Changing Etiologies and Prognostic Factors in Pediatric Acute Liver Failure.

After the implementation of universal hepatitis A virus vaccination in Argentina, the outcome of pediatric acute liver failure (PALF) remains unknown. We aimed to identify variables associated with the risk of liver transplantation (LT) or death and to determine the causes and short-term outcomes of PALF in Argentina. We retrospectively included 135 patients with PALF listed for LT between 2007 and 2016. Patients with autoimmune hepatitis (AIH), Wilson's disease (WD), or inborn errors of metabolism (IEM) were classified as PALF-chronic liver disease (CLD), and others were classified as "pure" PALF. A logistic regression model was developed to identify factors independently associated with death or need of LT and risk stratification. The most common etiologies were indeterminate (52%), AIH (23%), WD (6%), and IEM (6%). Overall, transplant-free survival was 35%, whereas 50% of the patients underwent LT and 15% died on the waiting list. The 3-month risk of LT or death was significantly higher among patients with pure PALF compared with PALF-CLD (76.5% versus 42.5%; relative risk, 1.8 [1.3-2.5]; P < 0.001), and 3 risk factors were independently associated with worse outcome: international normalized ratio (INR) ≥3.5 (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.3-7.2]), bilirubin ≥17 mg/dL (OR, 4.4; 95% CI, 1.9-10.3]), and pure PALF (OR, 3.8; 95% CI, 1.6-8.9). Patients were identified by the number of risk factors: Patients with 0, 1, or ≥2 risk factors presented a 3-month risk of worse outcome of 17.6%, 36.6%, and 82%, respectively. In conclusion, although lacking external validation, this simple risk-staging model might help stratify patients with different transplant-free survival rates and may contribute to establishing the optimal timing for LT.

Incidence, risk factors, and outcomes related with neurological events after liver transplantation in adult and pediatric recipients.

Controversy exists whether NE after LT are more frequently observed in children or adults. We aimed to compare the incidence and outcomes for NE after LT in pediatric and adult recipients. A single-center cohort study, including all LT between 2001 and 2013, was performed. Definition of NE included impaired consciousness, delirium, seizures, focal neurologic deficit, visual impairment, or slurred speech. A cohort of 443 consecutive LT recipients was included: 307 adults and 136 children. Cumulative incidence of NE was similar between adults 15% (n = 41) and children 16% (n = 20; P = .73) with a complete neurological recovery in 62% and 95% of the patients, respectively (P < .0001). Adults with NE had significantly lower survival (70% vs 76%; P = .015) with a HR of 2.36; this was similarly observed in children (45% vs 66%; HR 2.05, CI 0.66; 6.34). Independent risk factors for NE in adults were pre-LT ascites, delta sodium, and post-LT hypomagnesemia, whereas in children pre-LT encephalopathy ≥II and serum albumin were associated with NE. Although a similar incidence of NE after LT was observed, children were more likely to achieve neurological recovery. Risk factors for the development of NE are difficult to assess in both populations.

Liver transplantation for primary liver tumors in pediatrics. A case series. / Trasplante hepático para tumores hepáticos primarios en pediatría. Serie de casos.

Primary liver tumors are an increasing indication for pediatric liver transplantation. Here we report the cases of 10 patients who underwent liver transplantation for primary liver tumors in our hospital, from 2001 to date. Up to 2011, 1 transplant due to hepatoblastoma was done out of 117 liver transplants (0.8%). Since 2012, there were 9 patients out of 141 (6.4%) (5 due to hepatoblastoma, 2 due to hepatocellular carcinoma, 1 due to hepatic epithelioid hemangioendothelioma, and 1 due to hepatic mesenchymal hamartoma). Follow-up: 13.2 months (median); age at transplantation: living 4.7 years (median); weight: 17.6 kg (median). Eighty percent of patients received grafts from living donors. No tumor recurrence was observed. Survival was 100% in the follow-up period. In our series, patients with primary liver tumors requiring transplantation showed an adequate course, even in the case of hepatocellular carcinoma, Related living donors liver transplantation shortened the time between the indication and the surgery.

