Red Blood Cell Antigens Research Articles

A descriptive single-centre experience of the management and outcome of maternal alloantibodies in pregnancy.

Haemolytic disease of the fetus and newborn (HDFN) occurs when maternal IgG alloantibodies to fetal red blood cell antigens cross the placenta, causing haemolysis in the fetus and/or neonate. After delivery, the main concern is hyperbilirubinaemia, which can cause neurological damage. To summarise our current management and outcome data to inform health-care professionals counselling women whose pregnancies are at risk of HDFN and to compare these data with relevant studies. This is a retrospective descriptive study of all high-risk pregnancies at risk of HDFN at Guy's and St. Thomas' NHS Foundation Trust (GSTFT) Maternity Unit over a 7-year period. We defined high-risk pregnancies as those in whom anti-D, anti-c, anti-K or high (>32 or doubling strength) titres of all other antibodies were identified. A total of 130 pregnancies in 112 women were followed up. A single alloantibody was found in 93 pregnancies (71.5%) and multiple alloantibodies in 37 pregnancies (28.5%). Anti-D was most commonly encountered (n = 48, 36.9%), followed by anti-c (n = 31, 23.8%) and anti-E (n = 15, 11.5%). In 65 of 130 pregnancies (50%), antibody concentrations triggered scans to screen for fetal anaemia. Of 130 pregnancies, 6 (4.6%) required intrauterine transfusions, and 31 of 130 (26%) neonates required post-natal intervention. Overall, morbidity was 0.1% and mortality 0.002%. This study demonstrates that morbidity and mortality caused by HDFN is minimal. These results are reassuring for women at risk of HDFN as even severely affected cases are successfully managed in most instances. Further studies are needed to identify predictors of disease severity.

Stepwise partitioning of Xp21: a profiling method for XK deletions causative of the McLeod syndrome.

McLeod syndrome (MLS) is hematologically defined by the absence of the red blood cell (RBC) antigen Kx on the transmembrane RBC protein, XK, representing a highly specific diagnostic marker. Direct molecular assessment of XK therefore represents a desirable diagnostic tool. Whereas pathogenic point mutations may be simply identified, partial and complete deletions of XK on Xp21.1, eventually covering adjacent genes and causing multifaceted "continuous gene syndromes," are difficult to localize. Three different McLeod patient samples were tested using 16 initial positional polymerase chain reaction (PCR) procedures distributed over an approximately 2.8-Mbp Xp-chromosomal region, ranging telomeric from MAGEB16 to OTC, centromeric of XK. The molecular breakpoint of one sample with an apparent large Xp deletion was iteratively narrowed down by stepwise positioning further PCR procedures and sequenced. Two mutant XK genes, one previously published and serving as a positive control, were also sequenced. We confirmed the positive control as previously published and listed as XK*N.20 by the International Society of Blood Transfusion (ISBT). The other XK showed a novel four-nucleotide deletion in Exon 1, 195-198delCCGC (newly listed as XK*N.39 by the ISBT). The third sample had an approximately 151-kbp X-chromosomal deletion, reaching from Exon 2 of LANCL3, across XK to Exon 3 of CYBB (newly listed as XK*N.01.016 by the ISBT). Carrier status of the patients' sister was diagnosed using a diagnostic "gap-PCR." The stepwise partitioning of Xp21.1 is pragmatic and cost-efficient in comparison to other diagnostic techniques such as "massive parallel sequencing" given the rarity of MLS. All males with suspected MLS should be considered for molecular XK profiling.

Implementing a fully automated high‐throughput strategy for blood donor genotyping

BackgroundHigh‐throughput molecular assays are essential tools for the search of rare blood donors.Aims and methodsTo evaluate a fully automated workflow designed for genotyping blood donors’ red blood cell (RBC) and platelets (PTL) antigens using the OpenArray Real‐time PCR system.Results5487 blood donors were genotyped using the proposed strategy in two steps: (1) nucleic acid purification in the QIASymphony® equipment and (2) genotyping of the most important RBC and PTL antigens by a customized assay designed for the OpenArray Real‐time PCR system. 142 662 single nucleotide polymorphisms were genotyped with 99·6% of accuracy in 15 work‐days. Software was created for the purpose of data interfacing and organization of a database to be used in a regular basis to find compatible blood for alloimmunized patients.ConclusionsThe proposed fully automated genotyping strategy is accurate, fast and suitable for meeting the needs of a laboratory of molecular immunohematology.

