Isoinmunización Rh en bajas respondedoras: Reporte de caso / Rh Isoimmunization in Low Responders: Case Report / Isoimunização Rh em pacientes com baixa resposta: relato de caso

Introducción. La isoinmunización Rh consiste en la producción de anticuerpos maternos en una gestante Rh negativa contra los antígenos de los eritrocitos Rh positivos fetales ocasionados por una hemorragia fetomaterna. En población gestante, el 15% son Rh negativo y la severidad de la afectación fetal está relacionada con una serie de procesos inmunológicos y la historia obstétrica. Si una gestante Rh negativa con riesgo de isoinmunización no recibe profilaxis con inmunoglobulina Anti-D se inmuniza el 16% en la primera gestación, el 30% en la segunda y el 50% después de la tercera. Con este reporte de caso queremos describir el subgrupo de pacientes gestantes con isoinmunización Rh bajas respondedoras. Presentación del caso. G9P5C1A2Gem1V7 de 43 años, remitida en semana 30 de gestación por isoinmunización Rh, no recibió inmunoglobulina Anti-D durante este embarazo, ni en los anteriores ni en el posparto, reporte de Coombs indirecto de 1/4 que se eleva a 1/16, seguimiento ecográfico normal. En semana 35.3 presenta anemia fetal leve y por tratarse de un embarazo alrededor del término se finaliza por cesárea. Recién nacido con adecuado peso para la edad gestacional, quien fue dado de alta a las 72 horas con evolución satisfactoria. Discusión. Las gestantes con isoinmunización Rh bajas respondedoras se sensibilizan con altos volúmenes sanguíneos sin repercusión hemodinámica in utero, produciendo una enfermedad hemolítica fetal leve. Esta respuesta inmune es poco frecuente y está asociada a factores protectores; sin embargo, son necesarios más estudios que sustenten esta condición. Conclusiones. El control prenatal y el Coombs indirecto cuantitativo seriado son las principales herramientas para la prevención de la isoinmunización. El conocimiento de la respuesta inmunológica permite identificar el subgrupo de las bajas respondedoras que tienen una evolución clínica más leve y menor morbilidad neonatal. Palabras clave: Embarazo; Isoinmunización Rh; Eritroblastosis Fetal; Globulina Inmune RHO(D); Hidropesía Fetal.

Introduction. Rh isoimmunization consists of a Rh-negative pregnant woman producing maternal antibodies against the antigens of fetal Rh-positive erythrocytes due to fetomaternal hemorrhage. 15% of the pregnant population is Rh negative, and the severity of fetal effects is related to a series of immunological processes and the obstetric history. If a Rh-negative pregnant woman at risk of isoimmunization does not receive a prophylaxis of Anti-D immunolobulin, 16% are immunized in the first pregnancy, 30% in the second and 50% after the third. In this case report we will describe the subgroup of low responder pregnant patients with Rh isoimmunization. Case Presentation. G9P5C1A2Gem1V7, 43 years old, referred on the 30th week of pregnancy due to Rh isoimmunization. She did not receive Anti-D immunolobulin during this pregnancy, nor in her previous pregnancies, nor during postpartum. Indirect Coombs report of 1/4, which increases to 1/16. Ultrasound monitoring is normal. At week 35.3 she presented mild fetal anemia, and because the pregnancy was near its term, it was ended by cesarean section. Newborn with adequate weight considering the gestational age, who was then discharged after 72 hours with satisfactory evolution. Discussion. Low responder pregnant women with Rh isoimmunization are sensitized with high blood volumes but without hemodynamic repercussions in utero, producing a mild fetal hemolytic disease. This immune response is infrequent and is associated with protective factors; however, further studies are required to support this condition. Conclusions. Prenatal control and serialized quantitative indirect Coombs testing are the main tools for the prevention of isoimmunization. Knowledge of the immunological response enables identifying the subgroup of low responders who present a milder clinical evolution and lower newborn morbidity. Keywords: Pregnancy; Rh Isoimmunization; Erythroblastosis, Fetal; RHO(D) Immune Globulin; Hydrops Fetalis.

