Analysis of the effects of low/intermediate dose of coagulation factor Ⅷ on 30 adult patients with severe hemophilia A in a single center / 中华血液学杂志

Objective: To evaluate the clinical effects of low- and intermediate-dose factor Ⅷ (F Ⅷ) prophylaxis in Chinese adult patients with severe hemophilia A. Methods: Thirty adult patients with severe hemophilia A who received low- (n=20) /intermediate-dose (n=10) F Ⅷ prophylaxis at Nanjing Drum Tower Hospital affiliated with Nanjing University Medical College were included in the study. The annual bleeding rate (ABR), annual joint bleeding rate (AJBR), number of target joints, functional independence score of hemophilia (FISH), quality of life score, and health status score (SF-36) before and after preventive treatment were retrospectively analyzed and compared. Results: The median follow-up was 48 months. Compared with on-demand treatment, low- and intermediate-dose prophylaxis significantly reduced ABR, AJBR, and the number of target joints (P<0.05) ; the improvement in the intermediate-dose prophylaxis group was better than that in the low-dose prophylaxis group (P<0.05). Compared with on-demand treatment, the FISH score, quality of life score, and SF-36 score significantly improved in both groups (P<0.05), but there was no significant difference between the two groups (P>0.05) . Conclusion: In Chinese adults with severe hemophilia A, low- and intermediate-dose prophylaxis can significantly reduce bleeding frequency, delay the progression of joint lesions, and improve the quality of life of patients as compared with on-demand treatment. The improvement in clinical bleeding was better with intermediate-dose prophylaxis than low-dose prophylaxis.

Prophylaxis in hemophilia

Hemophilia is an inherited X-linked coagulopathy defined by a deficiency or abnormality in the clotting function of factor VIII (Hemophilia A) or factor IX (Hemophilia B). Prophylaxis ­ the regular administration of therapeutic products to maintain hemostasis and prevent bleeding ­ is the mainstream of treatment. Addressing the development and scientific evidence for administrating prophylaxis is the goal of this review. Prophylaxis is the therapeutic modality of choice for people with severe hemophilia, being considered, in principle, a lifelong treatment. It should have an early onset, ideally as a primary, or at least secondary. Even lifelong tertiary prophylaxis seems to offer benefit, although further studies are still lacking. Individualized strategies should lead to an optimization of the dilemma between better joint outcomes versus involved costs.

Estudio de costo-efectividad de profilaxis con emicizumab versus agentes hemostáticos alternativos en pacientes con hemofilia A grave en Perú / Cost-effectiveness study of prophylaxis with emicizumab versus bypassing agents in patients with severe hemophilia A in Peru

Contexto La hemofilia es un trastorno hemorrágico de la coagulación que ocurre en uno de cada 5000 nacimientos masculinos. Los pacientes con hemofilia A grave no tratados tienen complicaciones hemorrágicas, incluyendo sangrados articulares y menor sobrevida. El emicizumab es un anticuerpo monoclonal aprobado por los Estados Unidos para la profilaxis rutinaria de pacientes pediátricos y adultos con hemofilia A grave con inhibidores del factor VIII de coagulación. Objetivos Realizar un estudio de costo-efectividad de la profilaxis con emicizumab para niños y adultos con hemofilia A grave, en comparación con el actual manejo de esos pacientes en el Ministerio de Salud y el Seguro Social de Salud de Perú. Metodología Se modeló la transición del paciente entre estados médicos con la metodología de Markov y se estimó a lo largo de su vida costos y efectos incrementales de emicizumab comparados con el actual manejo. Se estimó el impacto presupuestario de emicizumab proyectando costos netos anuales y su valor presente a cinco años. Resultados Emicizumab generaría ahorros en el Ministerio de Salud entre 14,6 y 16,0 por niño y 11,8 por adulto, en US$ millones actuales, y en el Seguro Social de Salud de 12,8 a 14,9 por niño y 40,1 por adulto. Además, se generan ganancias en efectividad, medidas en años de vida ajustados por calidad, de 0,36 por niño y 0,56 por adulto y de 0,25 por niño y 0,36 por adulto en esas respectivas instituciones. El impacto presupuestario sería un ahorro anual neto, en US$ millones, de 12,8 y 15,0 en esas entidades. Conclusión El actual manejo de la enfermedad es muy costoso y con resultados de salud inferiores a los posibles con emicizumab. Este fármaco produciría grandes ahorros y mejor salud. Ambas entidades debieran implementar protocolos para la profilaxis y tratamiento de la hemofilia y financiarla con presupuesto propio.

