The blood group-specific human glycosyltransferases

Cloning, expression and characterisation of a novel mollusc α-1,2-Fucosyltransferase from Crassostrea gigas (CgFUT2)

Glycans containing fucose play crucial roles in cell biology, particularly in recognition processes. In humans, fucose found in H-blood group antigens is recognized by various pathogens, thereby influencing host-pathogen interactions. However, in invertebrate biology the specific functions of these modifications and the corresponding glycosyltransferases are not fully elucidated. Therefore, cloning these glycosyltransferases from different model systems will provide valuable insights into this process. Little is known about fucosyltransferases in molluscs. For this study, a sequence of the Pacific oyster, Crassostrea gigas, based on amino acid sequence homologies with rabbit and human α-1,2-fucosyltransferases, was chosen. The recombinant enzyme (350 amino acids) was able to transfer fucose from GDP-fucose to the galactose residue of type II disaccharides, terminal galactoses in complex N-glycan structures and several linear and branched galactans which were tested using a glycan microarray. The α-1,2-linkage formed was confirmed by NMR analysis. The enzyme was active in a broad pH-range, it was relatively stable upon storage conditions and its activity was not dependent on the presence of divalent cations. In this study, we were able to clone, express and characterise a novel α-1,2-fucosyltrasferase from Crassostrea gigas (CgFUT2).

ABO blood group-related mechanism of infection of SARS-CoV-2: an overview of systematic reviews

Among the host genetic factors playing a role in the susceptibility to infectious diseases, the ABO blood group system is of utmost importance. Following the first reports in early 2020, the association between ABO blood groups and SARS-CoV-2 infection or COVID-19 severity has been thoroughly investigated. The aim of this narrative review is to provide an overview of systematic reviews regarding the link between ABO blood groups and such risks. The possible molecular mechanisms underlying these associations will also be discussed. ABO blood group has a robust association with susceptibility to infection but not with disease severity, and studies on long COVID anre still missing.Prov.

Serological and molecular analysis of the B(A) subtype in China-A systematic review

OBJECTIVE

To study the serological and molecular biological characteristics of the B(A) subtype and its geographical distribution in China through case discussion and systematic review.

METHODS

A case of the B(A)02 subtype previously found in our laboratory was retrospectively analysed. The distribution characteristics and specific serological and genotypic characteristics of the B(A) subtype in China were systematically evaluated by searching four major Chinese databases.

RESULTS

In a previous case of an abnormal blood group, both the proband and her father were found to be genotype B(A)02/O02, while the mother was normal type B. After a systematic search, irrelevant studies were screened out, and 88 studies were included for analysis. The results showed that the B(A)04 subtype was significantly more frequently reported in the north than in the south, while the B(A)02 subtype was predominant in the southwest. The A antigen of the B(A)02 subtype reacts with monoclonal anti-A reagents in a wide range, while the A antigen of the B(A)04 subtype has a weak agglutination intensity of less than or equal to 2+.

CONCLUSION

The results showed that the B(A) subtype has specific characteristics in the Chinese population, and this study further enriched the serological and molecular biological characteristics of the B(A) subtype.

Structural basis for Lewis antigen synthesis by the α1,3-fucosyltransferase FUT9

Mammalian cell surface and secreted glycoproteins exhibit remarkable glycan structural diversity that contributes to numerous physiological and pathogenic interactions. Terminal glycan structures include Lewis antigens synthesized by a collection of α1,3/4-fucosyltransferases (CAZy GT10 family). At present, the only available crystallographic structure of a GT10 member is that of the Helicobacter pylori α1,3-fucosyltransferase, but mammalian GT10 fucosyltransferases are distinct in sequence and substrate specificity compared with the bacterial enzyme. Here, we determined crystal structures of human FUT9, an α1,3-fucosyltransferase that generates Lewisx and Lewisy antigens, in complex with GDP, acceptor glycans, and as a FUT9-donor analog-acceptor Michaelis complex. The structures reveal substrate specificity determinants and allow prediction of a catalytic model supported by kinetic analyses of numerous active site mutants. Comparisons with other GT10 fucosyltransferases and GT-B fold glycosyltransferases provide evidence for modular evolution of donor- and acceptor-binding sites and specificity for Lewis antigen synthesis among mammalian GT10 fucosyltransferases.

Anti-Neuroinflammatory Effects of the Human Milk Oligosaccharide, 2'-Fucosyllactose, Exerted via Modulation of M2 Microglial Activation in a Mouse Model of Ischemia-Reperfusion Injury

Cerebral ischemic stroke is one of the leading causes of death and disability worldwide. 2'-fucosyllactose (2'-FL), a human milk oligosaccharide, exerts anti-inflammatory effects and plays a protective role in arterial thrombosis; however, its role in ischemic stroke remains unclear. This study aimed to investigate the neuroprotective effects of 2'-FL and its potential mechanisms in a mouse model of ischemic stroke. Neurological score and behavior tests revealed that 2'-FL promoted the recovery of neurological deficits and motor function in middle cerebral artery occlusion (MCAO) mice, and that 2'FL led to a reduction in the size of cerebral infarct. Biochemical studies showed that administration of 2'-FL led to a reduction of reactive oxygen species (ROS)-related products in the brain of MCAO mice. 2'-FL upregulated IL-10 and downregulated TNF-α level. In addition, 2'-FL enhanced M2-type microglial polarization and upregulated CD206 expression at 7 days after MCAO. At 3 days after MCAO, 2'-FL increased IL-4 levels and activated STAT6. Our data show that 2'-FL reduced the neurological symptoms of ischemic stroke and ROS accumulation in the brain through IL-4/STAT6-dependent M2-type microglial polarization in MCAO mice. These results demonstrate that 2'-FL is a potentially effective therapeutic agent for ischemic stroke.

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.

ABO Blood Group and the Risk and Prognosis of Lymphoma

ABO blood group antigens exhibit alternative phenotypes and genetically derived structures that are located on the red cell surface. The role of ABO blood group in cancer biology has been intensely reported by several studies, and it is now widely recognized that ABO antigens are associated with the risk and prognosis of several types of tumors, namely gastric cancer and pancreatic cancer. However, there have been contentious limited issues with the association between the ABO blood group and lymphoma. In this narrative review, based on literature data, we discuss the role of ABO blood group in the risk and prognosis of lymphoma and summarize the current knowledge of the underlying pathogenic mechanisms of the association. The possible association of ABO blood group with racial disparities and pathological classification in lymphoma patients is also discussed.

ABO blood groups and expression of blood group antigens of epithelial ovarian cancer in Chinese women

BACKGROUND

ABO blood groups has been associated with risk of several cancers; however, the results for an association with ovarian cancer are inconsistent and little is known about the expression of histo-blood group (ABH) antigens and ABO gene in ovarian tumor tissues.

METHODS

To assess the impact of genotype-derived ABO blood types on the risk of EOC, we conducted a case-control study in 1,870 EOC and 4,829 controls. Expression of A and B antigen in 70 pairs of ovarian tumor tissues and adjacent normal tissues were detected by immunohistochemistry. Gene expression and DNA methylation profiling was conducted in ovarian tumor tissues.