Introdução. A isoimunização Rh consiste na produção de anticorpos maternos em uma gestante Rh negativa contra os antígenos dos eritrócitos fetais Rh positivos causados por hemorragia fetomaterna. Na população gestante, 15% são Rh negativos e a gravidade do envolvimento fetal está relacionada a uma série de processos imunológicos e ao histórico obstétrico. Se uma gestante Rh negativa com risco de isoimunização não receber profilaxia com imunoglobulina Anti-D, imuniza-se 16% na primeira gestação, 30% na segunda e 50% após a terceira. Com este relato de caso, queremos descrever o subgrupo de pacientes gestantes com isoimunização Rh de baixa resposta. Apresentação do caso. G9P5C1A2Gem1V7, 43 anos, encaminhada na 30ª semana de gestação para isoimunização Rh, não recebeu imunoglobulina Anti-D nesta gestação, nem nas anteriores nem no puerpério, laudo de Coombs indireto de 1/4 que sobe para 1/16, acompanhamento ultrassonográfico normal. Na semana 35,3, apresentou anemia fetal leve e por se tratar de uma gestação próxima ao termo, foi interrompida por cesariana. Recém-nascido com peso adequado para a idade gestacional, que recebeu alta às 72 horas com evolução satisfatória. Discussão. Gestantes com isoimunização Rh de baixa resposta são sensibilizadas com elevados volumes sanguíneos sem repercussões hemodinâmicas in utero, produzindo doença hemolítica fetal leve. Essa resposta imune é rara e está associada a fatores protetores; no entanto, mais estudos são necessários para fundamentar esta condição. Conclusões. O controle pré-natal e o Coombs indireto quantitativo seriado são as principais ferramentas para a prevenção da isoimunização. O conhecimento da resposta imunológica permite identificar o subgrupo de pacientes com baixa resposta que apresentam evolução clínica mais branda e menor morbidade neonatal. Palavras-chave: Gravidez; Isoimunização Rh; Eritroblastose Fetal; Inmunoglobulina RHO (D), Hidropisia Fetal.

Genotipificación del gen RHD en ADN fetal libre en plasma de embarazadas RhD negativo / Genotyping of the RHD gene in free fetal DNA in plasma of RhD negative pregnant women

Objetivo: Determinar el grupo RhD fetal a través del estudio del gen RHD en ADN fetal que se encuentra libre en plasma de embarazadas RhD negativo. Método: Se analizó la presencia de los genes RHD, SRY y BGLO en ADNfl obtenido de plasma de 51 embarazadas RhD negativo no sensibilizadas, utilizando una qPCR. Los resultados del estudio genético del gen RHD se compararon con el estudio del grupo sanguíneo RhD realizado por método serológico en muestras de sangre de cordón, y los resultados del estudio del gen SRY fueron cotejados con el sexo fetal determinado por ecografía. Se calcularon la sensibilidad, la especificidad, los valores predictivos y la capacidad discriminativa del método estandarizado. Resultados: El gen RHD estaba presente en el 72,5% de las muestras y el gen SRY en el 55,5%, coincidiendo en un 100% con los resultados del grupo RhD detectado en sangre de cordón y con el sexo fetal confirmado por ecografía, respectivamente. Conclusiones: Fue posible deducir el grupo sanguíneo RhD del feto mediante el estudio del ADN fetal que se encuentra libre en el plasma de embarazadas con un método molecular no invasivo desarrollado y validado para este fin. Este test no invasivo puede ser utilizado para tomar la decisión de administrar inmunoglobulina anti-D solo a embarazadas RhD negativo que portan un feto RhD positivo.

Objective: To determine the fetal RhD group through the study of the RHD gene in fetal DNA found free in plasma of RhD negative pregnant women. Method: The presence of the RHD, SRY and BGLO genes in fetal DNA obtained from plasma of 51 non-sensitized RhD negative pregnant women was analyzed using qPCR. The results of the genetic study of the RHD gene were compared with the RhD blood group study performed by serological method in cord blood samples, and the results of the SRY gene study were compared with the fetal sex determined by ultrasound. Sensitivity, specificity, predictive values and discriminative capacity of the standardized method were calculated. Results: The RHD gene was present in 72.5% of the samples and the SRY gene in 55.5%, coinciding 100% with the results of the RhD group detected in cord blood, and with the fetal sex confirmed by ultrasound, respectively. Conclusions: It was possible to deduce the RhD blood group of the fetus through the study of fetal DNA found free in the plasma of pregnant women with a non-invasive molecular method developed and validated for this purpose. This non-invasive test can be used to make the decision to administer anti-D immunoglobulin only to RhD-negative pregnant women carrying an RhD-positive fetus.

