a comparison, the c-index was calculated for the Khorana cancer type risk classification.

RESULTS

Of 36 150 patients with cancer (median age, 66 years; 48.7% females), 1018 (2.8%) developed VTE. C-indices at 12 months ranged from 0.56 (95% CI, 0.54-0.58) for the 5-SNP to 0.60 (95% CI, 0.58-0.62) for the extended 297-SNP scores. The subdistribution hazard ratios ranged from 1.36 (95% CI, 1.19-1.56) for the 5-SNP to 1.90 (95% CI, 1.68-2.16) for the extended 297-SNP scores and were consistent after adjusting for cancer type. For the Khorana cancer type classification, the c-index was 0.60 (95% CI, 0.58-0.61), which increased to 0.65 (95% CI, 0.63-0.67, +0.05; 95% CI, 0.04-0.07) when combined with the extended 297-SNP score.

CONCLUSION

These findings demonstrate that polygenic VTE risk scores can identify patients with cancer with a 1.9-fold higher VTE risk independent of cancer type. Combined clinical-genetic scores to improve cancer-associated VTE prediction should be evaluated further.

Plasma proteomic associations with genetics and health in the UK Biobank

The Pharma Proteomics Project is a precompetitive biopharmaceutical consortium characterizing the plasma proteomic profiles of 54,219 UK Biobank participants. Here we provide a detailed summary of this initiative, including technical and biological validations, insights into proteomic disease signatures, and prediction modelling for various demographic and health indicators. We present comprehensive protein quantitative trait locus (pQTL) mapping of 2,923 proteins that identifies 14,287 primary genetic associations, of which 81% are previously undescribed, alongside ancestry-specific pQTL mapping in non-European individuals. The study provides an updated characterization of the genetic architecture of the plasma proteome, contextualized with projected pQTL discovery rates as sample sizes and proteomic assay coverages increase over time. We offer extensive insights into trans pQTLs across multiple biological domains, highlight genetic influences on ligand-receptor interactions and pathway perturbations across a diverse collection of cytokines and complement networks, and illustrate long-range epistatic effects of ABO blood group and FUT2 secretor status on proteins with gastrointestinal tissue-enriched expression. We demonstrate the utility of these data for drug discovery by extending the genetic proxied effects of protein targets, such as PCSK9, on additional endpoints, and disentangle specific genes and proteins perturbed at loci associated with COVID-19 susceptibility. This public-private partnership provides the scientific community with an open-access proteomics resource of considerable breadth and depth to help to elucidate the biological mechanisms underlying proteo-genomic discoveries and accelerate the development of biomarkers, predictive models and therapeutics1.

Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias?

BACKGROUND

There are many ways in which selection bias might impact COVID-19 research. Here we focus on selection for receiving a polymerase-chain-reaction (PCR) SARS-CoV-2 test and how known changes to selection pressures over time may bias research into COVID-19 infection.

METHODS

Using UK Biobank (N = 420,231; 55% female; mean age = 66.8 [SD = 8·11]) we estimate the association between socio-economic position (SEP) and (i) being tested for SARS-CoV-2 infection versus not being tested (ii) testing positive for SARS-CoV-2 infection versus testing negative and (iii) testing negative for SARS-CoV-2 infection versus not being tested. We construct four distinct time-periods between March 2020 and March 2021, representing distinct periods of testing pressures and lockdown restrictions and specify both time-stratified and combined models for each outcome. We explore potential selection bias by examining associations with positive and negative control exposures.

RESULTS

The association between more disadvantaged SEP and receiving a SARS-CoV-2 test attenuated over time. Compared to individuals with a degree, individuals whose highest educational qualification was a GCSE or equivalent had an OR of 1·27 (95% CI: 1·18 to 1·37) in March-May 2020 and 1·13 (95% CI: 1.·10 to 1·16) in January-March 2021. The magnitude of the association between educational attainment and testing positive for SARS-CoV-2 infection increased over the same period. For the equivalent comparison, the OR for testing positive increased from 1·25 (95% CI: 1·04 to 1·47), to 1·69 (95% CI: 1·55 to 1·83). We found little evidence of an association between control exposures, and any considered outcome.

CONCLUSIONS

The association between SEP and SARS-CoV-2 testing changed over time, highlighting the potential of time-specific selection pressures to bias analyses of COVID-19. Positive and negative control analyses suggest that changes in the association between SEP and SARS-CoV-2 infection over time likely reflect true increases in socioeconomic inequalities.

Evaluation of Clinical Manifestations of Hemorrhoidal Disease, Carried Out Surgeries and Prolapsed Anorectal Tissues: Associations with ABO Blood Groups of Patients

Hemorrhoidal disease (HD) is a chronic multifactorial disease. Increased abdominal pressure, along with hyperperfusion, neovascularization, overexpression of inflammatory mediators, and dysbiosis, contributes to the development of HD. The deterioration of the anchoring connective tissue with reduced collagen content and altered collagen ratios, dilatation of blood vessels and thrombosis, muscle injury, and inflammation gradually lead to clinically manifesting prolapse and bleeding from hemorrhoids. The associations of the ABO blood types with a disease have been investigated for the upper gastrointestinal tract only. This study aimed to evaluate HD clinical manifestations, surgeries carried out, and the status of prolapsed anorectal tissues by exploring the associations with the patients' ABO blood groups. Clinical and various morphological methods, combined with extensive bioinformatics, were used. The blood type 0, grade III and IV HD individuals constituted the largest group in a moderately-sized cohort of equally represented males and females studied and submitted to surgical treatment of hemorrhoids. There were significantly more complaints reported by HD females compared to males (p = 0.0094). The Longo technique appeared mostly used, and there were proportionally more surgeries performed below the dentate line for HD individuals with blood type 0 compared to other blood type patients (24% vs. 11%). HD males were found to present with significantly more often inflamed rectal mucosa (p < 0.05). Loosening and weakening of collagenous components of the rectal wall combined with vascular dilation and hemorrhage was found to differ in 0 blood type HD individuals compared to other types. HD males were demonstrated to develop the ruptures of vascular beds significantly more often when compared to HD females (p = 0.0165). Furthermore, 0 blood type HD males were significantly more often affected by a disease manifested with tissue hemorrhage compared to the 0 blood type HD females (p = 0.0081). Collectively, the local status of chronically injured anorectal tissue should be considered when applying surgical techniques. Future studies could include patients with HD grades I and II to gain a comprehensive understanding of the disease progression, allowing for a comparison of tissue changes at different disease stages.

Prediction model for tibial plateau fracture combined with meniscus injury

Purpose

To investigate a prediction model of meniscus injury in patients with tibial plateau fracture.

