Detection of alloimmunization in Glanzmann Thrombasthenia and Bernard-Soulier Syndrome: Data from a Brazilian Center

ABSTRACT Introduction: The Glanzmann Thrombasthenia (GT) and Bernard-Soulier Syndrome (BSS) are rare hereditary disorders of platelet function. Their treatment often requires platelet transfusion, which can lead to the development of alloantibodies. Objective: In this study, we aim to develop a strategy for alloantibody detection and to describe the frequency of alloimmunization in a patient population from a single center in southeastern Brazil. Methods: Samples from patients with GT or BSS were tested using the Platelet Immunofluorescence Test (PIFT). If a positive result was obtained, a confirmatory step using the Monoclonal Antibody Immobilization of Platelet Antigens (MAIPA) and Luminex bead-based platelet assay (PAKLx) was executed. Main results: Among 11 patients with GT, we detected the presence of alloantibodies in 5 using PIFT, with confirmation through MAIPA and PAKLx in 2 (1 anti-HLA and 1 anti-HPA), resulting in a frequency of 18.1%. Among 4 patients with BSS, PIFT was positive in 3, with confirmation by MAIPA and PAKLx in 1 (anti-HLA), showing a frequency of 25%. The two patients with anti-HLA antibodies exhibited a panel reactive antibody (PRA-HLA) testing greater than 97%. Conclusion: Our study highlights the importance of identifying platelet alloimmunization in this patient population. The proposed algorithm for platelet alloantibodies detection allows resource optimization.

Red cell alloimunization and autoantibodies in transfusion dependent thalassemia patients of Jammu region

Background:Thalassemia is one of the most common genetic disorder of hemoglobin synthesis in Jammu region. Although RBC transfusion is life saving for these patients, it may be associated with some complications like RBC alloimmunization. Thus, alloimmunization against red blood cell antigens increases the need for transfusion and can significantly complicate transfusion therapy. Therefore, screening for unexpected antibodies should be a part of all pretransfusion testing,with antibody identification in the event of a positive result. The aim of the study was to determine the frequency of alloimmunization and autoimmunization and the most common alloantibodies involved.Methods:This was a descriptive study involving a total of 146 thalassemic patients in the age range of 2-32 years receiving regular blood transfusions, registered at SMGS blood bank, Jammu. Antibodies screening, antibody identification, and cross matching was doneon all patient samples included in the study, during the period between November 2014 and October 2015.Results:At the start of the study, 8 patients who tested positive for alloantibodies 3 patients had more than one antibody subtype. Anti-E was the commonest antibody found in 4 (50%) patients. Similarly, at the end of study, antibody screening and then identification revealed presence of antibodies in 10 patients. Only 1 patient had more than one antibody subtype. Anti E was again the commonest antibody found in 5 (50%) patients. Conclusions:The most common alloantibodies identified were anti Rh system antibodies (anti-E and anti-D) followed by Kell antibodies. In order to reduce alloimmunization, a policy for performing extended red cell phenotyping of these patients is essential and at least antigen E and Kell negative blood should be provided for transfusion to these patients.

Erythrocyte phenotyping for feline AB system in domestic cats from the Ilhéus-Itabuna microregion, Bahia, Brazil

ABSTRACT: This study aimed to determine the erythrocyte phenotypes of the feline AB system and to check the presence of antigens other than those present in the feline AB system in domestic cats from Ilhéus-Itabuna microregion, Bahia, Brazil. Three-hundred feline blood samples were collected at the Veterinary Hospital of the Universidade Estadual de Santa Cruz (UESC) and in home visits to perform blood phenotyping using the tube-method testing. The reverse phenotyping was made between cats that tested phenotype B with blood samples of cats that tested phenotype A to confirm the blood phenotype B. The cross-tested among cats with phenotype A was made in order to verify the presence of different antigens of AB system in this blood phenotype. The results underwent macroscopic and microscopic analyses. Among the 300 animals tested, regarding breed, 290 were mixed-breed cats and among the remaining ten, five were Persians, four Siamese, and one Angora. 297 (99%) presented with phenotype A (including all the breeding cats) and three (1%) with phenotype B, and all this cats were mixed-breed cats. None (0%) of the cats showed the phenotype AB. All phenotype B bloods reacted to reverse phenotyping with phenotype A, confirming the phenotype B of these cats. All phenotype A bloods were compatible among each other, so no further erythrocyte antigens were detected through this test. The mother of one of the phenotype B cats was identified and had phenotype A, demonstrating phenotype A parents with phenotype B offspring. This finding indicates heterozygosis in the studied population. This data enable to conclude that the studied population presented different erythrocyte phenotypes, subsequently highlighting the importance of conducting phenotype analyses in these animals before performing blood transfusion to avoid serious hemolytic complications associated with incompatibility.

