ABO blood group associations with markers of endothelial dysfunction in the Multi-Ethnic Study of Atherosclerosis

Association between blood groups and myocardial injury after non-cardiac surgery: a retrospective cohort study

Blood group is a potential genetic element in coronary artery disease. Nevertheless, the relationship between different ABO blood groups and myocardial injury after non-cardiac surgery (MINS) is poorly understood. This study verified whether ABO blood group is a potential MINS influencing factor. This retrospective cohort study included 1201 patients who underwent elective non-cardiac surgery and a mandatory troponin test on postoperative days 1 and 2 from 2019 to 2020 at a university-affiliated tertiary hospital. The primary outcome was associations between ABO blood groups and MINS, assessed using univariate and multivariate logistic-regression analyses. Path analysis was used to investigate direct and indirect effects between blood group and MINS. MINS incidence (102/1201, 8.5%) was higher in blood-type B patients than in non-B patients [blood-type B: 44/400 (11.0%) vs. non-B: 58/801 (7.2%); adjusted odds ratio = 1.57 (1.03-2.38); p = 0.036]. In the confounding factor model, preoperative hypertension and coronary artery disease medical history were associated with MINS risk [adjusted odds ratio: 2.00 (1.30-3.06), p = 0.002; 2.81 (1.71-4.61), p < 0.001, respectively]. Path analysis did not uncover any mediating role for hypertension, diabetes, or coronary artery disease between blood type and MINS. Therefore, blood-type B is associated with higher MINS risk; potential mediators of this association need to be investigated.

ABO gene polymorphisms are associated with acute coronary syndrome and with plasma concentration of HDL-cholesterol and triglycerides

The role of ABO gene polymorphisms in acute coronary syndrome (ACS) and lipid metabolism is increasingly recognized. We investigated whether ABO gene polymorphisms are significantly associated with ACS and the plasma lipid profile. Six ABO gene polymorphisms (rs651007 T/C, rs579459 T/C, rs495928 T/C, rs8176746 T/G, rs8176740 A/T, and rs512770 T/C) were determined by 5'exonuclease TaqMan assays in 611 patients with ACS and 676 healthy controls. The results demonstrated that the rs8176746 T allele was associated with a lower risk of ACS under the co-dominant, dominant, recessive, over-dominant, and additive models (P = 0.0004, P = 0.0002, P = 0.039,  P = 0.0009, and P = 0.0001, respectively). Furthermore, under co-dominant, dominant, and additive models, the rs8176740 A allele was associated with a lower risk of ACS (P = 0.041, P = 0.022, and P = 0.039, respectively). On the other hand, the rs579459 C allele was associated with a lower risk of ACS under the dominant, over-dominant, and additive models (P = 0.025, P = 0.035, and P = 0.037, respectively). In a subanalysis performed with the control group, rs8176746 T and rs8176740 A alleles were associated with low systolic blood pressure and with both high high-density lipoprotein-cholesterol (HDL-C) and low triglyceride plasma concentrations, respectively. In conclusion, ABO gene polymorphisms were associated with a lower risk of ACS, and lower systolic blood pressure and plasma lipid levels, suggesting a causal relationship between ABO blood groups and the incidence of ACS.

Association between ambient carbon monoxide levels and hospitalization costs of patients with myocardial infarction: Potential effect modification by ABO blood group

Previous researches have reported the association between air pollution and various diseases. However, few researches have investigated whether air pollutants are associated with the economic loss resulting from patients' hospitalization, especially the economic loss of hospitalization due to acute cardiovascular events. The purpose of our research was to explore the association between the levels of carbon monoxide (CO), taken as an index of pollution, and the hospitalization costs of myocardial infarction (MI), and the potential effect modification by the ABO blood group. A total of 3237 MI inpatients were included in this study. A multiple linear regression model was used to evaluate the association between ambient CO levels and hospitalization costs of MI patients. Moreover, we performed stratified analyses by age, gender, body mass index (BMI), season, hypertension, and ABO blood types. There was a positive association between the levels of CO in the air and the costs of hospitalization caused by MI. Furthermore, such association was stronger in males, BMI ≥25, <65 years, with hypertension, and non-O blood group. Interestingly, we found the association was particularly significant in patients with blood group B. Overall, our study first found that ambient CO levels could have an impact on the hospitalization costs for MI patients, and those with blood group B can be more sensitive.

Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke

BACKGROUND AND OBJECTIVES

Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke.

METHODS

We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18-59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS.

RESULTS

We observed genome-wide significant associations of EOS with 2 variants in ABO, a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85-0.91) in EOS vs 0.96 (95% CI: 0.92-1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11-1.21) for EOS vs 1.05 (0.99-1.11) in LOS; p-values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS (p = 0.008).

DISCUSSION

The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.

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.

A Phenome-Wide Association Study of genes associated with COVID-19 severity reveals shared genetics with complex diseases in the Million Veteran Program

The study aims to determine the shared genetic architecture between COVID-19 severity with existing medical conditions using electronic health record (EHR) data. We conducted a Phenome-Wide Association Study (PheWAS) of genetic variants associated with critical illness (n = 35) or hospitalization (n = 42) due to severe COVID-19 using genome-wide association summary data from the Host Genetics Initiative. PheWAS analysis was performed using genotype-phenotype data from the Veterans Affairs Million Veteran Program (MVP). Phenotypes were defined by International Classification of Diseases (ICD) codes mapped to clinically relevant groups using published PheWAS methods. Among 658,582 Veterans, variants associated with severe COVID-19 were tested for association across 1,559 phenotypes. Variants at the ABO locus (rs495828, rs505922) associated with the largest number of phenotypes (nrs495828 = 53 and nrs505922 = 59); strongest association with venous embolism, odds ratio (ORrs495828 1.33 (p = 1.32 x 10-199), and thrombosis ORrs505922 1.33, p = 2.2 x10-265. Among 67 respiratory conditions tested, 11 had significant associations including MUC5B locus (rs35705950) with increased risk of idiopathic fibrosing alveolitis OR 2.83, p = 4.12 × 10-191; CRHR1 (rs61667602) associated with reduced risk of pulmonary fibrosis, OR 0.84, p = 2.26× 10-12. The TYK2 locus (rs11085727) associated with reduced risk for autoimmune conditions, e.g., psoriasis OR 0.88, p = 6.48 x10-23, lupus OR 0.84, p = 3.97 x 10-06. PheWAS stratified by ancestry demonstrated differences in genotype-phenotype associations. LMNA (rs581342) associated with neutropenia OR 1.29 p = 4.1 x 10-13 among Veterans of African and Hispanic ancestry but not European. Overall, we observed a shared genetic architecture between COVID-19 severity and conditions related to underlying risk factors for severe and poor COVID-19 outcomes. Differing associations between genotype-phenotype across ancestries may inform heterogenous outcomes observed with COVID-19. Divergent associations between risk for severe COVID-19 with autoimmune inflammatory conditions both respiratory and non-respiratory highlights the shared pathways and fine balance of immune host response and autoimmunity and caution required when considering treatment targets.

Susceptibility of ABO blood group to COVID-19 infections: clinico-hematological, radiological, and complications analysis

In the wake of the COVID-19 pandemic, research indicates that the COVID-19 disease susceptibility varies among individuals depending on their ABO blood groups. Researchers globally commenced investigating potential methods to stratify cases according to prognosis depending on several clinical parameters. Since there is evidence of a link between ABO blood groups and disease susceptibility, it could be argued that there is a link between blood groups and disease manifestation and progression. The current study investigates whether clinical manifestation, laboratory, and imaging findings vary among ABO blood groups of hospitalized confirmed COVID-19 patients.This retrospective cohort study was conducted between March 1, 2020 and March 31, 2021 in King Faisal Specialist Hospital and Research Centre Riyadh and Jeddah, Saudi Arabia. Demographic information, clinical information, laboratory findings, and imaging investigations were extracted from the data warehouse for all confirmed COVID-19 patients.A total of 285 admitted patients were included in the study. Of these, 81 (28.4%) were blood group A, 43 (15.1%) were blood group B, 11 (3.9%) were blood group AB, and 150 (52.6%) were blood group O. This was almost consistent with the distribution of blood groups among the Saudi Arabia community. The majority of the study participants (79.6% [n = 227]) were asymptomatic. The upper respiratory tract infection (P = .014) and shortness of breath showed statistically significant differences between the ABO blood group (P = .009). Moreover, the incidence of the symptoms was highly observed in blood group O followed by A then B except for pharyngeal exudate observed in blood group A. The one-way ANOVA test indicated that among the studied hematological parameters, glucose (P = .004), absolute lymphocyte count (P = .001), and IgA (P = .036) showed statistically significant differences between the means of the ABO blood group. The differences in both X-ray and computed tomography scan findings were statistically nonsignificant among the ABO age group. Only 86 (30.3%) patients were admitted to an intensive care unit, and the majority of them were blood groups O 28.7% (n = 43) and A 37.0% (n = 30). However, the differences in complications' outcomes were statistically nonsignificant among the ABO age group.ABO blood groups among hospitalized COVID-19 patients are not associated with clinical, hematological, radiological, and complications abnormality.

