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.

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.

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)

Hemolysis risk after packed red blood cells transfusion with infusion pumps / Risco de hemólise após transfusão de concentrado de hemácias com bombas de infusão / Riesgo de hemólisis después de la transfusión de concentrados de glóbulos rojos con bombas de infusión

ABSTRACT Objective: To evaluate the hemolysis biomarkers of packed red blood cells transfused by two different linear peristaltic infusion pumps at two infusion rates. Method: An experimental and randomized study was designed simulating the clinical practice of transfusion. Two linear peristaltic infusion pumps from different manufactures were studied in triplicate at 100 mL/h and 300mL/h infusion rates. The chosen hemolysis biomarkers were total hemoglobin, free hemoglobin, hematocrit, potassium and degree of hemolysis. They were analyzed before and after each infusion. Results: Potassium showed statistically significant variations in all scenarios of the experiment (P<0.010). In a separated analysis, potassium increased mainly at 300mL/h rate (P=0.021) and free hemoglobin had significant variation when comparing infusion pumps from different manufacturers (P=0.026). Although hematocrit, total hemoglobin and degree of hemolysis had increased after infusion, no statistically significance variations were identified. Conclusions: Hemolysis risk induced by a linear peristaltic infusion pump was identified by an increase in free hemoglobin and potassium markers. As the potassium biomarker is often increased in aged packed red blood cells, we do not recommend using them in this scenario. Additional studies should be performed about other markers and using larger samples in order to reinforce the transfusion practice in nursing.

RESUMO Objetivo: avaliar os biomarcadores de hemólise de concentrado de hemácias transfundidos por duas bombas de infusão peristáltica linear distintas, em duas taxas de infusão. Método: estudo experimental randomizado desenhado para simular a prática clínica da transfusão. Duas bombas de infusão peristáltica linear de diferentes fabricantes foram estudadas em triplicata a 100 ml/h e 300 mL/h de infusão. Os biomarcadores de hemólise escolhidos foram hemoglobina total, hemoglobina livre, hematócrito, potássio e grau de hemólise. Eles foram analisados antes e após cada infusão. Resultados: o potássio apresentou variações estatisticamente significativas em todos os cenários do experimento (P < 0,010). Em análise separada, o potássio aumentou principalmente na taxa de 300 mL/h (P = 0,021) e a hemoglobina livre teve uma variação significativa no experimento comparando bombas de infusão de diferentes fabricantes (P = 0,026). Embora o hematócrito, a hemoglobina total e o grau de hemólise tenham aumentado após a infusão, não foram identificadas variações estatisticamente significativas. Conclusões: o risco de hemólise induzido por bombas de infusão peristáltica linear foi identificado com base em um aumento nos marcadores de hemoglobina livre e potássio. Como o biomarcador potássio é frequentemente aumentado em concentrados de hemácias envelhecidos, não se recomenda usá-los nesse cenário e estudos adicionais podem ser realizados. Vale a pena realizar estudos sobre outros marcadores e utilizar amostras maiores para fundamentar a prática de enfermagem transfusional.

RESUMEN Objetivo: evaluar los biomarcadores de hemólisis de concentrados de glóbulos rojos transfundidos por dos bombas de infusión peristálticas lineales diferentes a dos velocidades de infusión. Método: se hizo un estudio experimental y aleatorizado que simula la práctica clínica de la transfusión. Se estudiaron dos bombas de infusión peristálticas lineales de diferentes fabricantes por triplicado a velocidades de infusión de 100 ml/h y 300 ml/h. Los biomarcadores de hemólisis elegidos fueron la hemoglobina total, la hemoglobina libre, el hematocrito, el potasio y el grado de hemólisis. Fueron analizados antes y después de cada infusión. Resultados: El potasio mostró variaciones estadísticamente significativas en todos los escenarios del experimento (P <0.010). En análisis separados, el potasio aumentó principalmente a una tasa de 300 ml/h (P=0.021) y la hemoglobina libre tuvo una variación significativa en un experimento de un fabricante de bomba de infusión (P=0.026). Aunque el hematocrito, la hemoglobina total y el grado de hemólisis aumentaron después de la infusión, no se identificaron variaciones estadísticamente significativas. Conclusiones: el riesgo de hemólisis inducido por una bomba de infusión peristáltica lineal se identificó por un aumento en la hemoglobina libre y los marcadores de potasio. Debido a que el biomarcador de potasio a menudo aumenta en los glóbulos rojos concentrados de edad, no recomendamos utilizarlos en este escenario y se podrían realizar estudios adicionales. Vale la pena realizar estudios sobre otros marcadores y el uso de muestras más grandes para fundamentar la práctica de enfermería de transfusión de sangre.

