Manejo clínico y diagnóstico para pacientes con enfermedades de inmunodeficiencia primaria por déficit de producción de anticuerpos / Clinical management and diagnosis for patients with primary immunodeficiency diseases due to deficiency of antibody production

1. INTRODUCCIÓNLas inmunodeficiencias primarias son un grupo de más de 400 enfermedades, en las cuales el sistema inmune pierde sus funciones de reconocimiento de patógenos o funciona de forma inapropiada. Algunas de ellas son relativamente comunes; mientras otras son raras. Estas enfermedades son en ocasiones de por vida, debilitantes y costosas1,2.Sin embargo, muchos progresos se han hecho desde su des-cripción original en el año de 1952. Se han dado grandes pasos en cuanto a su entendimiento de las Inmunodeficiencias Pri-marias a nivel genético, de sus características, y tratamiento. Algunos tipos afectan un único tipo de célula; otros afectan más de un componente del sistema inmune2,3.Tomando en cuenta que la aproximación es entre 1-2% de la población, a nivel país se puede decir que un aproximado entre 170 000 a 340 000 pacientes en el país no cuentan con un diagnóstico y muchos mueren por falta de este. El número de afiliados al Instituto Ecuatoriano de Seguridad Social hasta julio de 2021 es de 3 672,611 por lo que se considera que un estimado de 36 726 a 73 452 pacientes podrían presentar este tipo de enfermedades y requerir de atención por infecciones a repetición, enfermedad autoinmune y enfermedades linfopro-liferativas, además de que sin un tratamiento específico po-drían fallecer debido a infecciones graves o tener discapacidad permanente, lo que implica mayor carga para el sistema de Seguridad Social en subsidios y menores ingresos. Ecuador, cuenta con 86 pacientes diagnosticados, según la base de datos de la Sociedad Latino-Americana de Inmunodeficiencias4.Algunas terapias, como la de reemplazo para inmunoglobu-linas, a la que es tributaria más del 60% de estas patologías permite que la esperanza de vida y la morbilidad casi alcancen a aquellos que no presentan la enfermedad5­7.

1. INTRODUCTIONPrimary immunodeficiencies are a group of more than 400 diseases, in which the immune system loses its pathogen recog-nition functions or functions inappropriately. Some of them are relatively common, while others are rare. These diseases are sometimes lifelong, debilitating, and costly1,2. However, much progress has been made since its original description in 1952. Great strides have been made in understanding Primary Immunodeficiencies at the genetic level, their characteristics, and treatment. Some types affect only one type of cell; others affect more than one component of the immune system2,3. Considering that the approximation is between 1 to 2% of the population, at the country level we could say that approximately between 170 000 to 340 000 patients in the country do not have a diagnosis and many die due to lack of it. The number of social security affiliates until July 2021 is 3 672,611, so we could consider that approximately 36 726 to 73 452 patients could present this type of disease and require care for recurrent infections, autoimmune disease and lymphoproliferative diseases, in addition to the fact that without specific treatment they could die due to serious infections or have permanent disability, which implies a greater burden for the social security system in subsidies and lower income. Currently the country has 86 diagnosed patients, according to the database of the Latin American Society of Immunodeficiencies4. Many of the therapies, such as immunoglobulin replacement therapy, to which more than 60% of these pathologies are de-pendent, allow life expectancy and morbidity to almost reach those who do not have the disease 5­7.

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.

Prevalence of anti-tissue transglutaminase antibodies in patients with irritable bowel syndrome in Duhok city / Prevalência de anticorpos antitransglutaminase tecidual em pacientes com síndrome do intestino irritável na cidade de Duhok

Abstract Background Irritable bowel syndrome (IBS) is a common gastrointestinal disorder; celiac disease is an autoimmune enteropathy that can mimic any functional gastrointestinal disorder. The aim of this study is to estimate the prevalence of celiac disease antibodies (anti Tissue Transglutaminase-tTG) in patients with irritable bowel syndrome. Patients and methods This cross sectional study was conducted on 70 patients with irritable bowel syndrome fulfilling Rome III criteria who visited Azadi Teaching Hospital in Duhok city-Iraq. Patients were classified according to irritable bowel syndrome subtypes into: Diarrhoea Predominant (D-IBS), Constipation Predominant (C-IBS) and Mixed (M-IBS). IgA and IgG anti tTG were used to screen patients for celiac disease. Results A total number of 70 patients (44 females and 26 males) were included; their mean age was 33 years (SD ± 7.64). Five patients (7.1%) were found to have positive both IgA and IgG anti tTG. Three of them have had D-IBS and the other two had C-IBS. No one of the M-IBS patients tested positive. Conclusion The prevalence of anti tTG antibodies in irritable bowel syndrome is high. Patients with D-IBS should be screened for celiac disease.