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types.

ABO Blood Group Differentials on Survival in Hepatocellular Carcinoma Patients Treated with Chemoembolization

BACKGROUND

The association between ABO blood group and the prognosis of hepatocellular carcinoma (HCC) remains unclear. We investigated the impact of ABO blood groups as a prognostic factor in HCC patients treated with transarterial chemoembolization (TACE).

MATERIALS AND METHODS

We revisited records of all HCC patients who underwent TACE between January 2007 and December 2019 at a tertiary care hospital. The inclusion criteria were HCC patients, Child-Pugh score A5-B7, and treated with TACE monotherapy. The baseline characteristics of each patient were compared against their blood group and the survival analysis was carried out using Cox's regression. With Bonferroni adjustment for multiple comparisons, P-values <.0125 were considered statistically significant.

RESULTS

Of 211 eligible patients, the frequencies of blood groups O, A, B, and AB were 89, 54, 56, and 12, respectively. Their respective months of median survival were 41, 20, 21, and 42. After adjustments in the six-and-twelve criteria and Child-Pugh scores, and using blood group O as the referent group, the coefficients (SE) of groups A, B, and AB were 0.69 (0.24), 0.47 (0.23), and 0.49 (0.49), respectively. A significant difference in survival was found only between patients with blood group O vs A (hazard ratio, 2.00; confidence interval, 1.25-3.21).

CONCLUSIONS

ABO blood group is associated with the prognosis of HCC patients treated with TACE monotherapy. In our data, patients with blood group O tended to have the best survival. However, only blood group A patients had a significantly shorter survival rate comparing to blood group O.

A Phenome-Wide Association Study of genes associated with COVID-19 severity reveals shared genetics with complex diseases in the Million Veteran Program

The study aims to determine the shared genetic architecture between COVID-19 severity with existing medical conditions using electronic health record (EHR) data. We conducted a Phenome-Wide Association Study (PheWAS) of genetic variants associated with critical illness (n=35) or hospitalization (n=42) due to severe COVID-19 using genome-wide association summary from the Host Genetics Initiative. PheWAS analysis was performed using genotype-phenotype data from the Veterans Affairs Million Veteran Program (MVP). Phenotypes were defined by International Classification of Diseases (ICD) codes mapped to clinically relevant groups using published PheWAS methods. Among 658,582 Veterans, variants associated with severe COVID-19 were tested for association across 1,559 phenotypes. Variants at the ABO locus (rs495828, rs505922) associated with the largest number of phenotypes (n_rs495828=53 and n_rs505922=59); strongest association with venous embolism, odds ratio (ORrs495828 1.33 (p=1.32 × 10^-199), and thrombosis OR_rs505922 1.33, p=2.2 × 10^-265. Among 67 respiratory conditions tested, 11 had significant associations including MUC5B locus (rs35705950) with increased risk of idiopathic fibrosing alveolitis OR 2.83, p=4.12 × 10^-191; CRHR1 (rs61667602) associated with reduced risk of pulmonary fibrosis, OR 0.84, p=2.26 × 10^-12. The TYK2 locus (rs11085727) associated with reduced risk for autoimmune conditions, e.g., psoriasis OR 0.88, p=6.48 × 10^-23, lupus OR 0.84, p=3.97 × 10^-06. PheWAS stratified by genetic ancestry demonstrated differences in genotype-phenotype associations across ancestry. LMNA (rs581342) associated with neutropenia OR 1.29 p=4.1 × 10^-13 among Veterans of African ancestry but not European. Overall, we observed a shared genetic architecture between COVID-19 severity and conditions related to underlying risk factors for severe and poor COVID-19 outcomes. Differing associations between genotype-phenotype across ancestries may inform heterogenous outcomes observed with COVID-19. Divergent associations between risk for severe COVID-19 with autoimmune inflammatory conditions both respiratory and non-respiratory highlights the shared pathways and fine balance of immune host response and autoimmunity and caution required when considering treatment targets.