RESULTS

We identified that blood group A was associated with increased risk for EOC compared to blood group O (OR = 1.18, 95% CI = 1.03-1.36, p = 0.019). Increased frequency of aberrant expression of histo-blood group antigens was observed in patients with blood group A (76.5%) compared to patients with blood group O (21.1%) and B (5.0%) by immunohistochemistry (p < 0.001). ABO gene expression was down-regulated in ovarian tumor tissues compared with paired adjacent normal tissues (p = 0.027). In addition, ABO gene expression was positively correlated with NFYB (r = 0.38, p < 0.001) and inversely correlated with DNA methylation level of four CpG sites on ABO gene (cg11879188, r = - 0.3, p = 0.002; cg22535403, r = - 0.30, p = 0.002; cg13506600, r = - 0.22, p = 0.025; cg07241568, r = - 0.21, p = 0.049) in ovarian tumor tissues.

CONCLUSION

We identified blood group A was associated with increased EOC risk in Chinese women and provided the clues of the possible molecular mechanisms of blood group A related to ovarian cancer risk.

Heme-induced genes facilitate endosymbiont (Sodalis glossinidius) colonization of the tsetse fly (Glossina morsitans) midgut

Tsetse flies (Glossina spp.) feed exclusively on vertebrate blood. After a blood meal, the enteric endosymbiont Sodalis glossinidius is exposed to various environmental stressors including high levels of heme. To investigate how S. glossinidius morsitans (Sgm), the Sodalis subspecies that resides within the gut of G. morsitans, tolerates the heme-induced oxidative environment of tsetse's midgut, we used RNAseq to identify bacterial genes that are differentially expressed in cells cultured in high versus lower heme environments. Our analysis identified 436 genes that were significantly differentially expressed (> or < 2-fold) in the presence of high heme [219 heme-induced genes (HIGs) and 217 heme-repressed genes (HRGs)]. HIGs were enriched in Gene Ontology (GO) terms related to regulation of a variety of biological functions, including gene expression and metabolic processes. We observed that 11 out of 13 Sgm genes that were heme regulated in vitro were similarly regulated in bacteria that resided within tsetse's midgut 24 hr (high heme environment) and 96 hr (low heme environment) after the flies had consumed a blood meal. We used intron mutagenesis to make insertion mutations in 12 Sgm HIGs and observed no significant change in growth in vitro in any of the mutant strains in high versus low heme conditions. However, Sgm strains that carried mutations in genes encoding a putative undefined phosphotransferase sugar (PTS) system component (SG2427), fucose transporter (SG0182), bacterioferritin (SG2280), and a DNA-binding protein (SGP1-0002), presented growth and/or survival defects in tsetse midguts as compared to normal Sgm. These findings suggest that the uptake up of sugars and storage of iron represent strategies that Sgm employs to successfully reside within the high heme environment of its tsetse host's midgut. Our results are of epidemiological relevance, as many hematophagous arthropods house gut-associated bacteria that mediate their host's competency as a vector of disease-causing pathogens.

Association of Plasma Metabolites and Lipoproteins with Rh and ABO Blood Systems in Healthy Subjects

This study investigated the associations between the levels of 27 plasma metabolites, 114 lipoprotein parameters, determined using nuclear magnetic resonance spectroscopy, and the ABO blood groups and the Rhesus (Rh) blood system in a cohort of n = 840 Italian healthy blood donors of both sexes. We observed good multivariate discrimination between the metabolomic and lipoproteomic profiles of subjects with positive and negative Rh. In contrast, we did not observe significant discrimination for the ABO blood group pairwise comparisons, suggesting only slight metabolic differences between these group-specific metabolic profiles. We report univariate associations (P-value < 0.05) between the subfraction HDL1 related to Apo A1, the subfraction HDL2 related to cholesterol and phospholipids, and the particle number of LDL2 related to free cholesterol, cholesterol, phospholipids, and Apo B and the ABO blood groups; we observed association of the lipid main fraction LDL4 related to free cholesterol, triglycerides, and Apo B; creatine; the particle number of LDL5; the subfraction LDL5 related to Apo B; the particle number of LDL4; and the subfraction LDL4 related to Apo B with Rh blood factors. These results suggest blood group-dependent (re)shaping of lipoprotein metabolism in healthy subjects, which may provide relevant information to explain the differential susceptibility to certain diseases observed in different blood groups.

A systematic review of prognosis of ABO blood group and rhesus factor on outcomes in patients with bladder cancer

BACKGROUND

Bladder cancer (BC) is the 10th most common malignancy worldwide, and some studies reported that ABO blood type or/and rhesus factor has been identified as a prognostic oncologic marker for patients with BC. We carried out a systematic review to assess the prognosis of ABO blood group and rhesus factor on outcomes in patients with bladder cancer.

METHODS

We searched databases through February 2022 for studies assessing blood group on outcomes in patients with bladder cancer.

RESULTS

We included ten studies with 15,204 participants. We found that blood type A is relevant to non-muscle-invasive BC patients treated with transurethral resection of bladder tumor and blood type B patients have a lower incidence of disease recurrence and progression. Blood type O and non-O blood type have not been found to be related to disease recurrence. However, in multivariable analyses, blood type O and non-O blood type are associated with cancer-specific mortality (CSM). Other than that, blood type B doesn't have statistical significance for BC patients accepted radical cystectomy (RC). The same results showed in blood type AB non-muscle-invasive bladder cancer patients treated with RC.

CONCLUSIONS

Our study confirmed that a particular association of blood type for prognosis of patients with BC, and ABO blood group antigen expression can be suitable biomarkers for BC. We also found that rhesus factor has no impact on prognosis of BC patients.

Dual role of fucosidase in cancers and its clinical potential

Glycosidases and glycosyltransferases greatly impact malignant phenotype of tumors though genetics and epigenetics mechanisms. As the member of glycoside hydrolase (GH) families 29A, α-L-fucosidases (AFUs) are involved in the hydrolysis of terminal L-fucose residues linked via α-1,2, α-1,3, α-1,4 or α-1,6 to the reducing end of N-acetyl glucosamine (GlcNAc) of oligosaccharide chains. The defucosylation process mediated by AFUs contributes to the development of various diseases, such as chronic inflammatory diseases, immune disorders, and autoimmune diseases by reducing the interaction between fucosylated adhesion molecules supporting leukocyte extravasation. AFUs also impair crucial cell-extracellular matrix (ECM) interactions and presumably subsequent cell signaling pathways, which lead to changes in tumor function and behavior. There are two isoforms of AFUs in human, namely α-L-fucosidase 1 (FUCA1) and α-L-fucosidase 2 (FUCA2), respectively. FUCA1 is a p53 target gene and can hydrolyze different fucosylation sites on epidermal growth factor receptor (EGFR), thereby determining the activation of EGFR. FUCA2 mediates the adhesion between Helicobacter pylori and gastric mucosa and is upregulated in 24 tumor types. Besides, based on the participation of AFU in signaling pathways and tumor progression, we discuss the prospect of AFU as a therapeutic target.