Effects of polysaccharide from Ophiopogon japonicus on immune response to Newcastle disease vaccine in chicken

In order to investigate the immune enhancement effects of Ophiopogon japonicus polysaccharide Ophiopogon japonicus (OJPS) on Newcastle disease (ND) live vaccine, chickens vaccinated against ND live vaccine was orally administered with the OJPS at high, medium and low concentrations respectively. In negative control group, chickens were given orally equal volume of physiological saline. On day 14, 21 and 28, the serum antibody titer, erythrocyte-C3b receptor rosette rate (E-C3bRR), erythrocyte-C3b immune complex rosette rate (E-ICRR) and peripheral lymphocyte proliferation were measured. The results showed that at most time points, the antibody titer, peripheral lymphocyte proliferation, E-C3bRR and elimination rate of immune complex of three OJPS administrating groups were significantly higher (P<0.05) than those in negative control group. It indicated that OJPS could significantly improve the immune efficacy of Newcastle disease live vaccine, Ophiopogon japonicus polysaccharide possessed synergistical immunoenhancement.(AU)

Anti-H Antibody Showing Agglutination in the Anti-Human Globulin Phase in a Korean Patient

No abstract available.

Antibody recognition of Plasmodium falciparum infected red blood cells by symptomatic and asymptomatic individuals in the Brazilian Amazon

In the Amazon Region, there is a virtual absence of severe malaria and few fatal cases of naturally occurring Plasmodium falciparum infections; this presents an intriguing and underexplored area of research. In addition to the rapid access of infected persons to effective treatment, one cause of this phenomenon might be the recognition of cytoadherent variant proteins on the infected red blood cell (IRBC) surface, including the var gene encoded P. falciparum erythrocyte membrane protein 1. In order to establish a link between cytoadherence, IRBC surface antibody recognition and the presence or absence of malaria symptoms, we phenotype-selected four Amazonian P. falciparum isolates and the laboratory strain 3D7 for their cytoadherence to CD36 and ICAM1 expressed on CHO cells. We then mapped the dominantly expressed var transcripts and tested whether antibodies from symptomatic or asymptomatic infections showed a differential recognition of the IRBC surface. As controls, the 3D7 lineages expressing severe disease-associated phenotypes were used. We showed that there was no profound difference between the frequency and intensity of antibody recognition of the IRBC-exposed P. falciparum proteins in symptomatic vs. asymptomatic infections. The 3D7 lineages, which expressed severe malaria-associated phenotypes, were strongly recognised by most, but not all plasmas, meaning that the recognition of these phenotypes is frequent in asymptomatic carriers, but is not necessarily a prerequisite to staying free of symptoms. .

Apoptosis of non-parasitised red blood cells in Plasmodium yoelii malaria

Recently, while studying erythrocytic apoptosis during Plasmodium yoelii infection, we observed an increase in the levels of non-parasitised red blood cell (nRBC) apoptosis, which could be related to malarial anaemia. Therefore, in the present study, we attempted to investigate whether nRBC apoptosis is associated with the peripheral RBC count, parasite load or immune response. To this end, BALB/c mice were infected with P. yoelii 17XL and nRBC apoptosis, number of peripheral RBCs, parasitaemia and plasmatic levels of cytokines, nitric oxide and anti-RBC antibodies were evaluated at the early and late stages of anaemia. The apoptosis of nRBCs increased at the late stage and was associated with parasitaemia, but not with the intensity of the immune response. The increased percentage of nRBC apoptosis that was observed when anaemia was accentuated was not related to a reduction in peripheral RBCs. We conclude that nRBC apoptosis in P. yoelii malaria appears to be induced in response to a high parasite load. Further studies on malaria models in which acute anaemia develops during low parasitaemia are needed to identify the potential pathogenic role of nRBC apoptosis.

