Individualized dose of anti-thymocyte globulin based on weight and pre-transplantation lymphocyte counts in pediatric patients: a single center experience.

Anti-thymocyte globulin (ATG) has become a standard in preventing GVHD in related and unrelated donor transplantation, but there is no consensus on the best administration schedule. The PARACHUTE trial reported excellent CD4 immune reconstitution (CD4 IR) using a dosing schedule based on the patient's weight and pre-conditioning absolute lymphocyte count (ALC). In 2015 we introduced the PARACHUTE dosing schedule for pediatric patients at our center. One hundred one patients were transplanted for malignant and non-malignant diseases. In this non-concurrent cohort CD4 IR+, defined by a single CD4 count >50/µL on day 90, was seen in 81% of patients. The incidence of grade II-IV and III to IV aGvHD was 26.6% and 15.3% and 5% for cGvHD with no severe cases. We found no difference in aGvHD between donor type and stem cell sources. Five-year EFS and OS were 77.5% and 83.5%. Grade III-IV GFRS was 75.2%. CD4 IR+ patients had better EFS (93.1% vs. 77.7%, p = 0.04) and lower non-relapse mortality (2.7% vs. 22.2%, p = 0.002). The PARACHUTE ATG dosing schedule individualized by weight and ALC results in good early immune reconstitution, low incidence of cGvHD, and favorable survival for patients with different disease groups, donor types, and stem cell sources.

5 years DKMS Chile: approach, results and impact of the first unrelated stem cell donor center in Chile.

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed worldwide to treat blood cancer and other life-threatening blood disorders. As successful transplantation requires an HLA-compatible donor, unrelated donor centers and registries have been established worldwide to identify donors for patients without a family match. Ethnic minorities are underrepresented in large donor registries. Matching probabilities are higher when donors and patients share the same ethnic background, making it desirable to increase the diversity of the global donor pool by recruiting donors in new regions. Here, we report the establishment and the first 5 years of operation of the first unrelated stem cell donor center in Chile, a high-income country in South America with a population of over 19 million. Methods: We used online and in-person donor recruitment practices through patient appeals and donor drives in companies, universities, the armed forces, and public services. After confirmatory typing donors were subjected to medical work-up and cleared for donation. Results: We recruited almost 170,000 donors in 5 years. There were 1,488 requests received for confirmatory typing and donor availability checks, of which 333 resulted in medical work-up, leading to 194 stem cell collections. Products were shipped to Chile (48.5%) and abroad. Even when the COVID-19 pandemic challenged our activities, the number of donors recruited and shipped stem cell products remained steady. In Chile there was an almost 8-fold increase in unrelated donor transplantation activity from 16 procedures in 2016-2018 to 124 procedures in 2019-2021, mainly for pediatric patients following the center's establishment. We estimate that 49.6% of Chilean patients would find at least one matched unrelated donor in the global DKMS donor pool. Discussion: Establishing a DKMS donor center in Chile has significantly increased donor availability for Chilean patients and contributed to an increase of unrelated donor stem cell transplant activity.

Porfiria eritropoyética congénita: reporte de un caso y recomendaciones de manejo / Congenital erythropoietic porphyria: case report and management recommendations

La porfiria eritropoyética congènita es una porfiria cutánea no aguda, extremadamente poco frecuente, autosómica recesiva, producida por la deficiencia de la enzima uroporfirinógeno III sintetasa codificada en el gen UROS, en el cromosoma 10q26.2. Esto genera el depósito y la acumulación de porfirinas en las córneas, los huesos y los dientes. Se presenta desde los primeros meses de vida con intensa fotosensibilidad, que se manifiesta con fragilidad cutánea con formación de vesículas, bulas y costras. El curso grave lleva a la mutilación de tejidos acrales, compromiso ocular, anemia hemolítica e hiperesplenismo. El manejo es complejo, basado, sobre todo, en la fotoprotección. Un correcto diagnóstico y enfrentamiento puede mejorar notablemente la calidad y expectativas de vida de estos pacientes. Se presenta el caso de un lactante con porfiria eritropoyética congénita confirmada con el estudio genético.

Congenital erythropoietic porphyria is an extremely rare, autosomal recessive, non-acute cutaneous porphyria, caused by uroporphyrinogen III synthase deficiency, codificated by UROS gene on the chromosome 10q26.2. Porphyrins deposit in cornea, bones and teeth. The first symptoms could be manifested in early childhood, with skin fragility, vesicles and bullae. Severe course produces acral tissues mutilation, eye involvement, hemolytic anemia and hypersplenism. The treatment is complex and it is based in the photoprotection. A correct diagnosis can significantly improve the quality and life expectancy of these patients. We present the case of a child with congenital erythropoietic porphyria confirmed by genetic analysis.

[Congenital erythropoietic porphyria: case report and management recommendations]. / Porfiria eritropoyética congénita: reporte de un caso y recomendaciones de manejo.