Resumo Introdução A síndrome do intestino irritável (SII) é um distúrbio gastrointestinal comum; a doença celíaca é uma enteropatia autoimune que pode imitar qualquer distúrbio gastrointestinal funcional. O objetivo deste estudo foi estimar a prevalência de anticorpos contra a doença celíaca (antitransglutaminase tecidual - tTG) em pacientes com SII. Pacientes e Métodos Este estudo transversal foi conduzido em 70 pacientes com síndrome do intestino irritável que atendiam aos critérios de Roma III e se apresentaram ao Hospital de Ensino Azadi na cidade de Duhok, no Iraque. Os pacientes foram classificados de acordo com os subtipos de síndrome do intestino irritável em: predominantemente diarreia (D-SII), predominantemente constipação (C-SII) e mista (M-SII). IgA e IgG antitTG foram usados para rastrear pacientes com doença celíaca. Resultados Um total de 70 pacientes (44 mulheres e 26 homens) foram incluídos; a idade média foi de 33 anos (DP ± 7,64). Cinco pacientes (7,1%) apresentaram IgA e IgG antitTG positivos. Três deles tinham D-SII e os outros dois tinham C-SII. Nenhum dos pacientes com M-SII apresentou teste positivo. Conclusão A prevalência de anticorpos antitTG na SII é alta. A presença de doença celíaca deve ser avaliada em pacientes com D-SII.

IgY antialérgenos específicos del grupo 1 de ácaros del polvo doméstico inducidos por oligopéptidos sintéticos no glicosilados / Specific IgY anti-group 1 dust mite allergens induced by unglycosylated synthetic oligopeptides

Resumen Introducción. La obtención de anticuerpos específicos capaces de detectar alérgenos del grupo 1 de ácaros del polvo doméstico representa una estrategia potencial de salud pública para reducir la exposición y la sintomatología clínica asociada con el asma y la rinitis alérgica. Objetivo. Producir y purificar anticuerpos aviares antialérgenos específicos del grupo 1 de los ácaros Dermatophagoides sp.y Blomia tropicalis utilizando la tecnología IgY. Materiales y métodos. Se diseñaron y sintetizaron oligopéptidos que evidenciaran epítopes inmunogénicos de los alérgenos Der p1, Der f1 y Blo t1 empleados posteriormente para producir anticuerpos IgY policlonales en gallinas Hy Line Brown. Las IgY presentes en las yemas de los huevos se purificaron mediante cromatografía tiofílica. Su inmunorreactividad y especificidad se determinaron mediante un inmunoensayo ELISA indirecto y Dot Blot. Resultados. Se obtuvo una reactividad elevada de las IgY contra epítopes de alérgenos presentes en extractos de cuerpo entero de D. farinae, D. pteronyssinus y B. tropicalis. Los niveles más altos de IgY se produjeron entre los días 32 y 40 de inmunización. Los anticuerpos mostraron mayor inmunorreactividad y especificidad en el reconocimiento de proteínas de D. farinae, con un límite de detección mayor de 0,03 µg de proteína total delcaroajo las condiciones experimentales analizadas. Las IgY purificadas no mostraron reactividad significativa frente al extracto de Periplaneta americana. Conclusión. La tecnología IgY permitió la producción de anticuerpos específicos contra alérgenos del grupo 1 de los ácaros del polvo al utilizar oligopéptidos sintéticos no glicosilados. Hasta donde se sabe, esta es la primera vez que se usan estos reactivos inmunológicos para la detección de ácaros de importancia médica.

Abstract Introduction: The use of specific antibodies capable of detecting allergens of the group 1 of house dust mites represents a potential strategy to reduce exposure and clinical symptomatology associated with asthma and allergic rhinitis. Objective: To produce and purify chicken antibodies specific for the dust mites Dermatophagoides sp. and B. tropicalis using the IgY technology. Materials and methods: We designed and synthesized oligopeptides showing immunogenic epitopes of Der p1, Der f1, and Blo t1. These were used to produce IgY antibodies in Hy Line Brown chickens. IgY were extracted from egg yolk using thiophilic chromatography. The immunogenicity and specificity were assayed by indirect ELISA and Dot Blot. Results: We obtained high reactivity of IgY antibodies against epitopes of allergens present in whole body mites extracts of D. farinae, D. pteronyssinus, and B. tropicalis. The highest IgY levels were registered between days 32 and 40 after immunization. The antibodies showed high immunoreactivity and specificity towards D. farinae proteins with detection limits above 0.03 µg of mite proteins under the experimental conditions used. Purified IgY did not show significant reactivity when binding to Periplaneta americana extract. Conclusion: The IgY technology allowed the production of specific antibodies against house dust mites group 1 allergens using non-glycosylated synthetic peptides. To our knowledge, this is the first time that this immunochemicals are used in the detection of mites of medical relevance.