RESUMO: O objetivo deste estudo foi determinar a frequência dos fenótipos eritrocitários do sistema AB felino e verificar a presença de outros antígenos, não pertencentes ao sistema AB felino, em gatos domésticos das cidades de Ilhéus e Itabuna, Bahia, Brasil. Amostras de sangue de 300 gatos foram coletadas no Hospital Veterinário da Universidade Estadual de Santa Cruz (UESC) e em visitas domiciliares para realizar a fenotipagem sanguínea usando o método de tubo. A fenotipagem reversa foi realizada em gatos que testaram o fenótipo B com amostras que testaram o fenótipo A, para confirmação do fenótipo sanguíneo. O teste cruzado foi realizado entre gatos do fenótipo A, para pesquisar a presença de diferentes antígenos do sistema AB dentro desse fenótipo sanguíneo. Os resultados foram submetidos a análises macroscópicas e microscópicas. Dos 300 animais testados, 110 eram machos e 190 fêmeas, e suas idades variaram de cinco meses à 15 anos. Sobre as raças, 290 eram gatos sem raça definida e dos 10 restantes, cinco eram Persas, quatro eram Siameses e um Angorá. 297 (99%) apresentaram fenótipo A (incluindo todos os gatos de raça) e três (1%) tiveram fenótipo B, sendo todos esses gatos sem raça definida. Nenhum (0%) dos gatos apresentou fenótipo AB. Todos os sangues com fenótipo B reagiram na fenotipagem reversa com o fenótipo A, confirmando o fenótipo B desses gatos. Todos os sangues com fenótipo A foram compatíveis entre si, portanto nenhum antígeno eritrocitário adicional foi detectado através deste teste. A genitora de um dos gatos com fenótipo B, foi encontrada e a mesma possuía fenótipo A, demonstrando pais com fenótipo A e cria com fenótipo B. Esse achado indica heterozigose na população estudada. Esses dados levam à conclusão de que diferentes fenótipos eritrocitários estão presentes na população estudada e destacam a importância da realização de testes fenotípicos nesses animais antes dos procedimentos de transfusão, a fim de evitar complicações hemolíticas graves decorrentes do envolvimento de animais incompatíveis.

Hemofilia A: una enfermedad huérfana / Hemophilia A: a rare disease

La hemofilia A es una enfermedad hereditaria ligada al cromosoma X, causada por mutaciones en el gen F8 del factor VIII de la coagulación. Se considera una enfermedad huérfana, ya que su prevalencia es baja, de 26,6 por cada 100.000 nacidos vivos de sexo masculino. Los pacientes con hemofilia A tienen fases de inicio y amplificación de la coagulación relativamente normales y son capaces de formar el tapón plaquetario inicial en el lugar de la hemorragia, pero debido a la deficiencia del factor VIII, son incapaces de generar una cantidad de trombina en la superficie de las plaquetas, que sea suficiente para estabilizar el coágulo de fibrina. En un paciente masculino con hemorragias inusuales debe descartarse un trastorno de coagulación tipo hemofilia A, y se debe solicitar un recuento de plaquetas y un tiempo de protrombina (TP), los cuales usualmente son normales, y un tiempo de tromboplastina parcial activado (TPT) que se presenta prolongado. Para el diagnóstico diferencial con otras coagulopatías se realiza la medición de factores de coagulación, y pruebas de corrección cuando existe la sospecha de un inhibidor o de una hemofilia adquirida. Los pacientes afectados pueden presentar formas leves, moderadas o severas de la enfermedad, según el nivel plasmático del factor. En Colombia y en el mundo, la hemofilia fue reconocida como una enfermedad huérfana que representa un problema de salud pública, debido a su proceso de atención altamente especializado, que incrementa los costos asociados con la asistencia sanitaria, y afecta la calidad de vida de los pacientes y de aquellos que los rodean, además de que representa un reto diagnóstico que requiere constante actualización, para que pueda ser tratada de manera efectiva

Hemophilia A is an X-linked inherited disease caused by mutations in the coagulation factor VIII F8 gene. It is considered a rare disease, as its prevalence is 26.6 per 100,000 live male births. Patients with hemophilia A have a relatively normal coagulation onset and amplification phases, and are able to form the initial platelet plug at the site of hemorrhage; but due to factor VIII deficiency, they are unable to generate a sufficient amount of thrombin on the platelet surface to stabilize the fibrin clot. In a male patient with unusual bleeding, a hemophilia A-type coagulation disorder should be ruled out, and blood tests such as a platelet count and prothrombin time (PT), which are usually normal, and an activated partial thromboplastin time (APTT), which is prolonged, should be requested immediately. For differential diagnosis with other coagulopathies, measurement of coagulation factors and correction tests are performed when there is suspicion of an inhibitor or acquired hemophilia. Affected patients may present mild, moderate or severe forms of the disease, depending on the plasma level of the factor. In Colombia and worldwide, hemophilia was recognized as a rare disease that represents a public health problem due to its highly specialized care, which increases the costs associated with health care, and affects the quality of life of patients and those around them, as well as representing a diagnostic challenge that requires constant updating, so that it can be treated effectively

