Red blood cell extended antigen typing in Omani patients with sickle cell disease to enhance daily transfusion practice.

Many Omani patients with sickle cell disease (SCD) undergo red blood cell (RBC) transfusions that are only matched for ABO and D, making RBC alloimmunization a significant concern in this population. Currently, the integration of molecular assays and hemagglutination testing helps to determine RBC phenotypes and genotypes, facilitating the provision of compatible blood and minimizing additional alloimmunization risks in patients with SCD. Based on this finding, our objective was to use molecular methods to predict the extended antigen profile of Omani patients with SCD across various blood group systems including Rh, Kell, Duffy, Kidd, Colton, Lutheran, Dombrock, Diego, Cartwright, and Scianna. This approach aims to implement RBC matching strategies and enhance daily transfusion practices for these patients. Molecular methods encompassed multiplex polymerase chain reaction for RHD, BeadChip arrays for variants of RHD and RHCE, and ID CORE XT for the primary allelic variants of RBCs. This study enrolled 38 patients with SCD, comprising 34 patients with homozygous HbSS, 1 patient with HbSC, and 3 patients with HbS Oman. The predominant ABO blood group was group O, observed in 44.7 percent of patients, followed by group A in 21.1 percent and group B in 13.2 percent. The most prevalent Rh phenotype predicted from the genotype was D+C+E-c+e+, identified in 34.2 percent of patients. All patient samples were K-, exhibiting the k+ Kp(b+) Js(b+) phenotype, with 81.6 percent demonstrating Fy(a-b-) due to the homozygous FY*02N.01 genotype and 28.9 percent displaying Jk(a+b-). RH variant alleles were detected in five patients (13.2 %), with only one type of RHD variant (RHD*DIIIa) and one type of RHCE variant (RHCE*ceVS.02.01) identified. Alloantibodies were present in 26 patients (68.4%). This study presents the initial comprehensive report of extended RBC antigen profiling in Omani patients with SCD, revealing disparities in the prevalence of RBC phenotypes compared with SCD patients from other regions and countries. Furthermore, our findings underscore a high rate of alloimmunization in these patients, emphasizing the need to implement antigen-matching programs to improve daily transfusion practices.

The rare holley antibody associated with a severe hemolytic transfusion reaction: the importance of this antibody identification to find a compatible blood unit.

The correct identification of erythrocyte antibodies is fundamental for the searching for compatible blood and haemolytic transfusion reactions prevention. Antibodies against antigens of high prevalence are difficult to identify because of the rarity of their occurrence and unavailability of negative red cells for confirmation. We report a case of 46-years-old woman, diagnosed with hemoglobinopathy, and who had symptomatic fall in hemoglobin levels (5.3g/dL) after blood transfusion suggestive of transfusion reaction. The patient's blood type was O RhD-positive. Irregular antibody screening was positive and demonstrated a panreaction against all erythrocytes tested, but this result was not reactive with dithiothreitol. Using negative red cells for antigens of high prevalence of our inventory we could identify in the serum of the same erythrocytes an anti-Holley antibody associated with anti-E. Molecular analysis confirmed that the patient was negative for E and Holley antigens. The crossmath with compatible units confirmed the results. Holley is a high prevalence antigen of the Dombrock blood system whose negative phenotype is extremely rare in all populations and is associated with hemolytic transfusion reactions. This is an antibody that is difficult to identify because laboratories need to have experience in solving complex cases, and have available a large stock of rare sera and erythrocytes, as well other tools such as enzymes, thiol reagents and molecular tests. The correct identification of a rare antibody is initial and mandatory for searching of compatible donors, and to guarantee a satisfactory transfusional support.

The rare holley antibody associated with a severe hemolytic transfusion reaction: the importance of this antibody identification to find a compatible blood unit / Raro anticorpo associado à reação transfusional hemolítica grave: a importância de sua identificação para encontrar uma unidade sanguínea compatível

ABSTRACT The correct identification of erythrocyte antibodies is fundamental for the searching for compatible blood and haemolytic transfusion reactions prevention. Antibodies against antigens of high prevalence are difficult to identify because of the rarity of their occurrence and unavailability of negative red cells for confirmation. We report a case of 46-years-old woman, diagnosed with hemoglobinopathy, and who had symptomatic fall in hemoglobin levels (5.3g/dL) after blood transfusion suggestive of transfusion reaction. The patient's blood type was O RhD-positive. Irregular antibody screening was positive and demonstrated a panreaction against all erythrocytes tested, but this result was not reactive with dithiothreitol. Using negative red cells for antigens of high prevalence of our inventory we could identify in the serum of the same erythrocytes an anti-Holley antibody associated with anti-E. Molecular analysis confirmed that the patient was negative for E and Holley antigens. The crossmath with compatible units confirmed the results. Holley is a high prevalence antigen of the Dombrock blood system whose negative phenotype is extremely rare in all populations and is associated with hemolytic transfusion reactions. This is an antibody that is difficult to identify because laboratories need to have experience in solving complex cases, and have available a large stock of rare sera and erythrocytes, as well other tools such as enzymes, thiol reagents and molecular tests. The correct identification of a rare antibody is initial and mandatory for searching of compatible donors, and to guarantee a satisfactory transfusional support.