Desarrollo de un producto anti-toxina shiga para la prevención del síndrome urémico hemolítico / Development of a product anti-Shiga toxin for prevention of the hemolytic uremic syndrome

El síndrome urémico hemolítico (SUH) típico es una enfermedad huérfana causada por cepas de Escherichia coli productoras de toxina Shiga (Stx) y caracterizada por daño renal agudo, anemia hemolítica microangiopática y plaquetopenia. Es endémico en Argentina, el país con mayor incidencia de SUH en el mundo. Debido al rol fundamental de la Stx en su patogenia, se puede considerar que, como otras toxemias conocidas, el SUH podría ser tratado con anticuerpos. Este trabajo describe el desarrollo de un nuevo tratamiento capaz de neutralizar el efecto tóxico de distintas variantes de la Stx. El tratamiento consiste en fragmentos F(ab')2 provenientes de un antisuero equino cuya eficacia y potencia contra Stx1 y Stx2 se comprobó en diferentes modelos preclínicos. El producto mostró ser seguro en animales, presentó la farmacocinética descripta para compuestos similares y se pudo establecer una posible ventana terapéutica para su adecuada administración. En conjunto, los resultados preclínicos obtenidos validan la realización de un estudio clínico de primer uso en humanos. En dicho estudio, que se realizará en el Hospital Italiano de Buenos Aires, se analizará la seguridad y la farmacocinética del producto en voluntarios adultos sanos. Estos resultados sentarán las bases para la realización del estudio clínico fase II en pacientes pediátricos con infección por cepas de E. coli productoras de Stx.

The typical hemolytic uremic syndrome (HUS) is an orphan disease caused by Shiga toxin(Stx) -producing Escherichia coli strains and characterized by acute kidney damage, microangiopathic hemolytic anemia and low platelet count. It is endemic in Argentina, the country with the highest incidence of HUS in the world. Stx is essential for its development and therefore, HUS is considered a toxemic non-bacteremic disorder, which could be treated with antibodies. Herein we describe the development of a new treatment capable of neutralizing the toxic effect of Stx and its variants. The treatment consists of F(ab')2 fragments from an equine antiserum whose efficacy and potency against Stx1 and Stx2 were proved in different preclinical models. The product was shown to be safe in animals. Furthermore, the anti-Stx F(ab')2 pharmacokinetic was shown to be similar to that of analogous compounds and a therapeutic window for its administration was determined. Altogether, these preclinical results warrant testing in humans. The phase I clinical trial will be performed at the Hospital Italiano in Buenos Aires to evaluate the safety and pharmacokinetics of the product in healthy adult volunteers. Based on the results of this study, a phase II clinical trial will be planned in pediatric patients diagnosed with infection by Stx-producing E. coli strains.

Encefalitis autoinmunitaria asociada a anticuerpos contra el receptor N-metil-D-aspartato: presentación de dos casos / Autoimmune encephalitis associated to antibodies against the N-methyl-D-aspartate receptor: Report of two cases

Resumen La encefalitis asociada a anticuerpos contra receptores N-metil-D-aspartato es un síndrome neurológico que se presenta más comúnmente en mujeres jóvenes y frecuentemente se asocia al teratoma de ovario. Se caracteriza por un cuadro clínico agudo con síntomas generales inespecíficos que evoluciona hacia deterioro neurológico, psicosis y convulsiones; en su etapa más avanzada, se asocia con movimientos anormales y disautonomía. Se reportan dos casos en mujeres de 23 y 12 años. Dada su baja incidencia, se explica el proceso clínico que llevó a su diagnóstico y las opciones de tratamiento empleadas.

Abstract Anti-N-methyl-D-aspartate receptor encephalitis is a neurological syndrome that is more common in young women and is often associated with ovarian teratoma. It is characterized by acute general unspecific symptoms that evolve to neurological deterioration, psychosis and seizures. In its more advanced stage it is associated with abnormal movements and dysautonomia. We report two cases in women of 23 and 12 years of age. Given its low incidence, we present the clinical exercise that led to their diagnoses and the treatment options employed.