Erythrocyte phenotyping for feline AB system in domestic cats from the Ilhéus-Itabuna microregion, Bahia, Brazil / Fenotipagem eritrocitária para sistema AB felino em gatos domésticos da microrregão Ilhéus-Itabuna, Bahia, Brasil

This study aimed to determine the erythrocyte phenotypes of the feline AB system and to check the presence of antigens other than those present in the feline AB system in domestic cats from Ilhéus-Itabuna microregion, Bahia, Brazil. Three-hundred feline blood samples were collected at the Veterinary Hospital of the "Universidade Estadual de Santa Cruz" (UESC) and in home visits to perform blood phenotyping using the tube-method testing. The reverse phenotyping was made between cats that tested phenotype B with blood samples of cats that tested phenotype A to confirm the blood phenotype B. The cross-tested among cats with phenotype A was made in order to verify the presence of different antigens of AB system in this blood phenotype. The results underwent macroscopic and microscopic analyses. Among the 300 animals tested, regarding breed, 290 were mixed-breed cats and among the remaining ten, five were Persians, four Siamese, and one Angora. 297 (99%) presented with phenotype A (including all the breeding cats) and three (1%) with phenotype B, and all this cats were mixed-breed cats. None (0%) of the cats showed the phenotype AB. All phenotype B bloods reacted to reverse phenotyping with phenotype A, confirming the phenotype B of these cats. All phenotype A bloods were compatible among each other, so no further erythrocyte antigens were detected through this test. The mother of one of the phenotype B cats was identified and had phenotype A, demonstrating phenotype A parents with phenotype B offspring. This finding indicates heterozygosis in the studied population. This data enable to conclude that the studied population presented different erythrocyte phenotypes, subsequently highlighting the importance of conducting phenotype analyses in these animals before performing blood transfusion to avoid serious hemolytic complications associated with incompatibility.(AU)

O objetivo deste estudo foi determinar a frequência dos fenótipos eritrocitários do sistema AB felino e verificar a presença de outros antígenos, não pertencentes ao sistema AB felino, em gatos domésticos das cidades de Ilhéus e Itabuna, Bahia, Brasil. Amostras de sangue de 300 gatos foram coletadas no Hospital Veterinário da Universidade Estadual de Santa Cruz (UESC) e em visitas domiciliares para realizar a fenotipagem sanguínea usando o método de tubo. A fenotipagem reversa foi realizada em gatos que testaram o fenótipo B com amostras que testaram o fenótipo A, para confirmação do fenótipo sanguíneo. O teste cruzado foi realizado entre gatos do fenótipo A, para pesquisar a presença de diferentes antígenos do sistema AB dentro desse fenótipo sanguíneo. Os resultados foram submetidos a análises macroscópicas e microscópicas. Dos 300 animais testados, 110 eram machos e 190 fêmeas, e suas idades variaram de cinco meses à 15 anos. Sobre as raças, 290 eram gatos sem raça definida e dos 10 restantes, cinco eram Persas, quatro eram Siameses e um Angorá. 297 (99%) apresentaram fenótipo A (incluindo todos os gatos de raça) e três (1%) tiveram fenótipo B, sendo todos esses gatos sem raça definida. Nenhum (0%) dos gatos apresentou fenótipo AB. Todos os sangues com fenótipo B reagiram na fenotipagem reversa com o fenótipo A, confirmando o fenótipo B desses gatos. Todos os sangues com fenótipo A foram compatíveis entre si, portanto nenhum antígeno eritrocitário adicional foi detectado através deste teste. A genitora de um dos gatos com fenótipo B, foi encontrada e a mesma possuía fenótipo A, demonstrando pais com fenótipo A e cria com fenótipo B. Esse achado indica heterozigose na população estudada. Esses dados levam à conclusão de que diferentes fenótipos eritrocitários estão presentes na população estudada e destacam a importância da realização de testes fenotípicos nesses animais antes dos procedimentos de transfusão, a fim de evitar complicações hemolíticas graves decorrentes do envolvimento de animais incompatíveis.(AU)

