International Society of Blood Transfusion Working Party on red cell immunogenetics and blood group terminology: Cancun report (2012)

Application of a simplified PCR-SSP method to detect A4GALT*01 and A4GALT*02 typing among Thai blood donors

OBJECTIVES

An intronic A4GALT single nucleotide variant, rs5751348:G>T, P2 or A4GALT*02 allele has a lower level of the enzyme-encoding A4GALT transcripts than the P1 individuals. Here, we first develop and validate a simple inhouse PCR-SSP method to detect A4GALT*01 and A4GALT*02 alleles, and second, apply this method to compare the allele frequencies between Thai and other populations.

MATERIAL AND METHODS

The conventional test tube technique was used to detect the P1 antigen in 222 blood samples from Thai blood donors at Thammasat University Hospital. A PCR-SSP method was optimized and validated for reproducibility and specificity to identify these alleles and was subsequently tested on 1,840 DNA samples of unknown phenotypes obtained from central, northern and southern Thais. In addition, allele frequencies of central Thais were compared with those of other populations.

RESULTS

In the tested cohort (n = 222), P1 and P2 phenotypes were typed in 26.13 and 73.87% of donors, respectively. The developed PCR-SSP was successfully optimized, and the outcomes were consistent with those of serological phenotyping and DNA sequencing results, demonstrating its validity for predicting P1/P2 phenotype. For central, northern and southern Thais, the A4GALT*01 frequency was 0.1579 (430/2,724), 0.1183 (71/600), and 0.2575 (206/800), whereas the A4GALT*02 frequency was 0.8421 (2,294/2,724), 0.8817 (529/600), and 0.7425 (594/800), respectively. Their observed frequencies among central Thais significantly differed from those in other populations (p < 0.05).

CONCLUSION

Our study has successfully developed a simple, precise, and reliable method to genotype A4GALT*01 and A4GALT*02 using inhouse developed PCR-SSP for predicting P1/P2 status.

Mixed-Up Sugars: Glycosyltransferase Cross-Reactivity in Cancerous Tissues and Their Therapeutic Targeting

The main categories of glycan changes in cancer are: (1) decreased expression of histo-blood group A and/or B antigens and increased Lewis-related antigens, (2) appearance of cryptic antigens, such as Tn and T, (3) emergence of genetically incompatible glycans, such as A antigen expressed in tumors of individuals of group B or O and heterophilic expression of Forssman antigen (FORS1), and (4) appearance of neoglycans. This review focuses on the expression of genetically incompatible A/B/FORS1 antigens in cancer. Several possible molecular mechanisms are exemplified, including missense mutations that alter the sugar specificity of A and B glycosyltransferases (AT and BT, respectively), restoration of the correct codon reading frame of O alleles, and modification of acceptor specificity of AT to synthesize the FORS1 antigen by missense mutations and/or altered splicing. Taking advantage of pre-existing natural immunity, the potential uses of these glycans for immunotherapeutic targeting will also be discussed.

Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology

Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H⁺ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b^0,+AT-rBAT and the SLC6 family heteromer B⁰AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.

Anti-Lan Antibodies: A Rare Etiology of Severe Blood Transfusion Reaction

Lan is a high prevalence red blood cell antigen present in the majority of the populations that belong to the Lan (Langereis) blood group system. Anti-Lan antibody is an immunoglobulin G (IgG) antibody that is known to cause delayed hemolytic transfusion reactions in adults as well as hemolytic disease in fetuses and newborns, however with variable clinical significance ranging from mild to severe. We present a 58-year-old woman with diffuse abdominal pain and a large gastric ulcer causing gastric outlet obstruction. She underwent antrectomy and Billroth I reconstruction surgery without complications. The patient’s hemoglobin upon presentation was 10g/dL and dropped acutely post-operatively to 6.4 g/dL requiring blood transfusion. The patient developed acute respiratory distress within minutes of starting a packed red blood cell (pRBC) transfusion, requiring discontinuation. Laboratory testing demonstrated pan-reactivity with additional reference testing demonstrating an anti-Lan antibody. The rarity of Lan negative pRBC units is a challenge in managing such patients requiring blood transfusions. Autologous blood donation or donation by a compatible family member is another option to consider in these rare cases.