Red blood cell alloimmunization in 184 patients with myeloid neoplasms treated with azacitidine – A retrospective single center experience

Alloimmunization to Red Blood Cell (RBC) antigens frequently occurs in patients with myeloid neoplasms (AML, MDS and CMML) and potentially poses the patient at risk for delayed hemolytic transfusion reactions and limited supply of compatible RBC-units. However, there is comparatively little data on transfusion associated characteristics in this patient cohort. We therefore retrospectively analyzed transfusion requirements and clinical outcomes of 184 patients with myloid neoplasms treated with azacitidine at the Paracelsus Medical University Salzburg, which were included in the Austrian Registry of Hypomethylating Agents.The mean blood component requirements for AML, MDS and CMML were 39.8, 67.4 and 31.4 RBC units and 31.7, 27.6 and 19.1 platelet (PLT) units respectively. In spite of an extended and stringent RBC unit matching policy (ABO, RhD, RhCcEe and K antigens), 20 (11%) patients formed at least one alloantibody (“allo-group”), whereas 164 patients (89%) did not (“non-allo-group”). The most frequent antibody specificity was anti-E, followed by anti-Wra −Lua, −D, −C and −Jka. Alloimmunization was associated with higher numbers of transfused RBC units (68 vs. 38; p=0.001), as well as with longer time under transfusion (16.7 vs. 9.4 months; p=0.014). Median overall survival (OS) did not differ significantly between the “allo”- and “non-allo-group”.

Interleukin-6 receptor α signaling on CD4+ T cells drives RBC alloantibody generation and T follicular helper cell differentiation in a murine model of RBC alloimmunization.

Abstract Alloimmunization to non-ABO red blood cell (RBC) antigens remains a significant clinical problem in transfusion medicine. Presence of these alloantibodies can lead to delayed hemolytic transfusion reactions resulting in significant morbidity and occasional mortality upon antigenic re-exposure. For patients that generate multiple alloantibodies, provision of compatible antigen-negative RBCs can be time and resource intensive. In rare cases, it can result in the inability to locate and provide a life-saving therapy. Despite the significant clinical consequences of RBC alloimmunization, our understanding of the fundamental molecular and cellular mechanisms regulating anti-RBC antibody generation is limited. We have combined a recently developed mouse model for transfusion mediated RBC alloimmunization with mice genetically deficient in interleukin-6 receptor (IL-6Rα) to investigate the role of IL-6Rα signaling in regulating RBC alloimmunization. We have demonstrated that IL-6Rα signaling plays a key role in the generation of anti-RBC alloantibodies in response to transfused RBCs. Additionally, we have shown that RBC alloimmunization requires IL-6Rα signaling specifically on T cells, and that these signals are required for maximal in vivo differentiation of naïve anti-RBC specific CD4+ T cells into T follicular helper (TFH) cells. We have identified for the first time a specific molecule (IL-6Rα), its downstream cellular target (CD4+ T cells) and resultant functional outcome (TFH differentiation) that regulates RBC alloimmunization. Collectively, our findings support the idea that currently available biologics targeting IL-6Rα could be a viable therapeutic option for the prevention of RBC alloimmunization.

Haemolysis, pure red cell aplasia and red cell antibody formation associated with major and bidirectional ABO incompatible haematopoietic stem cell transplantation.