Settings Hemophilia is a coagulation disorder that occurs in one in 5000 male births. Patients with untreated severe hemophilia A have hemorrhagic complications, including joint bleeds and decreased survival. Emicizumab is a monoclonal antibody approved by the United States for routine prophylaxis of pediatric and adult patients with severe hemophilia A with factor VIII inhibitors. Objectives To perform a cost-effectiveness study of emicizumab prophylaxis for children and adults with severe hemophilia A compared with the current disease management in the Peruvian Ministry of Health and Social Security Health Insurance. Methods The patient transition between medical states was modeled with Markov methodology, and the lifetime costs and incremental effects of emicizumab compared to current management were estimated. The budgetary impact of emicizumab was estimated by projecting annual net costs and its five-year present value. Results In the Ministry of Health, emicizumab would generate savings between 14.6 and 16.0 per child and 11.8 per adult, in current US$ million. Social Security Health Insurance savings would be 12.8 to 14.9 per child and 40.1 per adult. In addition, this strategy would generate effectiveness gains, measured in quality-adjusted life-years, of 0.36 per child and 0.56 per adult and 0.25 per child, and 0.36 per adult in those respective institutions. The budgetary impact would be a net annual saving of 12.8 and 15.0 US$ million in those entities. Conclusions The current management of hemophilia A is very costly and has health outcomes inferior to those possible with emicizumab. This drug would produce significant savings and better patient health. The Ministry of Health and Social Health Insurance should implement hemophilia prophylaxis and treatment protocols and finance this drug.

Efectividad de inducción de tolerancia inmune en niños con hemofilia A y aloanticuerpos neutralizantes / Immunotolerance induction effectivity in hemophilia A children and neutralizing alloantibodies

Resumen: Introducción: El desarrollo de aloanticuerpos neutralizantes anti-factor VIII en hemofilia A es la complicación más seria relacionada al tratamiento. La inducción de tolerancia inmune (ITI) o inmunotolerancia es el único tratamiento que erradica inhibidores, permitiendo utilizar nuevamente factor VIII para el tratamiento o profilaxis de eventos hemorrágicos. Objetivo: reportar la experiencia en niños sometidos a inmunotolerancia en la red pública del país. Pacientes y Método: Análisis retrospectivo y descriptivo de 13 niños con Hemofilia A severa e inhibidores persistentes de alto título, que recibieron ITI y seguimiento completo. Se utilizó concentrado de FVIII plasmático en dosis de 70-180 UI/Kg/diarias, definiendo éxito como la negativización del inhibidor y recu peración de la vida media del FVIII. Resultados expresados en media (rango). Resultados: En 13 pacientes se identificó el inhibidor, a una edad de 17,6 meses (2-48), tras 35,2 días (9-112) de exposición a FVIII. Once pacientes (84,6%) recuperaron la vida media del FVIII, tras 49,6 meses (26-70) de tratamiento. En los pacientes que respondieron, el título del inhibidor se negativizó en 7,3 meses (1-20). Conclusiones: En niños con hemofilia A e inhibidores persistentes de alto título, la ITI tiene un elevado éxito. Dado que el tiempo de respuesta es variable, la inmunotolerancia debe ser personalizada.

Abstract: Introduction: The development of anti-factor VIII neutralizing antibodies in hemophilia A is the most severe com plication related to treatment. Immune tolerance induction (ITI) is the only known treatment for eradicating inhibitors. A successful ITI allows using factor VIII (FVIII) again for the treatment or prophylaxis of hemorrhagic events. Objective: To report the experience of pediatric patients who underwent ITI in the country's public health care network. Patients and Method: Retrospective and descriptive analysis of 13 pediatric patients with severe Hemophilia A and high-titer inhibitors persis tence who underwent ITI and complete follow-up. Plasma-derived FVIII concentrate was used at 70 180 IU/kg/day doses. The success of the treatment is defined by achieving a negative titer and a half life recovery of the FVIII. The results were expressed in median (range). Results: In 13 patients, the inhibitor was identified at an average age of 17.6 months, after 35.2 days of exposure to the FVIII. 11 patients (84.6%) recovered the half-life of FVIII after 49.6 months of treatment. In the patients who responded to treatment, the inhibitor titer was negative at 6 months on average. Conclusions: ITI is the treatment of choice for patients with hemophilia A and inhibitors persistence. ITI must be perso nalized since the time response is variable in each patient.