Los tumores hepáticos primarios son indicación creciente de trasplante hepático pediátrico. Reportamos los 10 pacientes con trasplantes hepáticos por tumores hepáticos primarios en nuestro centro desde 2001 hasta la actualidad. Hasta el año 2011, se realizó un trasplante por hepatoblastoma de 117 trasplantes hepáticos (0,8 %). Desde 2012, fueron 9 pacientes de 141 (6,4 %) (5 hepatoblastomas, 2 hepatocarcinomas, 1 hemangioendotelioma epitelioide hepático y 1 hamartoma mesenquimático hepático). Seguimiento 13,2 meses (media), edad al trasplante 4,7 años (media), peso 17,6 kg (mediana). El 80 % recibió injertos desde donantes relacionados. No hubo recurrencia tumoral y la sobrevida fue del 100 % en el período de seguimiento. En nuestra serie, los pacientes con tumores hepáticos primarios que requirieron trasplante presentaron buena evolución, aun en hepatocarcinoma. El trasplante hepático con donante relacionado acortó los tiempos entre la indicación y la realización.

[Liver transplantation in hepatic epitheloid hemangioendothelioma and lung metastases: a case report]. / Trasplante hepático en hemangioendotelioma epiteloide hepático con metástasis pulmonares: reporte de un caso.

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular tumor of less malignancy than hemangiosarcoma. In the rare unilobar cases, partial hepatectomy may be indicated with risk of aggressive recurrence; in extensive liver disease, even with extrahepatic involvement, liver transplantation has been performed successfully. Metastases are more common in the lung, peritoneum, lymph nodes, spleen, and nervous system. We present the case of an asymptomatic adolescent with HEHE with lung metastases and abdominal lymph node involvement who received a liver transplant with a favorable outcome.

El hemangioendotelioma epiteloide hepático (HEHE) es un tumor vascular raro de menor malignidad que el hemangiosarcoma. En los poco frecuentes casos unilobulares, puede indicarse hepatectomía parcial con riesgo de recurrencia agresiva; en enfermedad hepática extensa, incluso con compromiso extrahepático, el trasplante hepático ha resultado efectivo. Las metástasis son más frecuentes en pulmón, peritoneo, ganglios linfáticos, bazo y sistema nervioso. Se presenta el caso de un adolescente asintomático con HEHE con metástasis pulmonares y compromiso ganglionar abdominal que recibió trasplante hepático con evolución favorable.

[Propranolol treatment in Kasabach-Merritt Syndrome secondary to congenital hepatic hemangioma. Clinical case]. / Tratamiento con propranolol en el síndrome de Kasabach-Merritt secundario a hemangioma hepático congénito. Caso clínico.

Hepatic hemangioma is the most common benign liver tumor. It can be congenital or infantile with different outcomes and complications. The clinical manifestation varies from asymptomatic to severe conditions with heart failure, Kasabach- Merritt syndrome or compartment syndrome. Diagnosis depends on medical history and imaging studies, especially ultrasound and Doppler examination in experienced hands. Differential diagnosis is essential with other hepatic lesions, mainly hepatoblastoma. In symptomatic patients, propranolol emerges as the first line treatment with good results and low frequency of adverse effects. We present the case of a newborn with a hepatic hemangioma and Kasabach-Merritt syndrome with an excellent response and tolerance to propranolol.

El hemangioma hepático es el tumor benigno de hígado más frecuente. Puede ser congénito o infantil, con diferentes evoluciones y complicaciones. La evolución clínica es muy variable, desde pacientes asintomáticos hasta cuadros de gravedad con insuficiencia cardíaca, síndrome de Kasabach- Merritt o síndrome compartimental. El diagnóstico se basa en la historia clínica y los estudios por imágenes, especialmente, la ecografía y el examen doppler en manos experimentadas. Resulta fundamental el diagnóstico diferencial con otras lesiones hepáticas, sobre todo, el hepatoblastoma. En los pacientes sintomáticos, el propranolol surge como primera línea terapéutica con buenos resultados y baja frecuencia de efectos adversos. Se presenta el caso de un recién nacido con hemangioma hepático asociado a síndrome de Kasabach- Merritt, con excelente respuesta y tolerancia al propranolol.

