[Microalbuminuria in pediatric patients diagnosed with hemolytic uremic syndrome]. / Microalbuminuria en Pacientes Pediátricos Con Diagnóstico de síndrome Hemolítico Urémico.

INTRODUCTION: Hemolytic uremic syndrome (HUS) is characterized by the presence of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. It is the leading cause of acute kidney failure in children under 3 years of age. A variable number of patients develop proteinuria, hypertension, and chronic renal failure. OBJECTIVE: To evaluate the renal involvement in pediatric patients diagnosed with HUS using the microalbumin/creatinine ratio. PATIENTS AND METHODS: Descriptive concurrent cohort study that analyzed the presence of microalbuminuria in patients diagnosed with HUS between January 2001 and March 2012, who evolved without hypertension and normal renal function (clearance greater than 90ml/min using Schwartz formula). Demographic factors (age, sex), clinical presentation at time of diagnosis, use of antibiotics prior to admission, and need for renal replacement therapy were evaluated. RESULTS: Of the 24 patients studied, 54% were male. The mean age at diagnosis was two years. Peritoneal dialysis was required in 45%, and 33% developed persistent microalbuminuria. Antiproteinuric treatment was introduce in 4 patients, with good response. The mean follow-up was 6 years (range 6 months to 11 years). The serum creatinine returned to normal in all patients during follow up. CONCLUSIONS: The percentage of persistent microalbuminuria found in patients with a previous diagnosis of HUS was similar in our group to that described in the literature. Antiproteinuric treatment could delay kidney damage, but further multicenter prospective studies are necessary.

[Translated article] Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy.

OBJECTIVE: The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy. METHODS: Observational, ambispective, and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in 5 hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre- and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations. RESULTS: Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (interquartile range (IQR) 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined. Mean pre- and post-dose concentration values detected during the maintenance phase were 243.8 (SD 240.6) µg/mL and 747.4 (standard deviation (SD) 444.3) µg/mL, respectively. Increased complement blockade was observed at higher pre-dose concentrations (P = .002) and decreased serum creatinine at both higher pre- and post-dose concentrations (P = .001 and P = .017, respectively). Using ROC curves, it was determined that a pre-dose concentration >149.0 µg/mL was optimal to achieve complement blockade, with an AUC of 0.87 (0.78-0.95). Finally, high inter-individual (48.9% variation coefficient (CV)) with low intra-individual variabilities (11.9% CV) in eculizumab clearance were observed. CONCLUSIONS: The present study reports supratherapeutic concentrations of eculizumab in patients with aHUS, and defines higher concentrations than those described in the data sheet to achieve blockade, thus encouraging the personalization of treatment with eculizumab.

Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy. / Farmacocinética de eculizumab en pacientes adultos y pediátricos con síndrome hemolítico urémico atípico y glomerulopatía C3.

OBJECTIVE: The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy. METHODS: Observational, ambispective and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in five hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre-dose and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations. RESULTS: Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (IQR 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined. Mean pre-dose and post-dose concentration values detected during the maintenance phase were 243.8 (SD 240.6) µg/mL and 747.4 (SD 444.3) µg/mL, respectively. Increased complement blockade was observed at higher pre-dose concentrations (p=0.002) and decreased serum creatinine at both higher pre- and post-dose concentrations (p=0.001 and p=0.017, respectively). Using ROC curves, it was determined that a pre-dose concentration >149.0 µg/mL was optimal to achieve complement blockade, with an AUC of 0.87 (0.78-0.95). Finally, high inter-individual (48.9% CV) with low intra-individual variabilities (11.9% CV) in eculizumab clearance were observed. CONCLUSIONS: The present study reports supratherapeutic concentrations of eculizumab in patients with aHUS, and defines higher concentrations than those described in the data sheet to achieve blockade, thus encouraging the personalization of treatment with eculizumab.

Thrombotic microangiopathies in critically ill children: The MATUCIP registry in Spain.