Inmunotolerancia en un paciente hemofílico pediátrico en Costa Rica / Immunotolerance induction in a pediatric hemophilic patient in Costa Rica

Resumen La hemofilia A es una enfermedad ligada al cromosoma X que predispone al sangrado. Se trata con Factor VIII, ya sea profilaxis o a demanda. La mayoría de países en el resto del mundo utilizan profilaxis, lo cual a la larga es más barato que tratar los pacientes cuando están con un sangrado activo. La producción de inhibidores del factor VIII es la complicación más común y seria del tratamiento. La inmunotolerancia (ITI) es la única opción de tratamiento que ha demostrado satisfactoriamente erradicar esta condición en los pacientes que desarrollan inhibidores, disminuyendo de esta manera no solo los inhibidores sino los costos del tratamiento. Se presenta un caso de inducción satisfactoria de inmunotolerancia con bajas dosis de factor VIII (FVIII) en un paciente pediátrico con hemofilia A severa. A pesar de que la inmunotolerancia se ha practicado antes en Costa Rica, un caso de estos nunca antes había sido publicado.

Abstract Hemophilia A is an X - linked bleeding disorder. It can be treated with Factor VIII prophylaxis or on demand treatment. Most countries in the world use prophylaxis as it is less expensive than treating patients when they are bleeding. The production of factor VIII inhibitors is the most common and serious complication of the treatment. Immune tolerance induction (ITI) is the only option of treatment when patients develop inhibitors proven to be successful to eradicate this condition, therefore decreasing inhibitors and costs. A case of a successful immune tolerance induction with low doses of factor VIII (FVIII) in a pediatric patient with severe hemophilia A and FVIII inhibitors is presented. Even though inmunotolerance has been practice before in our country, a case like this has never been published.

Avaliação de biomarcadores fenotípicos celulares e humorais na Hemofilia A

A hemofilia A (HA) congênita é um distúrbio hemorrágico com transmissão hereditária ligado a deficiência do fator VIII (FVIII). O tratamento da HA é baseado na reposição do FVIII, requerendo infusões intravenosas de concentrados de FVIII exógeno. Durante o tratamento, alguns pacientes desenvolvem uma resposta imune que produz anticorpos anti-FVIII (inibidores). Os inibidores neutralizam a atividade procoagulante do FVIII e diminuem a eficiência do tratamento. Apesar da relevância dos inibidores, os mecanismos imunológicos associados aos inibidores ainda não foram completamente elucidados. Neste trabalho analisou-se o perfil de citocinas intracitoplasmáticas de células do sistema imune inato e adaptativo de pacientes com HA e inibidores [HAalfa-FVIII(+)] e com HA sem inibidores [HAalfa-FVIII(−)]. Os resultados mostraram uma menor frequência de monócitos e neutrófilos TNF-alfa positivo, monócitos IL-5+ e neutrófilos IL-4+ e uma maior frequência de neutrófilos, linfócitos T CD4+, T CD8+ e T CD19+ IL-10+em pacientes do grupo HAalfa-FVIII(+). Em pacientes do grupo HAalfa-FVIII(−) observou-se uma maior frequência de monócitos TNF-alfa+e linfócitos B IL-4+e uma menor frequência de linfócitos T CD4+ e T CD8+ IL-10+.

Observou-se o predomínio de um padrão anti-inflamatório/regulador no grupo HAalfa-FVIII(+) e um padrão pró-inflamatório no grupo HAalfa-FVIII(−), sugerindo que o microambiente celular pode ser um elemento importante associado à capacidade de desenvolvimento de inibidores. Analisou-se também a presença de micropartículas plasmáticas (MPs) em pacientes com HA. Os resultados mostraram uma maior frequência de MPs derivadas de células endoteliais, granulócitos e linfócitos T em pacientes do grupo HAalfa-FVIII(−) e uma maior frequência de MPs derivadas de hemácias em pacientes do grupo HAalfa-FVIII(+). O predomínio de MPs no grupo HAalfa-FVIII(−) pode ser relacionado ao aumento da ativação celular e influência do microambiente pró-inflamatório.

MPs derivadas de hemácias induziram a investigação da presença de anticorpos em hemácias de pacientes com HA. Os resultados demonstraram que pacientes do grupo HAalfa-FVIII(+) têm uma maior frequência de anticorpos na superfície de hemácias. Em função deste resultado, investigou-se a presença de anticorpos anti-FVIII em concentrados de hemácias de pacientes do grupo HAalfa-FVIII(+). Foi possível detectar anticorpos anti-FVIII em concentrados de hemácias, sugerindo que essas células podem interagir com anticorpos anti-FVIII. Determinou-se ainda, a avidez de anticorpos anti-FVIII de pacientes do grupo HAalfa-FVIII(+). Os resultados demonstraram avidez superior de anticorpos IgG total e IgG1 anti-FVIII quando comparados a IgG4. Foi observada também uma correlação negativa entre os índices de avidez de anticorpos IgG4 anti-FVIII de pacientes graves aos títulos de Bethesda, sugerindo que existem variações na avidez dos anticorpos anti-FVIII dependendo do perfil dos pacientes com HA. No contexto da avaliação da resposta imune contra o FVIII, foi possível identificar biomarcadores fenotípicos celulares e humorais característicos de pacientes com e sem inibidores que podem contribuir para o monitoramento do desenvolvimento e manutenção de anticorpos inibidores do FVIII. Palavras-chave: Hemofilia A, Fator VIII, Coagulação Sanguínea.

