Akkermansia muciniphila exoglycosidases target extended blood group antigens to generate ABO-universal blood.

Matching donor and recipient blood groups based on red blood cell (RBC) surface ABO glycans and antibodies in plasma is crucial to avoid potentially fatal reactions during transfusions. Enzymatic conversion of RBC glycans to the universal group O is an attractive solution to simplify blood logistics and prevent ABO-mismatched transfusions. The gut symbiont Akkermansia muciniphila can degrade mucin O-glycans including ABO epitopes.

Truncated glycosyltransferase coding regions in novel ABO alleles give rise to weak A or B blood group expression and discrepant typing results.

Background: Correct ABO blood-group matching between donor and patient is crucial for safe transfusions. We investigated the underlying reason causing inconclusive ABO serology in samples referred to our laboratory.

Study Design And Methods: Flow cytometric analysis, ABO genotyping, and sequencing were used to characterize ABO-discrepant blood samples (n = 13).

ABO Genotyping finds more A to B kidney transplant opportunities than lectin-based subtyping.

ABO compatibility is important for kidney transplantation, with longer waitlist times for blood group B kidney transplant candidates. However, kidneys from non-A (eg, A) subtype donors, which express less A antigen, can be safely transplanted into group B recipients. ABO subtyping is routinely performed using anti-A lectin, but DNA-based genotyping is also possible.

Network pharmacology of triptolide in cancer cells: implications for transcription factor binding.

Background Triptolide is an active natural product, which inhibits cell proliferation, induces cell apoptosis, suppresses tumor metastasis and improves the effect of other therapeutic treatments in several cancer cell lines by affecting multiple molecules and signaling pathways, such as caspases, heat-shock proteins, DNA damage and NF-ĸB. Purpose We investigated the effect of triptolide towards NF-ĸB and GATA1. Methods We used cell viability assay, compare and cluster analyses of microarray-based mRNA transcriptome-wide expression data, gene promoter binding motif analysis, molecular docking, Ingenuity pathway analysis, NF-ĸB reporter cell assay, and electrophoretic mobility shift assay (EMSA) of GATA1.

A novel ABO allele with a 21-bp duplication identified in two unrelated European individuals with weak A expression.

Objectives: To carry out genetic and serological analyses of a Swiss blood donor and a Danish patient carrying an aberrant ABO phenotype with weak A expression.

Background: ABO is the most clinically important blood group system but also one of the most complex. The system antigens are determined by carbohydrate structures generated by A and B glycosyltransferases encoded by the ABO gene.

May the FORS be with you: a system sequel.

This article is an update of the review of the FORS system published in Immunohematology in 2017 (Hult AK, Olsson ML. The FORS awakens: review of a blood group system reborn. Immunohematology 2017;33:64-72).

GBGT1 is allelically diverse but dispensable in humans and naturally occurring anti-FORS1 shows an ABO-restricted pattern.

Background: The FORS histo-blood group system was described in 2013 and much remains to be investigated regarding its genetic and immunohematologic characteristics, as well as its clinical importance. While presence of the c.887G>A-mutated GBGT1 gene, which results in FORS1 glycosphingolipid expression on human red blood cells (RBCs), is rare in the populations tested so far, naturally occurring anti-FORS1 in plasma appears common.

The FORS awakens: review of a blood group system reborn.

The presence of the FORS1 antigen on red blood cells was discovered relatively recently, and in 2012, the International Society of Blood Transfusion (ISBT) acknowledged FORS as blood group system number 031. This rare antigen is carried by a glycosphingolipid and formed by elongation of the P antigen. Most people have naturally occurring anti-FORS1 in their plasma.

Identification of the Molecular and Genetic Basis of PX2, a Glycosphingolipid Blood Group Antigen Lacking on Globoside-deficient Erythrocytes.