[Treatment of hepatitis C virus infection with new direct-acting antivirals agents in pediatrics. Case report]. / Tratamiento de infección por virus hepatitis C con nuevos antivirales en pediatría: a propósito de un caso.

Hepatitis C virus infection in children occurs mainly through vertical transmission. The natural history at this age consists in a high rate of spontaneous clearance, asymptomatic infection, or minimal histological changes. Disease complications are commonly seen in adolescence or adulthood. The classic treatment with pegylated interferon and ribavirin presents adverse effects, prolonged duration and achieves sustained viral response (SVR) in 50 % of patients with genotype 1 infection (the most frequent). New direct-acting antiviral treatments have been available in recent years for their indication from 12 years of age with excellent tolerance and a high SVR rate. Expectant therapeutic behavior is suggested in asymptomatic patients until they can access to them. We report the case of an adolescent with chronic hepatitis C without cirrhosis who received 12 weeks treatment with ledipasvir/sofosbuvir, achieving SVR.

La infección por virus de la hepatitis C en pediatría se produce principalmente por transmisión vertical. La historia natural en niños consiste en alta tasa de eliminación espontánea, infección asintomática o cambios histológicos mínimos. Las complicaciones suelen observarse en la adolescencia o en la edad adulta. El tratamiento clásico con interferón pegilado y ribavirina presenta efectos adversos, es de duración prolongada y logra una respuesta virológica sostenida (RVS) en el 50 % de los pacientes con infección por genotipo 1. Los nuevos antivirales de acción directa se encuentran disponibles para su indicación a partir de los 12 años, con excelente tolerancia y alta tasa de RVS. Se sugiere conducta terapéutica expectante en pacientes asintomáticos hasta acceder a la medicación. Reportamos el caso de un adolescente con hepatitis C crónica sin cirrosis que recibió tratamiento durante 12 semanas con ledipasvir/ sofosbuvir y se logró una RVS.

Two-step transplantation for primary hyperoxaluria: cadaveric liver followed by living donor related kidney transplantation.

In PH, PLTX, although ideal in theory, is rarely achieved. Patients usually have reached end-stage kidney disease while requiring combined liver and kidney transplantation. In this combined procedure, the sudden high oxalates mobilization from blood and tissue stores jeopardizes the success of the kidney graft, with a high risk of post-transplant early kidney necrosis or chronic graft damage. Here, we report the case of a three-yr-old girl with PH and ESRF in whom we performed sequentially deceased donor liver transplantation followed four months later by living donor kidney transplant, after normalization of blood oxalate levels and improvement of urinary oxalate output. After this two-step transplantation, our patient showed normalization of renal function with good urinary output and maintained normal blood oxalate levels. This strategy seems to be a reasonable approach in order to avoid acute renal tubular injury because of oxalate excretion in these patients.

Trasplante hepático en hemangioendotelioma epiteloide hepático con metástasis pulmonares: reporte de un caso / Liver transplantation in hepatic epitheloid hemangioendothelioma and lung metastases: a case report

El hemangioendotelioma epiteloide hepático (HEHE) es un tumor vascular raro de menor malignidad que el hemangiosarcoma. En los poco frecuentes casos unilobulares, puede indicarse hepatectomía parcial con riesgo de recurrencia agresiva; en enfermedad hepática extensa, incluso con compromiso extrahepático, el trasplante hepático ha resultado efectivo. Las metástasis son más frecuentes en pulmón,peritoneo, ganglios linfáticos, bazo y sistema nervioso. Se presenta el caso de un adolescente asintomático con HEHE con metástasis pulmonares y compromiso ganglionar abdominal que recibió trasplante hepático con evolución favorable.

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular tumor of less malignancy than hemangiosarcoma. In the rare unilobar cases, partial hepatectomy may be indicated with risk of aggressive recurrence; in extensive liver disease, even with extrahepatic involvement, liver transplantation has been performed successfully. Metastases are more common in the lung, peritoneum, lymph nodes, spleen, and nervous system. We present the case of an asymptomatic adolescent with HEHE with lung metastases and abdominal lymph node involvement who received a liver transplant with a favorable outcome.