Dilataciones endoscópicas del tracto gastrointestinal / Endoscopic dilation of the gastrointestinal tract

Las dilataciones en el tracto gastrointestinal se llevan a cabo para aliviar la obstrucción sintomática, ya sea funcional u orgánica, secundarias a una variedad de patologías tanto benignas como malignas. Con el advenimiento de las nuevas tecnologías, virtualmente toda estenosis digestiva puede ser manejada en forma mínimamente invasiva. Pese a su amplia difusión en la práctica actual, existen pocos estudios controlados que comparen las diferentes modalidades de dilatación. En el presente artículo realizamos una revisión de esta técnica, así como de la evidencia disponible para su aplicación en los diferentes segmentos del tracto gastrointestinal. El futuro de la dilatación incluye el desarrollo de dilatadores que permitan evaluar la dilatación durante su realización. Estos advenimientos, así como la ejecución de estudios controlados prospectivos van a mejorar las indicaciones, beneficios y riesgos para cada uno de los sistemas de dilatación existentes.

The endoscopic dilation of the gastrointestinal tract is carried out to relieve either functional or organic disorders, secondary to a variety of both benign and malignant diseases. With the advent of new technologies, virtually all digestive stenosis can be managed in a minimally invasive way. Despite its wide dissemination in actual practice, there are few controlled studies comparing the different forms of endoscopic dilation. In this article, we review this technique and the evidence available for application in different segments of the gastrointestinal tract. The future of the dilations includes the development of dilators to assess dilation during the procedure. These advents and the implementation of prospective controlled studies will improve the indications, benefits and risks for each of the existing systems of dilations.

Hemophilia A: considerations for dental management of pediatric patients / Hemofilia tipo A: consideraciones en el manejo odontológico de pacientes infantiles

It comes to consulting the Faculty of Dentistry at the University of Nuevo León pediatric male patient of 9 years 10 months, who was admitted with a presumptive diagnosis of hemophilia due to a subsequent persistent bleeding to treatment with steel crowns made in an earlier appointment. Interconsultation is performed with the hematologist who by laboratory examinations notice decreased coagulation factor VIII confirming the diagnosis of hemophilia A. It plans and conducts comprehensive treatment dental team with the hematologist who said that patients in hospitals with the replacement of missing clotting factor is prepared by cryo precipitates or with concentrated factor VIII intravenously before and after his dental intervention. The aim of the article is to highlight that hemophilia can be a disease detected during dental surgery in some patients and for it to be successfully treated with multidisciplinary management protocol is required between hematologists and dentists.

Se presenta a consulta en la Facultad de Odontología de la Universidad Autónoma de Nuevo León paciente masculino pediátrico de 9 años 10 meses, el cual ingresa con un diagnóstico de presunción de hemofilia debido a un sangrado persistente posterior al tratamiento con coronas de acero realizadas en una cita anterior. Se efectúa interconsulta con el hematólogo quien mediante exámenes de laboratorio observa una disminución del factor VIII de coagulación lo que confirma el diagnóstico de hemofilia tipo A. Se planea y realiza el tratamiento integral odontológico en equipo con el hematólogo quien indica que se prepare al paciente a nivel hospitalario con la reposición del factor de coagulación faltante a través de crio precipitados o mediante concentrado del factor VIII por vía intravenosa previo y posterior a su intervención dental. El objetivo del artículo es destacar que la hemofilia puede ser una enfermedad detectada durante la consulta dental en algunos pacientes y que para que éstos sean tratados con éxito se requiere un protocolo del manejo multidisciplinario entre hematólogos y odontólogos.