Association between cardiovascular risk-factors and venous thromboembolism in a large longitudinal study of French women

Background

Previous studies have shown conflicting results regarding the influence of cardiovascular risk-factors on venous thromboembolism. This study aimed to determine if these risk-factors, i.e. physical activity, smoking, hypertension, dyslipidaemia, and diabetes, were associated with the risk of venous thromboembolism, and to determine if these associations were confounded by BMI.

Methods

We used data from the E3N cohort study, a French prospective population-based study initiated in 1990, consisting of 98,995 women born between 1925 and 1950. From the women in the study we included those who did not have prevalent arterial disease or venous thromboembolism at baseline; thus 91,707 women were included in the study. Venous thromboembolism cases were self-reported during follow-up, and verified via specific mailings to medical practitioners or via drug reimbursements for anti-thrombotic medications. Hypertension, diabetes and dyslipidaemia were self-reported validated against drug reimbursements or specific questionnaires. Physical activity, and smoking were based on self-reports. Cox-models, adjusted for BMI and other potential risk-factors were used to determine hazard ratios for incident venous thromboembolism.

Results

During 1,897,960 person-years (PY), 1, 649 first incident episodes of thrombosis were identified at an incidence rate of 0.9 per 1000 PY. This included 505 cases of pulmonary embolism and 1144 cases of deep vein thrombosis with no evidence of pulmonary embolism. Hypertension, dyslipidaemia, diabetes, smoking and physical activity were not associated with the overall risk of thrombosis after adjustment for BMI.

Conclusions

Traditional cardiovascular risk factors were not associated with the risk of venous thromboembolism after adjustment for BMI. Hypertension, dyslipidaemia and diabetes may not be risk-factors for venous thromboembolism.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00310-w.

Does ABO Blood Groups Affect Outcomes in Hospitalized COVID-19 Patients?

Background

Blood group type A has been associated with increased susceptibility for coronavirus disease 2019 (COVID-19) infection when compared to group O. The aim of our study was to examine outcomes in hospitalized COVID-19 patients among blood groups A and O.

Methods

This is an observational study. Kruskal-Wallis and Chi-square tests were used to compare continuous and categorical variables. Multivariable logistic regression models were used to examine association of blood groups with rates of mortality and severity of disease. All adult patients (> 18 years) admitted with COVID-19 infection between March 1, 2020 and March 10, 2021 at a large community hospital in Northeast Georgia were included. We compared mortality, severity of disease (use of mechanical ventilation, vasopressor, and acute renal failure), rates of venous thromboembolism and inflammatory markers between the blood groups. We used multivariable logistic regression model to adjust for demographical and clinical characteristics, use of COVID-19 medications and severity.

Results

A total of 3,563 of 5,204 admitted patients had information on blood groups. Of these, 1,301 (36.5%) were group A, 377 (10.6 %) were group B, 133 (3.7%) were group AB and 1,752 (49.2%) were group O. On adjusted analysis, there were no significant differences in rates of intensive care unit (ICU) admissions, mechanical ventilation, vasopressors, acute renal failure, venous thromboembolism and readmission rate between the blood groups A and O. In-hospital mortality was also not statistically different among the blood groups A and O (17.5% vs. 20.1%; P = 0.07). On adjusted analysis, in-hospital mortality was not lower in blood groups O (odds ratio (OR): 1.06; 95% confidence interval (CI): 0.80 - 1.40, P = 0.70).

Conclusions

Once hospitalized with COVID-19 infection, blood groups A and O are not associated with increased severity or in-hospital mortality.

Insights into genetic factors contributing to variability in SARS-CoV-2 susceptibility and COVID-19 disease severity

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we applied colocalization to compare summary statistics for 16 GWASs from the COVID-19 Host Genetics Initiative to investigate similarities and differences in their genetic signals. We identified 9 loci associated with susceptibility (one with two independent GWAS signals; one with an ethnicity-specific signal), 14 associated with severity (one with two independent GWAS signals; two with ethnicity-specific signals) and one harboring two discrepant GWAS signals (one for susceptibility; one for severity). Utilizing colocalization we also identified 45 GTEx tissues that had eQTL(s) for 18 genes strongly associated with GWAS signals in eleven loci (1-4 genes per locus). Some of these genes showed tissue-specific altered expression and others showed altered expression in up to 41 different tissue types. Our study provides insights into the complex molecular mechanisms underlying inherited predispositions to COVID-19-disease phenotypes.