Three non-classical mechanisms for anemic disease of the fetus and newborn, based on maternal anti-Kell, anti-Ge3, anti-M, and anti-Jra cases

Maternal alloantibody-mediated hemolytic disease of the fetus and newborn (HDFN) ranges from no or mild symptoms to severe hydrops and intrauterine fetal demise. Hemolytic anti-D-mediated HDFN proceeds via a long-known mechanism, to which three other pathways to fetal/neonatal anemia may be added: (0) Fetal erythrocyte destruction can proceed by extravascular phagocytosis. (1) An apoptotic pathway has been described for anti-Kell, and anti-Ge3. (2) Erythropoietic suppression may arise from altered or deformed erythroblast architecture in anti-M-mediated disease. (3) Clonal escape from erythropoietic suppression is hypothesized to arise from maternal anti-Jr^a immune pressure, albeit this requires further elucidation. Alloantibody-mediated anemic disease of the fetus and newborn (ADFN) is a designation we favor for cases when hemolysis or hyperbilirubinemia are not the dominant features, such as those provoked by anti-Kell, anti-Ge3, anti-M, and anti-Jr^a.

Characterization of sheep erythrocyte glycosphingolipids recognized by human anti-Forssman antibodies

The FORS histo-blood group system is the most recently discovered carbohydrate-based human blood group system. FORS is a rare blood group system, and most individuals have naturally occurring anti-FORS1 antibodies in plasma. Screening for anti-FORS1 antibodies is often done by hemagglutination assays using FORS1-expressing sheep erythrocytes, since FORS1-positive human erythrocytes are most often not available. Here, we have characterized the non-acid glycosphingolipids from sheep erythrocytes and isolated subfractions, with mass spectrometry, binding of antibodies and lectins, and by enzymatic hydrolysis. This demonstrated the presence of Forssman and Galili pentaosylceramides, and a Galili heptaosylceramide. Two complex glycosphingolipids recognized by human anti-FORS1 antibodies were characterized as a Forssman neolacto hybrid hexaosylceramide (GalNAcα3GalNAcβ3Galβ4GlcNAcβ3Galβ4Glcβ1Cer) and a Forssman Galili hybrid heptaosylceramide (GalNAcα3GalNAcβ3Galα3Galβ4GlcNAcβ3Galβ4Glcβ1Cer). These are novel glycosphingolipid structures, and to our knowledge, the first case of an elongated Galili antigen. Thus, the anti-Forssman antibodies in human serum bind not only to the classical Forssman pentaosylceramide (GalNAcα3GalNAcβ3Galα4Galβ4Glcβ1Cer), but also when the GalNAcα3GalNAcβ3 sequence is presented on a neolacto core chain and even on a Galili carbohydrate sequence.

Association of ABO blood group and antituberculosis drug-induced liver injury: A case-control study from a Chinese Han population

WHAT IS KNOWN AND OBJECTIVE

Antituberculosis drug-induced liver injury (ATLI) is a serious adverse drug reaction, and its pathogenic mechanism is still largely unknown. Rifampin (RIF) has been reported to cause haemolysis due to the production of drug-dependent antibodies, and haemolysis results in an increased level of free haem, which affects the function of hepatocytes. Blood group determinants can act as specific receptor sites for drug-antibody complexes, causing erythrocyte destruction in the presence of RIF. RIF-induced immune haemolysis may be a potential mechanism for ATLI. Thus, the study aimed to explore the role of ABO blood group systems in Chinese ATLI patients.

METHODS

A 1:4 matched case-control study was conducted among 146 ATLI cases and 584 controls. Multivariable conditional logistic regression and Cox proportional regression were used to estimate the association between ABO blood group and risk of ATLI by odds ratio (OR), hazards ratio (HR) and 95% confidence intervals (CIs), and liver disease history and taking hepatoprotectant were used as covariates.