Congenital erythropoietic porphyria is an extremely rare, autosomal recessive, non-acute cutaneous porphyria, caused by uroporphyrinogen III synthase deficiency, codificated by UROS gene on the chromosome 10q26.2. Porphyrins deposit in cornea, bones and teeth. The first symptoms could be manifested in early childhood, with skin fragility, vesicles and bullae. Severe course produces acral tissues mutilation, eye involvement, hemolytic anemia and hypersplenism. The treatment is complex and it is based in the photoprotection. A correct diagnosis can significantly improve the quality and life expectancy of these patients. We present the case of a child with congenital erythropoietic porphyria confirmed by genetic analysis.

La porfiria eritropoyética congènita es una porfiria cutánea no aguda, extremadamente poco frecuente, autosómica recesiva, producida por la deficiencia de la enzima uroporfirinógeno III sintetasa codificada en el gen UROS, en el cromosoma 10q26.2. Esto genera el depósito y la acumulación de porfirinas en las córneas, los huesos y los dientes. Se presenta desde los primeros meses de vida con intensa fotosensibilidad, que se manifiesta con fragilidad cutánea con formación de vesículas, bulas y costras. El curso grave lleva a la mutilación de tejidos acrales, compromiso ocular, anemia hemolítica e hiperesplenismo. El manejo es complejo, basado, sobre todo, en la fotoprotección. Un correcto diagnóstico y enfrentamiento puede mejorar notablemente la calidad y expectativas de vida de estos pacientes. Se presenta el caso de un lactante con porfiria eritropoyética congénita confirmada con el estudio genético.

Trasplante alogénico de precursores hematopoyéticos de sangre de cordón umbilical de donante no emparentado: primera experiencia, en tres casos, con donantes del banco público chileno de células de cordón / Allogenic hematopoietic stem cell transplantation with unrelated cord blood: Report of three cases from the Chilean cord blood bank

Public cord blood banks are a source of hematopoietic stem cells for patients with hematological diseases who lack a family donor and need allogeneic transplantation. In June 2007 we started a cord blood bank with units donated in three maternity wards in Santiago, Chile. We report the first three transplants done with cord blood units form this bank. Cord blood units were obtained by intrauterine collection at delivery. They were depleted of plasma and red cells and frozen in liquid nitrogen. Tests for total nucleated cells, CD34 cell content, viral serology, bacterial cultures and HLA A, B and DRB1 were done. Six hundred cord blood units were stored by March 2012. Three patients received allogeneic transplant with cord blood from our bank, two with high risk lymphoblastic leukemia and one with severe congenital anemia. They received conditioning regimens according to their disease and usual supportive care for unrelated donor transplantation until full hematopoietic and immune reconstitution was achieved. The three patients had early engraftment of neutrophils and platelets. The child corrected his anemia and the leukemia patients remain in complete remission. The post-transplant course was complicated with Epstein Barr virus, cytomegalovirus and BK virus infection. Two patients are fully functional 24 and 33 months after transplant, the third is still receiving immunosuppression.

[Allogenic hematopoietic stem cell transplantation with unrelated cord blood: report of three cases from the Chilean cord blood bank]. / Trasplante alogénico de precursores hematopoyéticos de sangre de cordón umbilical de donante no emparentado: primera experiencia, en tres casos, con donantes del banco público chileno de células de cordón.

Public cord blood banks are a source of hematopoietic stem cells for patients with hematological diseases who lack a family donor and need allogeneic transplantation. In June 2007 we started a cord blood bank with units donated in three maternity wards in Santiago, Chile. We report the first three transplants done with cord blood units form this bank. Cord blood units were obtained by intrauterine collection at delivery. They were depleted of plasma and red cells and frozen in liquid nitrogen. Tests for total nucleated cells, CD34 cell content, viral serology, bacterial cultures and HLA A, B and DRB1 were done. Six hundred cord blood units were stored by March 2012. Three patients received allogeneic transplant with cord blood from our bank, two with high risk lymphoblastic leukemia and one with severe congenital anemia. They received conditioning regimens according to their disease and usual supportive care for unrelated donor transplantation until full hematopoietic and immune reconstitution was achieved. The three patients had early engraftment of neutrophils and platelets. The child corrected his anemia and the leukemia patients remain in complete remission. The post-transplant course was complicated with Epstein Barr virus, cytomegalovirus and BK virus infection. Two patients are fully functional 24 and 33 months after transplant, the third is still receiving immunosuppression.

Uso de desmopresina en niños con disfunción plaquetaria congénita sometidos a adeno y/o amigdalectomía / Use of desmopressin in children with inherited platelet dysfunctions undergoing adenotonsillar procedures