Evaluation of ABO blood group in subjects with CVD risk factors in a population sample from northeastern Iran

BACKGROUND AND AIMS

The ABO blood group system is a genetic polymorphism which can affect the clearance of von Willebrand factor. We aimed to assess the levels of newer biomarkers of cardiovascular disease (CVD) risk; pro-oxidant-antioxidant balance (PAB), high sensitivity C-reactive protein (hs-CRP) and anti-heat-shock protein27 (anti-Hsp27) antibody titers in subjects with various blood groups (A, B, AB and O) and with or without traditional CVD risk factors.

METHODS

The cross-sectional study comprised 6910 subjects. Antigen-antibody agglutination was evaluated by the slide test method for identification of ABO blood groups.

RESULTS

Among three markers, only Serum anti-Hsp27 titers significantly differed between the four blood groups and showed the highest and lowest values in AB and O blood groups (0.26 ± 0.22 and 0.23 ± 0.18 OD, respectively; P < 0.05). Serum anti-Hsp27 was higher in individuals with an AB blood group with metabolic syndrome (MetS), dyslipidemia, hypertension (HTN) and obesity and it was lower in subjects with O blood group; though, two other biomarkers, serum PAB and hs-CRP, were not significantly different between the ABO blood groups. However, they were not different among blood groups in participants with or without diabetes mellitus (DM) (P > 0.05).

CONCLUSION

Individuals with an AB blood group and high levels of anti-Hsp27 antibody titers may be predisposed to CVDs that can be mediated through the traditional CVD risk factors among middle-aged subjects from northeastern Iran. The fact that differences in anti Hsp27 are only found in the subgroup with other risk factors suggest that the difference between ABO blood groups is a consequence rather than a cause.

ABO blood group and the risk of aortic disease: a nationwide cohort study

OBJECTIVES

To analyse the association between ABO blood group and aortic disease using data on blood donors and transfused patients from Sweden.

DESIGN

This was a retrospective study using data from the Swedish portion of the Scandinavian Donations and Transfusions Database. The association between ABO blood group and aortic disease was analysed using log-linear Poisson regression models and presented as incidence rate ratios (IRRs).

SETTING

Swedish population-based study.

PARTICIPANTS

The study cohort consisted of 1 164 561 Swedish blood donors and 961 637 transfused patients with a combined follow-up time of 29 390 649 person-years.

PRIMARY AND SECONDARY OUTCOME MEASURES

IRRs of aortic events (ie, aortic aneurysms and/or aortic dissections) in relation to patient blood group.

RESULTS

A total of 20 684 aortic events occurred during the study period. Non-O donors and patients had similar incidence of aortic events when compared with blood group O donors and patients with an IRR of 0.98 (95% CI, 0.93-1.04) and 1.00 (95% CI, 0.97-1.03), respectively. There were no differences between non-O and blood group O individuals when aortic dissections and aortic aneurysms were analysed separately. Blood group B conferred a lower risk of aortic aneurysms in the patient cohort when compared with blood group O (IRR, 0.90; 95% CI, 0.85-0.96).

CONCLUSIONS

In the present study, there were no statistically significant associations between ABO blood group and the risk of aortic disease. A possible protective effect of blood group B was observed in the patient cohort but this finding requires further investigation.

Human genetic determinants of the gut microbiome and their associations with health and disease: a phenome-wide association study

Small-scale studies have suggested a link between the human gut microbiome and highly prevalent diseases. However, the extent to which the human gut microbiome can be considered a determinant of disease and healthy aging remains unknown. We aimed to determine the spectrum of diseases that are linked to the human gut microbiome through the utilization of its genetic determinants as a proxy for its composition. 180 single nucleotide polymorphisms (SNPs) known to influence the human gut microbiome were used to assess the association with health and disease outcomes in 422,417 UK Biobank participants. Potential causal estimates were obtained using a Mendelian randomization (MR) approach. From the total sample analysed (mean age was 57 ± 8 years), 194,567 (46%) subjects were male. Median exposure was 66-person years (interquartile range 59-72). Eleven SNPs were significantly associated with 28 outcomes (Bonferroni corrected P value < 4.63·10-6) including food intake, hypertension, atopy, COPD, BMI, and lipids. Multiple SNP MR pointed to a possible causal link between Ruminococcus flavefaciens and hypertension, and Clostridium and platelet count. Microbiota and their metabolites might be of importance in the interplay between overlapping pathophysiological processes, although challenges remain in establishing causal relationships.