RESULTS AND DISCUSSION

Patients in the A, B, AB and non-O blood groups had a significantly higher risk of ATLI than those in the O blood group (OR = 1.832, 95% CI: 1.126-2.983, P = .015; OR = 1.751, 95% CI: 1.044-2.937, P = .034; OR = 2.059, 95% CI: 1.077-3.938, P = .029; OR = 1.822, 95% CI: 1.173-2.831, P = .007, respectively). After considering the time of ALTI occurrence, similar results were found in the A, B, AB and non-O blood groups (HR = 1.676, 95% CI: 1.072-2.620, P = .024; HR = 1.620, 95% CI: 1.016-2.584, P = .043; HR = 2.010, 95% CI: 1.130-3.576, P = .018; HR = 1.701, 95% CI: 1.138-2.542, P = .010, respectively). Furthermore, subgroup analysis also detected a significant association between ABO blood group and ATLI in patients taking RIF (P < .05). However, no significant difference was observed in patients not taking RIF (P > .05).

WHAT IS NEW AND CONCLUSION

The present study is the first to evaluate the role of ABO blood group systems in Chinese ATLI cases. Based on the present matched case-control study, the ABO blood group may be associated with susceptibility to ATLI in the Chinese antituberculosis population, especially in patients with blood groups A, B and AB who are taking RIF.

Blood Donation During Pregnancy Due to Anti-Ku Hemolytic Disease of the Fetus and Newborn

BACKGROUND

Management of pregnancy in patients with Kell-null phenotype can be challenging. The immune systems of these patients form an antibody that is universally reactive against the Kell Blood Group System and can cause hemolytic disease of the fetus and newborn.

METHODS

A 29-year-old woman, pregnant for the first time, developed anti-D and anti-Ku. The mother had to have labor induced when her fetus showed signs of severe anemia, but no compatible blood was available for transfusion. The induction was delayed so that a unit of blood could be collected from the mother.

RESULTS

Due to delayed cord clamping at delivery, the newborn did not have anemia and did not require a transfusion. The remaining blood was frozen for future needs.

CONCLUSION

Blood donation by a pregnant woman for potential transfusion to a newborn with anemia is safe for the mother and fetus, and is possibly the only option in hemolytic disease of the newborn due to a rare antibody.

Molecular and computational analysis of 45 samples with a serologic weak D phenotype detected among 132,479 blood donors in northeast China

Background

RH1 is one of the most clinically important blood group antigens in the field of transfusion and in the prevention of fetal incompatibility. The molecular analysis and characterization of serologic weak D phenotypes is essential to ensuring transfusion safety.

Methods

Blood samples from a northeastern Chinese population were randomly screened for a serologic weak D phenotype. The nucleotide sequences of all 10 exons, adjacent flanking intronic regions, and partial 5′ and 3′ untranslated regions (UTRs) were detected for RHD genes. Predicted deleterious structural changes in missense mutations of serologicl weak D phenotypes were analyzed using SIFT, PROVEAN and PolyPhen2 software. The protein structure of serologic weak D phenotypes was predicted using Swiss-PdbViewer 4.0.1.

Results

A serologic weak D phenotype was found in 45 individuals (0.03%) among 132,479 blood donors. Seventeen distinct RHD mutation alleles were detected, with 11 weak D, four partial D and two DEL alleles. Further analyses resulted in the identification of two novel alleles (RHD weak D 1102A and 399C). The prediction of a three-dimensional structure showed that the protein conformation was disrupted in 16 serologic weak D phenotypes.

Conclusions

Two novel and 15 rare RHD alleles were identified. Weak D type 15, DVI Type 3, and RHD1227A were the most prevalent D variant alleles in a northeastern Chinese population. Although the frequencies of the D variant alleles presented herein were low, their phenotypic and genotypic descriptions add to the repertoire of reported RHD alleles. Bioinformatics analysis on RhD protein can give us more interpretation of missense variants of RHD gene.

Long-range haplotype analysis of the malaria parasite receptor gene ACKR1 in an East-African population