Management of cirrhotic ascites in children: Review and recommendations. Part 2: Electrolyte disturbances, nonelectrolyte disturbances, therapeutic options. / Manejo de la ascitis secundaria a cirrosis en el paciente pediátrico: Revisión y recomendaciones. Parte 2: Complicaciones electrolíticas, complicaciones no electrolíticas, opciones terapéuticas.

Ascites is a major complication of cirrhosis. There are several evidence-based articles and guidelines for the management of adults, but few data have been published in relation to children. In the case of a pediatric patient with cirrhotic ascites (PPCA), the following questions are raised: How are the clinical assessment and ancillary tests performed? When is ascites considered refractory? How is it treated? Should fresh plasma and platelets be infused before abdominal paracentesis to prevent bleeding? What are the hospitalization criteria? What are the indicated treatments? What complications can patients develop? When and how should hyponatremia be treated? What are the diagnostic criteria for spontaneous bacterial peritonitis? How is it treated? What is hepatorenal syndrome? How is it treated? When should albumin be infused? When should fluid intake be restricted? The recommendations made here are based on pathophysiology and suggest the preferred approach to diagnostic and therapeutic aspects, and preventive care.

La ascitis es una complicación grave de la cirrosis. Existen numerosos artículos y guías basadas en la evidencia para adultos, pero poco se ha publicado para niños. Ante un paciente pediátrico con ascitis secundaria a cirrosis (PPAC), se plantean las siguientes preguntas: ¿Cómo se realiza la evaluación clínica y los exámenes complementarios? ¿Cuándo se considera que la ascitis es refractaria; cómo se trata? ¿Debe infundirse plasma fresco y plaquetas antes de la paracentesis abdominal para evitar el sangrado? ¿Cuáles son los criterios de hospitalización? ¿Cuáles son los tratamientos indicados? ¿Qué complicaciones puede presentar? ¿Cuándo y cómo debe tratarse la hiponatremia? ¿Qué criterios diagnósticos tiene la peritonitis bacteriana espontánea; cómo se trata? ¿Qué es el síndrome hepatorrenal; cómo se trata? ¿Cuándo debe infundirse albúmina? ¿Cuándo debe restringirse el aporte líquido? Las recomendaciones que efectuamos, basadas en la fisiopatología, sugieren el enfoque preferido para encarar sus aspectos diagnósticos, terapéuticos y los cuidados preventivos.

Management of cirrhotic ascites in children. Review and recommendations. Part 1: Pathophysiology, diagnostic evaluation, hospitalization criteria, treatment, nutritional management. / Manejo de la ascitis secundaria a cirrosis en el paciente pediátrico. Revisión y recomendaciones. Parte 1: Fisiopatología, evaluación diagnóstica, criterios de hospitalización, tratamiento, manejo nutricional.

Ascites is a major complication of cirrhosis. There are several evidence-based articles and guidelines for the management of adults, but few data have been published in relation to children. In the case of pediatric patients with cirrhotic ascites (PPCA), the following questions are raised: How are the clinical assessment and ancillary tests performed? When is ascites considered refractory? How is it treated? Should fresh plasma and platelets be infused before abdominal paracentesis to prevent bleeding? What are the hospitalization criteria? What are the indicated treatments? What complications can patients develop? When and how should hyponatremia be treated? What are the diagnostic criteria for spontaneous bacterial peritonitis? How is it treated? What is hepatorenal syndrome? How is it treated? When should albumin be infused? When should fluid intake be restricted? The recommendations made here are based on pathophysiology and suggest the preferred approach to its diagnostic and therapeutic aspects, and preventive care.

La ascitis es una complicación grave de la cirrosis. Existen numerosos artículos y guías basadas en la evidencia para adultos, pero poco se ha publicado para niños. Ante un paciente pediátrico con ascitis secundaria a cirrosis (PPAC), se plantean las siguientes preguntas: ¿Cómo se realiza la evaluación clínica y los exámenes complementarios? ¿Cuándo se considera que la ascitis es refractaria; cómo se trata? ¿Debe infundirse plasma fresco y plaquetas antes de la paracentesis abdominal para evitar el sangrado? ¿Cuáles son los criterios de hospitalización? ¿Cuáles son los tratamientos indicados? ¿Qué complicaciones puede presentar? ¿Cuándo y cómo debe tratarse la hiponatremia? ¿Qué criterios diagnósticos tiene la peritonitis bacteriana espontánea; cómo se trata? ¿Qué es el síndrome hepatorrenal; cómo se trata? ¿Cuándo debe infundirse albúmina? ¿Cuándo debe restringirse el aporte líquido? Las recomendaciones que efectuamos, basadas en la fisiopatología, sugieren el enfoque preferido para encarar sus aspectos diagnósticos, terapéuticos y los cuidados preventivos.