RESUMO A correta identificação dos anticorpos eritrocitários é fundamental na busca de sangue compatível e na prevenção das reações transfusionais hemolíticas. Anticorpos contra antígenos de alta prevalência são de difícil identificação, devido à raridade de sua ocorrência e à indisponibilidade de hemácias negativas para sua confirmação. Apresentamos aqui o caso de uma paciente do sexo feminino, 46 anos, com diagnóstico de hemoglobinopatia, que apresentou queda sintomática dos níveis de hemoglobina (5,3g/dL) após transfusão sanguínea, sugestiva de reação transfusional. O tipo sanguíneo da paciente era O RhD-positivo. A pesquisa de anticorpos irregulares foi positiva, demonstrando panreação contra todos os eritrócitos testados, mas não reativo ao ditiotreitol. Utilizando hemácias selecionadas negativas para antígenos de alta prevalência do nosso inventário, foi possível identificar no soro da mesma um anticorpo anti-Holley associado a um anti-E. A análise molecular confirmou que a paciente era negativa para os antígenos E e Holley, e as provas de compatibilidade com unidades fenotipadas confirmaram os resultados. Holley é um antígeno de alta prevalência do sistema sanguíneo Dombrock, cujo fenótipo negativo é extremamente raro em todas as populações e está associado a reações transfusionais hemolíticas. Trata-se de anticorpo de difícil identificação, pois os laboratórios precisam ter experiência na resolução de casos complexos, grande estoque de soros e eritrócitos raros, além de outras ferramentas, como enzimas, reagentes tiol e testes moleculares. A identificação correta de um anticorpo raro é inicial e obrigatória para a busca de doadores compatíveis, garantindo um suporte transfusional satisfatório.

Histo-blood group antigens and rotavirus vaccine shedding in Nicaraguan infants.

ABO, Lewis and secretor histo-blood group antigens (HBGA) are susceptibility factors for rotavirus in a P-genotype dependent manner and can influence IgA seroconversion rates following rotavirus vaccination. To investigate the association between HBGA phenotypes and rotavirus vaccine shedding fecal samples (n = 304) from a total of 141 infants vaccinated with Rotarix (n = 71) and RotaTeq (n = 70) were prospectively sampled in three time frames (≤3, 4-7 and ≥8 days) after first vaccination dose. Rotavirus was detected with qPCR and genotypes determined by G/P multiplex PCR and/or sequencing. HBGAs were determined by hemagglutination and saliva based ELISA. Low shedding rates were observed, with slightly more children vaccinated with RotaTeq (19%) than Rotarix (11%) shedding rotavirus at ≥4 days post vaccination (DPV). At ≥4 DPV no infant of Lewis A (n = 6) or nonsecretor (n = 9) phenotype in the Rotarix cohort shed rotavirus; the same observation was made for Lewis A infants (n = 7) in the RotaTeq cohort. Putative in-vivo gene reassortment among RotaTeq strains occurred, yielding mainly G1P[8] strains. The bovine derived P[5] genotype included in RotaTeq was able to replicate and be shed at long time frames (>13 DPV). The results of this study are consistent with that HBGA phenotype influences vaccine strain shedding as similarly observed for natural infections. Due to the low overall shedding rates observed, additional studies are however warranted.

Human erythrocyte antigens in Brazilian Capuchin monkeys (Sapajus sp.).

BACKGROUND: Investigation of erythrocyte antigens in New World monkeys, especially in the Brazilian ones, is scant and incomplete. METHODS: Determining the presence of 29 erythrocyte antigens from 11 human blood group systems (ABO, H, Rh, Kell, Duffy, Kidd, Lewis, P, MNS, Lutheran and Diego) on erythrocytes in nine Capuchin monkeys (Sapajus sp.). RESULTS: A majority (20 of 29) of human erythrocyte antigens were not found in this monkey genus. Erythrocyte phenotyping was very similar within this animal group, as five Capuchin monkeys differed from the other four in the ABO system only. CONCLUSION: The erythrocyte phenotype for this group of animals is less diversified than in humans. Some monkey erythrocyte antigens were similar in frequency, whereas others were different from those observed in human ethnicities.