The x2 glycosphingolipid is expressed on erythrocytes from individuals of all common blood group phenotypes and elevated on cells of the rare P/P1/P(k)-negative p blood group phenotype. Globoside or P antigen is synthesized by UDP-N-acetylgalactosamine:globotriaosyl-ceramide 3-β-N-acetylgalactosaminyltransferase encoded by B3GALNT1. It is the most abundant non-acid glycosphingolipid on erythrocytes and displays the same terminal disaccharide, GalNAcβ3Gal, as x2.

RIFINs are adhesins implicated in severe Plasmodium falciparum malaria.

Rosetting is a virulent Plasmodium falciparum phenomenon associated with severe malaria. Here we demonstrate that P. falciparum-encoded repetitive interspersed families of polypeptides (RIFINs) are expressed on the surface of infected red blood cells (iRBCs), where they bind to RBCs--preferentially of blood group A--to form large rosettes and mediate microvascular binding of iRBCs.

Do ABO blood group antigens hamper the therapeutic efficacy of mesenchymal stromal cells?

Investigation into predictors for treatment outcome is essential to improve the clinical efficacy of therapeutic multipotent mesenchymal stromal cells (MSCs). We therefore studied the possible harmful impact of immunogenic ABO blood groups antigens - genetically governed antigenic determinants - at all given steps of MSC-therapy, from cell isolation and preparation for clinical use, to final recipient outcome. We found that clinical MSCs do not inherently express or upregulate ABO blood group antigens after inflammatory challenge or in vitro differentiation.

Forssman expression on human erythrocytes: biochemical and genetic evidence of a new histo-blood group system.

In analogy with histo-blood group A antigen, Forssman (Fs) antigen terminates with α3-N-acetylgalactosamine and can be used by pathogens as a host receptor in many mammals. However, primates including humans lack Fs synthase activity and have naturally occurring Fs antibodies in plasma. We investigated individuals with the enigmatic ABO subgroup A(pae) and found them to be homozygous for common O alleles.

ABO blood groups influence macrophage-mediated phagocytosis of Plasmodium falciparum-infected erythrocytes.

Erythrocyte polymorphisms associated with a survival advantage to Plasmodium falciparum infection have undergone positive selection. There is a predominance of blood group O in malaria-endemic regions, and several lines of evidence suggest that ABO blood groups may influence the outcome of P. falciparum infection.

Flow cytometry evaluation of red blood cells mimicking naturally occurring ABO subgroups after modification with variable amounts of function-spacer-lipid A and B constructs.

Background: Kodecytes bearing synthetic blood group A and B antigens are increasingly being used in transfusion laboratories as serologic mimics of red blood cell (RBC) A(weak) and B(weak) subtypes. The aim of this study was to compare the flow cytometry profile of kodecytes with native ABO subgroups.

Study Design And Methods: A series of A/B kodecytes, each with decreasing A or B antigen expression, were prepared from group O RBCs that were modified with dilutions of function-spacer-lipid KODE technology (FSL) constructs representing a wide serologic range.

Weak A phenotypes associated with novel ABO alleles carrying the A2-related 1061C deletion and various missense substitutions.

Background: The 1061delC single-nucleotide polymorphism (SNP) has been reported mostly in the context of the common A(2)[A201] allele and typically produces an A(2) phenotype. This study evaluated new A(weak) alleles, each containing 1061delC.

Study Design And Methods: Twenty samples were referred to our laboratory for analysis due to suspected A(weak) phenotypes originally detected at the referring centers.

Many genetically defined ABO subgroups exhibit characteristic flow cytometric patterns.

Background: A flow cytometric method for detection of low levels of A/B antigen had been developed previously in our laboratory. The aim of this study was to investigate if this approach could be utilized to characterize different ABO subgroups and constitute a useful tool in a reference laboratory.

Study Design And Methods: Blood samples causing ABO discrepancies (n = 94) by routine serology were further analyzed by ABO genotyping and flow cytometry.

Investigation into A antigen expression on O2 heterozygous group O-labeled red blood cell units.

Background: There are two principal types of group O alleles; deletional alleles feature 261delG leading to nonfunctional truncated protein. Nondeletional alleles have the consensus guanosine at residue 261. The major nondeletional allele, O2, encodes full-length protein with Gly268Arg.