Tratamiento de infección por virus hepatitis C con nuevos antivirales en pediatría: a propósito de un caso / Treatment of hepatitis C virus infection with new direct-acting antivirals agents in pediatrics. Case report

La infección por virus de la hepatitis C en pediatría se produce principalmente por transmisión vertical. La historia natural en niños consiste en alta tasa de eliminación espontánea, infección asintomática o cambios histológicos mínimos. Las complicaciones suelen observarse en la adolescencia o en la edad adulta. El tratamiento clásico con interferón pegilado y ribavirina presenta efectos adversos, es de duración prolongada y logra una respuesta virológica sostenida (RVS) en el 50 % de los pacientes con infección por genotipo 1. Los nuevos antivirales de acción directa se encuentran disponibles para su indicación a partir de los 12 años, con excelente tolerancia y alta tasa de RVS. Se sugiere conducta terapéutica expectante en pacientes asintomáticos hasta acceder a la medicación. Reportamos el caso de un adolescente con hepatitis C crónica sin cirrosis que recibió tratamiento durante 12 semanas con ledipasvir/sofosbuvir y se logró una RVS.

Hepatitis C virus infection in children occurs mainly through vertical transmission. The natural history at this age consists in a high rate of spontaneous clearance, asymptomatic infection, or minimal histological changes. Disease complications are commonly seen in adolescence or adulthood. The classic treatment with pegylated interferon and ribavirin presents adverse effects, prolonged duration and achieves sustained viral response (SVR) in 50 % of patients with genotype 1 infection (the most frequent). New direct-acting antiviral treatments have been available in recent years for their indication from 12 years of age with excellent tolerance and a high SVR rate. Expectant therapeutic behavior is suggested in asymptomatic patients until they can access to them. We report the case of an adolescent with chronic hepatitis C without cirrhosis who received 12 weeks treatment with ledipasvir/sofosbuvir, achieving SVR.

Tratamiento con propranolol en el síndrome de Kasabach-Merritt secundario a hemangioma hepático congénito. Caso clínico / Propranolol treatment in Kasabach-Merritt Syndrome secondary to congenital hepatic hemangioma. Clinical case

El hemangioma hepático es el tumor benigno de hígado más frecuente. Puede ser congénito o infantil, con diferentes evoluciones y complicaciones. La evolución clínica es muy variable, desde pacientes asintomáticos hasta cuadros de gravedad con insuficiencia cardíaca, síndrome de Kasabach-Merritt o síndrome compartimental. El diagnóstico se basa en la historia clínica y los estudios por imágenes, especialmente, la ecografía y el examen doppler en manos experimentadas. Resulta fundamental el diagnóstico diferencial con otras lesiones hepáticas, sobre todo, el hepatoblastoma. En los pacientes sintomáticos, el propranolol surge como primera línea terapéutica con buenos resultados y baja frecuencia de efectos adversos. Se presenta el caso de un recién nacido con hemangioma hepático asociado a síndrome de Kasabach-Merritt, con excelente respuesta y tolerancia al propranolol

Hepatic hemangioma is the most common benign liver tumor. It can be congenital or infantile with different outcomes and complications. The clinical manifestation varies from asymptomatic to severe conditions with heart failure, Kasabach-Merritt syndrome or compartment syndrome. Diagnosis depends on medical history and imaging studies, especially ultrasound and Doppler examination in experienced hands. Differential diagnosis is essential with other hepatic lesions, mainly hepatoblastoma. In symptomatic patients, propranolol emerges as the first line treatment with good results and low frequency of adverse effects. We present the case of a newborn with a hepatic hemangioma and Kasabach-Merritt syndrome with an excellent response and tolerance to propranolol.