Informe diário de evidências COVID-19: busca realizada em 28 de julho de 2020 / COVID-19 daily evidence report: search conducted on July 28, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referentes ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 18 artigos e 3 protocolos.

Tratamento de pênfigo vulgar com imunoglobulina humana como adjuvante ao corticoide oral: um relato de caso / Pemphigus vulgaris treatment with human immunoglobulin as adjuvant to oral corticoid: a case report

Introdução: o pênfigo vulgar é uma doença de caráter autoimune, que leva à formação de bolhas locais ou generalizadas causadas pelo ataque de autoanticorpos às estruturas da epiderme. A terapêutica Recebido em: 25/09/2018 com imunoglobulina humana como adjuvante é uma excelente opção para os casos em que há resistência ao tratamento habitual, além de poder diminuir o tempo de tratamento com imunossupressores. Objetivo: descrever um relato de caso sobre um paciente portador de pênfigo vulgar submetido ao tratamento com imunoglobulina humana como adjuvante ao corticoide oral. Relato do caso: paciente 49 anos, foi internado apresentando lesões erosivas em mucosa oral e conjuntival, com piora sistêmica após início de tratamento com antibióticos e anti-inflamatório. Inicialmente realizou-se o tratamento convencional com corticoterapia, porém sem resultados satisfatórios. Devido ao agravamento da clínica, e ao estabelecimento do diagnóstico de pênfigo vulgar, foi incluída no tratamento a imunoglobulina humana como adjuvante, o que culminou em uma melhora progressiva do paciente. Conclusão: apesar de o tratamento do pênfigo vulgar ter os corticoides como primeira opção, é importante conhecer tratamentos adjuvantes e/ou alternativos, como as imunoglobulinas humanas, para auxiliar no tratamento dos pacientes que não respondem ao corticoide.

Introduction: Pemphigus Vulgaris is an autoimmune disease that leads to the formation of local or generalized blisters as a result of autoantibodies against epidermal structures. Therapy with human immunoglobulin as an adjuvant is an excellent option for cases where there is resistance to usual treatment, in addition to being able to reduce the time of treatment with immunosuppressant. Thus, it is an alternative treatment for patients with severe infections or immunological deficiencies. Aim: to describe a case report about a carrier patient of pemphigus vulgaris treated with human immunoglobulin as adjuvant to oral corticosteroids. Case report: patient with 49 years old, was hospitalized in the city of Belo Horizonte (MG) presenting erosive lesions in the oral and conjunctival mucosa, with systemic worsening after starting treatment with antibiotics and anti-inflammatory. Initially, conventional steroid therapy was performed, but with no satisfactory results. Due to worsening symptoms and the diagnosis of Pemphigus Vulgaris, human immunoglobulin was included in the treatment as an adjuvant, which resulted in a progressive improvement of the patient. Conclusion: although treatment of Pemphigus Vulgaris has steroids as the first option, it is vital that the physician knows adjuvant and/or alternative therapies, such as human immunoglobulins, to assist in the treatment of patients who do not respond to steroids.