INTRODUCTION: Thrombotic microangiopathies (TMA) are rare diseases usually presenting with renal, haematological, neurologic and cardiovascular involvement and nonspecific but severe symptoms. A registry of TMA cases managed in Spanish paediatric intensive care units (the MATUCIP Registry) was established with the aim of gaining knowledge on their clinical characteristics, diagnosis and acute-phase treatment. METHODS: We conducted a prospective multicentre observational study in 20 paediatric intensive care units (PICUs) in Spain from January 2017 to December 2021 in children aged more than 1 month with TMAs, who were followed up through the discharge from the PICU. RESULTS: The sample included 97 patients (51.5% female) with a median age of 2.6 years (interquartile range [IQR], 1.6-5.7). The initial manifestations were gastrointestinal (74.2%), respiratory (14.4%), fever (5.2%), neurologic (3.1%) and other (3.1%). At admission, 75.3% of patients had microangiopathic haemolytic anaemia, 95.9% thrombocytopenia and 94.8% acute kidney injury. Of the total sample, 57.7% of patients received a diagnosis of Shiga toxin-associated haemolytic uraemic syndrome (HUS), 14.4% of Streptococcus pneumoniae-associated HUS, 15.6% of atypical HUS, 10.3% of secondary TMA and 2.1% of thrombotic thrombocytopenic purpura. Eighty-seven patients (89.7%) developed arterial hypertension, and 49.5% gastrointestinal, 22.7% respiratory, 25.8% neurologic and 12.4% cardiac manifestations. Also, 60.8% required renal replacement therapy and 2.1% plasma exchange. Twenty patients received eculizumab. The median PICU stay was 8.5 days (IQR, 5-16.5). Two children died. CONCLUSIONS: The MATUCIP registry demonstrates the clinical variability of TMA cases requiring admission to the PICU. Knowledge of the presentation and outcomes of TMAs can facilitate early aetiological diagnosis. This registry can help improve our understanding of the clinical spectrum of these diseases, for which there is a dearth of published data.

Management of atypical uremic hemolytic syndrome in pregnant patient.

Atypical uremic haemolytic syndrome is a variant of thrombotic micro-andiopathy characterized by non-autoimmune hemolytic anemia, thrombocytopenia and acute renal failure as a result of excessive activation of the complement. Up to 60% of patients have mutations in the genes that encode the complement system. A disensing factor is required for its manifestation, including gestation. It is an entity with a high morbidity, which can decrease drastically if an early diagnosis is made and appropriate treatment is initiated. Administration of ecuilizumab has demonstrated rapid process disruption, reducing the need for extrarenal purification therapies and improving renal function and patient prognosis.

Diagnostic-therapeutic algorithm for thrombotic microangiopathy. A report of two cases.

Thrombotic microangiopathies (TMA) are a group of clinical syndromes associated with haemolytic anaemia, thrombocytopenia and organ dysfunction, mainly renal or neurological. They are associated with significant morbidity and mortality, so early diagnosis and treatment are essential. In this article we report two cases of TMA; a patient with thrombotic thrombocytopenic purpura (TTP) and a patient with atypical haemolytic uraemic syndrome (aHUS).

Management of atypical uremic hemolytic syndrome in pregnant patient. / Manejo de síndrome hemolítico urémico atípico en la paciente gestante.

Atypical uremic haemolytic syndrome is a variant of thrombotic micro-andiopathy characterized by non-autoimmune hemolytic anemia, thrombocytopenia and acute renal failure as a result of excessive activation of the complement. Up to 60% of patients have mutations in the genes that encode the complement system. A disensing factor is required for its manifestation, including gestation. It is an entity with a high morbidity, which can decrease drastically if an early diagnosis is made and appropriate treatment is initiated. Administration of ecuilizumab has demonstrated rapid process disruption, reducing the need for extrarenal purification therapies and improving renal function and patient prognosis.

Diagnostic-therapeutic algorithm for thrombotic microangiopathy. A report of two cases. / Algoritmo diagnóstico-terapéutico de las microangiopatías trombóticas. A propósito de 2 casos.