Maxadilan-simile expression in Nyssomyia neivai, a sandfly vector in an endemic region of Brazil, and its immunogenicity in patients with American tegumentary leishmaniasis

BACKGROUND Maxadilan (Max) is a salivary component in the sandfly Lutzomyia longipalpis (Lutz & Neiva 1912), a vector of visceral leishmaniasis. Max has a powerful vasodilatory effect and is a candidate vaccine that has been tested in experimental leishmaniasis. Nyssomyia neivai (Pinto 1926) is a vector of the pathogen responsible for American tegumentary leishmaniasis (ATL) in Brazil. OBJECTIVE We searched for Max expression in Ny. neivai and for antibodies against Max in ATL patients. METHODS cDNA and protein were extracted from the cephalic segment, including salivary glands, of Ny. neivai and analysed by polymerase chain reaction, DNA sequencing, and blotting assays. The results were compared with data obtained from Lu. longipalpis samples. We quantified antibodies against Max in serum samples from 41 patients with ATL (31 and 10 with the cutaneous and mucocutaneous forms, respectively) and 63 controls from the endemic northeastern region of São Paulo state, using enzyme-linked immunosorbent assay. FINDINGS Recognition of a Max-simile peptide by specific antibodies confirmed expression of a Max sequence in Ny. neivai (GenBank EF601123.1). Compared to controls, patients with ATL presented higher levels of antibodies against Max (p = 0.004); 24.4% of the patients with ATL and 3.2% of the controls presented anti-Max levels above the cutoff index (p = 0.014). The anti-Max levels were not associated with the specific clinical form of ATL, leishmanin skin test response, absence or presence of amastigotes in histopathologic exam, results of indirect immunofluorescence testing for leishmaniasis, or duration of cutaneous form disease. MAIN CONCLUSION High serum anti-Max levels did not protect patients against ATL, but confirmed previous natural exposure to Ny. neivai bites in this ATL endemic region.

Anticuerpos anticitomegalovirus y anti-virus de Epstein Barr pretrasplante renal en Cuba / Renal pretransplant anti-citomegalovirus and anti-Epstein Barr virus antibodies in Cuba

Introducción: las infecciones virales postrasplante de órganos sólidos constituyen las principales causas de morbilidad y mortalidad de los pacientes trasplantados. En Cuba se introdujo recientemente la detección de anticuerpos clase IgM e IgG, antivirus de Epstein Barr (EBV) y anticitomegalovirus (CMV) mediante técnicas de ELISA con analizador automático como parte del aseguramiento pretrasplante renal. Objetivo: determinar la prevalencia de las infecciones en los pacientes en espera de trasplante renal y si existe asociación entre la presencia de anticuerpos anti-EBV y anti-CMV con posibles eventos sensibilizantes y la presencia de anticuerpos anti-HLA. Métodos: se estudiaron 1 179 muestras de pacientes en espera de trasplante renal, entre agosto de 2013 y diciembre de 2014. Se realizaron 4 técnicas de inmunoensayos enzimáticos (ELISA) de tipo heterogéneo, no competitivo, cuantitativo e indirecto usando los estuches comerciales: Cytomegalovirus IgG ELISA, Cytomegalovirus IgM ELISA, Epstein-Barr virus VCA IgG y Epstein-Barr virus VCA IgM. El estado de aloinmunizacion anti-HLA clase I y II se definió de acuerdo a los estudios realizados por ELISA con los estuches comerciales: LIFECODES QuikScreen y LIFECODES B-Screen. Se empleó el estadígrafo Chi cuadrado de independencia para determinar la existencia de asociación entre la presencia de anticuerpos y el sexo, las transfusiones sanguíneas, trasplantes previos, hepatitis B, C y anticuerpos anti-HLA. Resultados: la prevalencia de infección con estos virus fue semejante en sujetos sanos y pacientes en espera de trasplante renal. Existió asociación entre IgM anti-CMV, IgG anti-CMV y IgM anti-EBV con el sexo, e IgG anti-CMV con las transfusiones, la seropositividad para la hepatitis C y los anticuerpos anti-HLA clase I. Conclusiones: se hace necesario tomar medidas para evitar el contagio peritrasplante por transmisión sanguínea de los pacientes seronegativos a estos virus pues debido a la inmunosupresión que provocan constituyen un riesgo para el éxito del trasplante renal(AU)