Fator VIII de origem recombinante para tratamento de pacientes com hemofilia A / Recombinant factor VIII for treatment of patients with hemophilia A

A hemofilia é uma doença hemorrágica hereditária, caracterizada pela deficiência dos fatores VIII (hemofilia A) ou IX (hemofilia B) da coagulação. É uma doença de herança recessiva ligada ao sexo, resultante de mutações nos genes que codificam os fatores VIII (hemofilia A) ou IX (hemofilia B), ambos localizados no braço longo do cromossomo X. Do ponto de vista clínico, a apresentação das hemofilias A e B são semelhantes, sendo o diagnóstico diferencial realizado através da dosagem da atividade dos fatores VIII e IX da coagulação. A classificação da hemofilia varia conforme o nível de atividade coagulante do fator deficiente, sendo o nível normal definido como 1 UI/ml ou 100%. A hemofilia é classificada como grave, moderada e leve caso a atividade do fator seja inferior a 1%, entre 1%­5% e > 5%­<40 % do normal, respectivamente. Atualmente, nos grandes centros mundiais de referência de hemofilia, já é possível prover um tratamento seguro e eficaz para a doença. Isso permite que pessoas com hemofilia, ainda que grave, nascendo hoje, tenham uma trajetória de vida quase normal do ponto de vista de expectativa de vida e com mínima morbidade. No entanto, isto depende do uso precoce e ao longo da vida de tratamento profilático com concentrado de fatores e da ausência de fatores de inibição de atividade. Nos centros com estas possibilidades de escolha, a família deve ser informada dos riscos potenciais de cada tipo de concentrado de fator, recombinante ou plasmático. Neste sentido, é importante informar que os concentrados derivados do plasma parecem estar associados a um menor risco de desenvolvimento de inibidor (fato ainda não completamente comprovado), e que os concentrados recombinantes parecem ser mais seguros em termos de risco de transmissão de agentes infecciosos e que ambos são igualmente eficazes do ponto de vista hemostático. Nestes centros, em geral, a decisão leva em conta a posição do médico tratador, do paciente e de sua família. A aquisição de ambos os tipos de concentrado, recombinante e plasmático, é desejável. Em especial, no caso do Brasil, país que possui a terceira maior população mundial de pacientes com hemofilia e, por isso, necessita adquirir grandes quantidades de concentrado de fator, fazendo­o, como único comprador, na figura do Ministério da Saúde. O Ministério da Saúde, buscando regular o fornecimento de tecnologias e ter autosuficiência para o tratamento da Hemofilia A no Brasil, bem como alcançar independência em relação ao mercado externo na produção do fator VIII, definiu como prioridade a contratação de transferência de tecnologia para a Hemobrás, empresa estatal ligada ao Ministério da Saúde, para a produção nacional do fator VIII de origem recombinante. Essa proposta engloba a compra do fator VIII recombinante para 50% de sua demanda anual, condicionada ao desenvolvimento de produção nacional dessa tecnologia por meio de parceria de desenvolvimento produtivo, até que haja autonomia da produção local. Durante a fase de transição, a seleção de pacientes para receber uma ou outra tecnologia será baseada em evidências e detalhada em protocolo clínico. Diante do exposto, os membros da CONITEC, presentes na 9ª reunião ordinária do dia 11/10/2012, por unanimidade, recomendaram a incorporação no SUS do fator VIII de origem recombinante para tratamento de pacientes com hemofilia A. A Portaria No-11, de 6 de março de 2013 - Torna pública a decisão de incorporar o medicamento fator VIII de origem recombinante para a profilaxia primária e tratamento de pacientes com hemofilia A no Sistema Único de Saúde (SUS).

Prevalence, Incidence, and Factor Concentrate Usage Trends of Hemophiliacs in Taiwan

PURPOSE: Hemophilia A and B (HA, HB) are the most common X-linked inherited bleeding disorders. The introduction of factor concentrates has allowed for control of the lifelong chronic disease. However, no studies have been published regarding the epidemiology of hemophilia in Taiwan. Our aim was to determine the prevalence, incidence, and mortality rate, as well as trends in the use of factor concentrates, in individuals with hemophilia in Taiwan. MATERIALS AND METHODS: A retrospective study was conducted using the National Health Insurance Research Database between 1997 and 2007. RESULTS: We identified 988 males with hemophilia (HA : HB ratio=5.4 : 1). The mean prevalence per 100000 males was 6.7+/-0.1 for HA and 1.2+/-0.1 for HB. The estimated mean annual incidence per live male birth was 1 in 10752 for HA and 1 in 47619 for HB. Standardized mortality ratios for males with hemophilia (all severities) or severe hemophilia were 1.3- and 2.1-fold higher than that of the general male population, respectively. Mean factor VIII (FVIII) and factor IX (FIX) usage was 1.5003+/-0.4029 and 0.3126+/-0.0904 international units (IUs) per capita, respectively. Mean FVIII and FIX usage per patient with hemophilia (all severities) or severe hemophilia was 44027+/-11532 and 72341+/-17298, respectively, and 49407+/-13015 and 74369+/-18411 IUs per person with HA or HB, respectively. CONCLUSION: Our data revealed epidemiologic and factor concentrate usage trends in males with hemophilia in Taiwan, highlighting a need for improvements in the mandatory National Health Insurance registry. A better-designed, patient-centered registry system would enable more detailed patient information collection and analysis, improving subsequent care.