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

OBJECTIVE

To determine the spectrum of phenotypes linked to the ABO blood group system, using genetic determinants of the ABO blood group system. Approach and Results: We assessed the risk of 41 health and disease outcomes, and 36 linear traits associated with the ABO blood group system in the UK Biobank cohort. A total of 406 755 unrelated individuals were included in this study. Blood groups A, B, and O were determined based on allele combinations of previously established single-nucleotide polymorphisms rs8176746, rs8176719 in the ABO gene. Group AB was excluded because of its relative small sample size. Overall, 187 387 (46%) were male with a mean (SD) age of 57±8.1 years and a median total exposure of 64 person-years (interquartile range, 57-70). Of 406 755 individuals, 182 621 (44.9%) participants had blood group O, 182 786 (44.9%) had blood group A, and 41 348 (10.2%) had blood group B. ABO blood groups were associated with 11 health and disease outcomes (P<2.19×10^-4). ABO blood groups were primarily associated with cardiovascular outcomes. Compared with individuals with blood group O, blood groups A and B were associated with increased odds of up to 1.56 (95% CI, 1.43-1.69) for thromboembolic events and decreased odds for hypertension (0.94 [95% CI, 0.92-0.97]).

CONCLUSIONS

The ABO blood group system is associated with several parameters of healthy aging and disease development. Knowledge of ABO blood groups might be of interest for more personalized approaches towards health maintenance and the prevention of diseases.

Multivariate Genome-wide Association Analysis of a Cytokine Network Reveals Variants with Widespread Immune, Haematological, and Cardiometabolic Pleiotropy

Cytokines are essential regulatory components of the immune system, and their aberrant levels have been linked to many disease states. Despite increasing evidence that cytokines operate in concert, many of the physiological interactions between cytokines, and the shared genetic architecture that underlies them, remain unknown. Here, we aimed to identify and characterize genetic variants with pleiotropic effects on cytokines. Using three population-based cohorts (n = 9,263), we performed multivariate genome-wide association studies (GWAS) for a correlation network of 11 circulating cytokines, then combined our results in meta-analysis. We identified a total of eight loci significantly associated with the cytokine network, of which two (PDGFRB and ABO) had not been detected previously. In addition, conditional analyses revealed a further four secondary signals at three known cytokine loci. Integration, through the use of Bayesian colocalization analysis, of publicly available GWAS summary statistics with the cytokine network associations revealed shared causal variants between the eight cytokine loci and other traits; in particular, cytokine network variants at the ABO, SERPINE2, and ZFPM2 loci showed pleiotropic effects on the production of immune-related proteins, on metabolic traits such as lipoprotein and lipid levels, on blood-cell-related traits such as platelet count, and on disease traits such as coronary artery disease and type 2 diabetes.

Genome-Wide Association Study on the Early-Phase Insulin Response to a Liquid Mixed Meal: Results From the NEO Study

Early-phase insulin secretion is a determinant of postprandial glucose homeostasis. In this study, we aimed to identify novel genetic variants associated with the early-phase insulin response to a liquid mixed meal by a genome-wide association study using a discovery and replication design embedded in the Netherlands Epidemiology of Obesity (NEO) study. The early-phase insulin response was defined as the difference between the natural logarithm-transformed insulin concentrations of the postprandial state at 30 min after a meal challenge and the fasting state (Δinsulin). After Bonferroni correction, rs505922 (β: -6.5% [minor allele frequency (MAF) 0.32, P = 3.3 × 10^-8]) located in the ABO gene reached genome-wide significant level (P < 5 × 10^-8) and was also replicated successfully (β: -7.8% [MAF 0.32, P = 7.2 × 10^-5]). The function of the ABO gene was assessed using in vitro shRNA-mediated knockdown of gene expression in the murine pancreatic β-cell line MIN6. Knocking down the ABO gene led to decreased insulin secretion in the murine pancreatic β-cell line. These data indicate that the previously identified elevated risk of type 2 diabetes for carriers of the ABO rs505922:C allele may be caused by decreased early-phase insulin secretion.