How autoantibodies interfere with the identification of alloantibodies / 中国输血杂志

【Objective】 To explore a method to accurately identify the specificity of alloantibodies or autoantibodies in autoimmune hemolytic anemia (AIHA)patients with both warm and cold antibodies, so as to provide guidance for the selection of blood components. 【Methods】 Blood samples of AIHA patients with both warm and cold antibodies were screened by the direct antiglobulin testing (DAT). The plasma of patients were treated with dilution or adsorption method and the erythrocyte was dispersed for specificity identification of alloantibodies or autoantibodies.According to the results of antibody identification, appropriate phenotype of red blood cells(RBCs) were transfused to patients, and the incidence of adverse reactions and efficacy of transfusion were observed. 【Results】 Alloantibodies or specific autoantibodies were detected in serum or elution in 14 of the 16 patients. 10 patients underwent blood transfusion during hospitalization, and all of them received RBCs with the same or compatible ABO/Rh (D) type as the patients and without any reaction to the alloantibodies and specific warm autoantibodies. No hemolytic reaction occurred, and anemia symptoms were improved after blood transfusion. 【Conclusion】 The selection of appropriate methods could eliminate the influence of autoantibodies on the identification of alloantibodies in AIHA patients with both warm and cold antibodies. Therefore, the selection of blood from compatible donors for transfusion could effectively avoid the occurrence of hemolytic reaction.

Frequência de anticorpos irregulares identificados em pacientes atendidos em um hemonúcleo no sudoeste do Paraná no ano de 2017 / Frequency of irregular antibodies identified in patients treated at the hemotherapy service in southwest of Paraná in 2017

Quando um indivíduo é exposto a antígenos eritrocitários não próprios, ocorre uma resposta imunológica, que leva à produção de anticorpos irregulares voltados contra esses antígenos. Esse processo é conhecido como aloimunização eritrocitária e acontece em decorrência de transfusões de sangue ou gestações incompatíveis. Na medicina transfusional a pesquisa de anticorpos irregulares é fundamental, pois a falha na detecção de um aloanticorpo pode provocar reações transfusionais, aloimunizações, anemias hemolíticas autoimunes e doença hemolítica perinatal. Este estudo tem por objetivo analisar a frequência de anticorpos irregulares de pacientes atendidos no Hemocentro Regional de Francisco Beltrão, Paraná, no ano de 2017. Os dados foram coletados a partir da revisão de registros em arquivos do Laboratório de Imunohematologia do Hemonúcleo. Foram avaliados dados de 49 protocolos de pacientes que apresentaram dificuldades transfusionais no ano de 2017. Dentre os pesquisados, 37 pacientes (75,5%) apresentaram anticorpos irregulares. Dentre os anticorpos anti-eritrocitários observados neste estudo, evidenciou-se a presença de doze pacientes com anti-D (27,2%), seis pacientes com anti-K (13,6%), quatro pacientes com anti-C (9,0%) e em seis pacientes (13,6%) foi observada a presença de autoanticorpos. Este estudo indica que, nos pacientes transfundidos, os anticorpos mais frequentes foram os aloanticorpos Anti-D do Sistema Rh, provavelmente devido ao seu alto grau de imunogenicidade. A prevalência desses anticorpos é semelhante a vários estudos encontrados na literatura.

When an individual is exposed to not-self red blood cell antigens, an immune response occurs, which leads to the production of irregular antibodies directed against these antigens. This process is known as erythrocyte alloimmunization and occurs as a result of blood transfusions or incompatible pregnancies. In transfusion medicine, the search for irregular antibodies is essential, since failure to detect an alloantibody can cause transfusion reactions, alloimmunizations, autoimmune hemolytic anemias, and perinatal hemolytic disease. This study aims at analyzing the frequency of irregular antibodies of patients seen at the Regional Blood Center of Francisco Beltrão, Paraná, in 2017. The data were collected from the review of records in files of the Immunohematology Laboratory of Hemonúcleo. Data from 49 protocols of patients who had transfusion difficulties in 2017 were evaluated. Among those surveyed, 37 patients (75.5%) had irregular antibodies. Among the anti-erythrocyte antibodies observed in this study, the presence of twelve patients with anti-D (27.2%), six patients with anti-K (13.6%), four patients with anti-C (9.0 %), and in six patients (13.6%) with the presence of autoantibodies were observed. This study indicates that, in transfused patients, the most frequent antibodies were the Rh System Anti-D alloantibodies, probably due to their high degree of immunogenicity. The prevalence of these antibodies is similar to several studies found in the literature.

Detection of red cell alloantibodies in thalassaemia patients

Background: ?-thalassaemia patients receive regular blood transfusion to thrive. Due to antigen disparity between the blood donors and these patients they develop red cell alloantibodies due to alloimmunization.' The objective of this study is to predict the frequency of red cell alloimmunization amongst ?-thalassaemia major patients receiving regular blood transfusion.Methods: This study including 106 patients with ?-thalassaemia was conducted in the department of Transfusion Medicine, S. C. B. Medical College, Cuttack for a period of 12 months. Alloantibodies to different red cell blood group antigens in multi-transfused thalassaemia patients were detected using the glass bead technology for blood group serology in the present study.Results: Out of 106 ?-thalassaemia major patients included in the study, 7.5% of patients developed alloantibodies, all being clinically significant. The alloantibodies were anti-E, anti c, anti e and anti-D. The rate of incidence of these alloantibodies was 3.8%, 1.9%, 0.9% and 0.9% respectively.' There was a significant association between alloantibody formation with number of transfused packed red cells (Mann-Whitney Test: p value = 0.035) and age at first transfusion (p value = 0.001). The factors having no association with alloimmunization to red cell antigens are age and gender.Conclusions: Alloimmunization to various erythrocyte blood group antigens is a common problem in multi-transfused ?-thalassaemia patients. There is an association between number of transfused packed red cells and age at first transfusion with alloantibody formation in the study.