Clinical effect of anti-D immunoglobulin in treatment of childhood immune thrombocytopenia: a Meta analysis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the clinical effect and safety of anti-D immunoglobulin (anti-D) in the treatment of children with newly diagnosed acute immune thrombocytopenia (ITP) through a Meta analysis.</p><p><b>METHODS</b>PubMed, EMBASE, Cohrane Library, Ovid, CNKI, and Wanfang Data were searched for randomized controlled trials (RCTs) published up to April 2017. Review Manager 5.3 was used for the Meta analysis.</p><p><b>RESULTS</b>Seven RCTs were included. The Meta analysis showed that after 72 hours and 7 days of treatment, the intravenous immunoglobulin (IVIG) group had a significantly higher percentage of children who achieved platelet count >20×10/L than the anti-D group (P<0.05). There were no significant differences in platelet count after 24 hours, 72 hours, and 7 days of treatment between the anti-D (50 μg/kg) group and the IVIG group (P>0.05), and there were also no significant differences in platelet count after 24 hours and 7 days of treatment between the 50 μg/kg and 75 μg/kg anti-D groups (P>0.05). The anti-D group had a significantly greater reduction in the hemoglobin level than the IVIG group after treatment, but did not need transfusion. No children in the anti-D group or the IVIG group experienced serious adverse reactions.</p><p><b>CONCLUSIONS</b>Intravenous injection of anti-D may have a similar effect as IVIG in improving platelet count in children with acute ITP, but it may be slightly inferior to IVIG in the rate of platelet increase after treatment. The anti-D dose of 50 μg/kg may have a similar effect as 75 μg/kg. The recommended dose of anti-D for treatment of ITP is safe.</p>

Identification of Anti-G in Pregnant Women with RhD Negative Blood: The First Case in Korea / 대한수혈학회지

Anti-G positivity can be misinterpreted as the presence of anti-D or -C antigen in an antibody identification test, as this antibody is known to show agglutination to D or C antigen-positive red cells. Correct identification of anti-G is important in pregnant women, as prenatal care or the need for RhIG administration can vary between anti-D and -C versus anti-G cases. We recently encountered a D-negative case with suspected anti-D and -C, which was ruled out by adsorption and elution tests, and ultimately confirmed the presence of anti-G. The pregnant woman was a 33-year-old patient with cde Rh phenotype with a previous history of spontaneous abortion, followed by administration of RhIG. The spouse's Rh phenotype was CDe. Initial antibody identification test showed 2+ positivity to C (homozygotes and heterozygotes) and trace to 1+ positivity to D. Upon additional adsorption and elution with R0r (cDe/cde) and r'r (Cde/ cde) red cells, we identified the antibody present in the patient's serum as anti-G. The patient is currently under close follow-up monitoring for anti-G titer using antibody titer testing with both CDe and CcDEe red cells. Periodic fetal cerebral Doppler examination is being carried out without evidence of fetal distress.

RH Factor and Clinical Transfusion Effectiveness for β-Thalassemia Children with Long-Term Blood Transfusion / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the irregular antibody production and its relationship with Rh factor genotypes and the loci of thalassemia gene mutations for the β-thalassemic children with long-term transfusion, so as provide experimental basis for clinical safe and effective transfusions for thalassemic children.</p><p><b>METHODS</b>The peripheral blood from 246 children with β-thalassemia was collected in our hospital; the extraction of genomic DNA and Rh factor (C/c, E/e) genotypes were assayed by PCR-SSP method, the irregular antibodies were screened and identified by serological method, the genotypes for thalassemia and gene mutations were analysed by PCR-RD method.</p><p><b>RESULTS</b>The genotypes of Rh factors classified by PCR- SSP in the 246 cases of β-thalassemia children were as follws: Ce/Ce (143/246, 58.1%), CE/ce (59/246, 24%), cE/cE (14/24, 5.7%), Ce/ce (12/246, 4.9%); The positive rate of irregular antibody was 7.7% (19/246), including anti-E (7/19), anti-c (5/19), anti-C (2/19), anti-E and anti-c (2/19), anti-e (1/19), anti-D (2/19); Of the 19 cases with positive irregular antibody, the genotypings of Rh factor were: Ce/Ce (11/19), CE/ce (2/19), cE/cE (2/19), Ce/ce (2/19), cE/ce (2/19); the gene mutations location of thalassemia for 19 cases with positive irregular antibody: CD41-42M (13/19), CD71-72M (2/19), IVS-II-654M (3/19), -28M (1/19).</p><p><b>CONCLUSION</b>The irregular antibody production for β-thalassemic children with long-term transfusion may have some relevance with Rh factor genotypes and thalassemia genetic mutations. This study possesses a certain significance for effective prevention of RBC alloimmune response of β-thalassemia children and improvement of efficacy and safety of clinical transfasion blood.</p>

Las trombopoyetinas en el tratamiento de la púrpura trombocitopénica inmunitaria y otras trombocitopenias / Thrombopoietines in the treatment of the thrombocytopenic purpura and other thrombocytopenics