[Screening and identifying of erythrocyte alloantibodies in patients with Thalassemia major referred to Ahvaz Shafa hospital]

Patients with thalassemia major are clinically dependent on red blood cell [RBC] transfusions. Performing multiple transfusions increase the risk of transfusion-related complications including blood-borne infections, iron overload and also RBC alloimmunization. This cross-sectional descriptive study was conducted on 70 thalassemia cases with regular blood transfusions. The serum samples were screened for the detection of the unexpected antibodies and the positive samples were subjected to antibody identification. Among 70 cases, 6 [8.6%] were identified as unexpected alloantibody; three cases as Anti-K, one as Anti-E and another one as Anti-D. Coincidence of Anti D and Anti-E was detected in one case. Eighteen patients [25.7%] were splenectomized. No significant correlation was seen between the presence of alloantibody and age, sex, the time of first transfusion and spleen condition. Considering that the most prevalent unexpected antibodies [8.6%] identified in this study were against the Kell and Rh system antigens, the evaluation of compatibility for antigens found can be recommended before the performing of transfusion. Therefore, this strategy may decrease the possibility of recipient immunization and production of the unexpected antibodies against donor RBCs

Fatores de risco para aloimunização em pacientes com anemia falciforme / Risk factors for alloimmunization in patients with sickle cell anemia

OBJETIVO: Determinar a imunofenotipagem eritrocitária em doadores de sangue e em pacientes com anemia falciforme (SS) atendidos no Hemocentro de Alagoas e descrever a frequência e os fatores associados à aloimunização eritrocitária. MÉTODOS: Estudo transversal com 102 pacientes SS e 100 doadores de sangue. Realizou-se a fenotipagem eritrocitária, teste de Coombs Direto e Indireto e detecção de anticorpos irregulares por painel de hemácias fenotipadas. Os dados foram comparados por meio do teste de Mann-Whitney, qui-quadrado ou teste exato de Fisher. Para análise dos fatores associados à aloimunização utilizou-se a regressão logística univariada e múltipla. RESULTADOS: Os antígenos mais frequentes entre os pacientes e os doadores foram c, e, M, s, JK(a). Observaram-se diferenças significativas entre as frequências dos fenótipos dos pacientes e dos doadores em relação aos antígenos s, FY(a) e JK(b). Dos 79 pacientes transfundidos, 10 (12,7 por cento) apresentaram Coombs Indireto positivo. Detectaram-se 13 aloanticorpos, sete do sistema Rh, dois do Kell e quatro não identificados. Os fatores associados à aloimunização foram o intervalo de tempo entre a última transfusão e a data do teste e ter recebido mais de dez transfusões de hemácias. Receber mais de dez transfusões representou uma chance 16,39 (IC 95 por cento: 2,23-120,59) vezes maior de ser aloimunizado, em comparação aos que receberam menos que dez. CONCLUSÃO: A prevalência de aloimunização nos pacientes SS foi 12,7 por cento, sendo 70 por cento dos anticorpos encontrados pertencentes a grupos sanguíneos Rh e Kell. Este estudo mostra a importância da fenotipagem eritrocitária em doadores e receptores para diminuir o risco de aloimunização.