Recurrence of Chronic Subdural Hematoma Is Independent of ABO Blood Type: A Retrospective Cohort Study

Objective

A previous study with a limited number of patients has shown that blood type A was a risk factor in the recurrence of CSDH. The primary objective of this study was to investigate the association between the recurrence of CSDH and ABO blood type based on a larger sample size.

Methods

The authors reviewed in-patients with symptomatic CSDH from August 2011 to August 2021. Hospitalization information and data on long-term outcomes and recurrence among these patients were gathered. For all clinical variables, numbers (percentages) and mean ± standard deviations were used for categorical and continuous variables, respectively. For intergroup comparisons, the χ2 test or one-way ANOVA was carried out. Multivariable logistic regression analyses were performed to identify the association between CSDH recurrence and blood types.

Results

We included 1,556 inpatients in this study. The recurrence rate of CSDH showed no differences among different blood types. In the multivariable logistic regression analyses, ABO blood type (A: OR, 1.064; 95% CI, 0.467-2.851, p = 0.793; B: OR, 0.682, 95% CI, 0.315-1.269, p = 0.164; AB: OR, 0.537, 95% CI, 0.426-1.861, p = 0.357) was not a significantly independent predictor of CSDH recurrence.

Conclusions

Our study demonstrated that ABO blood type was not a risk factor in the recurrence of CSDH. Thus, we should not pay too much attention to ABO blood type in terms of CSDH recurrence.

Influence of the ABO Blood Group System on Hepatocellular Carcinoma Recurrence After Liver Transplantation

BACKGROUND

The ABO blood group system may influence tumorigenesis, but its prognostic value in liver transplantation (LT) for hepatocellular carcinoma (HCC) has never been assessed.

METHODS

All consecutive patients who underwent LT for HCC between 2013 and 2017 at 9 centers were analyzed. Predictors of tumor recurrence were identified using multivariable analysis, while comparison between group A and non-A recipients was performed after propensity score matching.

RESULTS

Among 925 LT recipients, 406 were blood group A, 94 group B, 380 group O, and 45 group AB. On multivariable analysis, group A was associated with tumor recurrence (hazard ratio [HR] = 1.574 [95% confidence interval; 95% CI = 1.034-2.394] P = 0.034). After propensity score matching, 1- and 5-y recurrence rates were 7.4% and 20.1% in group A recipients versus 3.3% and 13.2% in non-A recipients (HR = 1.66 [95% CI = 1.12-2.45], P = 0.011). One and 5-y recurrence-free survivals were 85.2% and 66.8% in group A recipients versus 88.5% and 71.3% in non-A recipients (HR = 1.38 [95% CI = 1.01-1.90], P = 0.045). Among recipients within Milan criteria (n = 604), 1- and 5-y recurrence rates were 5.8% and 12.7% in group A recipients versus 3.1% and 12.2% in non-A recipients (HR = 1.197 [95% CI = 0.721-1.987], P = 0.485). Among recipients outside Milan criteria (n = 182), 1- and 5-y recurrence rates were 12.1% and 43.8% in group A recipients versus 3.9% and 15.6% in non-A recipients (HR = 3.175 [95% CI = 1.526-6.608], P = 0.002).

CONCLUSIONS

ABO blood system influences the oncological outcome of recipients undergoing LT for HCC. Its incorporation in the prognostication model of LT for HCC may allow improving the management of LT candidates.

ABO blood group and COVID-19: an updated systematic literature review and meta-analysis

BACKGROUND

Following the first reports in the literature, the association between the ABO blood group and SARS-CoV-2 infection has been investigated by a number of studies, although with varying results. The main object of this systematic review was to assess the relationship between the ABO blood group and the occurrence and severity of COVID-19.

MATERIALS AND METHODS

A systematic literature search using appropriate MeSH terms was performed through Medline and PubMed. The outcomes considered were the prevalence of the blood group O vs non-O types in SARS-CoV-2 infected and non-infected subjects, and the severity of SARS-CoV-2 infection according to ABO group. The methodological quality of the studies included in the analysis was assessed with the Newcastle-Ottawa Scale, and the overall quality of the available evidence using the GRADE system. Benchmarks used to evaluate the effect size were odd ratios (ORs) for case control studies and risk ratios (RRs) for cohort studies.

RESULTS

Twenty-one studies were included in the analysis. Overall, individuals with group O had a lower infection rate compared to individuals of non-O group (OR: 0.81; 95% CI: 0.75, 0.86). However, the difference in the effect size was significantly lower in cohort studies compared to case control studies. No evidence was found indicating an effect of the O type on the disease severity in the infected patients.

DISCUSSION

We have found low/very low evidence that group O individuals are less susceptible to SARS-CoV-2 infection compared to those in the non-O group. No evidence was found indicating an effect of the O type on disease severity in SARS-CoV-2 infection.

The relationship between ABO blood group, von Willebrand factor, and primary hemostasis

Numerous studies have reported significant associations between ABO blood group and risk of cardiovascular disease. These studies have consistently demonstrated that thrombotic risk is significantly reduced in individuals in blood group O. Nevertheless, the biological mechanisms through which ABO influences hemostasis have remained poorly understood. Exciting recent data have provided novel insights into how these ABO effects are modulated and have highlighted that ABO group significantly influences platelet plug formation at sites of vascular injury (primary hemostasis). In particular, ABO affects multiple aspects of von Willebrand factor (VWF) biology. In keeping with their reduced thrombotic risk, plasma VWF levels are ∼25% lower in healthy group O compared with healthy group non-O individuals. In addition, blood group O VWF demonstrates enhanced susceptibility to ADAMTS13 proteolysis. Finally, preliminary findings suggest that the interaction of group O VWF with platelets may also be reduced. Although the molecular mechanisms underlying these ABO effects on VWF have not been fully elucidated, it seems likely that they are mediated in large part by the ABO(H) carbohydrate structures that are carried on both the N- and O-linked glycans of VWF. Interestingly, ABO(H) determinants are also expressed on several different platelet surface glycoprotein receptors. Recent studies support the hypothesis that ABO group not only exerts major quantitative and qualitative effects on VWF, but also affect specific aspects of platelet function. Given the severe morbidity and the mortality associated with thrombotic disorders, defining the mechanisms underlying these ABO effects is not only of scientific interest, but also of direct clinical importance.

Characterizing human α-1,6-fucosyltransferase (FUT8) substrate specificity and structural similarities with related fucosyltransferases

Mammalian Asn-linked glycans are extensively processed as they transit the secretory pathway to generate diverse glycans on cell surface and secreted glycoproteins. Additional modification of the glycan core by α-1,6-fucose addition to the innermost GlcNAc residue (core fucosylation) is catalyzed by an α-1,6-fucosyltransferase (FUT8). The importance of core fucosylation can be seen in the complex pathological phenotypes of FUT8 null mice, which display defects in cellular signaling, development, and subsequent neonatal lethality. Elevated core fucosylation has also been identified in several human cancers. However, the structural basis for FUT8 substrate specificity remains unknown.Here, using various crystal structures of FUT8 in complex with a donor substrate analog, and with four distinct glycan acceptors, we identify the molecular basis for FUT8 specificity and activity. The ordering of three active site loops corresponds to an increased occupancy for bound GDP, suggesting an induced-fit folding of the donor-binding subsite. Structures of the various acceptor complexes were compared with kinetic data on FUT8 active site mutants and with specificity data from a library of glycan acceptors to reveal how binding site complementarity and steric hindrance can tune substrate affinity. The FUT8 structure was also compared with other known fucosyltransferases to identify conserved and divergent structural features for donor and acceptor recognition and catalysis. These data provide insights into the evolution of modular templates for donor and acceptor recognition among GT-B fold glycosyltransferases in the synthesis of diverse glycan structures in biological systems.