Introduction: Solid organ post-transplant viral infections are the main cause of worldwide morbi-mortality in transplanted patients. In Cuba it has been recently introduced the IgM and IgG anti Epstein Barr (EBV) and anti Citomegalovirus (CMV) antibody detection by ELISA with automatic analyzers as part of the pre transplant studies. Objective: to know population viral infection prevalence and to find possible association between anti EBV and anti CMV antibodies with sensitizing events and anti-HLA antibodies. Methods: An, investigation was carry out using 1179 samples from patients waiting for renal transplant at the Institute of Hematology and Immunology since August 2013 to December 2014. Four enzyme immunoassay (ELISA) heterogeneous type, non-competitive, quantitative and indirect were performed using commercial kits: Cytomegalovirus IgG ELISA, IgM ELISA Cytomegalovirus, Epstein-Barr virus VCA IgG and Epstein-Barr virus VCA IgM. Alloimmunization state anti-HLA class I and II are defined according to studies by ELISA with commercial kits: LIFECODES QuikScreen and LIFECODES B-Screen. Chi square test of independence was used to determine the existence of association between the presence of antibodies and sex, blood transfusions, previous transplantation, hepatitis B, C and anti-HLA antibodies. Results: It was found that the viral infection prevalence was the same as other populations, association of IgM anti CMV, IgG anti CMV and IgM anti EBV with sex and IgG anti CMV with blood transfusions, hepatitis C seropositivity and anti-HLA clase I antibodies. Conclusions : It is necessary to take measures to avoid peritransplant contagion of seronegative patients to theseviruses by blood transmission due to the immunosuppression that they cause, in order to obtain a renal transplant success(AU)

Encefalitis autoinmune por anticuerpos contra el receptor GABA-A: caso clínico / Autoimmune encephalitis induced by antibodies against GABA-A receptor

Among autoimmune encephalitides, a prevalent group are those associated with antibodies against the N-Methyl-D-aspartate receptor, which present with behavior abnormalities, psychosis, seizures and abnormal movements. A new variant, mediated by antibodies against the GABA-A receptor, was recen­tly described. We report a 66-years-old female with this form of encephalitis whose main manifestation was the presence of severe seizures leading to status epilepticus. The patient had a good response to immunomodulatory therapy with intravenous methylprednisolone, azathioprine and anticonvulsants. The laboratory tests initially detected anti-thyroid peroxidase antibodies which lead to the misdiagnosis of Hashimoto Encephalitis, which was ruled out after the detection of antibodies against GABA-A receptor. No malignancy was detected.

Trasplante renal en pacientes con anticuerpos dirigidos contra donante

En trasplante renal, los anticuerpos donante-específicos por ensayos de fase sólida predicen el rechazo temprano mediado por anticuerpos, incluso con resultados negativos de citometría de flujo o citotoxicidad dependiente del complemento. Aquí se describen los protocolos de inmunosupresión y los resultados a diez meses de cuatro pacientes en los que se detectó anticuerpos donante-específicos anti-antígenos leucocitarios humanos (HLA) por Luminex®, pero no detectados por el método de citotoxicidad dependiente de complemento (CDC) ni por citometría de flujo. Los cuatro pacientes recibieron tratamiento de inducción con 5 dosis de timoglobulina de 1.25 mg/kg y 5 dosis de inmunoglobulina intravenosa (IVIG) de 400 mg/kg. Además, uno recibió 20 mg de basiliximab el mismo día del trasplante y el día 4 postrasplante; otro recibió 3 sesiones de plasmaféresis en los días -5, -3, y -1 y eculizumab en dosis de 1200 mg antes del trasplante, 900 mg el día 1, and 600 mg por semana durante un mes. En todos los casos, la inmunosupresión de mantenimiento consistió en tacrolimus, micofenolato y deltisona. Todos presentaron buenos resultados en el corto plazo. Nuestra experiencia sugiere que los pacientes con anticuerpos donante-específicos anti-HLA detectados solo por Luminex® deben recibir un seguimiento estricto y que en esta población se pueden obtener buenos resultados a partir del uso de terapia de inducción con timoglobulina e IVIG.