Acute and delayed haemolysis, alloimmunisation and pure red cell aplasia (PRCA) are potential complications after ABO incompatible haematopoietic stem cell transplantation (HSCT). The aims of this study were to investigate acute and delayed red blood cell (RBC) antibody-associated complications, including haemolysis, PRCA and alloimmunisation in major and bidirectional ABO incompatible HSCT. We retrospectively examined the transplant courses of 36 recipients of bone marrow or peripheral blood stem cells from ABO incompatible donors and evaluated the current practice of performing plasmapheresis in patients with higher isoagglutinin titres. We investigated the role of ABO incompatibility in haematopoietic recovery, transfusion requirements, alloimmunisation and PRCA. Laboratory signs of acute haemolysis were noted in five (14%) patients, one (3%) of whom had clinically overt haemolysis. Patients with haemolysis had IgM titres ≥1:8 and received >16 mL of RBC in the HSCT. In patients with higher titres, plasmapheresis performed prior to the transplant prevented acute haemolysis. Delayed haemolysis was not recorded in the follow up. Haematopoietic recovery and transfusion requirements did not differ notably between patients with and without haemolysis. De novo RBC antibodies were detected in two (5.5%) patients after HSCT, and PRCA was noted in one (3%) patient. Carried out with adequate graft processing, plasmapheresis and blood component support, haemolysis is not a common complication after HSCT. Our results confirm that the occurrence of haemolysis depends on larger RBC volumes and higher isoagglutinin titres. Despite the reduction of patients' isoagglutinin titres by plasmapheresis, we still noted a critical combination for the development of laboratory signs of haemolysis (IgM titre ≥1:8 and RBC volume >16 mL). De novo immunisation to RBC antigens and PRCA are rare events following ABO incompatible HSCT.

Importance of extended blood group genotyping in multiply transfused patients

Blood group antigen systems are not limited to the ABO blood groups. There is increasing interest in the detection of extended blood group systems on the red cell surface. The conventional method used to determine extended blood group antigens or red cell phenotype is by serological testing, which is based on the detection of visible haemagglutination or the presence of haemolysis. However, this technique has many limitations due to recent exposure to donor red cell, certain drugs or medications or other diseases that may alter the red cell membrane. We aimed to determine the red cell blood group genotype by SNP real time PCR and to compare the results with the conventional serological methods in multiply transfused patients. Sixty-three patients participated in this study whose peripheral blood was collected and blood group phenotype was determined by serological tube method while the genotype was performed using TaqMan® Single Nucleotide Polymorphism (SNP) RT-PCR assays for RHEe, RHCc, Kidd and Duffy blood group systems. Discrepancies were found between the phenotype and genotype results for all blood groups tested. Accurate red blood cell antigen profiling is important for patients requiring multiple transfusions. The SNP RT-PCR platform is a reliable alternative to the conventional method.

Emergency transfusion of patients with unknown blood type with blood group O Rhesus D positive red blood cell concentrates: a prospective, single-centre, observational study

Emergency patients with unknown blood type usually receive O Rhesus D negative (RhD-) red blood cell concentrates until their blood group is determined to prevent RhD+ related adverse transfusion reactions. As 85% of individuals are RhD+, this consumption of O RhD- red blood cell concentrates contributes to shortages of O RhD- red blood cell concentrates, sometimes forcing transfusion of known RhD- patients with RhD+ red blood cell concentrates. Here we report the outcome of this transfusion policy transfusing all emergency patients with unknown blood type with O RhD+ red blood cell concentrates. In this prospective single-centre observational study done between Jan 1, 2001, and Dec 31, 2015, we assessed all consecutive RhD- patients at the University Medicine Greifswald who received RhD+ red blood cell concentrates (emergency patients with unknown blood type; and RhD- patients receiving RhD+ red blood cell concentrates during RhD- red blood cell concentrate shortages). No patients were excluded. The primary endpoint was anti-D allo-immunisation at 2 months follow-up or later. Patients were followed up and tested for immunisation against red blood cell antigens using the direct antiglobulin test and an antibody screen every 3-5 days for 4 weeks or until death, or hospital discharge. Surviving patients were screened for development of anti-D antibodies for up to 12 months (at the predefined timepoints 2, 3, 6, and 12 months) after RhD+ red blood cell transfusion. 437 emergency patients, of whom 85 (20%) were RhD-, received 2836 RhD+ red blood cell concentrates. The overall risk of inducing anti-D antibodies (in all 437 recipients) was 17 (4%, 95% CI 2·44-6·14) of 437 (assuming all patients lost to follow-up developed anti-D allo-immunisation). During this period, 110 known RhD- patients received RhD+ red blood cell concentrates during RhD- red blood cell concentrate shortages. Of these, 29 (26%; 95% CI 19·0-35·3) developed anti-D allo-immunisation (assuming all patients lost to follow-up developed anti-D), which was significantly higher than in the emergency patients with unknown blood type (p<0·0001). Transfusing emergency patients with unknown blood type with O RhD+ red blood cell concentrates has a low risk of inducing anti-D antibodies (3-6%), but saves more than 10% of the total O RhD- red blood cell concentrate demand, thereby reducing shortage of O RhD- red blood cell concentrates, the need to transfuse known RhD-patients with RhD+ red blood cell concentrates, and thus the overall risk to induce anti-D allo-immunisation in the population. These findings should be considered for transfusion guidelines. University Medicine Greifswald.