La purpura trombocitopénica inmunitaria y las trombocitopenias secundarias representan condiciones patológicas graves cuyo tratamiento plantea diversos grados de dificultad. La aproximación terapéutica convencional ha sido la administración de esteroides, la esplenectomía y el uso de inmunoglobulina intravenosa u otros tipos de anticuerpos (e.g., anti-D). La mejor comprensión de la fisiología y fisiopatología de la trombopoyesis aunado a los avances en biología molecular ha permitido el desarrollo de una nueva aproximación terapéutica, la aplicación de las trombopoyetinas sintéticas o no inmunogénicas. Dentro de este grupo resaltan dos compuestos: el romiplostin (una proteína de fusión) y el eltrombopag (un compuesto sintético de bajo peso molecular). Ambas se encuentran disponibles comercialmente. Los estudios clínicos indican que estos medicamentos tienen un efecto satisfactorio en el tratamiento de las trombocitopenias, particularmente en los casos refractarios a los tratamientos convencionales.

Immune thrombocytopenic purpura and the secondary thrombocytopenias are conditions potentially severe with diverse degrees of treatment difficulties. Steroids administration, splenectomy and the use of intravenous immunoglobulin and other antibodies (e.g., anti-D) had been the conventional therapy. The better understanding of the thrombopoiesis physiology and physiopathology togetter with the biology advances have permitted the development of a new terapheutic approach: the use of synthetic or nonimmunogenic thrombopoietines. Among this group highlights composites: romiplostim (a fusion protein) and eltrombopag (a synthetic composite with low molecular wheigt). Both are already available and produce a satisfactory effect particularly in nonrespondent cases to the conventional treatment.

Comparison of dexamethasone and Anti-D Immune globulin for immune thrombocytopenia purpura in children

Different therapeutic options in children with immune thrombocytopenic purpura include observation alone, periodic treatment with corticosteroids, intravenous immunoglobulin [IVIG] or anti-D, chronic administration of immunosuppressive agents, and splenectomy. Preference of the type of therapy depends on the degree of thrombocytopenia and clinical bleeding manifestations. Dexamethasone is safe but its side effects are the main disadvantages for its usage. Anti-D is more expensive than dexamethason but the side effect is rare and not dangerous and response to treatment is assessed in approximately 3 days after infusion

High-throughput genotyping multiplex ligation-dependent probe amplification for assisting diagnosis in a case of anti-Di(a)-induced severe hemolytic disease of the newborn / 南方医科大学学报

<p><b>OBJECTIVE</b>To report a rare case of hemolytic disease of the newborn (HDN) with kernicterus caused by anti-Di(a) diagnosed using high-throughput genotyping multiplex ligation-dependent probe amplification (MLPA).</p><p><b>METHODS</b>Conventional serological methods were used to detect the antibodies related with HDN. The genotypes of more than 40 red blood cell antigens for the newborn and her parents were obtained using the high-throughput MLPA assay. The antibody titers were tested using a standard serological method.</p><p><b>RESULTS</b>The unknown antibody against the low-frequency antigens was predicted based on the primary serological tests. The genotyping results for more than 40 red blood cell antigens of the newborn and her parents showed incompatible antigens of MNS and Diego blood group system, indicating the existence of anti-N or anti-Di(a). Further serological tests confirmed anti-Di(a) existence in the plasma of the newborn and her mother. The titer of anti-Di(a) in the mother's plasma was 1:32.</p><p><b>CONCLUSION</b>Severe HDN including kernicterus can result from anti-Di(a). High-throughput genotyping MLPA assay can help type some rare antigens in complicated cases. The reagent red cell panels including Di(a)-positive cells are necessary in routine antibody screening test in Chinese population.</p>

Genotype analysis of RhD-negative donors with immune antibodies / 中国实验血液学杂志

In order to analyze the genotype of RhD-negative blood donors with immune antibodies in Harbin, the voluntary blood donors from 1 April 2008 to 30 september 2011 were detected serologically to determine the RhD-negative donors. The blood donors confirmed to be RhD negative were detected to screen the immune antibodies, the samples with immune antibodies were analyzed by PCR-SSP and DNA sequencing to detect RhD genotype. The results showed that the 12 cases of the immune antibodies (0.95%) were screened out from 1265 cases of RhD-negative donors, among which 9 cases showed anti-D-antibody, 3 cases showed anti-(D+C) antibody; 10 cases were RhD-negative, 2 cases were RHD 711D(el)C. It is concluded that RhD negative and RHD 711D(el)C are easy to be immunized to produce the immune antibodies; RhD-negative population, especially women should be highly aware of avoiding mis-transfusion of RhD-positive blood, and also avoiding multiple pregnancies resulting in newborn's hemolytic disease.