OBJECTIVE: To determine erythrocyte phenotyping in blood donors and patients with sickle cell anemia (SS) treated at Hemocentro of Alagoas and describe the frequency and factors associated with erythrocyte alloimmunization. METHODS: Cross-sectional study with 102 SS patients and 100 blood donors. The following tests were performed: erythrocyte phenotyping, Direct and Indirect antiglobulin test, and detection of irregular antibodies by panel of phenotyped red blood cells. Data were compared by Mann-Whitney, qui-square or Fisher’s exact tests. Factors associated with alloimmunization were studied by univariate and multiple logistic regression analysis. RESULTS: The most frequent antigens found in patients and blood donors were: c, e, M, s, JK(a). Significant differences were observed between the frequency of the phenotype of patients and donors in regard to antigens s, FY(a) and JK(b). Of 79 transfused patients, 10 presented positive Indirect Coombs. Thirteen alloantibodies were found, 7 of the Rh system, 2 of Kell and 4 were not identified. Factors associated with alloimmunization were the period of time between the last transfusion and the date of the test and more than 10 red blood cell transfusions. Patients who received more than 10 transfusions were 16.39 (95 percent CI: 2.23-120.59) times more likely to be alloimmunized than patients with fewer transfusions. CONCLUSION: The prevalence of alloimmunization in SS patients was 12.7 percent, with 70 percent of antibodies belonging to the Rh and Kell systems. This study shows the importance of performing erythrocyte phenotyping in blood donors and receptors to decrease the risk of alloimmunization.

Captación de ácido siálico por larvas de Ascaris lumbricoides durante incubación in vivo / Sialic acid capture by Ascaris lumbricoides larvae during in vivo incubation / Captação de ácido siálico por vermes de Ascaris lumbricoides durante incubação in vivo

La agregación eritrocitaria afecta la microcirculación y su estudio es importante en las vasculopatías. Se comunicó que Ascaris lumbricoides puede capturar ácido siálico (AS) del eritrocito y alterar la carga aniónica del glóbulo. El objetivo de este trabajo fue estudiar la captación de AS por larvas de A. lumbricoides incubadas in vivo con eritrocitos. Se trabajó con un concentrado de larvas ([CLAL]) incubado en 4 tubos con buffer fosfato y antibióticos. En dos se agregaron eritrocitos Grupo O. Los restantes fueron controles. Se incubaron a 37 °C (5% CO2) durante 24 y 48 horas. Las larvas fueron separadas, recolectadas, concentradas y contadas microscópicamente (larvas/mL: [CLAL]1: 1500-1700; [CLAL]3 1600-1800; [CLAL]2 y 4: 200400). Se utilizaron las técnicas de Inhibición de la Agregación por Polibrene (IAP) y Alcian Blue (AB). La IAP mostró una diferencia significativa entre los Títulos de Polibrene diluido en solución fisiológica y en [CLAL]1 y 2 que fueron incubados con eritrocitos 24 y 48 horas respectivamente. No hubo variación en el Título de los Controles correspondientes ([CLAL]3 y [CLAL]4). AB realizada en [CLAL]1 y [CLAL]3, determinó CASCap%= 6,65% ± 0,36 y CAS[CLAL]3% = 0,67% ± 0,36. La experiencia demostró la captación de AS por las larvas incubadas in vivo con eritrocitos y sugirió que ellas no presentan AS intrínseco. El secuestro de AS durante la migración larvaria podría ser importante en la interacción parásito-hospedador.

Erythrocyte aggregation affects microcirculation and its study is important in vascular diseases. It was communicated that Ascaris lumbricoides can capture erythrocyte sialic acid (SA) and alter the anionic charge on the red cell. The aim of this work was to study SA capture by A. lumbricoides larvae incubated in vivo with erythrocytes. Work was performed with concentrated larvae ([ALLC]) incubated in 4 tubes with phosphate buffer and antibiotics. Group O erythrocytes were added in two Tubes. The remaining were Controls. They were incubated at 37 °C (5% CO2) for 24 and 28 hours. The larvae were separated, collected, concentrated and counted microscopically (larvae/mL: [ALLC]1:1500-1700; [ALLC]3: 1600-1800; [ALLC]2 and 4: 200- 400). Aggregation Inhibition by Polybrene (AIP) and Blue Alcian (BA) techniques were used. AIP showed a significant difference between Polybrene Titers diluted with physiological solution and with [ALLC]1 and 2, which were incubated with erythrocytes 24 and 48 hours respectively. There was no change in the Title of the corresponding Controls. BA performed in [ALLC]1 and [ALLC]3 determined CapSAC = 6.65% ± 0.36 and SAC[CLAL]3 %= 0.67% ± 0.36. The experience showed SA capture by larvae incubated in vivo with erythrocytes and it suggested that they have no intrinsic SA. SA kidnapping during the larval migration could be important in parasite-host interaction.