Methods

This retrospective study enrolled patients with tibial plateau fractures who were treated in the Third Hospital of Hebei Medical University from January 1, 2015, to June 30, 2022. Patients were divided into a development cohort and a validation cohort based on the time-lapse validation method. Patients in each cohort were divided into a group with meniscus injury and a group without meniscus injury. Statistical analysis with Student's t-test for continuous variables and chi square test for categorical variables was performed for patients with and without meniscus injury in the development cohort. Multivariate logistic regression analysis was used to screen the risk factors of tibial plateau combined with meniscal injury, and a clinical prediction model was constructed. Model performance was measured by examining discrimination (Harrell's C-index), calibration (calibration plots), and utility [decision analysis curves (DCA)]. The model was validated internally using bootstrapping and externally by calculating their performance in a validation cohort.

Results

Five hundred patients (313 [62.6%] males, 187 [37.4%] females) with a mean age of 47.7 ± 13.8 years were eligible and were divided into development (n = 262) and validation (n = 238) cohorts. A total of 284 patients had meniscus injury, including 136 in the development cohort and 148 in the validation cohort We identified high-energy injuries as a risk factor (OR = 1.969, 95%CI 1.131-3.427). Compared with blood type A, patients with blood type B were more likely to experience tibial plateau fracture with meniscus injury (OR = 2.967, 95%CI 1.531-5.748), and office work was a protective factor (OR = 0.279, 95%CI 0.126-0.618). The C-index of the overall survival model was 0.687 (95% CI, 0.623-0.751). Similar C-indices were obtained for external validation [0.700(0.631-0.768)] and internal validation [0.639 (0.638-0.643)]. The model was adequately calibrated and its predictions correlated with the observed outcomes. The DCA curve showed that the model had the best clinical validity when the threshold probability was 0.40 and 0.82.

Conclusions

Patients with blood type B and high-energy injuries are more likely to have meniscal injury. This may help in clinical trial design and individual clinical decision-making.

Blood Type Associated with the Risk of COVID-19 Infection in Pregnant Women

COVID-19 forced us to investigate risk factors to provide the best medical attention, especially in vulnerable groups, such as pregnant patients. Studies in other populations have analyzed blood groups in relation to infection, complications, and death. The present study aimed to analyze the association of blood groups with the risk of infection and complications in pregnant women and newborns from the Mexican-Mestizo population. We studied 1906 individuals. Quantitative variables were analyzed through the Student’s t-test. Categorical variables were analyzed through Pearson’s chi-square test, and logistic regression was used to analyze the association between categorical variables and outcomes. No significant association was observed between blood groups and infection risk. Individuals with the AB blood type are at higher risk for developing severe disease, although blood groups do not seem to be involved in the risk of SARS-CoV-2 infection. However, the AB blood group could be considered a risk factor for developing severe COVID-19 in the Mexican population.

Long COVID and the cardiovascular system-elucidating causes and cellular mechanisms in order to develop targeted diagnostic and therapeutic strategies: a joint Scientific Statement of the ESC Working Groups on Cellular Biology of the Heart and Myocardial and Pericardial Diseases

Long COVID has become a world-wide, non-communicable epidemic, caused by long-lasting multiorgan symptoms that endure for weeks or months after SARS-CoV-2 infection has already subsided. This scientific document aims to provide insight into the possible causes and therapeutic options available for the cardiovascular manifestations of long COVID. In addition to chronic fatigue, which is a common symptom of long COVID, patients may present with chest pain, ECG abnormalities, postural orthostatic tachycardia, or newly developed supraventricular or ventricular arrhythmias. Imaging of the heart and vessels has provided evidence of chronic, post-infectious perimyocarditis with consequent left or right ventricular failure, arterial wall inflammation, or microthrombosis in certain patient populations. Better understanding of the underlying cellular and molecular mechanisms of long COVID will aid in the development of effective treatment strategies for its cardiovascular manifestations. A number of mechanisms have been proposed, including those involving direct effects on the myocardium, microthrombotic damage to vessels or endothelium, or persistent inflammation. Unfortunately, existing circulating biomarkers, coagulation, and inflammatory markers, are not highly predictive for either the presence or outcome of long COVID when measured 3 months after SARS-CoV-2 infection. Further studies are needed to understand underlying mechanisms, identify specific biomarkers, and guide future preventive strategies or treatments to address long COVID and its cardiovascular sequelae.

Human Genes Involved in the Interaction between Host and Gut Microbiome: Regulation and Pathogenic Mechanisms

Introduction: The umbrella term “human gut microbiota” describes the complex ecosystem harboring our gut. It includes bacteria, viruses, protozoa, archaea, fungi, and yeasts. This taxonomic classification does not describe its functions, which encompass nutrients digestion and absorption, immune system regulation, and host metabolism. “Gut microbiome” indicates instead the genome belonging to these “microbes” actively involved in these functions. However, the interaction between the host genome and the microbial ones determines the fine functioning of our organism. Methods: We reviewed the data available in the scientific literature on the definition of gut microbiota, gut microbiome, and the data on human genes involved in the interaction with the latter. We consulted the main medical databases using the following keywords, acronyms, and their associations: gut microbiota, gut microbiome, human genes, immune function, and metabolism. Results: Candidate human genes encoding enzymes, inflammatory cytokines, and proteins show similarity with those included in the gut microbiome. These findings have become available through newer artificial intelligence (AI) algorithms allowing big data analysis. From an evolutionary point of view, these pieces of evidence explain the strict and sophisticated interaction at the basis of human metabolism and immunity regulation in humans. They unravel more and more physiopathologic pathways included in human health and disease. Discussion: Several lines of evidence also obtained through big data analysis support the bi-directional role of gut microbiome and human genome in host metabolism and immune system regulation.

Association of ABO Blood Group with Delayed Cerebral Ischemia and Clinical Outcomes Following Aneurysmal Subarachnoid Hemorrhage in Pakistan

Background The ABO blood type, due to its various hemostaseologic properties, has been associated with several vascular diseases, including aneurysmal subarachnoid hemorrhage (aSAH). However, the role of ABO blood type in delayed cerebral ischemia (DCI) onset and other clinical outcomes after aSAH is largely unexplored. This study aimed to investigate the association between ABO blood type and outcomes after aSAH, primarily DCI.

Methods A retrospective analysis was made on the data collected from 175 aSAH patients at a tertiary supraregional neurosurgery department over 5 years. Socio-demographic factors, clinical variables (DCI, mFG, WFNS grade, and Glasgow Outcome Scale at discharge), EVD placement, and aneurysm size were analyzed for their association with ABO blood type.