Prevalence of red blood cell alloimmunization in multiply transfused patients

Introduction: To analyze the prevalence of alloantibodies in multiply transfused patients. Methods: This study was a retrospective, exploratory and descriptive study with a quantitative approach. The study sample comprised 185 patients transfused at a referral service in the city of Passo Fundo, Rio Grande do Sul, from January 2016 to February 2018. Results: Overall, the antibodies identified were as follows: anti-E in 47 patients (18%), anti-D and anti-K in 28 patients each (11%), anti-C in 21 patients (8.1%), and inconclusive antibody results in 23 patients (8.9%). Females were a majority (55.7%), mean age was 48.8 years and mean quantity of blood transfused was 7.2 bags. Cardiovascular disorders were the most common comorbidities, in 39 patients (21.2%), followed by oncological disorders, in 38 patients (18.4%). Conclusion: Alloimmunization is an important and frequent clinical condition that increases the risk of hemolytic reactions and is associated with significant patient morbidity and mortality. (AU)

Anti-PP₁P(k) (Tj(a)) Antibody in a Korean Female Patient with p Phenotype Confirmed by Genotyping

Caracterización de donantes de sangre con rastreo de anticuerpos irregulares positivo en Montería, Colombia 2012-2015 / Blood donors characterization with positive irregular antibodies in Montería, Colombia 2012- 2015

Introducción: Los anticuerpos irregulares corresponden a aquellos distintos a los anticuerpos naturales anti-A o anti-B, los cuales pueden aparecer en respuesta a la exposición a un antígeno eritrocitario extraño (transfusión o trasplante) o por incompatibilidad materno-fetal. Objetivo: Caracterizar a los donantes con rastreo de anticuerpos irregulares positivo de un banco de sangre de Montería, Colombia, durante el periodo 2012-2015. Métodos: Estudio transversal y retrospectivo, con fuente de información secundaria, basada en los resultados del rastreo de anticuerpos en los donantes de un banco de sangre de Montería, Colombia, entre los años 2012 y 2015. La población estuvo conformada por todos los donantes voluntarios registrados en el tiempo del estudio (35 248 donantes), a quienes se les realizó rastreo de anticuerpos. Como muestra, se seleccionaron todos los casos que tuvieron resultados positivos (71 donantes). Los datos fueron organizados en tablas y analizados en el software SPSS 21.0, Microsoft Excel y en Epidat versión 3.1. Resultados: El 0,2 por ciento de la población presentó un rastreo de anticuerpos positivo con un intervalo de confianza entre 0,15 y 0,25 por ciento. Los anticuerpos irregulares fueron más frecuentes en los hombres y en donantes O Rh positivo. Se encontraron Ac irregulares con 13 especificidades diferentes, con predomino de anti-M, anti-Lea, anti-D y anti-E y porcentajes respectivos de 27,78 por ciento, 20,83 por ciento, 9,72 por ciento y 8,33 por ciento. El 50 por ciento de los donantes tenía 30,5 años o menos, el 49,3 por ciento había donado previamente y el 9,9 por ciento recibió al menos una transfusión en algún momento de su vida. Conclusión: La frecuencia de donantes con rastreo de anticuerpos irregulares positivo fue baja, el sexo masculino presentó mayor porcentaje, se detectó principalmente en el grupo sanguíneo O y dentro de los anticuerpos irregulares, anti-M presentó una mayor frecuencia(AU)

Introduction: Irregular antibodies correspond to those other than natural anti-A or anti-B antibodies, which may appear in response to exposure to a foreign erythrocyte antigen (transfusion or transplantation) or due to maternal-fetal incompatibility. Objective: To characterize the donors with positive irregular antibody screening of a blood bank in Monteria, Colombia during the period 2012-2015. Methods: Cross-sectional and retrospective study, with secondary information source, based on the results of the antibody screening in donors of a blood bank in Monteria, Colombia from 2012 to 2015. The population consisted of all voluntary donors registered in the study time (35 248 donors), who were screened for antibodies. As a sample, all cases that had positive results (71 donors) were selected. The data was organized in tables and analyzed in the software SPSS 21.0, Microsoft Excel and in Epidat version 3.1. Results: 0.2 percent of the population presented a positive antibody screen with a confidence interval between 0.15 and 0.25 percent Irregular antibodies were more frequent in men and in O Rh positive donors. Thirteen types of irregular antibodies were found, with predominance of anti-M, anti-Lea, anti-D and anti-E and respective percentages of 27.78 percent, 20.83 percent, 9.72 percent and 8.33 percent. 50 percent of the donors were 30.5 years old or less, 49.3 percent had previously donated and 9.9 percent received at least one transfusion at some point in their lives. Conclusion: The frequency of donors with irregular positive antibody screening was low, the male sex had a higher percentage, it was detected mainly in blood group O and within the irregular antibodies, anti-M showed a higher frequency(AU)