[Operational tolerance in a pediatric liver transplant recipient. Case report]. / Tolerancia operacional en un receptor pediátrico de trasplante hepático. Caso clínico.

Operational tolerance (absence of allograft rejection and good outcome without immunosuppression) has been object of intense research in pediatric liver transplant in the last years. The morbidity and mortality related to long-term immunosuppressive treatment of these patients are well known. We report a case of operational tolerance of our unit in a pediatric liver transplant recipient who is immunosuppressant-free since 16 month after transplant after progressive withdrawal related to asymptomatic Epstein-Barr virus first infection. He has good histological, clinical and serological outcome after 22 month of follow-up. To our knowledge, this is the first operational tolerance reported case in our country after liver transplant in a pediatric recipient and we believe that the study of these patients is important in order to detect characteristics that allow to identify a potentially tolerant group in which it is possible to withdraw immunosuppressive drugs.

[Human herpesvirus 8 related Kaposi's sarcoma in a pediatric liver transplant recipient: case report]. / Sarcoma de Kaposi por virus del herpes humano de tipo 8 en un receptor de trasplante hepático pediátrico: Caso clínico.

Patients under immunosuppressive treatment are at risk of developing malignant tumors. Primary infection or reactivation of human herpesvirus 8 (HHV-8) may predispose to Kaposi's sarcoma (KS) after solid organ transplantation. KS in pediatric liver transplant recipients has low incidence and poor prognosis. We report the clinical presentation of a KS in lymph node following HHV-8 infection in a pediatric patient presenting four months after liver transplantation. He had a good outcome with suspension of tacrolimus and conversion to sirolimus one month after diagnosis. To our knowledge, this is the frst KS reported case in our country after liver transplant in a pediatric recipient and we believe that this entity should be taken into consideration in the differential diagnosis of post-transplant complications.

[Fulminant hepatic failure due to tuberculostatic drugs: case report]. / Falla hepática secundaria a toxicidad por tuberculostáticos: Caso clínico.

Hepatoxicity of isoniazid, mainly in association with rifampin, is a rare secondary effect of tuberculostatic treatment. In the United States, it accounts for 0.2% of all pediatric orthotropic liver transplant, and 14% of transplants for drug hepatotoxicity. We report the case of a 10 year-old patient who presented with acute liver failure requiring orthotropic liver transplant after forty days of tuberculostatic treatment with isoniazid, rifampin and pyrazinamide.

[Rifaximin for hepatic encephalopathy in children. Case report]. / Rifaximina para encefalopatía hepática en niños. Caso clínico.

Rifaximin is an antibiotic recently approved for the treatment of hepatic encephalopathy in adults. In children more than 12 year-old, it has been approved for travelers' diarrhea and it is also widely used in inflammatory bowel disease. We report, to our knowledge, the first case of a pediatric patient who received rifaximin for hepatic encephalopathy with good clinical outcome.

Tolerancia operacional en un receptor pediátrico de trasplante hepático: Caso clínico / Operational tolerance in a pediatric liver transplant recipient: Case report

La tolerancia operacional (ausencia de rechazo del injerto y buena evolución sin inmunosupresión) ha sido objeto de intensa investigación en trasplante hepático pediátrico en los últimos años. La morbimortalidad relacionada con la exposición a drogas inmunosupresoras a largo plazo en estos pacientes es bien conocida. Reportamos un caso de tolerancia operacional de nuestro centro en un receptor pediátrico de trasplante hepático libre de inmunosupresión desde los 16 meses postrasplante luego de una progresiva disminución a partir de su primoinfección asintomática por virus de Epstein-Barr, con buena evolución histológica y clínico-humoral en 22 meses de seguimiento. De acuerdo con nuestro conocimiento, este es el primer caso de tolerancia operacional en un receptor pediátrico de trasplante hepático reportado en nuestro país y creemos que debería profundizarse el estudio de estos pacientes para detectar características que permitan identificar una población potencialmente tolerante en la cual es posible disminuir y suspender la inmunosupresión.