Results DCI was reported in 25% of patients with ‘O’ blood type and 9.6% with ‘non-O’ blood type. A stepwise logistic regression model showed that after adjusting for BMI, mFG, WFNS grade, and EVD placement, ‘O’ type blood group was an independent risk factor for DCI, greatly increasing the risk of DCI as compared to ‘non-O’ type groups (OR = 3.27, 95% CI: 1.21–8.82).

Conclusion This study provides evidence that individuals with ‘O’ blood type may have a higher risk of DCI onset after aSAH. However, further studies are essential to address the limitations of our work and confirm our findings.

Associations of ABO and Rhesus D blood groups with phenome-wide disease incidence: A 41-year retrospective cohort study of 482,914 patients

Background

Whether natural selection may have attributed to the observed blood group frequency differences between populations remains debatable. The ABO system has been associated with several diseases and recently also with susceptibility to COVID-19 infection. Associative studies of the RhD system and diseases are sparser. A large disease-wide risk analysis may further elucidate the relationship between the ABO/RhD blood groups and disease incidence.

Methods

We performed a systematic log-linear quasi-Poisson regression analysis of the ABO/RhD blood groups across 1,312 phecode diagnoses. Unlike prior studies, we determined the incidence rate ratio for each individual ABO blood group relative to all other ABO blood groups as opposed to using blood group O as the reference. Moreover, we used up to 41 years of nationwide Danish follow-up data, and a disease categorization scheme specifically developed for diagnosis-wide analysis. Further, we determined associations between the ABO/RhD blood groups and the age at the first diagnosis. Estimates were adjusted for multiple testing.

Results

The retrospective cohort included 482,914 Danish patients (60.4% females). The incidence rate ratios (IRRs) of 101 phecodes were found statistically significant between the ABO blood groups, while the IRRs of 28 phecodes were found statistically significant for the RhD blood group. The associations included cancers and musculoskeletal-, genitourinary-, endocrinal-, infectious-, cardiovascular-, and gastrointestinal diseases.

Conclusions

We found associations of disease-wide susceptibility differences between the blood groups of the ABO and RhD systems, including cancer of the tongue, monocytic leukemia, cervical cancer, osteoarthrosis, asthma, and HIV- and hepatitis B infection. We found marginal evidence of associations between the blood groups and the age at first diagnosis.

Funding

Novo Nordisk Foundation and the Innovation Fund Denmark.

Investigating the interrelatedness of clinical and non-clinical parameters affecting outcomes in COVID-19 patients: a retrospective study

The COVID-19 pandemic has affected millions globally. Several studies have been carried out to uncover factors affecting the severity of the resulting infection. Available location-specific data concerning the affective demographics as well as clinical aspect of the disease remains limited. In this study, a number of non-clinical as well as the clinical parameters were investigated for their role in adverse progression of the disease in patients admitted to intensive care unit (ICU) in a private tertiary hospital in Peshawar. The prevalence of comorbidities hypertension and diabetes as well as mortality was higher in age group of 70-79 years. Dyspnea was significantly linked to sepsis, invasive ventilation, and mortality; its late presentation, i.e. 15 to 20 days was significantly associated with mortality (p-value < 0.02). Acute kidney injury and acute respiratory distress syndrome were found to be the most strongly associated with sepsis and septic shock. Neither remdesivir nor tocilizumab was effective in preventing the infection-related complications, invasive ventilation, and mortality. Overall, dyspnea was found to be an indicator of the worst progression of the disease. Furthermore, while some parameters were closely linked, others were not.

The gut microbiome and hypertension

A large body of evidence has emerged in the past decade supporting a role for the gut microbiome in the regulation of blood pressure. The field has moved from association to causation in the last 5 years, with studies that have used germ-free animals, antibiotic treatments and direct supplementation with microbial metabolites. The gut microbiome can regulate blood pressure through several mechanisms, including through gut dysbiosis-induced changes in microbiome-associated gene pathways in the host. Microbiota-derived metabolites are either beneficial (for example, short-chain fatty acids and indole-3-lactic acid) or detrimental (for example, trimethylamine N-oxide), and can activate several downstream signalling pathways via G protein-coupled receptors or through direct immune cell activation. Moreover, dysbiosis-associated breakdown of the gut epithelial barrier can elicit systemic inflammation and disrupt intestinal mechanotransduction. These alterations activate mechanisms that are traditionally associated with blood pressure regulation, such as the renin-angiotensin-aldosterone system, the autonomic nervous system, and the immune system. Several methodological and technological challenges remain in gut microbiome research, and the solutions involve minimizing confounding factors, establishing causality and acting globally to improve sample diversity. New clinical trials, precision microbiome medicine and computational methods such as Mendelian randomization have the potential to enable leveraging of the microbiome for translational applications to lower blood pressure.

Galectin-3 and Blood Group: Binding Properties, Effects on Plasma Levels, and Consequences for Prognostic Performance

Previous studies have reported an association between ABO type blood group and cardiovascular (CV) events and outcomes. The precise mechanisms underpinning this striking observation remain unknown, although differences in von Willebrand factor (VWF) plasma levels have been proposed as an explanation. Recently, galectin-3 was identified as an endogenous ligand of VWF and red blood cells (RBCs) and, therefore, we aimed to explore the role of galectin-3 in different blood groups. Two in vitro assays were used to assess the binding capacity of galectin-3 to RBCs and VWF in different blood groups. Additionally, plasma levels of galectin-3 were measured in different blood groups in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study (2571 patients hospitalized for coronary angiography) and validated in a community-based cohort of the Prevention of Renal and Vascular End-stage Disease (PREVEND) study (3552 participants). To determine the prognostic value of galectin-3 in different blood groups, logistic regression and cox regression models were used with all-cause mortality as the primary outcome. First, we demonstrated that galectin-3 has a higher binding capacity for RBCs and VWF in non-O blood groups, compared to blood group O. Additionally, LURIC patients with non-O blood groups had substantially lower plasma levels of galectin-3 (15.0, 14.9, and 14.0 μg/L in blood groups A, B, and AB, respectively, compared to 17.1 μg/L in blood group O, p < 0.0001). Finally, the independent prognostic value of galectin-3 for all-cause mortality showed a non-significant trend towards higher mortality in non-O blood groups. Although plasma galectin-3 levels are lower in non-O blood groups, the prognostic value of galectin-3 is also present in subjects with a non-O blood group. We conclude that physical interaction between galectin-3 and blood group epitopes may modulate galectin-3, which may affect its performance as a biomarker and its biological activity.