Irradiation of Red Blood Cells and Alloimmunization.

Animal models suggest that red blood cell (RBC) damage incurred during storage can increase immunogenicity to some RBC antigens. We hypothesized that RBC irradiation, a source of oxidative damage, may result in higher RBC alloimmunization rates among transfusion recipients. Individuals receiving 1 or more gamma-irradiated RBC units, with follow-up antibody screening, were studied. We recorded diagnosis at the time of first irradiated RBC-unit transfusion, total irradiated RBCs received, and alloantibodies detected before and after irradiated RBC transfusion. The alloimmunization rate for patients receiving irradiated RBCs was 1.9% (3/154); this rate was not significantly different from the rate of 2.5% (5/200) derived from a control group that had undergone transfusion with nonirradiated RBCs ( P > .99). Most of the study subjects (83/154 [53.9%]) did not harbor an immunosuppressive disorder at the time of transfusion of irradiated RBCs, with postoperative bleeding (36/83 [43.4%]) being the most common diagnosis. This analysis provides reassurance that irradiated RBCs are not more immunogenic in patients with immunosuppression than in patients with immunocompetence.

Genotyping Applications for Transplantation and Transfusion Management: The Emory Experience.

Current genotyping methodologies for transplantation and transfusion management employ multiplex systems that allow for simultaneous detection of multiple HLA antigens, human platelet antigens, and red blood cell (RBC) antigens. The development of high-resolution, molecular HLA typing has led to improved outcomes in unrelated hematopoietic stem cell transplants by better identifying compatible alleles of the HLA-A, B, C, DRB1, and DQB1 antigens. In solid organ transplantation, the combination of high-resolution HLA typing with solid-phase antibody identification has proven of value for highly sensitized patients and has significantly reduced incompatible crossmatches at the time of organ allocation. This database-driven, combined HLA antigen/antibody testing has enabled routine implementation of "virtual crossmatching" and may even obviate the need for physical crossmatching. In addition, DNA-based testing for RBC antigens provides an alternative typing method that mitigates many of the limitations of hemagglutination-based phenotyping. Although RBC genotyping has utility in various transfusion settings, it has arguably been most useful for minimizing alloimmunization in the management of transfusion-dependent patients with sickle cell disease or thalassemia. The availability of high-throughput RBC genotyping for both individuals and large populations of donors, along with coordinated informatics systems to compare patients' antigen profiles with available antigen-negative and/or rare blood-typed donors, holds promise for improving the efficiency, reliability, and extent of RBC matching for this population.

Association of HLA‐DRB1 and HLA‐DQB1 with red‐blood‐cell alloimmunization in the Czech population

Alloimmune antibodies against red-blood-cell (RBC) antigens induced in susceptible individuals (responders) by transfusion, pregnancy or transplantation may have serious clinical consequences. The aim of this study was to investigate association of alloimmunization against selected RBC antigens with HLA-Class II. A total of 230 responders (106 monoresponders and 124 multiresponders) were enrolled into the study. HLA-DRB1 and HLA-DQB1 variants were determined by PCR-SSO and their frequencies compared between the patients (patient subgroups) and 375 ethnically and regionally matched controls. Development of multiple RBC antibodies was associated with HLA-DRB1*15 and HLA-DQB1*06 allelic groups in the patients, with the relationship being particularly apparent in those with anti-C+D antibodies. Furthermore, DRB1*13 and DQB1*06 were more frequent in multiresponders with anti-E+c antibodies and DRB1*03 and DQB1*02 in those with anti-E+Cw. For the first time, we confirmed the association of HLA-DRB1*15 with RBC antibody multiresponder status and found HLA-Class II associations for three frequent RBC antibody combinations. Our data support the concept that HLA restriction plays an important role in the response to RBC alloantigens.