In renal transplantation, donor specific antibodies (DSAs) detected by sensitive solid-phase assay foresee early antibody-mediated rejections, even with negative complement-dependent cytotoxicity or flow cytometry results. We describe the immunosuppression protocols and outcomes at 10 months of four renal transplant patients in whom anti-HLA DSAs were detected by Luminex® but not by CDC and flow cytometry. The four patients underwent induction treatment with five doses of thymoglobulin at 1.25 mg/kg and 5 doses of intravenous immunoglobulin (IVIG) at 400 mg/kg. In addition, one patient received 20 mg basiliximab on the day of transplant and on post-operative day 4; another patient underwent three sessions of plasmapheresis on days -5, -3, and -1 and also received 1200 mg eculizumab prior to transplant, 900 mg on day 1, and 600 mg each week during one month. In all of them, the maintenance immunosuppressive regimen consisted of tacrolimus, mycophenolate acid and deltisone. All patients had good short-term outcomes. Our findings suggest that patients with anti-HLA DSAs detected only by Luminex® should be monitored closely and can be treated successfully with induction therapy based on thymoglobulin and IVIG.

Inmunología perinatal / Perinatal immunology

Se ha considerado que el útero gestante es un lugar inmunológicamente privilegiado, donde el feto es protegido del rechazo por el sistema inmune materno, mediante un amplio repertorio de estrategias de evasión que contribuye a la sobrevivencia del feto. La gestación en sí misma constituye un acontecimiento de equilibrio inmunológico y la tolerancia inmunológica permite la progresión del embarazo, donde participan una secuencia sincronizada de eventos que se inicia desde la concepción y fertilización para dar lugar a la implantación y progresa hasta alcanzar un embarazo a término. El sistema inmune es la principal barrera que poseemos para protegernos de las infecciones. Durante la vida intrauterina, el feto está protegido por la madre de las agresiones externas, por lo que no necesita que su sistema inmunológico sea operativo, sin embargo, al nacer, recibe una avalancha de elementos extraños, por lo que necesitará disponer de cierta protección, así como una preparación para ejecutar las defensas necesarias para su protección inmunológica. La inmunidad sérica durante la vida fetal queda limitada a la transferencia a través de la placenta de IgG materna, a pesar de que el feto tiene la facultad de sintetizar inmunoglobulinas desde las primeras etapas de la gestación. Al nacimiento, el niño tiene su sistema inmunológico completo, aunque inmaduro, pero es capaz de responder a los estímulos antigénicos. Tiene múltiples anormalidades en el desarrollo de su sistema inmune, que involucran a los anticuerpos/inmunoglobulinas, complemento y granulocitos pudiendo contribuir a la alta incidencia de sus infecciones. El recién nacido carece de memoria inmunológica debido a que, en condiciones normales, el feto está exento de estímulos producidos por antígenos extraños. Dicha memoria se va adquiriendo a medida que entra en contacto con los diferentes antígenos. Se obtendrá cierta protección a las infecciones entéricas gracias a las IgA que aporta la lactancia materna. La exposición prenatal y postnatal a productos microbianos ambientales que pueden activar la inmunidad innata, puede acelerar el proceso de maduración del sistema inmune.(AU)

It has been considered the pregnant women`s womb as an immunological exceptional place, where fetus is protected against been rejected because of maternal immune system by means of a wide groups of evasive strategies that help in its survival. Pregnancy itself is an immunological equilibrium state and the immunological tolerance allow the progression of this event, where participate a synchronized sequence of biological events started from conception and fertilization to allow the implantation, and progress until to reach the pregnancy end. The immune system is our main barrier against infections. During intrauterine life fetus is protected by the mother against external aggressions, therefore he don`t need an operative immune system, nevertheless, at birth the new organisms receive an avalanche of strange elements needing some kind of protection as well as a preparation to carry out the necessary defense for his immunological protection. Serum immunity during fetal life is limited to the transference of maternal IgG through placenta, despite fetus capability to synthesize immunoglobulins from first stages of gestation. At birth the babe has a complete immunological system although immature but capable to respond to antigenic stimulus. He has multiples abnormalities in the immune system development that take account antibodies/immunoglobulin, complement and granulocytes contributing to his high incidence of infections. Newborn lack immunological memory because in normal conditions fetus is not stimulated by odd antigens. This memory is acquired through the contact with different antigens. It will be obtained some protection against enteric infections because IgA from maternal lactation. The prenatal and postnatal exposition to environmental microbial products that activate the innate immunity can accelerate the immune system maturing process.(AU)

Challenges with sensitized recipients in pediatric heart transplantation

The sensitization of patients to human leukocyte antigens prior to heart transplantation is increasingly being recognized as an important challenge both before and after the transplant, and the effects of sensitization on clinical outcomes are just beginning to be understood. Many patients are listed with the requirement of a negative prospective or virtual crossmatch prior to accepting a donor organ. This strategy has been associated with both longer waitlist times and higher waitlist mortality. An alternative approach is to transplant across a potentially positive crossmatch while utilizing strategies to decrease the significance of the human leukocyte antigen antibodies. This review will examine the challenges and the impact of sensitization on pediatric patients prior to and following heart transplantation.