Efficiency improvement of fully automatic microcolumn glass sphere technology used in blood group compatibility tests / 中国实验血液学杂志

The purpose of this study was to determine whether the fully automated ORTHO AutoVue Innova system, which based on the microcolumn glass sphere technology, is accurate enough to meet immunohematology testing needs at blood banks. 16 IgM anti-C, anti-c, anti-D, anti-E and anti-e dilution series were tested respectively, with corresponding antigen positive red blood cell solutions, by ORTHO AutoVue Innova system and saline medium test. 16 IgG anti-D dilution series were tested respectively with RhD positive red blood cell solutions by ORTHO AutoVue Innova system, polybrene test and antiglobulin test. The accuracies of microcolumn glass sphere technology were analysed, by comparing to the reference assays. The results showed that the sensitivities of the ORTHO AutoVue Innova tests were 1:69.8, 1:33.4, 1:1448.1, 1:139.6 and 1:32.0 for IgM anti-C, anti-c, anti-D, anti-E and anti-e respectively; the corresponding value of saline medium tests were 1:16.7, 1:16.6, 1:430.5, 1:34.9 and 1:9.9. There were statistically significant differences between the groups of each tests (t values were 14.38, 5.48, 10.25, 12.65 and 9.59 for IgM anti-C, anti-c, anti-D, anti-E and anti-e respectively, p < 0.05). For IgG anti-D, the sensitivities of the ORTHO AutoVue Innova test, polybrene test and antiglobulin test were 1:980.6, 1:181.0 and 1:304.4 respectively. There was statistically significant difference among the 3 groups (F = 51.15, p < 0.01). It is concluded the use of ORTHO AutoVue Innova system for blood group compatibility test can obtain more accurate results than traditional tube tests, it is reliable and safe for routine tests performed in immunohematology laboratories.

Atualizações na profilaxia da isoimunização Rh / Updates in the prophylaxis of the Rh isoimmunization

O conhecimento da isoimunização Rh e das bases moleculares do gene RHD e de suas variantes cresceu muito nos últimos anos. Esse crescimento permitiu a introdução de ferramentas realmente úteis no acompanhamento a gestantes isoimunizadas ou em risco de desenvolver a doença hemolítica perinatal (DHPN). A introdução da imunoprofilaxia RhD, por volta dos anos 1960, propiciou uma significativa redução na incidência de aloimunização materna por anti-D. Essa redução torna-se ainda mais significante quando há a associação da profilaxia pós-natal à antenatal, entretanto, seu uso ainda não é amplamente difundido no Brasil e sua eficiência está diretamente relacionada à dose correta, que vai depender da idade gestacional e da quantidade de hemorragia feto-materna (HFM). Sabe-se ainda que a imunoglobulina anti-D policlonal, por ser de origem humana, não é isenta de riscos à gestante ou ao concepto. Dada essa limitação, anticorpos monoclonais têm sido produzidos e avaliados a fim de substituir o anti-D policlonal. Todavia, até o momento, o sucesso dessa nova tecnologia tem sido apenas parcial. Como uma importante alternativa, entretanto, tem sido estudada a habilidade de indução de tolerância à proteína RhD, em ratos transgênicos, a partir de peptídios sintéticos