The human ACKR1 gene encodes a glycoprotein expressing the Duffy blood group antigens (Fy). The Duffy protein acts as a receptor for distinct pro-inflammatory cytokines and malaria parasites. We determined the haplotypes of the ACKR1 gene in a population inhabiting a malaria-endemic area. We collected blood samples from 60 healthy volunteers in Ethiopia’s southwestern low-altitude tropical region. An assay was devised to amplify the ACKR1 gene as a single amplicon and determine its genomic sequence. All haplotypes were resolved at 5178 nucleotides each, covering the coding sequence (CDS) of the ACKR1 gene and including the 5′- and 3′-untranslated regions (UTR), intron 1, and the 5′- and 3′-flanking regions. When necessary, allele-specific PCR with nucleotide sequencing or length polymorphism analysis was applied. Among the 120 chromosomes analyzed, 18 ACKR1 alleles were confirmed without ambiguity. We found 18 single-nucleotide polymorphisms (SNPs); only one SNP was novel. The non-coding sequences harbored 14 SNPs. No SNP, other than c.-67T>C, indicative of a non-functional allele, was detected. We described haplotypes of the ACKR1 gene in an autochthonous East-African population and found 18 distinct ACKR1 alleles. These long-range alleles are useful as templates to phase and analyze next-generation sequencing data, thus enhancing the reliability of clinical diagnostics.

Researchers have surveyed genetic diversity related to malaria resistance in a region of Ethiopia where malaria is endemic. Duffy antigens, a component of blood type, are encoded by the ACKR1 gene, and individuals with the Duffy-negative blood type are resistant to malaria. Although the genes encoding resistant types have been identified, they have not been fully surveyed in malaria-endemic regions, where novel types are most likely to be found. Willy Flegel at the National Institutes of Health, Bethesda, USA, and co-workers sequenced ACKR1 in 60 people from Gambela, Ethiopia, where malaria is endemic. They detected 18 variants, including one never before documented. Almost all (16 of 18) of the variants encoded the Duffy-negative blood type. The authors plan to compare the genetic diversity in this region with a nearby region where malaria is not endemic.

Blood transcriptomic markers of Mycobacterium tuberculosis load in sputum

BACKGROUND

Peripheral blood transcriptome signatures that distinguish active pulmonary tuberculosis (TB) from control groups have been reported, but correlations of these signatures with sputum mycobacterial load are incompletely defined.

METHODS

We assessed the performance of published TB transcriptomic signatures in Haiti, and identified transcriptomic biomarkers of TB bacterial load in sputum as measured by Xpert® MTB/RIF molecular testing. People in Port au Prince, Haiti, with untreated pulmonary TB (n = 51) formed the study cohort: 19 people with low and 32 with high sputum Mycobacterium tuberculosis load. Peripheral whole blood transcriptomes were generated using RNA sequencing.

RESULTS

Twenty of the differentially expressed transcripts in TB vs. no TB were differentially expressed in people with low vs. high sputum mycobacterial loads. The difference between low and high bacterial load groups was independent of radiographic severity. In a published data set of transcriptomic response to anti-tuberculosis treatment, this 20-gene subset was more treatment-responsive at 6 months than the full active TB signature.

CONCLUSION

We identified genes whose transcript levels in the blood distinguish active TB with high vs. low M. tuberculosis loads in the sputum. These transcripts may reveal mechanisms of mycobacterial control of M. tuberculosis during active infection, as well as identifying potential biomarkers for bacterial response to anti-tuberculosis treatment.

Transfusion Medicine and Molecular Genetic Methods

Transfusion procedures are always complicated by potential genetic mismatching between donor and recipient. Compatibility is determined by several major antigens, such as the ABO and Rhesus blood groups. Matching for other blood groups (Kell, Kidd, Duffy, and MNS), human platelet antigens, and human leukocyte antigens (HLAs) also contributes toward the successful transfusion outcomes, especially in multitransfused or highly immunized patients. All these antigens of tissue identity are highly polymorphic and thus present great challenges for finding suitable donors for transfusion patients. The ABO blood group and HLA markers are also the determinants of transplant compatibility, and mismatched antigens will cause graft rejection or graft-versus-host disease. Thus, a single and comprehensive registry covering all of the significant transfusion and transplantation antigens is expected to become an important tool in providing an efficient service capable of delivering safe blood and quickly locating matching organs/stem cells. This review article is intended as an accessible guide for physicians who care for transfusion-dependent patients. In particular, it serves to introduce the new molecular screening methods together with the biology of these systems, which underlies the tests.