Prevalência de aloimunização eritrocitária em pacientes portadores de anemia falciforme / Prevalence of red blood cell alloimmunization in patients with sickle cell anemia

Embora as transfusões de concentrado de hemácias sejam importantes para o tratamento de pacientes com anemia falciforme, elas acarretam riscos imunológicos tais como a aloimunização a antígenos eritrocitários. Aproximadamente 50% dos pacientes de anemia falciforme recebem transfusões no decorrer da vida, e entre 5% a 10% destes pacientes são submetidos a um programa de transfusão crônica. A aloimunização eritrocitária é uma complicação séria da transfusão, mas relativamente comum. Esta condição pode inclusive levar a reações transfusionais hemolíticas tardias e contribuir para aumentar as comorbidades da doença. Importantes medidas para prevenção destas complicações nestes pacientes são o uso de hemácias previamente fenotipadas, além da fenotipagem do próprio receptor de concentrado de hemácias, determinando seu correto perfil fenotípico e possibilitando a escolha de concentrado de hemácias com antígenos correspondentes ao do paciente a ser transfundido. Extensa genotipagem eritrocitária profilática para selecionar doadores para pacientes que receberão repetidas transfusões durante um longo período é uma aplicação atraente de tipagem de sangue baseados em DNA. Isto é, particularmente relevante para pacientes com doença falciforme onde a taxa de aloimunização é elevada.

Although packed red blood cells transfusions are important for treating patients with sickle cell anemia, this intervention may lead to immunological disturbs, such as alloimmunization by erythrocyte antigens. Approximately 50% of patients with sickle cell anemia receive blood transfusions during their life span, and about 5 to 10% of them require a chronic transfusion scheme. The red blood cell alloimmunization is a serious but common transfusion reaction. This condition could lead to delayed hemolytic transfusion reactions, contributing to increase comorbidities of the disease. Important measures to prevent these complications in patients are the use of previously phenotyped red blood cells, in addition to the phenotyping of red blood cells from the acceptor patient, determining the correct phenotypic profile and enabling the choice of red blood cells with corresponding antigens to the patient to be transfused. Extensive prophylactic red blood cell genotyping to select donors for patients receiving repeated transfusions over a long period of time is a compelling application of DNA-based blood typing. This is particularly relevant for patients with sickle cell disease where the rate of alloimmunization is high.

Effect of red blood cell preservation by droplet freezing with non-permeable cryoprotective agents in blood group antigen reactivity.

BACKGROUND: In the last few decades, various red blood cell (RBC) freezing techniques have been developed and improved to enable the preservation of erythrocytes for future use in pre-transfusion tests in reference immunohaematology laboratories. However, not all these techniques have been sufficiently evaluated for the preservation of blood group antigens. OBJECTIVES: In this study, we evaluated the antigenic pattern of RBCs preserved by droplet freezing in liquid nitrogen in a blood bank context. METHODS: Blood samples were evaluated for the reactivity of blood group antigens after droplet freezing using the non-permeable cryoprotective agent polyvinylpyrrolidone (PVP) and sucrose-dextrose (S + D) solutions. RESULTS: No qualitative changes were observed in RBC reactivity after freezing and thawing for the antigens Fyb , Leb , C, E, Cw , Lua , Lub , Kpa , Kpb and Dia . However, cryopreservation using PVP resulted in a significant increase in reactivity of Fyb antigen on comparing fresh and frozen samples (P < 0·001). CONCLUSION: The establishment of detailed protocols for cryopreservation of RBCs, which take into account the maintenance of antigenic characteristics, is necessary to increase security in pre-transfusion testing using frozen RBCs.

Survey of Two New (Kai 1 and Kai 2) and Other Blood Groups in Dogs of North America.

BACKGROUND: Based upon serology, >10 canine blood group systems have been reported. OBJECTIVE: We surveyed dogs for dog erythrocyte antigen (DEA) 1 and 2 new blood types (Kai 1 and Kai 2), and some samples also were screened for Dal and DEA 3, 4, and 7. METHODS: Blood samples provided by owners, breeders, animal blood banks, and clinical laboratories were typed for DEA 1 by an immunochromatographic strip technique with a monoclonal antibody and analysis of band intensity. Both new antigens, the Dal and other DEAs (except DEA 7 by tube method), were assessed by a gel column method with either monoclonal or polyclonal antibodies. The same gel column method was applied for alloantibody detection. RESULTS: Of 503 dogs typed, 59.6% were DEA 1+ with 4% weakly, 10% moderately, and 45.6% strongly DEA 1+. Regarding Kai 1 and Kai 2, 94% were Kai 1+/Kai 2-, 5% were Kai 1-/Kai 2- and 1% were Kai 1-/Kai 2+, but none were Kai 1+/Kai 2+. There was no relationship between Kai 1/Kai 2 and other blood types tested. Plasma from DEA 1-, Kai 1-, Kai 2- dogs, or some combination of these contained no detectable alloantibodies against DEA 1 and Kai 1 or Kai, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: The new blood types, called Kai 1 and Kai 2, are unrelated to DEA 1, 3, 4, and 7 and Dal. Kai 1+/Kai 2- dogs were most commonly found in North America. The clinical relevance of Kai 1 and Kai 2 in canine transfusion medicine still needs to be elucidated.