Issues in solid-organ transplantation in children: translational research from bench to bedside

In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children.

An antibody reactive to the Gly63-Lys68 epitope of NT-proBNP exhibits O-glycosylation-independent binding

The N-terminal fragment of prohormone brain natriuretic peptide (NT-proBNP) is a commonly used biomarker for the diagnosis of congestive heart failure, although its biological function is not well known. NT-proBNP exhibits heavy O-linked glycosylation, and it is quite difficult to develop an antibody that exhibits glycosylation-independent binding. We developed an antibody that binds to the recombinant NT-proBNP protein and its deglycosylated form with similar affinities in an enzyme immunoassay. The epitope was defined as Gly63-Lys68 based on mimetic peptide screening, site-directed mutagenesis and a competition assay with a peptide mimotope. The nearest O-glycosylation residues are Thr58 and Thr71; therefore, four amino acid residues intervene between the epitope and those residues in both directions. In conclusion, we report that an antibody reactive to Gly63-Lys68 of NT-proBNP exhibits O-glycosylation-independent binding.

Production of Egg Yolk Antibodies Specific to House Dust Mite Proteins

PURPOSE: House dust mites (HDMs) are an important source of indoor allergens associated with asthma, rhinitis and atopic dermatitis. Chicken immunoglobulin (Ig) Y is known to be a good alternative to mice and rabbit antibody production. In this study, we produced IgYs specific to HDMs and investigated their IgE immunoreactivities. MATERIALS AND METHODS: Total IgYs were isolated from the yolks of White Leghorn hens immunized with either Dermatophagoides pteronyssinus or D. farinae protein extract. Control antibodies were separated from the yolks of immunized hens with phosphate buffered saline. IgYs specific to HDMs were analyzed using enzyme-linked immunosorbent assay and Western blotting analysis. RESULTS: The concentration of egg IgY specific to D. farinae in an immunized hen increased and the highest achieved was 661.3 ug/mg (per an egg) on day 47, compared with 760 ug/mg IgY specific to D. pteronyssinus on day 16. The D. pteronyssinus or D. farinae-specific IgY was detected by binding of each mite proteins, and their immunoreactivities were elevated dependent of the specific IgY concentration. CONCLUSION: IgY specific to HDMs may be a promising antibody for immunological diagnosis as well as identification of possible resistance relating to HDM allergy.

Kinetics of epsilon antitoxin antibodies in different strategies for active immunization of lambs against enterotoxaemia / Cinética dos anticorpos antitoxina epsilon em diferentes estratégias de imunização ativa em cordeiros contra a enterotoxemia

Enterotoxaemia, a common disease that affects domestic small ruminants, is mainly caused by the epsilon toxin of Clostridium perfringens type D. The present study tested four distinct immunization protocols to evaluate humoral response in lambs, a progeny of non-vaccinated sheep during gestation. Twenty-four lambs were randomly allocated into four groups according to age (7, 15, 30 and 45 days), receiving the first dose of epsilon toxoid commercial vaccine against clostridiosis with booster after 30 days post vaccination. Indirect ELISA was performed after the first vaccine dose and booster to evaluate the immune response of the lambs. Results showed that for the four protocols tested all lambs presented serum title considered protective (≥0.2UI/ml epsilon antitoxin antibodies) and also showed that the anticipation of primovaccination of lambs against enterotoxaemia conferred serum title considered protective allowing the optimization of mass vaccination of lambs.

Enterotoxemia, uma das mais comuns enfermidades que acomete os pequenos ruminantes domésticos, é causada principalmente pela toxina épsilon de Clostridium perfringens tipo D. O presente estudo avaliou a resposta humoral conferida por quatro protocolos distintos de primovacinação na progênie de ovelhas não vacinadas durante a gestação. Vinte e quatro cordeiros foram aleatoriamente divididos em quatro grupos de acordo com a idade (dias) que receberam a primeira dose da vacina comercial contra clostridiose contendo toxóide epsilon na sua formulação. Todos os cordeiros foram vacinados aos 7, 15, 30 ou 45 dias de idade e receberam um reforço da dose 30 dias após a vacinação. A avaliação sorológica dos cordeiros pelo teste de ELISA indireto foi realizada por ocasião da administração da primeira dose da vacina. Os resultados elucidaram não haver comprometimento da resposta imune de cordeiros vacinados tanto aos 7, 15, 30 ou 45 dias de idade associada ao reforço da dose 30 dias após, demonstrando assim que a antecipação da primeira vacinação conferiu proteção aos cordeiros contra a enterotoxemia, permitindo otimizar o planejamento da vacinação em massa dos cordeiros.