Peritransplantation Red Blood Cell Transfusion Is Associated with Increased Risk of Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

More than 90% of allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients receive red blood cell (RBC) or platelet transfusions in the peritransplantation period. We tested the hypothesis that transfusions are associated with the development of severe (grade III-IV) acute graft-versus-host disease (aGVHD) or mortality after allo-HSCT in a retrospective study of 322 consecutive patients receiving an allogeneic bone marrow or granulocyte colony-stimulating factor-mobilized blood stem cell graft for a hematologic malignancy. Counting transfused RBC and platelet units between day -7 pretransplantation and day +27 post-transplantation, but excluding transfusions administered after a diagnosis of aGVHD, yielded medians of 5 RBC units and 2 platelet units transfused. Sixty-three patients (20%) developed a maximal grade III-IV aGVHD with onset up to day +150 post-transplantation (median aGVHD onset of 28 days). HLA mismatch (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.2 to 4.7; P = .01), and transfusion of more than the median number of RBC units (HR, 2.1; 95% CI, 1.1 to 3.7; P = .02) were independently associated with greater risk of grade III-IV aGVHD in a multivariable analysis model. Disease risk strata (HR, 1.7; 95% CI, 1.2 to 2.4 for high risk versus low risk; P = .005) and transfusion of more than the median number of RBC units (HR, 1.4; 95% CI, 1.0 to 2.0; P = .054) were independently associated with inferior overall survival. These data support our hypothesis that peritransplantation RBC transfusions are associated with the risk of developing severe aGVHD and worse overall survival following allo-HSCT, and suggest that strategies to reduce routine RBC transfusion may favorably reduce the incidence and severity of GVHD.

Transfusion strategy for weak D Type 4.0 based on RHD alleles and RH haplotypes in Tunisia

BACKGROUND

With more than 460 RHD alleles, this gene is the most complex and polymorphic among all blood group systems. The Tunisian population has the largest known prevalence of weak D Type 4.0 alleles, occurring in one of 105 RH haplotypes. We aimed to establish a rationale for the transfusion strategy of weak D Type 4.0 in Tunisia.

STUDY DESIGN AND METHODS

Donors were randomly screened for the serologic weak D phenotype. The RHD coding sequence and parts of the introns were sequenced. To establish the RH haplotype, the RHCE gene was tested for characteristic single-nucleotide positions.

RESULTS

We determined all RHD alleles and the RH haplotypes coding for the serologic weak D phenotype among 13,431 Tunisian donations. A serologic weak D phenotype was found in 67 individuals (0.50%). Among them, 60 carried a weak D Type 4 allele: 53 weak D Type 4.0, six weak D Type 4.2.2 (DAR), and one weak D Type 4.1. An additional four donors had one variant allele each: DVII, weak D Type 1, weak D Type 3, and weak D type 100, while three donors showed a normal RHD sequence. The weak D Type 4.0 was most often linked to RHCE*ceVS.04.01, weak D Type 4.2.2 to RHCE*ceAR, and weak D Type 4.1 to RHCE*ceVS.02, while the other RHD alleles were linked to one of the common RHCE alleles.

CONCLUSIONS

Among the weak D phenotypes in Tunisia, no novel RHD allele was found and almost 90% were caused by alleles of the weak D Type 4 cluster, of which 88% represented the weak D Type 4.0 allele. Based on established RH haplotypes for variant RHD and RHCE alleles and the lack of adverse clinical reports, we recommend D+ transfusions for patients with weak D Type 4.0 in Tunisia.

Serological weak D phenotypes: a review and guidance for interpreting the RhD blood type using the RHD genotype

Approximately 0·2-1% of routine RhD blood typings result in a "serological weak D phenotype." For more than 50 years, serological weak D phenotypes have been managed by policies to protect RhD-negative women of child-bearing potential from exposure to weak D antigens. Typically, blood donors with a serological weak D phenotype have been managed as RhD-positive, in contrast to transfusion recipients and pregnant women, who have been managed as RhD-negative. Most serological weak D phenotypes in Caucasians express molecularly defined weak D types 1, 2 or 3 and can be managed safely as RhD-positive, eliminating unnecessary injections of Rh immune globulin and conserving limited supplies of RhD-negative RBCs. If laboratories in the UK, Ireland and other European countries validated the use of potent anti-D reagents to result in weak D types 1, 2 and 3 typing initially as RhD-positive, such laboratory results would not require further testing. When serological weak D phenotypes are detected, laboratories should complete RhD testing by determining RHD genotypes (internally or by referral). Individuals with a serological weak D phenotype should be managed as RhD-positive or RhD-negative, according to their RHD genotype.