Whole genome sequence association with E-selectin levels reveals loss-of-function variant in African Americans

E-selectin mediates the rolling of circulating leukocytes during inflammatory processes. Previous genome-wide association studies in European and Asian individuals have identified the ABO locus associated with E-selectin levels. Using Trans-Omics for Precision Medicine whole genome sequencing data in 2249 African Americans (AAs) from the Jackson Heart Study, we examined genome-wide associations with soluble E-selectin levels. In addition to replicating known signals at ABO, we identified a novel association of a common loss-of-function, missense variant in Fucosyltransferase 6 (FUT6; rs17855739,p.Glu274Lys, P = 9.02 × 10-24) with higher soluble E-selectin levels. This variant is considerably more common in populations of African ancestry compared to non-African ancestry populations. We replicated the association of FUT6 p.Glu274Lys with higher soluble E-selectin in an independent population of 748 AAs from the Women's Health Initiative and identified an additional pleiotropic association with vitamin B12 levels. Despite the broad role of both selectins and fucosyltransferases in various inflammatory, immune and cancer-related processes, we were unable to identify any additional disease associations of the FUT6 p.Glu274Lys variant in an electronic medical record-based phenome-wide association scan of over 9000 AAs.

Genome-wide mapping of plasma protein QTLs identifies putatively causal genes and pathways for cardiovascular disease

Identifying genetic variants associated with circulating protein concentrations (protein quantitative trait loci; pQTLs) and integrating them with variants from genome-wide association studies (GWAS) may illuminate the proteome's causal role in disease and bridge a knowledge gap regarding SNP-disease associations. We provide the results of GWAS of 71 high-value cardiovascular disease proteins in 6861 Framingham Heart Study participants and independent external replication. We report the mapping of over 16,000 pQTL variants and their functional relevance. We provide an integrated plasma protein-QTL database. Thirteen proteins harbor pQTL variants that match coronary disease-risk variants from GWAS or test causal for coronary disease by Mendelian randomization. Eight of these proteins predict new-onset cardiovascular disease events in Framingham participants. We demonstrate that identifying pQTLs, integrating them with GWAS results, employing Mendelian randomization, and prospectively testing protein-trait associations holds potential for elucidating causal genes, proteins, and pathways for cardiovascular disease and may identify targets for its prevention and treatment.

Venous thromboembolism, factor VIII and chronic kidney disease

Chronic kidney disease (CKD) affects 30 million Americans and is associated with approximately a two-fold increased risk of venous thromboembolism (VTE). There is a graded increased risk of VTE across declining kidney function, as measured by estimated glomerular filtration rate (eGFR) and albuminuria. When patients with end-stage kidney disease (ESKD) experience VTE they are more likely than the general population to be hospitalized and they have a higher mortality. The incidence and consequences of VTE may also differ depending on the cause of kidney disease. In addition, kidney transplant patients with VTE are at a greater risk for death and graft loss than transplant patients without VTE. The reasons that patients with CKD are at increased risk of VTE are not well understood, but recent data suggest that factor VIII is a mediator. Factor VIII is an essential cofactor in the coagulation cascade and a strong risk factor for VTE in general. It is inversely correlated with eGFR and prospective studies demonstrate that factor VIII activity predicts incident CKD and rapid eGFR decline. The etiology of CKD may also influence factor VIII levels. This review summarizes the epidemiology VTE in CKD and reviews the biochemistry of factor VIII and determinants of its levels, including von Willebrand factor and ABO blood group. We explore mechanisms by which the complications of CKD might give rise to higher factor VIII and suggests future research directions to understand how factor VIII and CKD are linked.

Prognostic role of ABO blood group in patients with unresectable hepatocellular carcinoma after transarterial chemoembolization

Background

The association of ABO blood group with prognosis of several malignancies has been established. However, its role in hepatocellular carcinoma (HCC) remains unclear.