Thrombotic microangiopathies (TMA) are a group of clinical syndromes associated with haemolytic anaemia, thrombocytopenia and organ dysfunction, mainly renal or neurological. They are associated with significant morbidity and mortality, so early diagnosis and treatment are essential. In this article we report two cases of TMA; a patient with thrombotic thrombocytopenic purpura (TTP) and a patient with atypical haemolytic uraemic syndrome (aHUS).

Farmacocinética de eculizumab en pacientes adultos y pediátricos con síndrome hemolítico urémico atípico y glomerulopatía C3 / Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy

Objetivo analizar y describir las concentraciones de eculizumab y el bloqueo del complemento en los pacientes con síndrome hemolítico urémico atípico (SHUa) y glomerulopatía C3, y definir un margen terapéutico donde se alcance una alta probabilidad de conseguir eficacia terapéutica. Métodos estudio observacional, ambispectivo y multicéntrico que incluyó pacientes adultos y pediátricos diagnosticados de SHUa y glomerulopatía C3 desde septiembre de 2020 hasta octubre de 2022 en 5 hospitales de España. Eculizumab se administró a las dosis recomendadas por la ficha técnica. Se determinaron las concentraciones pre y posdosis de eculizumab, así como del bloqueo de la vía clásica del complemento (CH50). Se recogieron variables sociodemográficas, analíticas y clínicas, y se calcularon los parámetros farmacocinéticos. Para establecer el punto de corte de las concentraciones de eculizumab que predecían el bloqueo del complemento se realizó un análisis de curvas ROC (Receiver Operating Characteristic). Se utilizó el test de Kruskal-Wallis para contrastar las diferencias en distintos parámetros según las concentraciones de eculizumab. Resultados se incluyeron 25 pacientes, 19 adultos (76,0%) y 6 pediátricos (24,0%), con edades medianas de 43,4 (RIC 35,7-48,8) y 10,1 (RIC 9,6-11,3) años, respectivamente. De ellos, 22 (88,0%) pacientes fueron diagnosticados con SHUa y 3 (12,0%) con glomerulopatía C3. Se determinaron un total de 111 concentraciones de eculizumab. Las concentraciones predosis y posdosis medias detectadas durante la fase de mantenimiento fueron 243,8 (SD 240,6) μg/ml y 747,4 (SD 444,3) μg/ml, respectivamente (AU)

Objective The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy. Methods Observational, ambispective and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in five hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre-dose and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations. Results Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (IQR 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined (AU)

Síndrome urémico hemolítico: reporte de dos casos pediátricos con nexo epidemiológico / Hemolytic uremic syndrome: report of two pediatric clinical cases with epidemiologic link / Síndrome urémico hemolítico: reporte de casos pediátricos con nexo epidemiológico

Introducción: el síndrome hemolítico urémico (SHU) es en muchos países, de las causas más frecuentes de insuficiencia renal aguda. La mayoría de los casos ocurre luego de un episodio de gastroenteritis aguda (GEA) por Escherichia coli productora de toxina Shiga (STEC). En Uruguay a pesar de ser una enfermedad de notificación obligatoria, existe subregistro. Objetivo: describir dos casos clínicos de SHU asociados a GEA con nexo epidemiológico. Casos clínicos: se trata de dos varones de 4 y 5 años, sanos. En los días previos, ingesta de carne en el mismo local comercial. Consultaron por dolor abdominal, deposiciones líquidas y vómitos reiterados. El niño de 4 años presentaba fiebre y deposiciones líquidas con sangre. El niño de 5 años dolor abdominal. El estado de hidratación y las constantes vitales eran normales en ambos. Fueron admitidos a cuidados moderados. A las 48 horas y a los 5 días, respectivamente, agregan palidez cutáneo-mucosa intensa, edemas y oliguria. Estudios complementarios: anemia, plaquetopenia e insuficiencia renal. Ingresaron a cuidados intensivos y se realizó diálisis peritoneal. La investigación de STEC fue negativa y la evolución favorable. Conclusiones: en menores de 5 años el SHU asociado a GEA es la forma de enfermedad más frecuente. En Uruguay predominan las cepas STEC no-O157. En estos casos no se pudo identificar el agente. La existencia de un nexo epidemiológico alerta sobre la necesidad de extremar los cuidados en la preparación y cocción de la carne. Debido a la asociación con una enfermedad prevalente, es necesario tener presente esta complicación para poder sospecharla e iniciar el tratamiento en forma precoz y oportuna.