Glycoproteomic analysis identifies cryptdin-related sequence 1 as O-glycosylated protein modified with α1,2-fucose in the small intestine

The modification of galactose with α1,2-fucose is involved in symbiosis with intestinal bacteria and elimination of pathogenic bacteria. It is postulated that α1,2-fucosylated mucin secreted from goblet cells is involved in defending an organism against infections, but the detailed molecular mechanisms are yet to be elucidated. It was previously reported that Paneth cells of the small intestine were positive for UEA-1 lectin staining. However, glycoproteins in Paneth cells carrying α1,2-fucose have not yet been identified. Glycoproteomic analysis of ileal lysates identified 3212 O-linked and 2962 N-linked glycopeptides. In particular, cryptdin-related sequence 1 (CRS1) expressed in Paneth cells was found to be α1,2-fucosylated. Unlike other antimicrobial α-defensin proteins, CRS1 contains unique Thr residues, which are modified with O-glycans, with 3HexNAc2Hex1Fuc1NeuAc being the main glycoform. Identification of α1,2-fucose on the O-glycans of CRS1 expressed in Paneth cells will pave the way for a mechanistic understanding of α1,2-fucose-dependent symbiosis with intestinal bacteria and elimination of pathogenic bacteria in the intestine.

Expresser phenotype determines ABO(H) blood group antigen loading on platelets and von Willebrand factor

ABO blood group is associated with cardiovascular disease, with significantly lower risk in blood group O individuals. ABO(H) blood group determinants are expressed on different glycoproteins on platelet surfaces. In addition, ABO(H) structures are also present on VWF glycans. These ABO(H) carbohydrates influence both platelet and VWF function. Previous studies have reported that approximately 5-10% of normal blood donors express abnormally high or low levels of A or B blood group antigens on their platelet surfaces (high expresser phenotype, HXP or low expresser phenotype, LXP respectively). In this study, the biological effects of the ABO Expresser phenotype were investigated. ABO(H) expression on platelets and plasma VWF was studied in a series of 541 healthy blood donors. Overall, 5.6% of our study cohort were classified as HXP, whilst 4.4% satisfied criteria for LXP. We demonstrate that genotype at the ABO blood group locus plays a critical role in modulating the platelet HXP phenotype. In particular, A1A1 genotype is a major determinant of ABO high-expresser trait. Our data further show that ABH loading on VWF is also affected by ABO expresser phenotype. Consequently, A antigen expression on VWF was significantly elevated in HXP individuals and moderately reduced in LXP subjects (P < 0.05). Collectively, these findings suggest that ABO expresser phenotype influences primary hemostasis though several different pathways. Further studies will be required to define whether inter-individual variations in ABO(H) expression on platelets and/or VWF (particularly HXP and LXP) impact upon risk for cardiovascular disease.

ABO blood group relationships to kidney transplant recipient and graft outcomes

Introduction

Certain ABO blood types have been linked to cardiovascular disease, infection and cancers. The effect of recipient ABO blood group on patient and graft survival has not been studied in ABO-matched kidney transplantation. This study aims to determine the association between kidney transplant recipient ABO blood groups with patient and graft survival in Australian and New Zealand.

Methods

All Australian and New Zealand transplant recipients who received ABO-compatible primary kidney transplants between 1995–2016 were analysed using a de-identified dataset from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Primary analysis was undertaken of recipient ABO blood group O versus non-O blood groups. The primary outcome was patient survival post kidney transplantation and the secondary outcome was death censored graft survival. Recipient age at first transplant, gender, ethnicity, body mass index, smoking status, vascular disease, presence of diabetes mellitus, chronic lung disease, primary kidney disease, donor source, donor age and gender, and era of transplants were included in the multivariate model as confounders.

Results and conclusions

On analysis of 15,523 kidney transplant recipients, blood group O was not associated with patient survival (hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.89–1.04) nor death censored graft survival (HR 0.97, 95% CI 0.89–1.05) compared to non-blood group O recipients. Competing risks analyses showed an increased risk of cancer-related mortality in blood group O recipients on univariate analyses (HR 1.18, 95% CI 1.01–1.37) however, this became insignificant on multivariate analyses. On secondary analyses, recipient blood group AB (4.11% participants) was associated with inferior death censored graft survival compared to those with blood group O (HR 1.24, 95% CI 1.02–1.50). Although recipient ABO blood groups were not associated with patient nor graft survival, differences in cause-specific mortality between individual blood groups cannot be excluded based on current analyses.

The Impact of Blood Type O on Major Outcomes in Patients With Severe Burns

ABO blood type has been reported to be a predictor of poor prognosis in critically ill patients. Here, we aim to correlate different blood types with clinical outcomes in patients with severe burns. We conducted a single-center retrospective cohort study by enrolling patients with severe burn injuries (≥40% TBSA) between January 2012 and December 2017. Baseline characteristics and clinical outcomes were compared between disparate ABO blood types (type O vs non-O type). Multivariate logistic and linear regression analyses were performed to identify an association between ABO blood type and clinical outcomes, including in-hospital mortality, the development of acute kidney injury (AKI), and hospital or ICU length of stay. A total of 141 patients were finally enrolled in the current study. Mortality was significantly higher in patients with type O blood compared with those of other blood types. The development of AKI was significantly higher in patients with blood type O vs non-O blood type (P = .001). Multivariate analysis demonstrated that blood type O was independently associated with in-hospital mortality and AKI occurrence after adjusting for other potential confounders. Our findings indicated the blood type O was an independent risk factor of both increased mortality and the development of AKI postburn. More prudent and specific treatments are required in treating these patients to avoid poor prognosis.

Blood group antigen A on von Willebrand factor is more protective against ADAMTS13 cleavage than antigens B and H

BACKGROUND

ADAMTS13 specifically cleaves the peptide bond between Y1605 and M1606 within the VWF-A2 domain.

OBJECTIVE

The VWF contains ABO(H) blood group antigens, which may influence the susceptibility of VWF to ADAMTS13.

METHODS

Using a unique monoclonal antibody recognizing the Y1605 residue, we have developed a sandwich ELISA to analyze the generation of a VWF-DP by ADAMTS13 quantitatively.