Molecular typing for blood group antigens within 40 min by direct polymerase chain reaction from plasma or serum

Determining blood group antigens by serological methods may be unreliable in certain situations, such as in patients after chronic or massive transfusion. Red cell genotyping offers a complementary approach, but current methods may take much longer than conventional serological typing, limiting their utility in urgent situations. To narrow this gap, we devised a rapid method using direct polymerase chain reaction (PCR) amplification while avoiding the DNA extraction step. DNA was amplified by PCR directly from plasma or serum of blood donors followed by a melting curve analysis in a capillary rapid-cycle PCR assay. We evaluated the single nucleotide polymorphisms underlying the clinically relevant Fy^a , Fy^b , Jk^a and Jk^b antigens, with our analysis being completed within 40 min of receiving a plasma or serum sample. The positive predictive value was 100% and the negative predictive value at least 84%. Direct PCR with melting point analysis allowed faster red cell genotyping to predict blood group antigens than any previous molecular method. Our assay may be used as a screening tool with subsequent confirmatory testing, within the limitations of the false-negative rate. With fast turnaround times, the rapid-cycle PCR assay may eventually be developed and applied to red cell genotyping in the hospital setting.

Emerging strategies of blood group genotyping for patients with hemoglobinopathies

Red cell alloimmunization is a serious problem in chronically transfused patients. A number of high-throughput DNA assays have been developed to extend or replace traditional serologic antigen typing. DNA-based typing methods may be easily automated and multiplexed, and provide reliable information on a patient. Molecular genotyping promises to become cheaper, being not dependent on serologic immunoglobulin reagents. Patients with hemoglobinopathies could benefit from receiving extended genomic typing. This could limit post transfusional complications depending on subtle antigenic differences between donors and patients. Patient/donor compatibility extended beyond the phenotype Rh/Kell may allows improved survival of transfused units of red blood cells (RBC) and lead to reduced need for blood transfusion and leading to less iron overload and reduced risk of alloimmunization. Here we discuss the advantages and limitations of current techniques, that detect only predefined genetic variants. In contrast, target enrichment next-generation sequencing (NGS) has been used to detect both known and de novo genetic polymorphisms, including single-nucleotide polymorphisms, indels (insertions/deletions), and structural variations. NGS approaches can be used to develop an extended blood group genotyping assay system.

Histo-blood group glycans in the context of personalized medicine

BACKGROUND

A subset of histo-blood group antigens including ABO and Lewis are oligosaccharide structures which may be conjugated to lipids or proteins. They are known to be important recognition motifs not only in the context of blood transfusions, but also in infection and cancer development.

SCOPE OF REVIEW

Current knowledge on the molecular background and the implication of histo-blood group glycans in the prevention and therapy of infectious and non-communicable diseases, such as cancer and cardiovascular disease, is presented.

MAJOR CONCLUSIONS

Glycan-based histo-blood groups are associated with intestinal microbiota composition, the risk of various diseases as well as therapeutic success of, e.g., vaccination. Their potential as prebiotic or anti-microbial agents, as disease biomarkers and vaccine targets should be further investigated in future studies. For this, recent and future technological advancements will be of particular importance, especially with regard to the unambiguous structural characterization of the glycan portion in combination with information on the protein and lipid carriers of histo-blood group-active glycans in large cohorts.

GENERAL SIGNIFICANCE

Histo-blood group glycans have a unique linking position in the complex network of genes, oncodevelopmental biological processes, and disease mechanisms. Thus, they are highly promising targets for novel approaches in the field of personalized medicine. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.

International society of blood transfusion working party on red cell immunogenetics and terminology: report of the Seoul and London meetings

The Working Party has met twice since the last report: in Seoul, South Korea 2014, and in London, UK 2015, both in association with the International Society of Blood Transfusion (ISBT) Congress. As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. Eleven new blood group antigens were added to seven blood group systems. This brings the current total of blood group antigens recognized by the ISBT to 346, of which 308 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known blood group system.

Antigen negative red blood cell inventory of Indian blood donors

BACKGROUND

Screening the donor population for clinically important antigens and creating a database of phenotyped donors will eliminate the tedious task of large scale screening for antigen negative units. The aim of the present study is to identify donors lacking common antigens and a combination of common antigens to establish an antigen negative inventory.