Introducción y objetivos: La cirugía de adenoides y/o amígdalas representa un desafío hemostático importante en pacientes pediátricos con disfunción plaquetaria congénita leve. Si bien existen recomendaciones para el manejo perioperatorio de la hemostasia en estos pacientes, no hay informes de resultados del manejo con las distintas recomendaciones en niños sometidos a cirugía adenoamigdalina. Nuestro objetivo es evaluar el uso de desmopresina para la prevención de la hemorragia perioperatoria en niños con disfunción plaquetaria congénita leve sometidos a adeno y/o amigdalectomía en nuestro centro. Métodos: Estudio retrospectivo descriptivo dirigido a determinar la tasa de hemorragia perioperatoria y complicaciones en niños con disfunción plaquetaria congénita leve en quienes se utilizó desmopresina cuando fueron sometidos a adeno y/o amigdalectomía. Resultados: Entre los años 2004 y 2010, 27 niños con disfunción plaquetaria congénita leve fueron sometidos a cirugía de adenoides y/o amígdalas y recibieron desmopresina. Un paciente (3,7%) desarrolló hemorragia perioperatoria. Se registró un caso (3,7%) de hipotensión transitoria como efecto adverso atribuible a la desmopresina. Conclusiones: El uso de desmopresina permitió un buen manejo preventivo de la hemorragia perioperatoria en pacientes con disfunción plaquetaria congénita leve sometidos a adenoamigdalectomía, sin presentar complicaciones graves(AU)

Introduction and goals: Adenotonsillar surgery represents a major haemostatic challenge in paediatric patients with mild inherited platelet dysfunction. While there are recommendations for perioperative haemostatic management, there are no reports of the outcomes with the different recommendations in these children when undergoing adenotonsillectomy. Our objective was to evaluate the management of perioperative bleeding with desmopressin in children with mild platelet dysfunctions who underwent adenotonsillar surgery in our hospital. Methods: We performed a retrospective study aimed at determining the perioperative bleeding and complication rate in children with mild inherited platelet dysfunction in whom desmopressin was used while undergoing adenotonsillar procedures. Results: Between 2004 and 2010, 27 children with mild inherited platelet dysfunction underwent adenotonsillar procedures in our hospital and were treated with desmopressin. One patient developed perioperative bleeding (3.7%) and there was 1 child (3.7%) who presented transitory hypotension as a side effect of desmopressin. Conclusions: The use of desmopressin allowed adequate perioperative bleeding prophylaxis management in children with mild inherited platelet dysfunction who underwent adenotonsillar procedures without presenting severe complications(AU)

Hematopoietic stem cell transplantation: clinical use and perspectives.

Hematopoietic stem cell transplantation is the accepted therapy of choice for a variety of malignant and non-malignant diseases in children and adults. Initially developed as rescue therapy for a patient with cancer after high doses of chemotherapy and radiation as well as the correction of severe deficiencies in the hematopoietic system, it has evolved into an adoptive immune therapy for malignancies and autoimmune disorders. The procedure has helped to obtain key information about the bone marrow environment, the biology of hematopoietic stem cells and histocompatibility. The development of this new discipline has allowed numerous groups working around the world to cure patients of diseases previously considered lethal. Together with the ever growing list of volunteer donors and umbilical cord blood banks, this has resulted in life saving therapy for thousands of patients yearly. We present an overview of the procedure from its cradle to the most novel applications, as well as the results of the HSC transplant program developed at our institution since 1989.

[Use of desmopressin in children with inherited platelet dysfunctions undergoing adenotonsillar procedures]. / Uso de desmopresina en niños con disfunción plaquetaria congénita sometidos a adeno y/o amigdalectomía.

INTRODUCTION AND GOALS: Adenotonsillar surgery represents a major haemostatic challenge in paediatric patients with mild inherited platelet dysfunction. While there are recommendations for perioperative haemostatic management, there are no reports of the outcomes with the different recommendations in these children when undergoing adenotonsillectomy. Our objective was to evaluate the management of perioperative bleeding with desmopressin in children with mild platelet dysfunctions who underwent adenotonsillar surgery in our hospital. METHODS: We performed a retrospective study aimed at determining the perioperative bleeding and complication rate in children with mild inherited platelet dysfunction in whom desmopressin was used while undergoing adenotonsillar procedures. RESULTS: Between 2004 and 2010, 27 children with mild inherited platelet dysfunction underwent adenotonsillar procedures in our hospital and were treated with desmopressin. One patient developed perioperative bleeding (3.7%) and there was 1 child (3.7%) who presented transitory hypotension as a side effect of desmopressin. CONCLUSIONS: The use of desmopressin allowed adequate perioperative bleeding prophylaxis management in children with mild inherited platelet dysfunction who underwent adenotonsillar procedures without presenting severe complications.

Hematopoietic stem cell transplantation: clinical use and perspectives

Hematopoietic stem cell transplantation is the accepted therapy of choice for a variety of malignant and non-malignant diseases in children and adults. Initially developed as rescue therapy for a patient with cancer after high doses of chemotherapy and radiation as well as the correction of severe deficiencies in the hematopoietic system, it has evolved into an adoptive immune therapy for malignancies and autoimmune disorders. The procedure has helped to obtain key information about the bone marrow environment, the biology of hematopoietic stem cells and histocompatibility. The development of this new discipline has allowed numerous groups working around the world to cure patients of diseases previously considered lethal. Together with the ever growing list of volunteer donors and umbilical cord blood banks, this has resulted in life saving therapy for thousands of patients yearly. We present an overview of the procedure from its cradle to the most novel applications, as well as the results of the HSC transplant program developed at our institution since 1989.