RESULTS

Production of VWF-DP after exposure to four different degrees of high shear stress was validated in comparison to the reduction in high-molecular-weight multimers using VWF multimer analysis. In analysis of plasma from 259 healthy individuals, plasma levels of VWF antigen (VWF:Ag) were significantly lower in blood group O than in the other groups and were significantly correlated with plasma VWF-DP levels. The ratio between VWF-DP and VWF:Ag was significantly higher in blood group O than in blood groups A and AB. The ratio in blood group B was also significantly higher than those in A and AB, but did not differ from blood group O. Finally, to examine whether ABO(H) blood group antigens contributed to VWF cleavage, 82 plasma samples were exposed to high shear stress using a cone-plate shear stress inducer. The difference in the VWF-DP/VWF:Ag ratio before and after high shear stress in blood group O was significantly greater than those in groups A and AB.

CONCLUSION

These results indicate that blood group antigen A on VWF was more protective against ADAMTS13 cleavage than antigens B and H.

Fucosyltransferase gene expression in goat endometrium during the estrous cycle and early pregnancy

Regulation of the expression of the alpha(1,2)fucosyltransferase (FUT) genes and their enzymatic products, including the H-type 1 antigen (HT1), on the luminal surface of the uterus is believed to be critical for establishment of pregnancy in mammals. The FUT1 gene is a marker for conception rates in dairy cows and HT1 is a marker for uterine receptivity in rodents. To determine the spatiotemporal expression patterns of FUT1 and FUT2 genes in goats, endometrial tissues were obtained on six days spanning the estrous cycle (Days 5, 11, 13, 15, 17 and 19) and seven days spanning early pregnancy (Days 5, 11, 13, 15, 17, 19 and 25). In all data, we found no effect of status (cyclic or pregnant; P > 0.1) and pooled data where appropriate. We cloned FUT1 cDNA from goat endometrium and made probes from it for Northern and slot blot analyses. The analyses indicated that FUT1 gene expression was high until Day 13, and then declined. In situ hybridization revealed a change in the cell-specificity of FUT1 gene expression over the estrous cycle and early pregnancy. In situ hybridization signal intensity scores indicated that FUT1 expression by uterine epithelium was high on Day 5, moderate on Day 11, and minimal on subsequent days. In situ hybridization signals in uterine glandular epithelial cells remained high from Day 5 to Day 13, with weaker signals thereafter. Quantitative reverse transcription-PCR (RT-qPCR) assays were used for quantitation of FUT1 and FUT2 mRNAs. Quantitative RT-qPCR data were generated from endometrium collected from cyclic and pregnant animals on Days 5, 11 and 17. Relative levels of FUT1 mRNA were high on Days 5 and 11, but then fell 5-fold by Day 17 (P < 0.01). FUT2 mRNA concentrations were below the accurate detectable limit of the assay. High levels of HT1 were observed on the apical surface of uterine luminal epithelia on Days 5, 15, 17 and 19, with much lower levels on Days 11 and 13. Thus, data suggests that FUT1 is the primary enzyme responsible for the high levels of HT1 antigen present on the uterine luminal epithelium between Days 5 and 11 of the estrous cycle and early pregnancy. But changes in the expression of the FUT1 gene does not directly correlate to HT1 staining, which increased from Day 13-15. Future studies are required to understand the regulation of the HT1 antigen on the luminal surface of endometrium.

ABO Blood Group and Diabetes Mellitus Influence the Risk for Pancreatic Cancer in a Population from China

Background

The mechanism by which diabetes mellitus (DM) impacts the association between ABO blood types and pancreatic cancer is unclear.

Material/Methods

A retrospective case-control study of 264 patients with pancreatic cancer and 423 age- and sex-matched individuals with nonmalignant diseases was performed to assess whether ABO blood group and DM jointly contribute to pancreatic cancer risk.

Results

A multivariate analysis with adjustments for risk factors revealed that blood type, chronic pancreatitis, and DM were significantly associated with increased pancreatic cancer risk. The estimated adjusted odds ratios (AORs with 95% confidence intervals [CIs]) were 2.130 (1.409–3.220) for blood type A, 2.383 (1.313–4.325) for blood type AB, 1.518 (1.012–2.276) for DM, and 10.930 (1.202–99.405) for chronic pancreatitis. Blood type A significantly modified the risk for pancreatic cancer in individuals with DM (AOR, 3.506; 95% CI, 1.659–7.409).

Conclusions

The risk for pancreatic cancer was associated with ABO blood type, DM, and chronic pancreatitis in a Chinese population. The risk was greatest for individuals with blood type A and DM.

ABO histo-blood group and risk of respiratory atopy in children: a review of published evidence

Besides their fundamental role in transfusion medicine, ABO and other histo-blood group antigens are associated with the pathogenesis of some human diseases such as malignancy and thrombosis. Reports also show a possible relationship with the risk of asthma and other forms of respiratory atopy. This paper aims to critically review the current evidence linking ABO histo-blood group with the risk of respiratory atopy in children and adults. A literature search was conducted with PubMed to gather baseline data about this relationship. The search extended to studies published within the past 45 years. First, the molecular mechanism underpinning the role of ABO antigenic system in human diseases comprises a fascinating relationship with von Willebrand factor and several pro-inflammatory and adhesion molecules. Second, specific blood group types vary with asthma phenotypes; severe asthma is associated with B phenotype, while mild and moderate asthma is associated with O and A phenotypes. Third, O phenotype has been linked to allergic rhinitis but only in males. Furthermore, asthma risk is related to O/Lewis negative/secretor phenotypes, while a significant relationship has also been established with B phenotype but not with A and O phenotypes. However, one study failed to establish a significant relationship with any of the ABO blood group antigens. In conclusion, there is no unanimity on the specific histo-blood groups linked to respiratory atopy risk, although asthma phenotypes are associated with specific blood groups. Despite the prospect that this relationship holds for the use of blood-group typing in evaluating respiratory atopy risk in children, more evidence-based studies are still required for its validation.

Biological functions of fucose in mammals

Fucose is a 6-deoxy hexose in the l-configuration found in a large variety of different organisms. In mammals, fucose is incorporated into N-glycans, O-glycans and glycolipids by 13 fucosyltransferases, all of which utilize the nucleotide-charged form, GDP-fucose, to modify targets. Three of the fucosyltransferases, FUT8, FUT12/POFUT1 and FUT13/POFUT2, are essential for proper development in mice. Fucose modifications have also been implicated in many other biological functions including immunity and cancer. Congenital mutations of a Golgi apparatus localized GDP-fucose transporter causes leukocyte adhesion deficiency type II, which results in severe developmental and immune deficiencies, highlighting the important role fucose plays in these processes. Additionally, changes in levels of fucosylated proteins have proven as useful tools for determining cancer diagnosis and prognosis. Chemically modified fucose analogs can be used to alter many of these fucose dependent processes or as tools to better understand them. In this review, we summarize the known roles of fucose in mammalian physiology and pathophysiology. Additionally, we discuss recent therapeutic advances for cancer and other diseases that are a direct result of our improved understanding of the role that fucose plays in these systems.