Operational tolerance (absence of allograft rejection and good outcome without immunosuppression) has been object of intense research in pediatric liver transplant in the last years. The morbidity and mortality related to long-term immunosuppressive treatment of these patients are well known. We report a case of operational tolerance of our unit in a pediatric liver transplant recipient who is immunosuppressant-free since 16 month after transplant after progressive withdrawal related to asymptomatic Epstein-Barr virus first infection. He has good histological, clinical and serological outcome after 22 month of follow-up. To our knowledge, this is the first operational tolerance reported case in our country after liver transplant in a pediatric recipient and we believe that the study of these patients is important in order to detect characteristics that allow to identify a potentially tolerant group in which it is possible to withdraw immunosuppressive drugs.

Tolerancia operacional en un receptor pediátrico de trasplante hepático: Caso clínico / Operational tolerance in a pediatric liver transplant recipient: Case report

La tolerancia operacional (ausencia de rechazo del injerto y buena evolución sin inmunosupresión) ha sido objeto de intensa investigación en trasplante hepático pediátrico en los últimos años. La morbimortalidad relacionada con la exposición a drogas inmunosupresoras a largo plazo en estos pacientes es bien conocida. Reportamos un caso de tolerancia operacional de nuestro centro en un receptor pediátrico de trasplante hepático libre de inmunosupresión desde los 16 meses postrasplante luego de una progresiva disminución a partir de su primoinfección asintomática por virus de Epstein-Barr, con buena evolución histológica y clínico-humoral en 22 meses de seguimiento. De acuerdo con nuestro conocimiento, este es el primer caso de tolerancia operacional en un receptor pediátrico de trasplante hepático reportado en nuestro país y creemos que debería profundizarse el estudio de estos pacientes para detectar características que permitan identificar una población potencialmente tolerante en la cual es posible disminuir y suspender la inmunosupresión.(AU)

Operational tolerance (absence of allograft rejection and good outcome without immunosuppression) has been object of intense research in pediatric liver transplant in the last years. The morbidity and mortality related to long-term immunosuppressive treatment of these patients are well known. We report a case of operational tolerance of our unit in a pediatric liver transplant recipient who is immunosuppressant-free since 16 month after transplant after progressive withdrawal related to asymptomatic Epstein-Barr virus first infection. He has good histological, clinical and serological outcome after 22 month of follow-up. To our knowledge, this is the first operational tolerance reported case in our country after liver transplant in a pediatric recipient and we believe that the study of these patients is important in order to detect characteristics that allow to identify a potentially tolerant group in which it is possible to withdraw immunosuppressive drugs.(AU)

Sarcoma de Kaposi por virus del herpes humano de tipo 8 en un receptor de trasplante hepático pediátrico: Caso clínico / Human herpesvirus 8 related Kaposi's sarcoma in a pediatric liver transplant recipient: Case report

Los pacientes que reciben tratamiento inmunosupresor están en riesgo de desarrollar tumores malignos. La infección primaria o reactivación del virus del herpes humano de tipo 8 (HHV-8) puede predisponer al sarcoma de Kaposi después del trasplante de un órgano sólido. En los receptores de trasplantes pediátricos, este sarcoma tiene baja incidencia y mal pronóstico. Se informa la presentación clínica de un sarcoma de Kaposi en un ganglio linfático luego de una infección por HHV-8 en un niño a los 4 meses del trasplante hepático. El paciente tuvo buena evolución con suspensión del tacrolimus y conversión a sirolimus un mes después del diagnóstico. En nuestro conocimiento, este es el primer caso de sarcoma de Kaposi en un receptor pediátrico de trasplante hepático informado en nuestro país y creemos que esta entidad debería considerarse como diagnóstico diferencial en las complicaciones postrasplante.

Patients under immunosuppressive treatment are at risk of developing malignant tumors. Primary infection or reactivation of human herpesvirus 8 (HHV-8) may predispose to Kaposi's sarcoma (KS) after solid organ transplantation. KS in pediatric liver transplant recipients has low incidence and poor prognosis. We report the clinical presentation of a KS in lymph node following HHV-8 infection in a pediatric patient presenting four months after liver transplantation. He had a good outcome with suspension of tacrolimus and conversion to sirolimus one month after diagnosis. To our knowledge, this is the frst KS reported case in our country after liver transplant in a pediatric recipient and we believe that this entity should be taken into consideration in the differential diagnosis of post-transplant complications.