Introduction: hemolytic uremic syndrome (HUS) is one of the most frequent causes of acute renal failure in many countries. Most cases occur after an episode of acute gastroenteritis (GEA) due to the Shiga toxin producing Escherichia Soli (STEC). In Uruguay, despite being a disease that requires mandatory notification, it is under reported. Objective: to describe two clinical cases of HUS associated with GEA with an epidemiological link. Clinical cases: these are two healthy boys aged 4 and 5 years. In the previous days, they reported meat intake in the same commercial premises. They consulted for abdominal pain, liquid stools and repeated vomiting. The 4 year old boy had a fever and bloody stools. The 5 year old boy had abdominal pain. They both showed normal hydration levels and vital signs. They were admitted to moderate care. At 48 hours and 5 days, respectively, they showed intense skin and mucosal paleness, edema and oliguria. Complementary studies: anemia, thrombocytopenia and renal failure. They were admitted to intensive care and peritoneal dialysis was performed. The STEC's investigation was negative and the evolution favorable. Conclusions: in children under 5 years of age, HUS associated with GEA is the most frequent form of the disease. In Uruguay, non-O157 STEC strains predominate. In these cases, the agent could not be identified. The existence of an epidemiological link warns us about the need for extreme care in the preparation and cooking of meat. Due to the association with a prevalent disease, it is necessary to keep this complication in mind in order to suspect it and initiate early and timely treatment.

Introdução: a síndrome hemolítico urêmica (SHU) é uma das causas mais frequentes de insuficiência renal aguda em muitos países. A maioria dos casos ocorre após um episódio de gastroenterite aguda (GEA) devido à Escherichia Coli, a toxina produtora de Shiga (STEC). No Uruguai, apesar de ser uma doença de notificação compulsória, há subnotificação. Objetivo: descrever dois casos clínicos de SHU associada à AGE com vínculo epidemiológico. Casos clínicos: dois meninos saudáveis com idades entre 4 e 5 anos. Nos dias anteriores, eles reportaram consumo de carne nos mesmos estabe- lecimentos comerciais. Eles consultaram para dor abdominal, fezes líquidas e vômitos repetidos. O menino de 4 anos teve febre e fezes com sangue. O menino de 5 anos teve dores abdominais. O estado de hidratação e os sinais vitais foram normais em ambos meninos. Foram internados em cuidados moderados. Às 48 horas e 5 dias, respectivamente, apresentaram aliás palidez intensa da pele e mucosas, edema e oligúria. Realizaramse estudos complementares: anemia, trombocitopenia e insuficiência renal. Eles foram internados em terapia intensiva e realizouse diálise peritoneal. A investigação do STEC foi negativa e a evolução favorável. Conclusões: em crianças menores de 5 anos, a SHU associada à GEA é a forma mais frequente da doença. No Uruguai, predominam cepas STEC não-O157. Nesses casos, o agente não pôde ser identificado. A existência de um nexo epidemiológico alerta para a necessidade de extremo cuidado no preparo e cozimento da carne. Devido à associação com doença prevalente, é necessário considerar essa complicação para suspeitar e iniciar o tratamento precoce e oportunamente.