2016: medio centenario del Instituto de Hematología e Inmunología / 2016: half a century of the Institute of Hematology and Immunology

El primero de diciembre de 2016 arribará a sus cincuenta años de fructífera existencia el Instituto de Hematología e Inmunología (IHI), surgido por voluntad del Ministerio de Salud Pública de la República de Cuba con el objetivo de realizar las investigaciones biomédicas en sus ramas, garantizar la cobertura nacional de especialistas y brindar atención médica de alta calificación a nuestro pueblo en sus especialidades. El IHI inició sus actividades con solamente 4 médicos, 2 técnicos, 2 enfermeras, y escasos recursos proporcionados por los hospitales que le han servido de sede: General Docente Enrique Cabrera y Pediátrico Docente William Soler , ya que, contrario a la mayoría de las especialidades médicas en Cuba, la Hematología surgió durante el proceso revolucionario y se desarrolló plenamente con la creación del instituto. La Inmunología, como ciencia nueva en aquella época, comenzó también a desarrollarse a raíz de la creación del instituto...

El antígeno Diego alcanza los 60 años de edad: su descubrimiento y desarrollo / Diego antigen reach 60 years old: discovery and development

El antigeno Diego fue descubierto en junio de 1953 por el hematólogo estadounidense Philip Levine (1900-1987) en una muestra de sangre enviada desde Venezuela por el pediatra Miguel Raga Mendoza (1917-1986). El propósitus, de nombre Diego, había fallecido a los 3 días de edad por causa de una enfermedad hemolítica del recién nacido. Levine bautizó al nuevo antigeno con el nombre de diego y lo clasificó como un factor privado o familiar de baja prevalencia. En 1955, los hematólogos Miguel Layrisse (1919-2002) y Tulio Arents (1918-1990), y el obstetra Rafael Dominguez Sisco (1908-1980) llegaron a la conclusión de que el antígeno Diego tenía una mayor frecuencia que la reportada por Levine y que por tanto constituía un grupo sanguíneo de alta prevalencia en poblaciones indigenas venezolanas. Estos resultados fueron extendidos a otras poblaciones indígenas de América, demostrandose también su existencia en personas de origen asiático (mongoloides) y su ausencia en las razas caucasoide y negroide. El antígeno Diego se transformó así en el primer marcador mongoloide de gran valor antropológico, genético y clínico. En la década de 1990 se demostró que el antígeno Diego estaba asociado con la proteína eritrocitaria denominada banda 3; esta funciona como un intercambiador de aniones (AE-1) que se expresa también en células del túbulo renal. Actualmente, el grupo snguíneo Diego está formado por 22 antígenos o alelos.

On June 1953, the American hematologist Philip Levine (1900-1987) discovered a new erythrocyte antigen in the blood of a sick child collected in Venezuela by the pediatrician Miguel Raga Mendoza (1917-1986). The propositus, named Diego, was affected by a hemolytic disease of the newborn and died 3 days after delivery. Levine named the antigen Diego (Diª) and classified it as a private or familial factor of low prevalence. In 1955, the hematologists Miguel Layrisse (1919-2002) and Tulio Arends (1918-1990), and the obstetrician Rafael Dominguez Sisco (1908-1980) concluded that the Diego antigen had a greater frecuency than that reported by Levine, constituting a blood group of high prevalence in Venezuelan aboriginal populations. Similar results were obtained in other aboriginal populations of the American continent. The Diego antigen was also present in high frequency in people of asiatic origin (mongoloids), and absent in caucasoid and negroid people. Thus, the Diego antigen became the first mongoloid marker of great anthropological, genetic and clinical importance. In 1992, the Diego antigen was found associated with the erythrocyte protein named band 3, later known to function as an anion exchanger (AE-1). Band 3 is also expressed on cells of the renal tubules. Presenthy, the Diego blood group is formed by 22 antigens or allelles.

Blood transfusion-related immunomodulation

The phenomenon of transfusion-related immunomodulation (TRIM) has been studied since the observation of a higher kidney allograft survival in patients who had received a higher number of transfusions. Conversely, it has been suggested as one of the possible causes related to the development of infections in patients with multiple blood transfusions and/or after a major surgery, and has been also associated with a decreased function of natural killer cells (NK) and antigen-presenting cells (APCs), reduced cell-mediated immunity, and increased regulatory T cells (Tregs). This review aimed to conceptualize TRIM and discuss some aspects related to its mechanisms and the prevention of immunomodulatory events.