Red blood cell alloimmunization among hospitalized patients: transfusion reactions and low alloantibody identification rate

ABSTRACT Background: Unexpected red blood cell alloantibodies can cause hemolytic transfusion reactions. In this study, the prevalence of alloimmunization, the rate of identification of alloantibodies and the rate of blood transfusion reactions among transfused patients were identified in a clinical emergency hospital in Brazil. Methods: Transfusions and clinical records of patients who had a positive indirect antiglobulin test between January and December 2013 were analyzed. Results: Of 1169 patients who received blood transfusions, 28 had positive indirect antiglobulin tests, with one patient having two positive tests at different times, resulting in 29 positive tests during the period of this study. Alloantibodies were identified in 58.6% (17/29) of the cases. In 27.5% (8/29), identification was inconclusive and it was not possible to confirm alloimmunization. The rate of red blood cell alloimmunization was 1.71% (21/1169). Of 21 cases of alloimmunization, four (19%) were unidentified due to an unusual agglutination profile. All identified alloantibodies were clinically significant (10/17 anti-Rh, 5/17 anti-Kell and 2/17 anti-MNS). In two patients who had positive indirect antiglobulin tests, one had an unidentified alloantibody, and the other had an inconclusive test and developed a hemolytic transfusion reaction. Conclusion: The prevalence of clinically important red blood cell alloantibodies and hemolytic transfusion reactions among patients with unidentified alloantibodies suggests that specific laboratory techniques should be performed to identify alloantibodies in cases of pan-reactivity or autoantibodies to improve transfusion safety.

Detection of canine anti-DEA 1 antibodies using flow cytometry in dogs following DEA 1-positive blood transfusion / Detecção de anticorpos caninos anti-AEC 1 por citometria de fluxo em cães pós-transfundidos com sangue AEC 1 positivo

The shortage of dog blood donors in veterinary emergencies can lead to blood transfusions between animals whose blood type has not been identified. The antibody profile serves as a warning sign for animals that require a second blood transfusion, which is only advisable from compatible donor dogs. This article focuses on determination of anti-DEA 1 antibodies using the flow cytometry technique in dogs that have undergone a transfusion using DEA 1-positive blood, compared to results obtained from crossmatching. Blood from 18 DEA 1-positive donors ranked according to the chromatographic technique was used to transfuse thirty-three animals with unknown blood types and which demonstrated negative crossmatching to donors. On post-transfusion days 7, 14, 21 and 28, 45% and 27% of the animals tested positive for the anti-DEA 1 antibody, through crossmatching and flow cytometry, respectively. Detecting antibodies using the flow cytometric technique has high specificity and sensitivity, while crossmatching methods are highly sensitive but manifest low specificity. Following blood transfusion, animals that did not present as positive through crossmatching or flow cytometry were considered different from all other DEA 1-positive blood groups.(AU)

A escassez de cães doadores de sangue em situações de emergência na Medicina Veterinária pode levar a realização de transfusões de sangue entre animais que não tiveram seu tipo sanguíneo previamente determinado. O padrão de anticorpos serve como um sinal de alerta para animais que serão submetidos a uma segunda transfusão sanguínea, sendo essa somente recomendável a partir de cães doadores compatíveis. Este artigo aborda a pesquisa de anticorpos anti-AEC 1 pela técnica de citometria de fluxo em cães que receberam uma transfusão utilizando sangue do grupo AEC 1 positivo, comparando os resultados com aqueles obtidos a partir de reação cruzada. Foi utilizado sangue de 18 animais doadores do tipo AEC 1 positivo classificados por técnica cromatográfica para transfundir trinta e três animais com tipos sanguíneos desconhecidos, os quais mostraram reação cruzada negativa aos doadores. Nos dias 7, 14, 21 e 28 pós-transfusão, 45% e 27% dos animais mostraram-se positivos para os anticorpos anti-AEC 1, respectivamente, pela reação cruzada e através de citometria de fluxo. A pesquisa de anticorpos com o emprego da técnica de citometria de fluxo tem alta especificidade e sensibilidade, enquanto a reação cruzada, altamente sensível, tem baixa especificidade. Animais que não apresentaram positividade após a transfusão de sangue na reação cruzada e na citometria de fluxo concomitantemente foram considerados de qualquer outro grupo sanguíneo diferente do grupo sanguíneo AEC 1 positivo.(AU)