ABO blood group and ovarian reserve: a meta-analysis and systematic review

Ovarian reserve reflects a woman's fertility potential. The ABO blood group system is a very stable genetic marker. Although many recent studies have explored the relationship between ABO blood group and ovarian reserve, a consensus has not yet been reached. This paper is the first meta-analysis and systematic review of the relationship between ABO blood type and ovarian reserve. We analyzed seven cross-sectional studies evaluating follicle stimulating hormone (FSH) or anti-Mullerian hormone (AMH) levels in 55,113 participants to determine ovarian reserve. This study found no relationship between ABO blood type and ovarian reserve when FSH was used as an indicator of ovarian reserve (A vs non-A:OR=1.03, 95% CI:0.96-1.11; B vs non-B: OR=0.98, 95% CI:0.75-1.29; AB vs non-AB:OR=0.96, 95% CI:0.71-1.30; O vs non-O:OR=1.03, 95%CI:0.74-1.43).There was also no relationship between ABO blood type and ovarian reserve when AMH was used as an indicator (A vs non-A:OR=0.89, 95% CI:0.76-1.03; B vs non-B:OR=1.02, 95% CI:0.80-1.30; AB vs non-AB:OR=1.14, 95% CI:0.80-1.64, O vs non-O:OR=1.07, 95% CI:0.86-1.34). Overall, the current study found no relationship between ABO blood group and ovarian reserve. However, additional rigorous, high-quality and multi-indicator studies with large sample sizes are required for further verification.

Classic thrombophilic gene variants

Thrombophilia is defined as a condition predisposing to the development of venous thromboembolism (VTE) on the basis of a hypercoagu-lable state. Over the past decades, great advances in the pathogenesis of VTE have been made and nowadays it is well established that a thrombophilic state may be associated with acquired and/or inherited factors. The rare loss-of-function mutations of the genes encoding natural anticoagulant proteins (i. e. protein C, protein S and antithrombin) and the more common gain-of-function polymorphisms factor V Leiden and prothrombin G20210A are the main genetic determinants of thrombophilia. In addition, non-O blood group has been consistently demonstrated to be the most frequent inherited marker of an increased risk of VTE. The mechanism role of these inherited thrombophilia markers will be discussed in this narrative review.

Histo-Blood Group Antigen Presentation Is Critical for Binding of Norovirus VLP to Glycosphingolipids in Model Membranes

Virus entry depends on biomolecular recognition at the surface of cell membranes. In the case of glycolipid receptors, these events are expected to be influenced by how the glycan epitope close to the membrane is presented to the virus. This presentation of membrane-associated glycans is more restricted than that of glycans in solution, particularly because of orientational constraints imposed on the glycolipid through its lateral interactions with other membrane lipids and proteins. We have developed and employed a total internal reflection fluorescence microscopy-based binding assay and a scheme for molecular dynamics (MD) membrane simulations to investigate the consequences of various glycan presentation effects. The system studied was histo-blood group antigen (HBGA) epitopes of membrane-bound glycosphingolipids (GSLs) derived from small intestinal epithelium of humans (type 1 chain) and dogs (type 2 chain) interacting with GII.4 norovirus-like particles. Our experimental results showed strong binding to all lipid-linked type 1 chain HBGAs but no or only weak binding to the corresponding type 2 chain HBGAs. This is in contrast to results derived from STD experiments with free HBGAs in solution where binding was observed for Lewis x. The MD data suggest that the strong binding to type 1 chain glycolipids was due to the well-exposed (1,2)-linked α-l-Fucp and (1,4)-linked α-l-Fucp residues, while the weaker binding or lack of binding to type 2 chain HBGAs was due to the very restricted accessibility of the (1,3)-linked α-l-Fucp residue when the glycolipid is embedded in a phospholipid membrane. Our results not only contribute to a general understanding of protein-carbohydrate interactions on model membrane surfaces, particularly in the context of virus binding, but also suggest a possible role of human intestinal GSLs as potential receptors for norovirus uptake.

The Interface between Immunotransfusion and Hemostasis and Thrombosis Testing

Increasing evidence supports the existence of a close relationship between immunotransfusion, hemostasis, and thrombosis. The best example of such linkage is given by the influence of the ABO blood group antigens on von Willebrand factor (VWF) plasma levels and activity. It is well known, for instance, that individuals with non-O blood type (i.e., A, B, and AB) have higher VWF and factor VIII plasma levels than O blood type subjects and are consequently exposed to an increased thrombotic risk. There is also a close relationship between immunotransfusion, hemostasis, and thrombosis testing. The first part of this narrative review is dedicated to the issue of the relationship between immunotransfusion, hemostasis, and thrombosis, while the second part is focused on the relationship between immunotransfusion and hemostasis and thrombosis testing, as well as the effects on hemostasis of the transfusion of blood components (i.e., red blood cells, platelet concentrates, and fresh frozen plasma) and plasma-derived products.

A novel L-fucose-binding lectin from Fenneropenaeus indicus induced cytotoxicity in breast cancer cells

Lectins are omnipresent in almost all life forms, being the proteins which specifically bind to carbohydrate moieties on the cell surface; they have been explored for their anti-tumour activities. In this study, we purified a fucose specific-lectin (IFL) from Fenneropenaeus indicus haemolymph using fucose-affinity column and characterized for its haemagglutination activity, carbohydrate specificity, dependency on cations and cytotoxicity against cancer cells. The lectin showed non-specificity against human erythrocytes. It was a Ca²⁺-dependent lectin which remained stable over wide pH and temperature ranges. The lectin showed effective dose dependent cytotoxicity against different human cancer cell lines and induced apoptosis in MCF-7 cells as evidenced by DNA ladder assay and PARP cleavage in a dose dependent manner. Moreover, an increased p21 level corresponding to cyclin D downregulation in response to IFL treatment was observed which might work as probable factors to inhibit cell growth and induce apoptosis of MCF-7 cells. Therefore, we report a novel lectin from the prawn haemolymph with high specificity for L-fucose and antiproliferative towards human cancer cells. However, further establishment of the modus operandi of this lectin is required to enable its biotechnological applications.

The relationship between ABO blood group and cardiovascular disease: results from the Cardiorisk program

BACKGROUND

The ABO blood group exerts a profound influence on hemostasis, and it has hence been associated with the development of thrombotic cardiovascular adverse events. In this study, we evaluated the relationship between the ABO blood group and the risk of cardiovascular disease assessed with the Cardiorisk score.

METHODS

All blood donors aged between 35 and 65 years were enrolled in the Cardiorisk program, which included the assessment of 8 variables (sex, age, total cholesterol, high-density lipoprotein (HDL) cholesterol, plasma glucose, arterial blood pressure, anti-hypertensive therapy and smoking) which were used to generate a score. Individuals with a resulting score ≥20, considered at high cardiovascular risk, underwent additional instrumental tests (chest X-ray, stress electrocardiogram and Doppler ultrasound of supra-aortic trunks) and were closely clinically monitored.