Ligature of external carotid artery as an optional technique in a patient with von Willebrand disease

The von Willebrand disease (vWD) is a hereditary coagulopathy. There is no gender predilection. Clinically characterized by mucocutaneous bleeding, especially nose bleeding, menorrhagia and bleeding after trauma. This article reports a case of a 52-year-old Caucasian male patient with vWD, who presented with extensive bleeding in the tongue after a lacerating injury caused by accidental biting, and describes some clinical, pathological and treatment aspects of vWD. After repeated attempts to suture the wound and replace clotting factors, a decision was made to perform the ligature of the external carotid artery ipsilateral to the injury. There was favorable resolution of the case, with a good aspect of the scar 2 months after ligation. This case reinforces that it is extremely important to make a thorough review of medical history of all patients, searching for possible bleeding disorders or previous family history.

A doença de von Willebrand (DvW) é uma coagulopatia hereditária. Não há predileção por sexo. Clinicamente caracteriza-se por hemorragias mucocutâneas, sobretudo nasais, menorragias e hemorragias pós-trauma. Este artigo relata um caso clínico de DvW em paciente de 52 anos de idade, leucoderma, do sexo masculino, que apresentou extensa hemorragia em bordo lateral de língua após ferimento lacerante, além de descrever alguns aspectos clínicos, patológicos e terapêuticos da DvW. Após repetidas tentativas de sutura do ferimento e reposição dos fatores de coagulação, optou-se pela ligadura da artéria carótida externa ipsilateral ao ferimento, com resolução favorável do caso, notando-se bom aspecto cicatricial 2 meses após a ligadura. Este caso reforça que é de extrema importância a realização de anamnese criteriosa, buscando-se identificar possíveis distúrbios hemorrágicos prévios ou antecedentes familiares.

Inmunogenicidad de los concentrados de Factor VIII doblemente inactivados producidos en UNC-Hemoderivados / Immunogenecity of double inactivation FVIII concentrates manufactures by UNC-Hemoderivados

El tratamiento de elección en la hemofilia A es la administración de concentrados de factor VIII y hasta un 33 % de estos pacientes pueden desarrollar inhibidores dirigidos contra el factor infundido. Varias causas pueden estar involucradas en este proceso inmune siendo la intensidad de la terapia y tipo de concentrados empleados uno de los más estudiados. Por lo tanto, el análisis cuali / cuantitativo de diferentes proteínas que hacen a un concentrado más inmunogénico que otros cobra vital importancia. En este trabajo se evaluaron los niveles de factor VIII antígeno (FVIII:Ag), factor von Willebrand (FvW) funcional e inmunológico, factor de crecimiento transformador ß1 (TGF-ß1), fibrinógeno e inmunoglobulinas G, A y M en diferentes lotes de concentrados de factor VIII manufacturados en UNC-Hemoderivados y fueron comparados con otros productos comerciales de similares características. Se estudiaron 6 lotes de 250 UI y 2 de 500 UI producidos en UNC-Hemoderivados, dos lotes de 250 UI producidos por las firmas A y B y un lote de 500 UI comercializado por la firma C. Para las determinaciones de factor VIII/factor de von Willebrand, funcional y antigénico, se emplearon métodos estándares y para el TGF-ß1 se utilizó un ELlSA comercial. Los resultados obtenidos mostraron que las relaciones entre FVIII:C/FVIII:Ag y FVIII:C/FvW funcional fueron en promedio 0.60 y 0.52 para el producto de UNC-Hemoderivados y 0.50 y 0.38 para los productos de origen comercial. Los valores TGF­ß1 y la actividad específica arrojaron mejores resultados en el producto de UNC-Hemoderivados que los productos A, B y C y en las otras proteínas analizadas no hubo diferencias. Por lo tanto podemos concluir que los concentrados de FVIII producidos en UNC-­Hemoderivados presentan propiedades que potencialmente indicarían una menor respuesta inmune contra el FVIII infundido.