A agregação eritrocitária afeta a microcirculação e seu estudo é Importante nas vasculopatias. Foi comunicado que o Ascaris lumbricoides pode capturar ácido siálico (AS) do eritrocito e alterar a carga aniônica do glóbulo. O objetivo deste trabalho foi estudar a captação de AS por vermes de A. lumbricoides incubados in vivo com eritrocitos. Trabalhouse com uma concentração de larvas ([CLAL]) incubada em 4 tubos com buffer fosfato e antibióticos. Em dois foram agregados eritrocitos Grupo O. Os restantes foram controles. Foram incubados a 37 °C (5% CO2) durante 24 e 48 horas. As larvas foram separadas, coletadas, concentradas e contadas microscopicamente (larvas/mL: [CLAL]1: 1500-1700; [CLAL]3 1600-1800; [CLAL]2 e 4: 200-400). As técnicas utilizadas foram de Inibição da Agregação por Polybrene (IAP) e Alcian Blue (AB). A IAP mostrou uma diferenga significativa entre os Títulos de Polybrene diluido em solução fisiológica e em [CLAL]1 e 2 que foram incubados com eritrocitos 24 e 48 horas respectivamente. Näo houve variação no Título dos Controles correspondentes ([CLAL]3 e [CLAL]4). AB realizada em [CLAL]1 e [CLAL]3, determinou CASCap%= 6,65% ± 0,36 e CAS[CLAL]3% = 0,67% ± 0,36. A experiencia demons-trou a captação de AS pelos vermes incubados in vivo com eritrócitos e sugeriu que eles näo apresentam AS intrínseco. O sequestro de AS durante a migração de larvas poderia ser importante na interação parasita-hospedeiro.

Pregnancy malaria: cryptic disease, apparent solution

Malaria during pregnancy can be severe in non-immune women, but in areas of stable transmission, where women are semi-immune and often asymptomatic during infection, malaria is an insidious cause of disease and death for mothers and their offspring. Sequelae, such as severe anaemia and hypertension in the mother and low birth weight and infant mortality in the offspring, are often not recognised as consequences of infection. Pregnancy malaria, caused by Plasmodium falciparum, is mediated by infected erythrocytes (IEs) that bind to chondroitin sulphate A and are sequestered in the placenta. These parasites have a unique adhesion phenotype and distinct antigenicity, which indicates that novel targets may be required for development of an effective vaccine. Women become resistant to malaria as they acquire antibodies against placental IE, which leads to higher haemoglobin levels and heavier babies. Proteins exported from the placental parasites have been identified, including both variant and conserved antigens, and some of these are in preclinical development for vaccines. A vaccine that prevents P. falciparum malaria in pregnant mothers is feasible and would potentially save hundreds of thousands of lives each year.

Incidência de aloimunização eritrocitária em pacientes poli transfundidos / Prevalence of erythrocyte alloimmunization in polytransfused patients