RESULTS

Between January 2005 and December 2015, 289 blood donors with Cardiorisk ≥20 were identified, 249 of whom were included in the study with at least 2 years of follow-up. Among these, 36 (14.5%) had instrumental abnormality tests and developed adverse cardiovascular events (10 acute coronary syndrome, 2 cerebral ischemia, 3 cardiac arrhythmia, 8 stenosis of supra-aortic trunks or iliac arteries) during a median follow-up of 5.3 years. In this group of 249 high risk individuals, a statistically significant association (P=0.02) was found between the non-O blood type and the risk of developing subclinical or clinical cardiovascular events (odds ratio, 3.3; 95% CI, 1.1-10.1; P=0.033).

CONCLUSIONS

The results of this study underline the both key role of ABO blood group for the risk of developing arterial thrombotic events and the need for including such unmodifiable variable on the scores assessing the thrombotic risk.

The prognostic value of ABO blood group in cancer patients

The antigens of the ABO system are expressed on red blood cell membranes as well as on the surface of several other normal and pathological cells and tissues. Following the first clinical observations more than 60 years ago, the role of ABO blood group in cancer biology has been intensely studied by several investigators, and it is now widely recognised that ABO antigens are associated with the risk of developing several types of tumours, namely pancreatic and gastric cancers. However, whether this association also affects the clinical outcome of cancer patients is less certain. In this narrative review, based on literature data, we discuss the role of ABO blood types as prognostic biomarkers in different types of cancers. The current knowledge of the underlying pathogenic mechanisms of the association is also analysed.

Chemical Basis for Qualitative and Quantitative Differences Between ABO Blood Groups and Subgroups: Implications for Organ Transplantation

Blood group ABH(O) carbohydrate antigens are carried by precursor structures denoted type I-IV chains, creating unique antigen epitopes that may differ in expression between circulating erythrocytes and vascular endothelial cells. Characterization of such differences is invaluable in many clinical settings including transplantation. Monoclonal antibodies were generated and epitope specificities were characterized against chemically synthesized type I-IV ABH and related glycans. Antigen expression was detected on endomyocardial biopsies (n = 50) and spleen (n = 11) by immunohistochemical staining and on erythrocytes by flow cytometry. On vascular endothelial cells of heart and spleen, only type II-based ABH antigens were expressed; type III/IV structures were not detected. Type II-based ABH were expressed on erythrocytes of all blood groups. Group A1 and A2 erythrocytes additionally expressed type III/IV precursors, whereas group B and O erythrocytes did not. Intensity of A/B antigen expression differed among group A1 , A2 , A1 B, A2 B and B erythrocytes. On group A2 erythrocytes, type III H structures were largely un-glycosylated with the terminal "A" sugar α-GalNAc. Together, these studies define qualitative and quantitative differences in ABH antigen expression between erythrocytes and vascular tissues. These expression profiles have important implications that must be considered in clinical settings of ABO-incompatible transplantation when interpreting anti-ABO antibodies measured by hemagglutination assays with reagent erythrocytes.

Fucosyltransferase 2: a genetic risk factor for primary sclerosing cholangitis and Crohn's disease--a comprehensive review

Fucosyltransferase 2 (FUT2) mediates the inclusion of fucose in sugar moieties of glycoproteins and glycolipids. ABO blood group antigens and host-microbe interactions are influenced by FUT2 activity. About 20 % of the population has a "non-secretor" status caused by inactivating variants of FUT2 on both alleles. The non-sense mutation G428A and the missense mutation A385T are responsible for the vast majority of the non-secretor status in Caucasians, Africans, and Asians, respectively. Non-secretor individuals do not secrete fucose-positive antigens and lack fucosylation in epithelia. They also appear to be protected against a number of infectious diseases, such as Norovirus and Rotavirus infections. In recent years, genome-wide association studies (GWAS) identified inactivating variants at the FUT2 locus to be associated with primary sclerosing cholangitis (PSC), Crohn's disease (CD), and biochemical markers of biliary damage. These associations are intriguing given the important roles of fucosylated glycans in host-microbe interactions and membrane stability. Non-secretors have a reduced fecal content of Bifidobacteria. The intestinal bacterial composition of CD patients resembles the one of non-secretors, with an increase in Firmicutes and decreases in Proteobacteria and Actinobacteria. Non-secretor individuals lack fucosylated glycans at the surface of biliary epithelium and display a different bacterial composition of bile compared to secretors. Notably, an intact biliary epithelial glycocalix is relevant for a stable 'biliary HCO3 (-) umbrella' to protect against toxic effects of hydrophobic bile salt monomers. Here, the biology of FUT2 will be discussed as well as hypotheses to explain the role of FUT2 in the pathophysiology of PSC and Crohn's disease.

Evolutionary aspects of ABO blood group in humans

The antigens of the ABO blood group system (A, B and H determinants) are complex carbohydrate molecules expressed on red blood cells and on a variety of other cell lines and tissues. Growing evidence is accumulating that ABO antigens, beyond their key role in transfusion medicine, may interplay with the pathogenesis of many human disorders, including infectious, cardiovascular and neoplastic diseases. In this narrative review, after succinct description of the current knowledge on the association between ABO blood groups and the most severe diseases, we aim to elucidate the particularly intriguing issue of the possible role of ABO system in successful aging. In particular, focus will be placed on studies evaluating the ABO phenotype in centenarians, the best human model of longevity.

The intriguing relationship between the ABO blood group, cardiovascular disease, and cancer

Other than being present at the surface of red blood cells, the antigens of the ABO blood group system are efficiently expressed by a variety of human cells and tissues. Several studies recently described the involvement of the ABO blood group in the pathogenesis of many human disorders, including cardiovascular disease and cancer, so that its clinical significance extends now beyond the traditional boundaries of transfusion medicine. In a large cohort study recently published in BMC Medicine and including over 50,000 subjects, Etemadi and colleagues reported that nearly 6% of total deaths and as many as 9% of cardiovascular deaths could be attributed to having non-O blood groups, a condition that was also found to be associated with increased risk of gastric cancer. In this commentary, the clinical implications of ABO blood groups are critically discussed and a possible common pathogenic mechanism involving the von Willebrand factor is described.

Is ABO blood group truly a risk factor for thrombosis and adverse outcomes?

ABO blood type is one of the most readily available laboratory tests, and serves as a vital determinant in blood transfusion and organ transplantation. The ABO antigens are expressed not only on red blood cell membranes, determining the compatibility of transfusion, but also on the surface of other human cells, including epithelium, platelet and vascular endothelium, therefore extending the research into other involvements of cardiovascular disease and postoperative outcomes. ABO blood group has been recognized as a risk factor of venous thrombosis embolism since the 1960’s, effects now understood to be related to ABO dependent variations are procoagulant factor VIII (FVIII) and von Willebrand factor (vWF) levels. Levels of vWF, mostly genetically determined, are strongly associated with venous thromboembolism (VTE). It mediates platelet adhesion aggregation and stabilizes FVIII in plasma. Moreover, many studies have tried to identify the relationship between ABO blood types and ischemic heart disease. Unlike the clear and convincing associations between VTE and ABO blood type, the link between ABO blood type and ischemic heart disease is less consistent and may be confusing. Other than genetic factors, ischemic heart disease is strongly related to diet, race, lipid metabolism and economic status. In this review, we’ll summarize the data relating race and genetics, including ABO blood type, to VTE, ischemic heart disease and postoperative bleeding after cardiac surgery.