Genome-wide genotype-serum proteome mapping provides insights into the cross-ancestry differences in cardiometabolic disease susceptibility

Identification of protein quantitative trait loci (pQTL) helps understand the underlying mechanisms of diseases and discover promising targets for pharmacological intervention. For most important class of drug targets, genetic evidence needs to be generalizable to diverse populations. Given that the majority of the previous studies were conducted in European ancestry populations, little is known about the protein-associated genetic variants in East Asians. Based on data-independent acquisition mass spectrometry technique, we conduct genome-wide association analyses for 304 unique proteins in 2,958 Han Chinese participants. We identify 195 genetic variant-protein associations. Colocalization and Mendelian randomization analyses highlight 60 gene-protein-phenotype associations, 45 of which (75%) have not been prioritized in Europeans previously. Further cross-ancestry analyses uncover key proteins that contributed to the differences in the obesity-induced diabetes and coronary artery disease susceptibility. These findings provide novel druggable proteins as well as a unique resource for the trans-ancestry evaluation of protein-targeted drug discovery.

Impact of ABO-blood group type on haemorrhagic and thromboembolic complications after resection of intracranial meningiomas

OBJECTIVE

Recent studies have suggested an impact of the ABO-blood group type on thromboembolic and haemorrhagic events following trauma and surgical procedures. However, only limited data are available on the impact of ABO-blood group types in neurosurgical patients. The goal of the present study was to evaluate the role of the ABO-blood group type on the frequency of thromboembolic and haemorrhagic complications in patients treated surgically for intracranial meningiomas at our institution.

METHODS

We retrospectively analysed the medical records of consecutive patients undergoing resection of intracranial meningiomas at our institution during a period of 12.5 years (2006-2018). Clinical characteristics, modalities of surgical treatment, histopathological results and the postoperative course of patients were analysed with specific focus on ABO-blood group typing results, need for transfusion of blood products, events of postoperative thromboembolism and intracranial re-haemorrhage requiring surgical revision, as well as in-hospital mortality.

RESULTS

A total of 1,782 patients were included in this study. Based on the ABO-blood group type, patients were subdivided into four categories, corresponding to their ABO-blood group: Blood group A (n = 773; 43%); blood group B (n = 222; 12%); blood group AB (n = 88; 5%); and blood group O (n = 699; 39%). Intracranial re-haemorrhage requiring re-craniotomy and haematoma evacuation occurred in a total of 49 patients (2.7%). Thromboembolic events such as pulmonary embolism occurred in a total of 27 patients (1.5%). Statistical analysis showed no significant differences regarding the ABO-blood group type in patients suffering from re-haemorrhage or thromboembolism compared with patients with uneventful course after surgery. The overall in-hospital mortality rate was 0.17% (n = 3).

CONCLUSION

Our findings suggest a lack of relevance of the ABO-blood group type regarding haemorrhagic and thromboembolic complications in patients undergoing neurosurgical meningioma resection.

ABO blood group antigens and differential glycan expression: Perspective on the evolution of common human enzyme deficiencies

Enzymes catalyze biochemical reactions and play critical roles in human health and disease. Enzyme variants and deficiencies can lead to variable expression of glycans, which can affect physiology, influence predilection for disease, and/or directly contribute to disease pathogenesis. Although certain well-characterized enzyme deficiencies result in overt disease, some of the most common enzyme deficiencies in humans form the basis of blood groups. These carbohydrate blood groups impact fundamental areas of clinical medicine, including the risk of infection and severity of infectious disease, bleeding risk, transfusion medicine, and tissue/organ transplantation. In this review, we examine the enzymes responsible for carbohydrate-based blood group antigen biosynthesis and their expression within the human population. We also consider the evolutionary selective pressures, e.g. malaria, that may account for the variation in carbohydrate structures and the implications of this biology for human disease.

Blood group B and decreased risk of coronary artery disease in hypertensive elderly

Although ABO blood groups have been associated with cardio-vascular disease, little is known about whether ABO blood groups contribute to the risk of the presence and severity of coronary artery disease (CAD) in elderly individuals with hypertension. This study was aimed to explore this as-sociation. A total of 793 hypertensive patients aged ≥60 years out of 2095 patients who underwent primary coronary angiography were retrospectively included. They were divided into CAD and non-CAD groups. Demographic and clinical characteristics, ABO blood groups and other biochemical parameters were compared. Further evaluation was performed to determine the impact of ABO blood groups on CAD severity using the Gensini score and the number of significantly diseased vessels. A logistic regression model was constructed to identify the association of ABO blood groups with CAD. There was a substantial difference in the distribution of ABO blood groups in elderly and hypertensive adults with and without CAD (p=0.022). Hypertensive patients with CAD had a significantly lower proportion of the blood group B than those without CAD (p=0.008). Compared to those with non-Blood group B, hypertensive elderly with a blood group B tended to have significantly lower concentrations of TC, LDL -C and Apo B, and a lower number of significantly stenosed vessels. The blood group B was found to be an independent protective factor for CAD in elderly with hypertension. The blood group B is significantly associated with a decreased risk of CAD and is inversely correlated with the severity of coronary stenosis in the elderly with hypertension.

Regulation of VWF (Von Willebrand Factor) in Inflammatory Thrombosis

Increasing evidence indicates that inflammation promotes thrombosis via a VWF (von Willebrand factor)-mediated mechanism. VWF plays an essential role in maintaining the balance between blood coagulation and bleeding, and inflammation can lead to aberrant regulation. VWF is regulated on a transcriptional and (post-)translational level, and its secretion into the circulation captures platelets upon endothelial activation. The significant progress that has been made in understanding transcriptional and translational regulation of VWF is described in this review. First, we describe how VWF is regulated at the transcriptional and post-translational level with a specific focus on the influence of inflammatory and immune responses. Next, we describe how changes in regulation are linked with various cardiovascular diseases. Recent insights from clinical diseases provide evidence for direct molecular links between inflammation and thrombosis, including atherosclerosis, chronic thromboembolic pulmonary hypertension, and COVID-19. Finally, we will briefly describe clinical implications for antithrombotic treatment.

Role of the ABO Blood Groups as a Risk Factor for Retinal Vein Occlusion

INTRODUCTION

A recent study suggested that non-O blood groups had an increased risk for the presence of retinal vein occlusion (RVO). In this study, we investigated (i) an association between blood group and the presence of RVO and (ii) whether this association correlated to other RVO risk factors.

METHODS

We included 485 RVO patients and 295 control subjects who were recruited in this case-control study. We determined ABO genotypes rs8176719 as a marker for the O allele and rs8176746 for the B allele by polymerase chain reaction.