MATERIALS AND METHODS

Blood samples of 1221 regular blood donors were phenotyped for the clinically important common antigens of the Rh, Duffy, Kell, Kidd and MNS blood group systems using standard tube technique.

RESULTS

Out of 1221 total donors tested, we observed that 261 donors lacked a combination of clinically important common antigens (C, D, e, Fya, Jka, s). After excluding the RhD negative donors in this study 15.56% lacked a combination of two or three common antigens. Of all donors, 3.2% lacked Fya and Jka antigens, 1.96% Fya and s, 1.88% Jka and s antigens and 0.57% lacked three common antigens.

DISCUSSION

An antigen negative inventory of donors who lack a single common antigen or a combination of common antigens was prepared from regular donors which will prove useful for efficient management of transfusion therapy in patients with multiple antibodies against common antigens.

Frequencies of polymorphisms of the Rh, Kell, Kidd, Duffy and Diego systems of Santa Catarina, Southern Brazil

Background

Red blood cell genes are highly polymorphic with the distribution of alleles varying between different populations and ethnic groups. The objective of this study was to investigate gene polymorphisms of blood groups in the state of Santa Catarina, Southern Brazil.

Methods

Three hundred and seventy-three unrelated blood donors and 31 transfusion-dependent patients were evaluated to investigate polymorphisms of the Rh, Kell, Duffy, Kidd, and Diego blood group systems in a population from the state of Santa Catarina. The subjects, from seven regions that comprise the blood-banking network of the state, were assessed between August 2011 and March 2014. The genotypes of the Rh, Kell, Duffy, Kidd, and Diego systems were determined using the restriction fragment length polymorphism-polymerase chain reaction and allele-specific polymerase chain reaction techniques.

Results

The genotype frequencies in this study were significantly different when populations from different regions of Santa Catarina were compared. Furthermore, there were also significant differences in the genetic frequencies compared to other Brazilian states. The genotype frequencies of the Kell and Kidd blood groups are similar to European populations from Naples, Italy and Zurich, Switzerland.

Conclusion

This article reports for the first time the frequency of polymorphisms of blood group systems in blood donors from Santa Catarina, Southern Brazil.

The European Hematology Association Roadmap for European Hematology Research: a consensus document

The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap.The EHA Roadmap identifies nine 'sections' in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders.The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.

Comprehensive red blood cell and platelet antigen prediction from whole genome sequencing: proof of principle

BACKGROUND

There are 346 serologically defined red blood cell (RBC) antigens and 33 serologically defined platelet (PLT) antigens, most of which have known genetic changes in 45 RBC or six PLT genes that correlate with antigen expression. Polymorphic sites associated with antigen expression in the primary literature and reference databases are annotated according to nucleotide positions in cDNA. This makes antigen prediction from next-generation sequencing data challenging, since it uses genomic coordinates.

STUDY DESIGN AND METHODS

The conventional cDNA reference sequences for all known RBC and PLT genes that correlate with antigen expression were aligned to the human reference genome. The alignments allowed conversion of conventional cDNA nucleotide positions to the corresponding genomic coordinates. RBC and PLT antigen prediction was then performed using the human reference genome and whole genome sequencing (WGS) data with serologic confirmation.

RESULTS

Some major differences and alignment issues were found when attempting to convert the conventional cDNA to human reference genome sequences for the following genes: ABO, A4GALT, RHD, RHCE, FUT3, ACKR1 (previously DARC), ACHE, FUT2, CR1, GCNT2, and RHAG. However, it was possible to create usable alignments, which facilitated the prediction of all RBC and PLT antigens with a known molecular basis from WGS data. Traditional serologic typing for 18 RBC antigens were in agreement with the WGS-based antigen predictions, providing proof of principle for this approach.

CONCLUSION

Detailed mapping of conventional cDNA annotated RBC and PLT alleles can enable accurate prediction of RBC and PLT antigens from whole genomic sequencing data.

Congenital CD59 Deficiency

The severe clinical symptoms of inherited CD59 deficiency confirm the importance of CD59 as essential complement regulatory protein for protection of cells against complement attack, in particular protection of hematopoietic cells and human neuronal tissue. Targeted complement inhibition might become a treatment option as suggested by a case report. The easy diagnostic approach by flow cytometry and the advent of a new treatment option should increase the awareness of this rare differential diagnosis and lead to further studies on their pathophysiology.