Seroprevalencia de anticuerpos contra dengue en niños de uno a nueve años luego de una epidemia, Aguilares, Tucumán, 2009 / Seroprevalence of Dengue Antibodies in One-to Nine-Year-Old Children after an Outbrea, Aguilares, Tucumán 2009

INTRODUCCIÓN: El brote de dengue de 2009 constituyó el primero con casos autóctonos en Tucumán. Los departamentos de Río Chico y Capital fueron los más afectados. Hubo baja notificación de niños de uno a nueve años (2,6/1.000). Este hallazgo impulsó a conocer el real impacto del brote en la población infantil. OBJETIVO: Estimar la incidencia de dengue en niños de uno a nueve años. MÉTODOS: Se realizó un estudio transversal de sero prevalencia(IgG) en julio de 2009 en Aguilares (Departamento de Río Chico),con una muestra probabilística de niños de uno a nueve años que habían residido allí en los últimos seis meses. Los criterios de exclusión fueron: hogar inhabitado, rechazo a participar o niño con enfermedad aguda. Se utilizó una prueba de neutralización por reducciónde placas. RESULTADOS: Se obtuvieron muestras de 118 niños. Hubo 18 rechazos a participar. El 24...

INTRODUCTION: The 2009 dengue outbreak became the first with autochthonous cases in Tucumán. The departments of Río Chico and Capital were the most affecte dones. There was low incidence in one- to nine-year-old children(2.6/1000). This finding led to a study to know the real impact of the outbreak on children. OBJECTIVE: To estimate dengue incidence in one- to nine-year-old children. METHODS: Across-sectional seroprevalence (IgG) study was carried out in July 2009 in Aguilares (Department of Río Chico), with aprobability sample composed by one- to nine-year-old children who had lived there in the last six months. Exclusion criteria were: uninhabited home, refusal to participate or seriously illchild. The laboratory study consisted of a plaque reduction neutralization test. RESULTS: A total of 118 samples were obtained. There were 18 refusals to participate. 24...

Resposta humoral de bovinos vacinados contra as toxinas botulínicas tipos c e dem diferentes faixas etárias / Humoral response of vaccinated cattle against toxins of Clostridium botulinum types c and d at different ages

Foi verificada pelo teste de ELISA indireto a resposta humoral contra os toxoides botulínicos C e D em bovinos de diferentes idades. O estudo envolveu 90 animais, que foram divididos em três grupos (n = 30), de acordo com a sua faixa etária; inferior a 2 anos de idade (G1), entre 2 e 5 anos (G2) e superior a 5 anos (G3). Os grupos experimentais foram vacinados com duas doses de vacina antibotulínica bivalente (C e D) comercial, nos dias 0 e 42 após a primo-vacinação (booster). Na avaliação, quando realizada 30 dias após o booster, os animais do G3 apresentaram maior produção de anticorpos (p < 0,05) em relação aos demais grupos. Entre o G1 e G2 não houve diferença significativa na resposta humoral contra a toxina C, no entanto, contra a toxina D, os animais do G1 apresentaram maior produção de anticorpos. Todos os grupos produziram uma resposta significativa de anticorpos contra as toxinas botulínicas após a 2ª dose da vacina bivalente comercial, principalmente contra o tipo D.

Humoral response of vaccinated cattle against toxins of clostridium botulinum types C and D at different ages. Cattle humoral response against type C and D botulinum toxoids (indirect ELISA) was verified in animals of different ages. The animals (n = 90) were divided in three groups (n = 30): group one (G1): less than two years old; group two (G2): from 2 to 5 years old; group three (G3): more than 5 years old. The groups were vaccinated with two doses [0 and 42 days after primary vaccination (booster)] of bivalent (C and D) antibotulinum vaccine. Group three had higher antibody production (p ≤ 0.05) compared to the other groups, 30 days after the booster. There was no difference (G1 and G2; p ≥ 0.05) in the humoral response against C toxin, however, against D toxin, group one had higher antibody production. It was possible to conclude that after two doses of the commercial bivalent vaccine all groups produced a significant antibody response against botulinum toxins, especially against D type.