RESULTS

We did not find an association between ABO blood group and the presence of RVO. In detail, the proportion of ABO blood groups was similar among RVO patients and control subjects (p = 0.527). In a logistic regression, non-O blood group was associated with 1.06-fold higher odds of being a RVO patient (95% CI: 0.78-1.45, p = 0.693), and this lack of association prevailed upon multivariable adjustment for age, gender, history of stroke and venous thromboembolism, and co-medication with lipid-lowering agents.

DISCUSSION

Although non-O blood groups are a known risk factor for thrombotic and cardiovascular disease, they do not seem to be a major risk factor for the development of RVO.

The Roles of Gut Microbiome and Plasma Metabolites in the Associations between ABO Blood Groups and Insulin Homeostasis: The Microbiome and Insulin Longitudinal Evaluation Study (MILES)

Non-O blood groups are associated with decreased insulin sensitivity and risk of type 2 diabetes. A recent study pinpointed the associations between ABO blood groups and gut microbiome, which may serve as potential mediators for the observed increased disease risks. We aimed to characterize associations between ABO haplotypes and insulin-related traits as well as potential mediating pathways. We assessed insulin homeostasis in African Americans (AAs; n = 109) and non-Hispanic whites (n = 210) from the Microbiome and Insulin Longitudinal Evaluation Study. The ABO haplotype was determined by six SNPs located in the ABO gene. Based on prior knowledge, we included 21 gut bacteria and 13 plasma metabolites for mediation analysis. In the white study cohort (60 ± 9 years, 42% male), compared to the O1 haplotype, A1 was associated with a higher Matsuda insulin sensitivity index, while a lower relative abundance of Bacteroides massiliensis and lactate levels. Lactate was a likely mediator of this association but not Bacteroides massiliensis. In the AAs group (57 ± 8 years, 33% male), we found no association between any haplotype and insulin-related traits. In conclusion, the A1 haplotype may promote healthy insulin sensitivity in non-Hispanic whites and lactate likely play a role in this process but not selected gut bacteria.

ABO O blood group as a risk factor for platelet reactivity in heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is an unpredictable, potentially catastrophic adverse effect resulting from an immune response to platelet factor 4 (PF4)/heparin complexes. We performed a genome-wide association study (GWAS) with positive functional assay as the outcome in a large discovery cohort of patients divided into 3 groups: (1) functional assay-positive cases (n = 1269), (2) antibody-positive (functional assay-negative) controls (n = 1131), and (3) antibody-negative controls (n = 1766). Significant associations (α = 5 × 10-8) were investigated in a replication cohort (α = 0.05) of functional assay-confirmed HIT cases (n = 177), antibody-positive (function assay-negative) controls (n = 258), and antibody-negative controls (n = 351). We observed a strong association for positive functional assay with increasing PF4/heparin immunoglobulin-G (IgG) level (odds ratio [OR], 16.53; 95% confidence interval [CI], 13.83-19.74; P = 1.51 × 10-209) and female sex (OR, 1.15; 95% CI, 1.01-1.32; P = .034). The rs8176719 C insertion variant in ABO was significantly associated with positive functional assay status in the discovery cohort (frequency = 0.41; OR, 0.751; 95% CI, 0.682-0.828; P = 7.80 × 10-9) and in the replication cohort (OR, 0.467; 95% CI, 0.228-0.954; P = .0367). The rs8176719 C insertion, which encodes all non-O blood group alleles, had a protective effect, indicating that the rs8176719 C deletion and the O blood group were risk factors for HIT (O blood group OR, 1.42; 95% CI, 1.26-1.61; P = 3.09 × 10-8). Meta-analyses indicated that the ABO association was independent of PF4/heparin IgG levels and was stronger when functional assay-positive cases were compared with antibody-positive (functional assay-negative) controls than with antibody-negative controls. Sequencing and fine-mapping of ABO demonstrated that rs8176719 was the causal single nucleotide polymorphism (SNP). Our results clarify the biology underlying HIT pathogenesis with ramifications for prediction and may have important implications for related conditions, such as vaccine-induced thrombotic thrombocytopenia.

Rare Blood Groups in ABO, Rh, Kell Systems - Biological and Clinical Significance

Background: The frequency of ABO, Rh and Kell blood group antigens differs among populations of different ethnic ancestry. There are low-frequency antigens (<1%) and high-frequency antigens (>90%). A rare blood group is defined as the absence of a high-frequency antigen in the general population, as well as absence of multiple frequent antigens within a single or multiple blood group systems. Aim: To perform red blood cell typing and to calculate the antigen and phenotype frequencies, in order to identify rare blood group donors within the clinically most important АВО, Rh and Kell systems. Material and Methods: АВО, Rh (D, C, E, c, e) and Kell (K) antigen typing was performed using specific monoclonal sera and microplate technique, while Cellano (k) typing was performed with a monoclonal anti-k, antihuman globulin and column agglutination technique. Weak ABO subgroups were determined using the absorption elution method or molecular genotyping (PCR-SSP). Results: ABO antigen frequency is: A (40.89%), O (34.22%), B (16.97%), AB (7.92%) and weak ABO subgroups (0, 009 %). The established genotypes were AxO1 (0, 0026%) and AxB (0, 001%). Rh antigen frequency is: D (85.79%), C (71.7%), c (76.0%), E (26.0%) and е (97.95%). The most common Rh pheno-type is the DCcee (32.7%) while the rarest phenotype is the DCCEE phenotype (0. 003%). The prevalence of K and k antigen is 7.5% and 99.94%, respectively. The frequency of the rare phenotype K+k- is 0.06%. Conclusion: Large scale phenotyping of blood group antigens enables the identification of blood donors with rare blood groups for patients with rare phenotypes or with antibodies to high-frequency antigens and to frequent antigens within one or more blood group systems.

Microbiome-associated human genetic variants impact phenome-wide disease risk

Human genetic variation associates with the composition of the gut microbiome, yet its influence on clinical traits remains largely unknown. We analyzed the consequences of nearly a thousand gut microbiome-associated variants (MAVs) on phenotypes reported in electronic health records from tens of thousands of individuals. We discovered and replicated associations of MAVs with neurological, metabolic, digestive, and circulatory diseases. Five significant MAVs in these categories correlate with the relative abundance of microbes down to the strain level. We also demonstrate that these relationships are independently observed and concordant with microbe by disease associations reported in case-control studies. Moreover, a selective sweep and population differentiation impacted some disease-linked MAVs. Combined, these findings establish triad relationships among the human genome, microbiome, and disease. Consequently, human genetic influences may offer opportunities for precision diagnostics of microbiome-associated diseases but also highlight the relevance of genetic background for microbiome modulation and therapeutics.