Monoclonal anti-A activity against the FORS1 (Forssman) antigen

BACKGROUND

The FORS blood group system (originally recognized as the Apae phenotype) was discovered by sporadic activity against polyclonal anti-A reagents and activity against the lectin Helix pomatia. The extent of monoclonal anti-A reagent activity against the FORS1 antigen is serologically and immunochemically incomplete.

STUDY DESIGN AND METHODS

In the absence of natural FORS1-positive red blood cells (RBCs), kodecytes were created with synthetic disaccharide and pentasaccharide Forssman function-spacer-lipid (FSL) constructs, Fsdi -kodecytes, and FORS1-kodecytes, respectively. FSL constructs were also applied to solid surfaces and used in solid-phase enzyme immunoassays. A range of characterized monoclonal anti-A and anti-B reagents were then serologically and immunochemically characterized against these Forssman antigens. Polyclonal human anti-A, anti-B, the lectin H. pomatia serologic reagents; and canine RBCs were used as serologic controls.

RESULTS

None of 19 different monoclonal anti-A reagents were able to detect the pentasaccharide Forssman on FORS1-kodecytes, while three reagents were able to detect disaccharide Forssman on Fsdi -kodecytes. Most anti-A reagents were immunochemically reactive with both the di- and the pentasaccharide Forssman antigens in the solid-phase assays. Historic polyclonal human anti-A and the lectin H. pomatia reacted strongly with the FORS1-kodecytes, correlating with the discovery of the Apae phenotype and supporting the use of FORS1-kodecytes as FORS1 surrogates.

CONCLUSIONS

Monoclonal anti-A reagents, despite showing reactivity against the FORS1 antigen in solid-phase assays are unlikely to cause the agglutination of FORS1 antigen-positive RBCs.

Genetic variation of the whole ICAM4 gene in Caucasians and African Americans

BACKGROUND

Landsteiner-Wiener (LW) is the human blood group system Number 16, which comprises two antithetical antigens, LW(a) and LW(b) and the high-prevalence antigen LW(ab) . LW is encoded by the intracellular adhesion molecule 4 (ICAM4) gene. The ICAM4 protein is part of the Rhesus complex in the red cell membrane and is involved in cell-cell adhesion.

STUDY DESIGN AND METHODS

We developed a method to sequence the whole 1.9-kb ICAM4 gene from genomic DNA in one amplicon. We determined the nucleotide sequence of Exons 1 to 3, the two introns, and 402-bp 5'-untranslated region (UTR) and 347-bp 3'-UTR in 97 Caucasian and 91 African American individuals.

RESULTS

Seven variant ICAM4 alleles were found, distinct from the wild-type ICAM4 allele (GenBank KF712272), known as LW*05 and encoding LW(a) . An effect of the LW(a) /LW(b) amino acid substitution on the protein structure was predicted by two of the three computational modeling programs used.

CONCLUSIONS

We describe a practical approach for sequencing and determining the ICAM4 alleles using genomic DNA. LW*05 is the ancestral allele, which had also been observed in a Neanderthal sample. All seven variant alleles are immediate derivatives of the prevalent LW*05 and caused by one single-nucleotide polymorphism (SNP) in each allele. Our data were consistent with the NHLBI GO Exome Sequencing Project (ESP) and the dbSNP databases, as all SNPs had been observed previously. Our study has the advantage over the other databases in that it adds haplotype (allele) information for the ICAM4 gene, clinically relevant in the field of transfusion medicine.

Is Next Generation Sequencing the future of blood group testing?

Blood group genotyping has many advantages over conventional phenotyping for both blood donors and patients, and a number of high-throughput methods have now been developed. However, these are limited by a requirement for existing knowledge of the relevant blood group gene polymorphisms, and rare or novel mutations will not be detected. These mutations could be successfully identified by DNA sequencing of the blood group genes, and such an approach has been made feasible by the introduction of Next Generation Sequencing (NGS) technology. NGS enables many genes from multiple samples to be sequenced in parallel, resulting in sequencing information that could be used to obtain accurate blood group phenotype predictions in both blood donors and patients.