ABO blood group and thrombotic vascular disease

ABO blood group antigens are complex carbohydrate molecules expressed on red blood cells and a variety of tissues. The ABO blood type is implicated in the development of a number of human diseases and there is increasing evidence regarding its involvement in the pathogenesis of cardiovascular disorders, mainly through its effect on von Willebrand factor levels. In this review, after a brief analysis of the potential molecular mechanisms by which the blood group influences haemostasis, we focus on the clinical implications of such interaction. Overall, the literature data document the close relationship between venous thromboembolism (VTE) and non-O blood type, which is associated with an approximately two-fold increased risk of venous thrombosis. A supra-additive effect on VTE risk is observed when an inherited thrombophilic condition is associated with non-O blood group. A weaker association exists between non-O blood type and arterial thrombosis, which needs to be further investigated.

ABO blood type A is associated with increased risk of ARDS in whites following both major trauma and severe sepsis

BACKGROUND

ABO glycosyltransferases catalyze antigen modifications on various glycans and glycoproteins and determine the ABO blood types. Blood type A has been associated with increased risk of vascular diseases and differential circulating levels of proteins related to inflammation and endothelial function. The objective of this study was to determine the association of ABO blood types with ARDS risk in patients with major trauma and severe sepsis.

METHODS

We conducted prospective cohort studies in two populations at an urban tertiary referral, level I trauma center. Critically ill patients (n 5 732) presenting after major trauma were followed for 5 days for ARDS development. Additionally, 976 medical patients with severe sepsis were followed for 5 days for ARDS. Multivariable logistic regression was used to adjust for confounders.

RESULTS

ARDS developed in 197 of the 732 trauma patients (27%). Blood type A was associated with increased ARDS risk among whites (37% vs 24%; adjusted OR, 1.88; 95% CI, 1.14-3.12; P 5 .014), but not blacks (adjusted OR, 0.61; 95% CI, 0.33-1.13; P=.114). ARDS developed in 222 of the 976 patients with severe sepsis (23%). Blood type A was also associated with an increased ARDS risk among whites (31% vs 21%; adjusted OR, 1.67; 95% CI, 1.08-2.59; P=.021) but, again, not among blacks (adjusted OR, 1.17; 95% CI, 0.59-2.33; P=.652).

CONCLUSIONS

Blood type A is associated with an increased risk of ARDS in white patients with major trauma and severe sepsis. These results suggest a role for ABO glycans and glycosyltransferases in ARDS susceptibility.

Selective proliferation of intestinal Barnesiella under fucosyllactose supplementation in mice

The oligosaccharides 2-fucosyllactose and 3-fucosyllactose are major constituents of human breast milk but are not found in mouse milk. Milk oligosaccharides have a prebiotic action, thus affecting the colonisation of the infant intestine by microbiota. To determine the specific effect of fucosyllactose exposure on intestinal microbiota in mice, in the present study, we orally supplemented newborn mice with pure 2-fucosyllactose and 3-fucosyllactose. Exposure to 2-fucosyllactose and 3-fucosyllactose increased the levels of bacteria of the Porphyromonadaceae family in the intestinal gut, more precisely members of the genus Barnesiella as analysed by 16S pyrosequencing. The ability of Barnesiella to utilise fucosyllactose as energy source was confirmed in bacterial cultures. Whereas B. intestinihominis and B. viscericola did not grow on fucose alone, they proliferated in the presence of 2-fucosyllactose and 3-fucosyllactose following the secretion of linkage-specific fucosidase enzymes that liberated lactose. The change in the composition of intestinal microbiota mediated by fucosyllactose supplementation affected the susceptibility of mice to dextran sulphate sodium-induced colitis, as indicated by increased resistance of mice subjected to 2-fucosyllactose supplementation for 6 weeks. The present study underlines the ability of specific milk oligosaccharides to change the composition of intestinal microbiota and thereby to shape an intestinal milieu resilient to inflammatory diseases.

ABO Blood Groups and Cardiovascular Diseases

ABO blood groups have been associated with various disease phenotypes, particularly cardiovascular diseases. Cardiovascular diseases are the most common causes of death in developed countries and their prevalence rate is rapidly growing in developing countries. There have been substantial historical associations between non-O blood group status and an increase in some cardiovascular disorders. Recent GWASs have identified ABO as a locus for thrombosis, myocardial infarction, and multiple cardiovascular risk biomarkers, refocusing attention on mechanisms and potential for clinical advances. As we highlight in this paper, more recent work is beginning to probe the molecular basis of the disease associations observed in these observational studies. Advances in our understanding of the physiologic importance of various endothelial and platelet-derived circulating glycoproteins are elucidating the mechanisms through which the ABO blood group may determine overall cardiovascular disease risk. The role of blood group antigens in the pathogenesis of various cardiovascular disorders remains a fascinating subject with potential to lead to novel therapeutics and prognostics and to reduce the global burden of cardiovascular diseases.

ABO blood group, hypercoagulability, and cardiovascular and cancer risk

The antigens of the ABO system (A, B, and H determinants, respectively) consist of complex carbohydrate molecules. It has been known for nearly half a century that the ABO blood group exerts a major influence on plasma levels of the von Willebrand factor (VWF)-factor VIII (FVIII) complex and that normal group O individuals have significantly lower levels of VWF and FVIII than do non-O individuals. As a consequence, several investigators have studied the association between ABO blood group and the risk of developing bleeding or thrombotic events. A number of epidemiological studies have also analyzed the biologic relevance of this interaction by assessing whether the ABO blood group could influence human longevity through the regulation of VWF-FVIII plasma levels. In this review, the molecular mechanisms by which the ABO blood group determines plasma VWF and consequently, FVIII levels, the possible clinical implications, and the current knowledge on the association between the ABO blood group and the risk of developing certain cancers will be reviewed.

Relationship between ABO blood group and von Willebrand factor levels: from biology to clinical implications

Although a number of studies have demonstrated the influence of ABO blood group on plasma levels of von Willebrand factor (VWF), the nature of this association and its clinical importance is still largely unknown.

In this review, the most recent advances in our understanding of the mechanisms by which ABO blood group determines plasma VWF levels and their clinical impact will be discussed.

ABO blood group determines plasma von Willebrand factor levels: a biologic function after all?

For many years, an association between ABO histo-blood group and risk of thrombosis has been recognized. Blood group non-O (A, B, and AB) individuals have consistently been found to demonstrate increased incidence of both arterial and venous thrombotic disease, compared to group O individuals. This increased risk is attributable to the fact that ABO blood group influences plasma levels of a coagulation glycoprotein named von Willebrand factor (VWF). VWF levels are 25 percent higher in non-O compared to group O individuals. The mechanism by which ABO group determines plasma VWF levels has not been determined. ABO(H) carbohydrate antigenic determinants, however, are expressed on the N-linked glycan chains of circulating plasma VWF. This review will focus on the carbohydrate structures of VWF and recent studies suggesting that subtle variations in these structures (particularly differences in ABO blood group antigen expression) may have clinically significant effects on VWF proteolysis and clearance.