Separation of autologous red blood cells from specimen of the transfused sickle cell disease patients using hypotonic saline

Background: Red blood cell (RBC) antigen typing in transfused sickle cell disease (SCD) patients is a difficult task due to contamination of the transfused red cells. Aim: This pilot study was aimed to standardize an easy approach to separate the autologous RBCs from the transfused patient for RBC antigen typing in SCD. Materials and Methods: The RBCs from transfused patients with SCD were separated by hypotonic saline and tested with various antisera by standard serological methods. Results: Ten antisera showing negative reaction with donors' RBCs reacted positively with the patients' autologous RBCs separated by treatment with hypotonic saline. Seven antisera reacted with the donors' RBCs were nonreactive with the patients' autologous RBCs after elimination of the donor's RBCs by treatment with hypotonic saline. Conclusion: The hypotonic saline can be used as method to separate the autologous RBCs from the mixture with the transfused RBC in patients with SCD.

Association of HLA-DRB1 and DQB1 alleles with red blood cell alloimmunization in Chinese

Few systematic investigations have assessed the correlations between red blood cell (RBC) antibodies and human leukocyte antigen (HLA)-DRB1 alleles in the Chinese population. In this case-control study, we investigated whether specific HLA-DRB1 alleles were associated with RBC alloimmunization by calculating the odds ratios for the frequencies of HLA alleles associated with alloimmunization to different RBC antigens. Three hundred and eight patients harboring RBC alloantibodies were analyzed as the case group, and the frequencies of the HLA-DRB1and HLA-DQB1 alleles in control individuals were analyzed by collecting data from the China Marrow Donor Program (including more than 1.6 million healthy people). HLA alleles were genotyped by single specific primer-polymerase chain reaction. The development of anti-C was associated with DRB1*07, DQB1*06, and DQB1*08; anti-C,e was associated with DRB1*07 and DQB1*06; and anti-E and anti-M were associated with DQB1. Other associations were identified between anti-E and DRB1*09 and between anti-Le^a and DRB1*01. Thus, our findings confirmed that HLA-DRB1 and DQB1 restriction played an important role in the generation of RBC alloantibodies in Chinese individuals.

Blood Group Change in Acute Myeloid Leukemia

Blood group antigens are either sugars or proteins found attached to the red blood cell membrane. ABO blood group antigens are the most clinically important antigens because they are the most immunogenic. As red blood cell antigens are inherited traits, they are usually not altered throughout the life of an individual. There have been occasional case reports of ABO blood group antigen change in malignant conditions. We report two such cases of ABO antigen alteration associated with acute myeloid leukemia. These patients had suppression of their blood group antigens during their leukemic phase, and the antigens were reexpressed when the patients attained remission.

Modeling alloantibody formation to high-incidence red blood cell antigens in immune responders using genotypic data

Alloimmunization to red blood cell antigens is unpredictable and poorly understood. Patients who are negative for high-incidence antigens (HIAs) are at risk for developing the corresponding antibodies. Molecular methods can easily predict the lack of an antigen and thus, the risk of an individual to become immunized. We examined the prevalence and risk factors for HIA alloimmunization in patients at risk based on genotyping results. Genotyping using a molecular method (HEA BeadChip™, Immucor, Warren, NJ) was performed on all patient specimens referred for molecular testing over 45 months; serologic and clinical data were analyzed. We used simple and multiple logistic regression to model the risk factors for alloimmunization to an HIA. Of the 2591 patients genotyped, 32 (1.2%) were homozygous for at least one variant predicting absence of an HIA. Of these 32 patients, prior transfusion or pregnancy history was available for 29 (91%). Four susceptible patients made an antibody to an HIA (12.5% of all, 13.8% of those with a documented exposure). Two of these four patients (50%) had made an alloantibody to another antigen. The odds of forming an antibody to an HIA were not related to the total number of transfusions (p = 0.47), the total number of alloantibodies (p = 0.61), or diagnosis of sickle cell disease (p = 0.77) in simple logistic regression. Adjustment for the other two variables in a multiple logistic regression was also not significant for each variable (p = 0.6, p = 0.7, and p = 0.7, respectively). Although they had a known exposure to alloantigens through transfusion or pregnancy, 86.2 percent of patients (25 of 29) at risk for alloantibody formation to an HIA in fact did not mount an immune response to that antigen. Possible risk factors including the number of transfused units or the total number of alloantibodies made were not predictors of making an alloantibody to an HIA in our sampling. Our results suggest that other patient-specific risk factors for alloimmunization exist.