The Clinical Utility of ABO and RHD Systems as Potential Indicators of Health Status, a Preliminary Study in Greek Population

Objective: The objective of this study is to further highlight the differences between different ABO blood groups and Rhesus types with health biomarkers. Methods: In total 150 active healthy blood donors participated in our study comprising of 80 males from 19–61 years and 70 females aged from 21 to 64. Participants carrying blood group A were 55 individuals, blood group B 32, blood group O 51, and blood group AB 12, RHD+ 132, and RHD- 18. All the volunteer regular blood donors were selected recognizing them as a healthy population excluding drug and supplements intake. Their blood samples were analyzed just before blood donation for biochemical, hematological, and antioxidant markers. Statistical computations were performed using the SPSS tool, specifically, the one-way ANOVA test, Chi-square statistics, and logistic regression were used as statistical models. Results: O blood donors presented better iron absorption and the worst lipid profile. Indeed, a significant trend of high atheromatic index values revealed an increased risk for hyperlipidemia, in contrast with blood group A presenting a better lipid profile with lower atheromatic index values. There was also a gender related association for blood group A compared with O that was further highlighted using binary logistic regression. Conclusion: In this study, a significant difference was observed among the ABO blood groups in several of the examined biochemical and hematological biomarkers. O blood group appeared different behavior in comparison to all the tested blood groups and furthermore the RHD-group presented a better lipid profile in comparison to the RHD+ group. In order to obtain a more comprehensive view of the correlation between the ABO blood group and biochemical markers, further studies are required.

Association of ABO blood group with respiratory disease hospitalization and severe outcomes: a retrospective cohort study in blood donors

OBJECTIVES

Environmental, socioeconomic, and genetic factors all are associated with respiratory diseases. We aimed to investigate the association between the ABO blood group and the susceptibility to respiratory diseases.

METHODS

We constructed a retrospective cohort study of blood donors in Shaanxi, China between January 1, 2012, and December 31, 2018, to investigate the impacts of the ABO blood group on the risk of hospitalization due to respiratory diseases.

RESULTS

Of 1,686,263 enrolled participants (680,788 females), 26,597 were admitted to the hospital for respiratory diseases. Compared with blood group O, blood groups A, B, and AB all demonstrated a higher risk for diseases of the upper respiratory tract (International Classification of Diseases, Tenth Revision: J30-J39) (ARR (Adjusted relative risk) 1.139, 95% confidence interval [1.106-1.225]; 1.095 [1.019-1.177]; 1.178 [1.067-1.30], respectively). Conversely, blood group A was found to have a lower risk (0.86 [0.747-0.991]) for influenza (J09-J11) and blood group B had a lower risk for pneumonia (J12-J18) (0.911 [0.851-0.976]) than blood group O. The duration of hospitalization was significantly different across the blood groups in J09-J11 and J30-J39 (P <0.05).

CONCLUSION

The blood group appears to be a prognostic factor in differentiating the occurrence of specific respiratory diseases and duration.

Proteome-wide Mendelian randomization identifies causal links between blood proteins and severe COVID-19

In November 2021, the COVID-19 pandemic death toll surpassed five million individuals. We applied Mendelian randomization including >3,000 blood proteins as exposures to identify potential biomarkers that may indicate risk for hospitalization or need for respiratory support or death due to COVID-19, respectively. After multiple testing correction, using genetic instruments and under the assumptions of Mendelian Randomization, our results were consistent with higher blood levels of five proteins GCNT4, CD207, RAB14, C1GALT1C1, and ABO being causally associated with an increased risk of hospitalization or respiratory support/death due to COVID-19 (ORs = 1.12-1.35). Higher levels of FAAH2 were solely associated with an increased risk of hospitalization (OR = 1.19). On the contrary, higher levels of SELL, SELE, and PECAM-1 decrease risk of hospitalization or need for respiratory support/death (ORs = 0.80-0.91). Higher levels of LCTL, SFTPD, KEL, and ATP2A3 were solely associated with a decreased risk of hospitalization (ORs = 0.86-0.93), whilst higher levels of ICAM-1 were solely associated with a decreased risk of respiratory support/death of COVID-19 (OR = 0.84). Our findings implicate blood group markers and binding proteins in both hospitalization and need for respiratory support/death. They, additionally, suggest that higher levels of endocannabinoid enzymes may increase the risk of hospitalization. Our research replicates findings of blood markers previously associated with COVID-19 and prioritises additional blood markers for risk prediction of severe forms of COVID-19. Furthermore, we pinpoint druggable targets potentially implicated in disease pathology.

ABO blood group and Rh factor distributions in patients with epilepsy

OBJECTIVE

We investigated the ABO blood group and Rh factor distributions in patients with epilepsy (PWE) in comparison with a comparator population.

METHODS

We recruited patients who were admitted to the epilepsy ward at Namazi hospital in Shiraz, Iran, in 2021. We classified epilepsies into two categories: focal vs. generalized. We also used the anonymous data from Fars Blood Transfusion Organization from 15th June to 30th June, 2021, as the comparator population (to estimate the frequencies of various blood types in the cohort from which PWE were recruited).

RESULTS

Overall, 390 PWE were included [131 (33.6%) with generalized and 259 (66.4%) with focal epilepsy]. We also included 7672 blood donors [from Fars Blood Transfusion Organization data]. The O phenotype had the highest frequencies in both PWE and the comparator population, followed by A, B, and AB blood groups. Similar patterns were observed in patients with focal and generalized epilepsy. With regard to Rh blood group, the Rh-positive phenotype was more prevalent in all groups. The differences between the groups were not significant in any of the comparisons.

CONCLUSION

While we did not observe any significant associations between blood group and epilepsy in the current study, previous studies have demonstrated compelling evidence that risks of some neuropsychiatric disorders are related to the chemistry of blood, including blood group classification. The issue of the association between epilepsy and blood group should be investigated in large and well-designed studies in the future.

Genetic Examination of Hematological Parameters in SARS-CoV-2 Infection and COVID-19

Background

People hospitalized with COVID-19 often exhibit hematological alterations, such as lower lymphocyte and platelet counts, which have been reported to associate with disease prognosis. It is unclear whether inter-individual variability in baseline hematological parameters prior to acute infection influences risk of SARS-CoV-2 infection and progression to severe COVID-19.

Methods

We assessed the association of blood cell counts and indices with incident SARS-CoV-2 infection and severe COVID-19 in UK Biobank and the Vanderbilt University Medical Center Synthetic Derivative (VUMC SD). Since genetically determined blood cell measures better represent cell abundance across the lifecourse, we used summary statistics from genome-wide association studies to assess the shared genetic architecture of baseline blood cell counts and indices on COVID-19 outcomes.