Replacement therapy using plasma factor VIII (FVIII) concentrates is currently the major mean of preventing and controlling bleeding in hemophilia A patients. However. approximately a 33% of these patients may develop inhibitors to the substituted FVIII. Several causes may be involved in the immune process being the intensity of therapy and type of concentrate used one of the most studied. Therefore. the study quali/quantitative analysis of different proteins which make a concentrated more immunogenic than other takes a vital importance. In this study we evaluated FVIII antigen (FVIII: Ag), von Willebrand factor (vWF) functional and immunological, TGF-Beta1, fibrinogen and immunoglobulins G, A and M levels in FVIII concentrates manufactured in UNC-Hemoderivados and compared with other commercial products of similar characteristics. We studied 6 lots of 250 IU and 2 lots of 500 IU manufactured in UNC-Hemoderivados, 2 lots of 250 IU produced by two pharmaceutical companies named A and B and 1 batch of 500 IU marketed by C. For the determinations of F VIII/FvW functional and antigenic we used standards methods and the TGF-ß1 was assayed by ELlSA test. The results show that the relationship between FVIII/FVIII:Ag and FVIII/vWF functional were in average 0.6 and 0.52 for the product of UNC-Hemoderivados and 0.5 and 0.38 for products from commercial sources. TGF-ß1 levels and the specific activity showed upper values in UNC-Hemoderivados compared to commercial products and none difference was observed in the other proteins assayed. Therefore we can conclude that FVIII concentrates produced at UNC-Hemoderivados have properties that indicate a potentially lower immune response against the infused FVIII.

Anticuerpos anti-FVIII: su evaluación por citometría de flujo / Anti FVIII antibodies: evaluation by flow cytometry

En este trabajo se describe un sistema para evaluar y caracterizar los anticuerpos anti-FVIII en pacientes con Hemofilia A Severa (HAS) que reciben el Factor como tratamiento de sustitución. Consiste en el empleo combinado de microesferas y Citometria de Flujo (CF). El rFVIII fue acoplado a microesferas de 2 µm de diámetro (m-FVIII) las cuales se incubaron con diluciones de plasma o suero de pacientes con (n=13) o sin (n=17) inhibidor, pacientes en Tratamiento Inmunotolerante (TIT)(n=5) y dadores normales (N) (n=12). Los anticuerpos se revelaron con anti-lgG humana, anti-lgG1, anti-lgG2, anti-IgG3 o anti-lgG4 biotiniladas, seguido por streptavidina-ficoeritrina. Se registraron los valores de Intensidad de Fluorescencia Media (IFM). Microesferas sin FVIII (m-Control) se utilizaron como control. El resultado se expresó como índice: (IFM de m-FVIII/IFM de m-Control) multiplicado por la inversa de la dilución de máxima respuesta. Se determinó el porcentaje de contribución de cada subclase de IgG. Los resultados presentaron un 86 por ciento de concordancia con la prueba de Bethesda y un 80 por ciento con ELISA. El método fue útil para el seguimiento de los pacientes durante el TIT. La IgG4 prevaleció en pacientes con alto título y al comienzo del TIT. La CF es fácil y rápida y requiere sólo 200 µl de muestra.

In this study, a Flow Cytometry (FC) system is described for detecting and characterizing antibodies (inhibitors) to Factor VIII (FVIII) in Severe Haemophilia A (SHA) patients following FVIII infusion. A combination of microspheres and Flow Cytometry (FC) was employed. First, rFVIII was coupled to microspheres of 2 µm of diameter (m-FVIII). Then, they were reacted with dilutions of plasma or serum of patients with (n=13) or without (n=17) inhibitors. Five patients receiving Immunotolerant Treatment (ITI) and 12 normal donors were included. Microspheres without rFVIII were used as control (m-Control). Captured anti-FVIII antibodies were detected using biotinylated anti-Human IgG, IgG1, IgG2, IgG3 or IgG4 followed by streptavidin-phycoerythrin. FC analysis was performed recording Mean Fluorescence Intensity (MFI). Results were given as an Index: the highest MFI ratio between m-FVIII and m-Control multiplied by the inverse of the corresponding plasma dilution. The contribution of each IgG subclass was expressed as percentage. FC results had 86 per cent and 80 per cent of coincidence with the Bethesda method and ELISA respectively. The test was useful to measure anti-FVIII antibodies during the ITI. IgG4 was the prevalent IgG subclass in patients with high level of inhibitors and previously to ITI. FC was easy, fast and requires only 200 µl of sample.