Recognizing and resolving ABO discrepancies

Patient samples are routinely typed for ABO prior to transfusion. Determining the ABO group requires both red blood cell (RBC) antigen typing for A and B (forward type) and testing for anti-A and anti-B in the plasma (reverse type). An ABO discrepancy exists when the result of an ABO RBC typing, or forward type, does not agree with the result of the plasma typing, or reverse type. This brief review examines several causes of ABO discrepancies encountered in the clinical transfusion service. Options for resolving these discrepancies are presented, including a discussion of which discrepancies should be resolved using molecular testing. Finally, case studies illustrate transfusion options in patients with ABO discrepancies. Discrepancies can also be encountered when ABO typing is performed on samples from blood or tissue donors, although those discrepancies will not be discussed in this review.

Assessment of common red blood cell pretreatments to yield an accurate serologic antigen phenotype compared with genotype-predicted phenotype.

For patients requiring multiple transfusions and patients with positive direct antiglobulin tests (DATs), an extended red blood cell (RBC) phenotype can provide valuable information and help to determine the risk of forming alloantibodies. In some instances, the phenotype may be used for prophylactic matching. Phenotyping in this patient population is often hindered by the presence of circulating donor cells and/or by a positive DAT. Several methods, such as EDTA glycine acid (EGA) treatment to remove IgG, hypotonic saline wash to separate autologous RBCs, or reticulocyte separation, are often used in these situations to isolate patient RBCs for serologic phenotyping. This study aimed to determine the accuracy of each RBC pretreatment method by comparing serologically determined antigen types with those predicted by RBC genotyping. Forty-eight peripheral blood samples from recently transfused patients were phenotyped for selected antigens in the Rh, Kell, MNS, Duffy, and Kidd systems. Treatment methods for the sample sets were reticulocyte separation (N = 12), EGA (N = 16), and hypotonic saline wash (N = 20). DNA was extracted using standard methods, and genotyping was performed using the HEA BeadChip panel. In addition, 21 samples positive for RBC-bound IgG were EGAtreated up to two times. These samples were analyzed pre- and post-EGA treatment for RBC-bound IgG by tube DAT and by flow cytometry with fluorescein isothiocyanate-labeled antihuman IgG. After reticulocyte separation, 3 of the 12 samples had discordant types with one antigen each: Fyb, N, and K; serologic results were negative compared with genotype-predicted positive phenotype results. The EGA-treated sample set showed one discordant type: Fyb; serologic results were negative compared with genotype-predicted positive phenotype results. Four of the 20 samples had discordant types involving the following antigens: Fyb, N, e, and M; serologic results were negative compared with genotype-predicted positive phenotype results. After EGA treatment of 21 samples, 14 (67%) were negative for RBC-bound IgG by tube DAT, and 7 remained positive. Using flow cytometry, EGA treatment rendered only 4 samples negative, and 17 remained positive. In the antigen testing sample set of 48 samples, 10 of 511 total antigen types tested were discordant. Discordant types were most frequent in the hypotonic saline wash sample set (N = 6). In the flow cytometry sample set, 48 percent of the samples negative by tube DAT after EGA elution had detectable RBCbound IgG by flow cytometry. These findings suggest that caution should be taken when using phenotype results from all pretreated RBCs and support the use of RBC genotyping to predict RBC antigen expression in samples from recently transfused patients.