A Case of Packed red Cell Transfusion-Associated Anti-K Antibody

Anti-K alloantibody is a type of red blood cell (RBC) antibody which is generated through immunization. It is well noted that the anti-K antibody causes hemolytic transfusion reactions. Although Koreans generally do not have the K antigen on RBCs, we report a rare case of transfusion-related anti-K antibody in Korean patient. Just twelve pints of packed RBCs had been transfused to the patient before the anti-K was identified for the first time, but the donor information about Kell phenotype (K or k) was not available. The anti-K had been continuously detected, and the patient neither received immunoglobulins nor experienced bacterial infections which could generate anti-K antibody. Therefore we believe that her anti-K is the truly positive, previously transfused packed RBCs-related alloantibody. The packed RBCs transfused to our patient were likely to be donated from other races. The pre-transfusion irregular antibody detection test should be performed carefully to detect very rare RBC alloantibodies.

Identification of anti-C alloantibodies accompanying anti-e autoantibodies / 中国输血杂志

Objective To confirm the specificity of antibodies recently found in a hospitalized patient.Methods Methods including antibody screening,antibodies identification,alloantibody titers,isolation of red blood cells by high speed capillary centrifugation and determination of Rh phenotype were employed to investigate the characteristics of antibodies.Results Anti-C alloantibody and anti-e autoantibodies were detected in the patient.Autoantibodies were non-specific in the early stages,and gradually changed into specific auti-e antibodies.The titers of anti-C alloantibody were always lower than 4.Conclusion The identification of antibodies should be integrated as far as possible in various aspects of methodology.

Antibodies identification and crossmatching of a case with alloanti-C, e combing autoantibody mimicking alloanti-e / 中国输血杂志

Objective To understand the difference of serological characteristic between alloantibodies,'simple'Rhspecific autoantibodies and autoantibodies mimicking alloantibodies by studies of a patient who produces alloantibodies and autoantibodies that to distinguish Serologically them in order to more appropriate RBC component transfusion administration would be performed for patients.Methods Several serological methods were performed to the patient's serum samples for identification of antibodies by using two antibody screening cell reagents from different manufacturers.Using adsorption of the patient's Rh antibodies in the presence of LISS with the antibody was similar to that of the antigen negative cell from a donor who had a ccDEE Rh type and O type,and to detect antibodies in the absorbed serum and the eluting solution.Results The patient had a ccDEE Rh type with a positive direct antiglobulin test (DAT).Serum antibodies were identified as IgM anti-C,anti-e and IgG anti-e;the possibility of anti-Ce antibody is not excluded.After absorption,serum antibodies were identified as IgM anti-C,anti-e and IgG anti-e;anti-Ce antibody is not excluded.The antibody in patient's RBC elution was identified as IgG anti-e antibody.Conclusion Alloantibody and mimicking alloantibody can be distinguished by comprehensive analysis of patient's Rh phenotype,DAT result and antibody specificity in the serum and absorbed serum and elution of RBC.The low affinity antibody can be better absorbed by adding low ionic liquid (LISS).

Erythrocyte Transfusion and Alloimmunisation Patterns among Sickle Cell Disease Patients, Benin City, Nigeria.

Introduction: Blood transfusion remains a mainstay therapy in sickle cell disease (SCD).Transfusional therapy may be complicated by allo-immunisation due to exposure to foreign red cell antigens. However, the prevalence and patterns of atypical antibodies in Nigerian SCD has been sparsely reported majorly due to underdeveloped blood banking systems. A prospective study was therefore undertaken to assess patterns of blood transfusion and allo-immunisation among SCD patients in Benin City, Nigeria. Methodology: The study was conducted among adult and paediatric SCD subjects seen at a sickle cell centre in Benin City, Nigeria. All subjects (parents in case of children) who gave consent/assent to the study were interviewed using a structured questionnaire to obtain details on bio-data, SCD history and blood transfusion history. Blood specimen obtained from each participant was subjected to antibody screening/identification test using tube agglutination technique. Association of categorical variables was tested using chi-square or fisher exact test as appropriate. Results: Fifty five SCD patients were studied with a mean (SEM) age of 22.95 (1.66) years. More of the subjects (67.3%) were aged 15 years and above. 74.5% of the subjects have a past history of blood transfusion. Four (7.3%) of the subjects had unexpected erythrocyte allo-antibodies. Antibodies belonging to the Rh and Kell blood group systems were implicated. The risk of alloimmunisation increased with total lifetime transfusions (p = 0.002) Conclusion: Erythrocyte alloimmunisation is a significant therapy related complication in Nigerian SCD. Hydroxyurea use reduces transfusion requirements and should be maximized. There is need to upgrade local/regional transfusion services to include routine allo-antibody screening/identification as part of precompatibility testing particularly SCD patients who have received more than 10 units of red cell transfusion.