The knowledge of the Rh isoimmunization and the molecular bases of RHD gene and its variants has grown in recent years. This growth allowed the introduction of useful tools in monitoring pregnant women with alloimmunization or at risk of developing hemolytic disease of the newborn (HDN). The introduction of RhD immunoprophylaxis, in the 1960 years, provided a significant reduction in the incidence of maternal alloimmunization by anti-D. This reduction becomes even more significant when associated with antenatal prophylaxis, however, its use is not yet widespread in Brazil and its efficiency is directly related to the correct dose that will depends on the gestational age and the fetomaternal hemorrhage (FMH) quantity. It is also known that anti-D polyclonal, to be of human origin, is not without risk to the mother or the fetus. Given this limitation, monoclonal antibodies have been produced and evaluated in order to replace the polyclonal anti-D. Nevertheless, so far the success of this new technology has been only partial. As an important alternative, however, the ability to induce tolerance to the RhD protein in transgenic mice from synthetic peptides has been studied

Seguridad viral de la Gammaglobulina anti-D / Viral safety in human anti-D immunoglobulin

Introducción. El Parvovirus B19 humano (B19) es considerado como uno de los mayores contaminantes de plasma, sangre y hemoderivados. Con el propósito de reducir el riesgo de contaminación, la Farmacopea Europea estableció el control por PCR del ADN del Parvovirus B19 en los pool es de plasma destinados a la producción de Gammaglobulina anti-D (Rh), un producto utilizado en mujeres embarazadas para pre­venir la enfermedad hemolítica del recién nacido. Además del control del ADN viral se aplican otros procesos y procedimientos adicionales para optimizar la seguridad viral y el aprovechamiento de la materia prima. Objetivos. Demostrar que el control por PCR del ADN/B19, la presencia de anticuerpos neutralizantes y la inactivación viral por pasteurización en la producción de preparados de Gammaglobulina anti-D permiten obtener un hemoderivado seguro. Materiales y Métodos. Los pooles de plasma fueron analizados para ADN/B19 mediante una técnica de PCR "in house" de adecuada sensibilidad y validada con un Standard Internacional. La extracción del ADN se realizó con columnas de sílica y la amplificación se realizó con primers específicos. Se analizaron los anticuerpos IgG contra proteína VP2 del B19 por ELISA en muestras de plasma de donaciones individuales. Se validó la pasteurización como método de inactivación viral, con virus envueltos y desnudos y se controlaron las Gammaglobulinas anti-D por PCR para descartar presencia de ADN del parvovirus B19 en producto final. Resultados. Se detectó que el 18% (n= 73) del total de pooles de plasma por PCR poseen una carga mayor a 1500 UI/ ml y el 82% con títulos menores a 1500 UI/ml. Los anticuerpos IgG anti-VP2 del B19 fueron detectados en el 75% de las muestras de plasma de donaciones individuales. La pasteurización resultó efectiva para virus envueltos y desnudos donde se detectó una pérdida de la infectividad mayor a 4.0 log de virus... (TRUNCADO)

Background. Human Parvovirus B19 (B19) is recognized as one of the majors contaminants of plasma, blood products and plasma-derived products. To reduce the risk of contamination, B19 DNA plasma pool testing by PCR during the manufacturing of anti-D Inmunoglobulin has been established by European Pharmacopoeia. This is a plasma-derived product used in pregnant women to prevent the hemolytic disease of the newborn. In addition, to optimize the viral safety and minimize the loose of plasma pools, additionals practises and procedures are implemented. Objectives. Demonstrate the B19 DNA control by PCR, the presence of antibodys with neutralizing activity and the viral inactivation by pasteurization in manufacturing of anti-D Inmunoglobulin are suitables procedures to allow to obtain a safety plasma-derived product. Materials and methods. The plasma pools were tested for B19 DNA by an "in house" PCR technique with appropriate sensitivity and validated with an Internacional Standard. The DNA was extracted with silica columns and the amplification reaction was made with specific primers. Plasma single donations were tested for VP2-specific anti-B19 IgG antibodies by ELlSA. The pasteurization was validated as a viral inactivation method, against enveloped and nude viruses. Anti-D inmunoglobulin batches were analized with PCR to ensure the absence of B19 DNA. Results. Of 73 plasma pools, 18% were found to be B19 DNA positive with a viralload > 1500 IU/ml and 82% were < 1500 IU/ml. 75% of single plasma donations were positive for VP2-specific anti-B 19 IgG antibodies. The pasteurization was effective for enveloped and nude viruses where the lost of infectivity was > 4.0 log of virus. AII anti-D inmunoglobulin batch es were negatives for B19 DNA by PCR... (TRUNCATED)