Stability guidelines for dithiothreitol-treated red blood cell reagents used for antibody detection methods in patients treated with daratumumab

Daratumumab (DARA), a drug used to treat patients with multiple myeloma, causes interference in pre-transfusion testing. Samples from patients receiving DARA exhibit panreactivity in antibody detection and identification tests with red blood cells (RBCs). Many hospitals are sending these samples to reference laboratories. Dithiothreitol (DTT), a sulfhydryl chemical treatment of RBCs, negates this reactivity. This study investigated the stability of the antigens on DTT-treated RBCs to determine if large quantities of RBCs could be treated at one time, stored, and used for testing at a later time. Panel cells were treated with DTT and then stored as three sets. Set 1 DTT-treated RBCs were stored in Alsever's solution at 2°C to 8°C, washed daily, and suspended in pH 7.3 phosphate-buffered saline (PBS) prior to antigen typing. Set 2 DTT-treated RBCs were stored in pH 7.3 PBS. Set 3 DTT-treated RBCs were stored in Alsever's solution. Sets 2 and 3 were inspected daily for 14 days for observation of hemolysis. In Set 1, all antigen reactivity remained at ≥2+ with both single- and double-dose cells for 14 days. The Rh antigens gave stronger reactions longer, compared with those tested in the Duffy, Kidd, and MNS blood group systems. Sets 2 and 3 were monitored for hemolysis. On day 3, Set 2 began displaying hemolysis, with complete hemolysis by day 8. Set 3 did not display hemolysis in 14 days. In conclusion, a large volume of RBCs can be treated with DTT and stored in Alsever's solution for use without deterioration of the RBC antigens, saving institutions tech time, resources, and money.

Application of a multiplex PCR genotyping assay of 31 red blood cell antigens for establishment of a panel of reference DNA in China

DNA based blood group genotyping has been widely used in clinical blood transfusions, and a number of different molecular blood group testing methods have been developed, including the detection of single nucleotide polymorphism (SNP) and genomic DNA sequencing. As the molecular bases of blood groups can differ widely between ethnic groups, a set of reference DNAs, especially for the Chinese population, is required for the development and validation of these methods, and for their optimal use in routine practice in China. In this study, a total of 100 DNA samples obtained from 60 established cell lines and 40 Chinese blood donors were typed for 31 red blood cell antigens of 13 blood group systems using a multiplex polymerase chain reaction (PCR) assay. Finally, nine DNA samples were selected to establish a panel of reference DNA that included M, N, S, s, Mur, Lu^a, Lu^b, Au^a, Au^b, K, k, Fy^a, Fy^b, Jk^a, Jk^b, Di^a, Di^b, Sc1, Sc2, Do^a, Do^b, Co^a, Co^b, Kn^a, Kn^b, In^b, Vel antigens and Fy (a-b-) null phenotype.

Phenotype frequencies of blood group systems and alloantibodies to red blood cells in blood transfusion recipients in Kayseri (Turkey)

Aim: In this study, we aimed to asses the antigen and phenotype frequencies of various blood groups among recipients of erythrocyte suspensions in Kayseri. Materials and Methods: The study was conducted as retrospective, cross sectional and multicenter study. In all, 48750 blood recipients old typed in terms of the ABO, Rh, MNS, Duffy, Lewis, P, Kell, Lutheran, and Kidd systems were subjected to erythrocyte phenotyping using a gel centrifugation method within the age group of 18-60 years. Results: Of the ABO blood group, A was most frequent (44%) followed by O, B, and AB (30.3%, 16.2%, and 6.5%, respectively). The frequencies of Rh antigens were 88% D-positive and 12% D-negative. Alloantibodies were detected by screening in 196 (0.4%) of 48,750 patients, and decreased in the order anti-E (62%), -C (43%), -D (42%), -C (11%), -c (11%), -e (8%), -M (7%), -Fy a (5%), -Jk a (5%), -Kp a (4%), -Le a (3%), -Jk b (2%) ,-S (2%), -Le b (1%), and -P (1%). The most frequently detected alloantibodies were anti-E (31.6%) and -K (21.9%). Conclusion: Knowledge of the phenotypic frequencies of red blood cell antigens allows the creation of banks of appropriate antigennegative blood, thus preventing transfusion reactions in patients requiring multiple transfusions or who express alloantibodies.