Prevalence of Rh, Duffy, Kell, Kidd & MNSs blood group antigens in the Indian blood donor population.

Background & objectives: Little data are available regarding the frequencies of the blood group antigens other than ABO and RhD in the Indian population. Knowledge of the antigen frequencies is important to assess risk of antibody formation and to guide the probability of finding antigen-negative donor blood, which is especially useful when blood is required for a patient who has multiple red cell alloantibodies. This study was carried out to determine the frequencies of the D, C, c, E, e, K, k, Fya, Fyb, Jka, Jkb, M, N, S and s antigens in over 3,000 blood donors. Methods: Samples from randomly selected blood donors from Delhi and nearby areas (both voluntary and replacement) were collected for extended antigen typing during the period January 2009 to January 2010. Antigens were typed via automated testing on the Galileo instrument using commercial antisera. Results: A total of 3073 blood samples from donors were phenotyped. The prevalence of these antigens was found to be as follows in %: D: 93.6, C: 87, c: 58, E: 20, e: 98, K: 3.5, k: 99.97, Fya: 87.4, Fyb: 57.6, Jka: 81.5, Jkb: 67.4, M: 88.7, N: 65.4, S: 54.8 and s: 88.7. Interpretation & conclusions: This study found the prevalence of the typed antigens among Indian blood donors to be statistically different to those in the Caucasian, Black and Chinese populations, but more similar to Caucasians than to the other racial groups.

Frequency of class I anti-HLA alloantibodies in patients infected by HIV-1

The aim of this study was to evaluate the presence of class I anti-HLA alloantibodies in patients infected by HIV-1 and relate it with the different clinical courses of the disease. Blood samples were collected in EDTA tubes from 145 individuals. HIV-1 infection was confirmed by ELISA test. The presence of class I anti-HLA alloantibodies and HLA allele's were determined. Clinical evolution was set as fast (<1 year between diagnostic and death), moderate (1-3 years) or slow (>3 years). Class I anti-HLA alloantibodies presence was lower in healthy individuals than in those infected by HIV-1 (4.2 percent against 32.4 percent). However, an equal distribution of these alloantibodies was found among the individuals infected, independent on the clinical evolution. Thus, class I anti-HLA alloantibodies was not a determinant factor for patient worsening.

O objetivo deste estudo foi avaliar a presença de aloanticorpos anti-HLA classe I em pacientes infectados pelo HIV-1 e relacioná-la aos diferentes cursos clínicos da doença. Amostras de sangue de 145 indivíduos HIV positivo foram coletadas em tubos com EDTA. A infecção pelo HIV-1 foi confirmada por teste ELISA e a presença de aloanticorpos anti-HLA classe I determinada em seguida. A evolução clínica foi definida como rápida (<1 ano entre diagnóstico e morte), moderada (1-3 anos) ou lenta (>3 anos). A presença de aloanticorpos anti-HLA classe I foi menor em indivíduos saudáveis em relação aos infectados pelo HIV-1 (4,2 por cento contra 32,4 por cento). Porém, a distribuição destes aloanticorpos entre os indivíduos infectados foi igual, independente da evolução clínica. Deste modo, a presença de aloanticorpos anti-HLA classe I não é um fator determinante na piora clínica do paciente.

The Characteristics of Concurrent Blood Group Antibodies Detected by Unexpected Antibody Screening Tests / 대한수혈학회지

BACKGROUND: Multiple alloimmunization is the production of two or more alloantibodies by an individual. These antibodies are significant because they can present major problems in compatibility testing. The goal of this study was to determine the properties of concurrent blood group (BG) antibodies in Korea. METHODS: The transfusion records of 540 patients from Dong-A University Hospital were reviewed to identify alloimmunized individuals. The records spanned a time period from September 2002 to March 2010. The data regarding transfusions and the clinical characteristics of those patients making concurrent antibodies were gathered. RESULTS: Concurrent blood group antibodies were found in 23.9% (45/188) of alloimmunized patients, constituting 40.7% (100/246) of all antibodies. The most common alloantibody pair were anti-E/-c and anti-C/-e. The mean transfused RBC units, mean interval, and mean transfusion frequencies before detection of two or more antibodies were 2.4 units, 92 days, and 2.4 times, respectively. The majority of alloantibody pairs appeared and were undetectable at the same time. Among 45 patients (mean age 55.9 years, range 32 to 82 years), twenty-six (57.8%) were female and the remaining nineteen were male. Non-hematological malignancy accounted for a major share (26.7%) in the underlying disease. CONCLUSION: Antibody concurrence varied by BG antigenic specificity. Rh antibodies, in particular anti-E with anti-c appeared to be highly linked. Unlike in Western countries, anti-K was less common in Korea and so the pairs involving this antibody were scarce. More prospective investigations are needed to delineate the immunologic phenomenon of multiple alloimmunization.