Results

We observed inconsistent associations between measured blood cell indices and both SARS-CoV-2 infection and COVID-19 hospitalization in UK Biobank and VUMC SD. In Mendelian randomization analyses using genetic summary statistics, no putative causal relationships were identified between COVID-19 related outcomes and hematological indices after adjusting for multiple testing. We observed overlapping genetic association signals between hematological parameters and COVID-19 traits. For example, we observed overlap between infection susceptibility-associated variants at PPP1R15A and red blood cell parameters, and between disease severity-associated variants at TYK2 and lymphocyte and platelet phenotypes.

Conclusions

We did not find convincing evidence of a relationship between baseline hematological parameters and susceptibility to SARS-CoV-2 infection or COVID-19 severity, though this relationship should be re-examined as larger and better-powered genetic analyses of SARS-CoV-2 infection and severe COVID-19 become available.

Using a Systems Approach to Explore the Mechanisms of Interaction Between Severe Covid-19 and Its Coronary Heart Disease Complications

Frontiers requested research on how a systems approach can explore the mechanisms of cardiovascular complications in Covid-19. The focus of this paper will thus be on these detailed mechanisms. It will elucidate the integrated pathogenic pathways based on an extensive review of literature. Many severe Covid-19 cases and deaths occur in patients with chronic cardiovascular comorbidities. To help understand all the mechanisms of this interaction, Covid-19 complications were integrated into a pre-existing systems-based coronary heart disease (CHD) model. Such a complete model could not be found in literature. A fully integrative view could be valuable in identifying new pharmaceutical interventions, help understand how health factors influence Covid-19 severity and give a fully integrated explanation for the Covid-19 death spiral phenomenon seen in some patients. Covid-19 data showed that CHD hallmarks namely, Hypercoagulability, Hypercholesterolemia, Hyperglycemia/Hyperinsulinemia, Inflammation and Hypertension have an important effect on disease severity. The pathogenic pathways that Covid-19 activate in CHD were integrated into the CHD model. This fully integrated model presents a visual explanation of the mechanism of interaction between CHD and Covid-19 complications. This includes a detailed integrated explanation of the death spiral as a result of interactions between Inflammation, endothelial cell injury, Hypercoagulability and hypoxia. Additionally, the model presents the aggravation of this death spiral through the other CHD hallmarks namely, Hyperglycemia/Hyperinsulinemia, Hypercholesterolemia, and/or Hypertension. The resulting model further suggests systematically how the pathogenesis of nine health factors (stress, exercise, smoking, etc.) and seven pharmaceutical interventions (statins, salicylates, thrombin inhibitors, etc.) may either aggravate or suppress Covid-19 severity. A strong association between CHD and Covid-19 for all the investigated health factors and pharmaceutical interventions, except for β-blockers, was found. It is further discussed how the proposed model can be extended in future to do computational analysis to help assess the risk of Covid-19 in cardiovascular disease. With insight gained from this study, recommendations are made for future research in potential new pharmacotherapeutics. These recommendations could also be beneficial for cardiovascular disease, which killed five times more people in the past year than Covid-19.

Complications Post-COVID-19 and Risk Factors among Patients after Six Months of a SARS-CoV-2 Infection: A Population-Based Prospective Cohort Study

In October 2020, we conducted a population-based prospective cohort study to determine post-COVID-19 complications, recovery, return to usual health, and associated risk factors in 536 cases of COVID-19 outbreak in Borriana (Spain) by administering an epidemiological questionnaire via phone interviews. A total of 484 patients participated (90.3%), age mean 37.2 ± 17.1 years, and 301 females (62.2%). Mild illness was the most common COVID-19 manifestation. After six months, 160 patients (33.1%) suffered at least one complication post-COVID-19, and 47 (29.4%) of them sought medical assistance. The most frequent persistent symptoms were hair loss, fatigue, loss of smell or taste, and headache. Risk factors associated with a complication were female sex (adjusted relative risk, [aRR] = 1.93 95% confidence interval [CI] 1.41-2.65), age 35 years and above (aRR = 1.50 95% CI 1.14-1.99), B blood group (aRR = 1.51 95% CI 1.04-2.16), current smoker (RR = 1.61 95% CI 1.02-2.54), and at least a COVID-19 exposure (aRR = 2.13 95% CI 1.11-4.09). Male sex, age younger than 35 years, and low COVID-19 exposures were associated with better recovery and return to usual health. A third of patients presented persistent symptoms compatible with the long-COVID-19 syndrome. In conclusion, an active medical follow-up of post-COVID-19 patients must be implemented.

Genetic Loci Associated With COVID-19 Positivity and Hospitalization in White, Black, and Hispanic Veterans of the VA Million Veteran Program

SARS-CoV-2 has caused symptomatic COVID-19 and widespread death across the globe. We sought to determine genetic variants contributing to COVID-19 susceptibility and hospitalization in a large biobank linked to a national United States health system. We identified 19,168 (3.7%) lab-confirmed COVID-19 cases among Million Veteran Program participants between March 1, 2020, and February 2, 2021, including 11,778 Whites, 4,893 Blacks, and 2,497 Hispanics. A multi-population genome-wide association study (GWAS) for COVID-19 outcomes identified four independent genetic variants (rs8176719, rs73062389, rs60870724, and rs73910904) contributing to COVID-19 positivity, including one novel locus found exclusively among Hispanics. We replicated eight of nine previously reported genetic associations at an alpha of 0.05 in at least one population-specific or the multi-population meta-analysis for one of the four MVP COVID-19 outcomes. We used rs8176719 and three additional variants to accurately infer ABO blood types. We found that A, AB, and B blood types were associated with testing positive for COVID-19 compared with O blood type with the highest risk for the A blood group. We did not observe any genome-wide significant associations for COVID-19 severity outcomes among those testing positive. Our study replicates prior GWAS findings associated with testing positive for COVID-19 among mostly White samples and extends findings at three loci to Black and Hispanic individuals. We also report a new locus among Hispanics requiring further investigation. These findings may aid in the identification of novel therapeutic agents to decrease the morbidity and mortality of COVID-19 across all major ancestral populations.

ABO blood group in aneurysmal subarachnoid haemorrhage-a pilot study

PURPOSE

To evaluate the distribution and impact of ABO blood group on the baseline characteristics and clinical outcomes of patients presenting with aneurysmal subarachnoid haemorrhage (aSAH).