Patients and methods

In this study, we investigated the prognostic role of ABO blood group in unresectable HCC patients receiving transarterial chemoembolization (TACE) as an initial treatment. Medical records of 2,611 HCC patients were collected, and clinical data of 282 unresectable HCC patients receiving TACE were ultimately analyzed retrospectively. A prognostic nomogram was generated for predicting 1-, 2-, and 3-year overall survival (OS) probability. A total of 114 (40.4%), 69 (24.5%), 64 (22.7%), and 35 (12.4%) HCC patients had blood groups O, A, B, and AB, respectively.

Results

The median OS times for patients with blood groups O, A, B, and AB were 24, 23, 20, and 20 months, respectively. Patients with blood group AB (hazard ratio [HR]=2.050, 95% confidence interval [CI], 1.331–3.157, P=0.001) or group non-O (HR=1.479, 95% CI, 1.110–1.972, P=0.008) had a poorer OS than those with blood group O. The prognostic nomogram, with a c-index of 0.701, was modest in predicting OS of unresectable HCC patients.

Conclusion

Patients with non-O blood group, particularly blood group AB, had a worse OS compared with those having blood type O. ABO blood group can predict the prognosis in patients with unresectable HCC undergoing TACE as an initial therapy. Further external validation in larger cohorts is necessary to confirm their usefulness in clinical practice.

ABO blood group is associated with peripheral arterial disease in African Americans: The Multi-Ethnic Study of Atherosclerosis (MESA)

INTRODUCTION

Peripheral artery disease (PAD) affects 8.5 million Americans and thus improving our understanding of PAD is critical to developing strategies to reduce disease burden. The objective of the study was to determine the association of ABO blood type with ankle brachial index (ABI) as well as prevalent and incident PAD in a multi-ethnic cohort.

METHODS

The Multi-Ethnic Study of Atherosclerosis includes non-Hispanic White, African, Hispanic, and Chinese Americans aged 45-84. ABO blood type was estimated using ABO genotypes in 6027 participants who had ABI assessed at the baseline exam. Associations with ABO blood type were evaluated categorically and under an additive genetic model by number of major ABO alleles. After excluding those with ABI>1.4, prevalent PAD was defined as ABI≤0.9 at baseline and incident PAD as ABI≤0.9 for 5137 participants eligible for analysis.

RESULTS

There were 222 prevalent cases and 239 incident cases of PAD. In African Americans, each additional copy of the A allele was associated with a 0.02 lower baseline ABI (p=0.006). Each copy of the A allele also corresponded to 1.57-fold greater odds of prevalent PAD (95% CI, 1.17-2.35; p=0.004), but was not associated with incident PAD. No associations were found in other racial/ethnic groups for ABI, prevalent PAD, or incident PAD across all races/ethnicities.

CONCLUSIONS

Blood type A and the A allele count were significantly associated with baseline ABI and prevalent PAD in African Americans. Further research is needed to confirm and study the mechanisms of this association in African Americans.

Soluble vascular cell adhesion molecular-1 is a potential biological indicator of hemophilic arthropathy

Hemophilic arthropathy is the most common chronic complication in patients with hemophilia. The pathogenesis of hemophilic arthropathy involves the inflammatory processes associated with rheumatoid arthritis (RA). Determining the severity and/or progression of joint damage is crucial when evaluating the effect of treatment modalities. Identifying reliable biomarkers in the peripheral blood of patients with hemophilic arthropathy may be beneficial in clinical practice. Circulating soluble vascular cell adhesion molecule-1 (sVCAM-1), E-selectin, and P-selectin levels are elevated in patients with RA. Our study investigated whether these soluble adhesion molecules can be used as biological indicators in the course of joint damage in patients with hemophilia A.Patients with hemophilia A (mild, moderate, and severe) were enrolled. The plasma levels of sVCAM-1, E-selectin, and P-selectin in patients with hemophilia A and control were measured using specific enzyme-linked immunosorbent assay kits. Joint damages were evaluated using Pettersson scores.No statistically significant differences were observed in E-selectin and P-selectin levels between patients and controls. The sVCAM-1 level was significantly higher in patients with hemophilia A than in controls. The differences remained significant in patients with severe hemophilia A but not in patients with mild or moderate hemophilia A. The degree of hemophilic arthropathy was evaluated using Pettersson scores, and a score higher than 5 indicated marked arthropathy. Patients with more than 1 joint with marked arthropathy showed significantly higher sVCAM-1 levels.sVCAM-1 levels in patients with hemophilia A are associated with the severity of hemophilic arthropathy.