Evaluación de neoantígenos en concentrados de factor VIII analizados por enzimoinmunoensayo / Neoantigens evaluation on F VIII concentrates analyzed by enzymeimmunoassay (EIA)

El propósito de este estudio fue evaluar la inmunogenicidad de concentrados de factor VIII producidos en UNC-Hemoderivados antes y después del tratamiento térmico empleando un enzimoinmunoensayo (EIE) desarrollado en nuestro laboratorio. Materiales y método: Para ese propósito se obtuvieron anticuerpos contra factor VIII calentado y no-calentado por inmunización de conejos y la inmunoglobulina G específica fue aislada por afinidad a Proteína A-Sepharosa. El EIE fue realizado empleando como antígeno de captura el factor VIII con o sin tratamiento térmico (0.5 ug/pocillo), los sitios inespecíficos bloqueados con albúmina al 2 por ciento y el anticuerpo revelado con un anti-IgG de conejo conjugada a peroxidasa. La presencia de neoantígenos fue estudiada por incubar durante 2 hs a 37°C y luego a 4°C toda la noche, con cantidades crecientes de factor VIII antes y después del tratamiento térmico (0.03 a 600 ug de proteínas), con cantidades adecuadas de IgG anti-factor VIII calentado y no-calentado. Luego de centrifugar la muestra para la separación de los inmunocomplejos, se valoró la presencia de anticuerpos en el sobrenadante por EIE tanto para factor VIII calentado y no calentado. Resultados: Los resultados obtenidos permitieron observar que para ambos anticuerpos (calentado y no calentado) se neutralizaba la misma cantidad de factor VIII calentado y no calentado (0.30 ug) y además, se pudo comprobar que esta conducta se repetía cuando se empleaban en el EIE como antígeno de captura, factor VIII con y sin tratamiento térmico. Conclusiones: Los datos obtenidos de este estudio nos permiten concluir que el tratamiento térmico aplicado a los concentrados de factor VIII elaborados en la UNC-Hemoderivados no producen ninguna formación de neoantígenos. A juzgar por el sensible y específico EIE desarrollado en nuestro laboratorio.

Introduction: with the purpose of improving viral security, plasma-derived products are generally subjects of solvent/detergent and heating (100°C for 30 minutes) treatment which are introduced during the manufacturing process. The formation of neoantigens in factor VIII concentrates produced after the heat treatment could trigger an immune response against the modified protein and the native protein. Objetives: the purpose of this study was to evaluate the immunogenicity of factor VIII concentrates produced in UNC-Hemoderivados before and after heat treatment, using an EIA developed in our laboratory. Materials and methods: antibodies against factor VIII with and without heating treatment were obtained by rabbit immunization. The specific IgG was isolated by protein-A-Sepharose affinity chromatograpy. Two EIA plates were coated (0.5 ug/well) one with factor VIII heated (H) and the other one with factor VIII no-heat (no-H) and the antibodies detection were performed using rabbit anti-lgG peroxidase conjugated. The neoantigens were studied by incubation of increasing concentrations of factor VIII (0.03-600 ug of proteins) before and after heating treatment during 2 hours at 37 °C and overnight at 4 °C with adequate concentrations of anti-factor VIII IgG (with and without treatment). The immunocomplexes were removed by centrifugation and the free antibodies in the supernatant were measured by EIA in plates H and no-H. Results: the EIA showed a linear behavior between antibodies dilution ranged from 1/8000 to 1/512000. With these results we can conclude that the same concentration of factor VIII heated and unheated (0.30 ug) were neutralized with either antibodies (heated and unheated). These results were similar in both EIA plates coated with factor VIII H and no-H...

Inhibidor adquirido del Factor VIII y medicina transfusional / Acquired inhibitor anti-factor VIII antibodies and transfusion therapy

La presencia del Inhibidor Adquirido de Factor VIII, con una frecuencia poblacional de 1 caso por millón al año, es una patología que puede presentar episodios de sangrados muy graves. Cerca del 50 por ciento de los casos son idiopáticos. En esta presentación se reportan dos casos internaados en nuestra institución entre 2006 y 2007.

Plasma protein variations in hemophiliacs receiving factor replacement therapy.

OBJECTIVE: Post transfusion manifestations and its affiliated factors are vital to understand in a disease like hemophilia where multi-transfusions are given to the patients. METHODS: To investigate the implications of factor replacement therapy on plasma proteins, 52 hemophiliacs and 68 carrier females were examined for 12 plasma proteins using various electrophoretic techniques. RESULTS: Severe hemophiliacs showed raised levels ( p< 0.05) of a2 M, IgG and Albumins where values were found to be 4.78 +/- 0.865 g/l, 21.48 +/- 3.38 g/l, 66.26 +/- 11.92 g/l respectively at 95% confidence intervals however, controls and carriers showed trivial variations. CONCLUSION: Juxtaposing the dissimilarities of 12 plasma proteins in carriers, controls and hemophiliacs, it has been gleaned that factor replacement therapy do play role when seen in severe hemophiliacs with raised levels.