Objective: To determine the incidence and the rate of red blood cell alloimmunization in polytransfused patients. Methods: A polytransfused patient was defined as having received at least 6 units of red cell concentrates during a 3-month period. The recordsof all patients (n = 12,904) who had received red blood cell units were examined retrospectively by searching the computer database at Hospital Israelita Albert Einstein in São Paulo, Brazil, over a 6-year period, between 2003 and 2009. Results: During this time, 77,049 red cell concentrate transfusions were performed in 12,904 patients. There were 3,044 polytransfused patients, 227 of whom (7.5%) presented with irregular erythrocyte antibodies. The prevalence of alloantibody specificity was: Anti-E>anti-D>anti-K>anti-C>anti-Dia>anti-c>anti-Jka>anti-S in 227 polytransfused patients. We found combinations of alloantibodies in 79 patients (34.8%), and the most commonspecificities were against the Rh and/or Kell systems. These antibodies show clinical significance, as they can cause delayed hemolytic transfusion reactions and perinatal hemolytic disease. About 20% of the patients showed an IgG autoantibody isolatedor combined with alloantibodies. Interestingly, a high incidence of antibodies against low frequency antigens was detected in this study, mainly anti-Dia. Conclusion: Polytransfused patients have a high probability of developing alloantibodies whetheralone or combined with autoantibodies and antibodies against low frequency antigens. Transfusion of red blood cells with a phenotype-compatible with RH (C, E, c), K, Fya, and Jka antigens is recommended for polytransfused patients in order to preventalloimmunization and hemolytic transfusion reactions.

Objetivo: Determinar a incidência e a taxa de aloimunização eritrocitária em pacientes politransfundidos. Métodos: Foram classificados como politransfundidos todos os pacientes que receberam no mínimo 6 unidades de concentrado de hemácias no período de 3 meses. Foram examinados retrospectivamente os prontuários de todos os pacientes(n = 12.904) que receberam transfusões de unidades de hemácias procurados nas bases de dados computadorizados do Hospital Israelita Albert Einstein, em São Paulo (SP), no período de 6 anos, entre 2003 e 2009. Resultados: Nesse período foram realizadas 77.049 transfusões de concentrado de hemácias em 12.904 pacientes. Os pacientes politransfundidos totalizaram 3.044, sendo que 227 (7,5%) apresentam anticorpos eritrocitários irregulares. A prevalência da especificidade dos aloanticorpos encontrados nos 227 pacientes politransfundidos foi: Anti-E>anti-D>anti-K>anti-C>anti-Dia>antic>anti-Jka>anti-S. Em 79 pacientes (34,8%) foram encontradas associações de aloanticorpos e as combinações mais freqüentes foram dos anticorpos dos sistemas Rh e/ou Kell. Esses anticorpos têm importância clínica, pois podem causar reações transfusionais hemolíticas tardias e doença hemolítica perinatal. Cerca de 20% dos pacientes apresentavam autoanticorpo IgG isolado ou em associação com aloanticorpos. Um achado interessante neste estudo foi a alta incidência de anticorpos contra antígenos de baixa frequência, com predomínio anti-Dia. Conclusão: Pacientes politransfundidos têm alta probabilidade de desenvolver aloanticorpos isolados ou em associação com autoanticorpos e anticorpos contra antígenos de baixa frequência. A transfusão de concentrado de hemácias com fenótipo compatível para os antígenos RH (C, E, c), K, Fya, e Jka deve ser recomendada para o grupo de pacientes politransfundidos, com objetivo de evitar a aloimunização e a reação transfusional hemolítica.

Anaemia & expression levels of CD35, CD55 & CD59 on red blood cells in Plasmodium falciparum malaria patients from India.

Background & objectives: Severe anaemia in Plasmodium falciparum (Pf) associated malaria is a leading cause of death despite low levels of parasitaemia. In an effort to understand the pathogenesis of anaemia we studied expression level of RBC complement regulatory proteins, CR1 (CD35), CD55 and CD59 with haemoglobin status in a group of malaria cases from Assam, Goa and Chennai, and in healthy controls. Methods: Flowcytometry was used to study expression of CR1, CD55 and CD59 in 50 Pf cases and 30 normal healthy volunteers. Giemsa stained thick and thin blood films were used for microscopic detection and identification of malarial parasites and parasite count. Results: No correlation was found between degree of expression of RBC surface receptors CR1, CD55 and CD59 with haemoglobin level. However, expression of CD55 was less in malaria cases than in healthy controls. Interpretation & conclusions: The present findings indicate that malaria infection changes the expression profile of complement regulatory protein CD55 irrespective of severity status of anaemia. Further studies are needed to explore the pathophysiology of anaemia in malaria cases in Assam where expression of RBC complement receptors appears to be low even in normal healthy population.