METHODS

Retrospective, single-centre study of patients admitted to a neurosurgical department in the UK, with a diagnosis of spontaneous subarachnoid haemorrhage between May 2014 and January 2020. Patients were categorised by ABO blood type and by Rhesus status. Clinical outcomes such as initial bleeding, rebleeding, delayed cerebral ischaemia (DIND) and venous thromboembolism were analysed in relation to the size of their association with ABO blood type. Hospital mortality rate, Glasgow Outcome Score (GOS) - at discharge and 3 months post-ictus, requirement for ventriculoperitoneal shunt insertion, discharge destination and inpatient length of stay were also considered.

RESULTS

Four-hundred twelve adult patients admitted with aSAH were included in our analysis. The distribution of ABO group or Rhesus status in our cohort did not differ significantly from the general population in the UK. Blood group A patients had a significantly increased risk of developing DIND, compared with non-blood group A patients (OR, 1.88 [95% CI: 1.10-3.21]).

CONCLUSIONS

ABO blood type appears to influence aSAH sequelae. Blood group A patients are at highest risk of DIND following aSAH.

An Updated Review on the Role of Single Nucleotide Polymorphisms in COVID-19 Disease Severity: A Global Aspect

Abstract:

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and recently has become a serious global pandemic. Age, gender, and comorbidities are known to be common risk factors for severe COVID-19 but are not enough to fully explain the magnitude of their effect on the risk of severity of the disease. Single nucleotide polymorphisms (SNPs) in several genes have been reported as a genetic factor contributing to COVID-19 severity. This comprehensive review focuses on the association between SNPs in four important genes and COVID-19 severity in a global aspect. We discuss a total of 39 SNPs in this review: five SNPs in the ABO gene, nine SNPs in the angiotensin-converting enzyme 2 (ACE2) gene, 19 SNPs in the transmembrane protease serine 2 (TMPRSS2) gene, and six SNPs in the toll-like receptor 7 (TLR7) gene. These SNPs data could assist in monitoring an individual's risk of severe COVID-19 disease, and therefore personalized management and pharmaceutical treatment could be planned in COVID-19 patients.

Allelic Variants Within the ABO Blood Group Phenotype Confer Protection Against Critical COVID-19 Hospital Presentation

Introduction: Coronavirus disease 2019 (COVID-19) disease severity differs widely due to numerous factors including ABO gene-derived susceptibility or resistance. The objective of this study was to investigate the association of the ABO blood group and genetic variations of the ABO gene with COVID-19 severity in a heterogeneous hospital population sample from the United Arab Emirates, with the use of an epidemiological and candidate gene approach from a genome-wide association study (GWAS). Methods: In this cross-sectional study, a total of 646 participants who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were recruited from multiple hospitals and population-based (quarantine camps) recruitment sites from March 2020 to February 2021. The participants were divided into two groups based on the severity of COVID-19: noncritical (n = 453) and critical [intensive care unit (ICU) patients] (n = 193), as per the COVID-19 Reporting and Data System (CO-RADS) classification. The multivariate logistic regression analysis demonstrated the association of ABO blood type as well as circulating anti-A antibodies and anti-B antibodies as well as A and B antigens, in association with critical COVID-19 hospital presentation. A candidate gene analysis approach was conducted from a GWAS where we examined 240 single nucleotide polymorphisms (SNPs) (position in chr9: 136125788-136150617) in the ABO gene, in association with critical COVID-19 hospital presentation. Results: Patients with blood group O [odds ratio (OR): 0.51 (0.33, 0.79); p = 0.003] were less likely to develop critical COVID-19 symptoms. Eight alleles have been identified to be associated with a protective effect of blood group O in ABO 3'untranslated region (UTR): rs199969472 (p = 0.0052), rs34266669 (p = 0.0052), rs76700116 (p = 0.0052), rs7849280 (p = 0.0052), rs34039247 (p = 0.0104), rs10901251 (p = 0.0165), rs9411475 (p = 0.0377), and rs13291798 (p = 0.0377). Conclusion: Our findings suggest that there are novel allelic variants that link genetic variants of the ABO gene and ABO blood groups contributing to the reduced risk of critical COVID-19 disease. This study is the first study to combine genetic and serological evidence of the involvement of the ABO blood groups and the ABO gene allelic associations with COVID-19 severity within the Middle Eastern population.

Effect of ABO blood groups on length of hospital stay according to age in Covid-19 patients

INTRODUCTION

Coronavirus Disease 2019 (COVID-19) is a novel viral disease with person-to-person transmission that has spread to many countries since the end of 2019. Although many unknowns were resolved within a year and the vaccine is available, it is still a major global health problem.

OBJECTIVE

COVID-19 infection may present with a considerably wide spectrum of severity and host factors play a significant role in determining the course of the disease. One of these factors is blood groups. Based on previous experience, it is believed that the ABO blood group type affects prognosis, treatment response and length of stay in the hospital. In this study, our aim was to evaluate whether the blood group had an effect on the length of the hospital stay. To the best of our knowledge, no previous studies have assessed the effect of ABO blood groups, as well as age, on the length of the hospital stay in these settings.

METHODS

In this retrospective cohort study, 969 patients admitted to our hospital between March 15, 2020 and May 15, 2020 were evaluated. The patients were divided into 4 groups according to ABO blood groups. The effect of the ABO blood group by age on the course of the disease, need for intensive care, duration of hospitalization and mortality in patients with COVID-19 infection, especially in geriatric patients, was evaluated.

RESULTS

Of all the patients, 9.1% required admission to the intensive care unit (ICU), of whom 83% died. The average length of ICU stay was 11 days (0 - 59). The observed mortality rates in blood groups A, B, AB and 0 were 86.4%, 93.3%, 80.0% and 70.8%, respectively, indicating similar death rates in all ABO blood types. When the Rh phenotype was taken into consideration, no significant changes in results were seen.

CONCLUSION

As a result, we could not observe a significant relationship between blood groups and clinical outcomes in this study, which included a sample of Turkish patients with COVID-19.

Country-level factors dynamics and ABO/Rh blood groups contribution to COVID-19 mortality

The identification of factors associated to COVID-19 mortality is important to design effective containment measures and safeguard at-risk categories. In the last year, several investigations have tried to ascertain key features to predict the COVID-19 mortality tolls in relation to country-specific dynamics and population structure. Most studies focused on the first wave of the COVID-19 pandemic observed in the first half of 2020. Numerous studies have reported significant associations between COVID-19 mortality and relevant variables, for instance obesity, healthcare system indicators such as hospital beds density, and bacillus Calmette-Guerin immunization. In this work, we investigated the role of ABO/Rh blood groups at three different stages of the pandemic while accounting for demographic, economic, and health system related confounding factors. Using a machine learning approach, we found that the "B+" blood group frequency is an important factor at all stages of the pandemic, confirming previous findings that blood groups are linked to COVID-19 severity and fatal outcome.