Frecuencia de hospitalizaciones por síndrome urémico hemolítico en niños de 0 a 14 años en el Perú, periodo 2015 a 2022

Introducción. Existen limitados reportes epidemiológicos del síndrome urémico hemolítico (SUH) en Latinoamérica. Objetivo. Describir la frecuencia y características de las hospitalizaciones por SUH en niños de 0 a 14 años. Métodos. Se realizó un estudio descriptivo de análisis secundario con datos de hospitalizaciones por SUH de instituciones de salud de Perú en el periodo 2015-2022. Resultados. Se registraron 228 hospitalizaciones. El 52,2% fueron varones. El 88,6% fue menor de cinco años y el 11% menor de un año. Los departamentos con más hospitalizaciones fueron Lima y Arequipa con 133 y 46 casos. Las instituciones del Ministerio de Salud (MINSA) y del Seguro Social (EsSalud) reportaron el 42,5% y 27,6% de las hospitalizaciones. Del 2015 al 2022, la incidencia varió de 0,42 a 1,13 casos/100 000 niños menores de cinco años. Conclusiones. Las hospitalizaciones por SUH fueron más frecuentes en menores de cinco años y en las instituciones del MINSA.

Introduction. There are limited epidemiological reports of hemolytic uremic syndrome (HUS) in Latin America. Objective. To describe the frequency and characteristics of hospitalizations due to HUS in children aged 0 to 14 years. Methods. Descriptive study of secondary analysis was performed with data on hospitalizations due to HUS from healthcare institutions from Peru, 2015-2022. Results. Two hundred twenty-eight hospitalizations were registered, 52.2% were male, 88.6% were under five years old, and 11% were under one year old. The departments with more hospitalizations were Lima (133 cases) and Arequipa (46 cases). The institutions of the Ministry of Health (MINSA) and Social Security (EsSalud) reported 42.5% and 27.6% of hospitalizations. From 2015 to 2022, the incidence ranged from 0.42 to 1.13 cases/100,000 children under five years of age. Conclusions. Hospitalizations due to HUS were more frequent in children under five years of age and MINSA institutions.

Successful kidney transplant with eculizumab, thymoglobulin and belatacept therapy in a highly-sensitised patient with atypical haemolytic uraemic syndrome due to factor H mutation. / Trasplante renal exitoso con protocolo de eculizumab, timoglobulina y belatacept en paciente altamente sensibilizada con síndrome hemolítico urémico atípico por mutación del factor H.

Atypical haemolytic uremic syndrome is a disease caused by complement regulation abnormalities that generally progresses to chronic end-stage renal disease with a high rate of recurrence in kidney transplantation and a high risk of graft loss. Anti-complement therapy has improved the prognosis of these patients, achieving disease remission in most cases, increasing the likelihood of a successful kidney transplant and increasing patient and graft survival. Drugs with low risk of induction of thrombotic microangiopathies such as belatacept and mycophenolate have also been used with satisfactory results. We present the case of a young patient at high immunological risk, with atypical haemolytic uraemic syndrome due to factor H mutation, who underwent a successful kidney transplantation with eculizumab, thymoglobulin, belatacept, mycophenolate and steroids, to date preserving excellent graft function without disease recurrence.

Características del síndrome urémico hemolítico en pacientes de un hospital pediátrico de Perú, 2010-2020 / Characteristics of hemolytic uremic syndrome in patients from a pediatric hospital in Peru, 2010-2020

RESUMEN El propósito del presente estudio fue describir las características clínicas, epidemiológicas, laboratoriales, tratamiento y seguimiento de pacientes con síndrome urémico hemolítico (SUH). Se revisaron las historias clínicas de los pacientes con SUH hospitalizados en el Instituto Nacional de Salud del Niño-Breña (INSN-B) de Lima, Perú. Se incluyeron a 83 pacientes. La mediana de edad fue de 22 meses. El 71,1% (n=59) registró uso previo de antibióticos. El 86,8% (n=72) tuvieron oligoanuria y el 74,6% (n=62) diarrea. Cinco cultivos fueron positivos (dos Escherichia coli enterohemorrágica). Cuarenta y nueve (59%) requirieron terapia de reemplazo renal. Ningún paciente falleció durante la hospitalización. Al año del seguimiento, siete pacientes presentaron nefropatía pos-SUH. En conclusión, en el INSN-B, la mediana de edad fue similar que años anteriores y hubo una mayor frecuencia de oligoanuria y terapia de reemplazo renal en comparación con reportes previos.

ABSTRACT This study aimed to describe the clinical-epidemiological, laboratory, treatment, and follow-up characteristics of patients with hemolytic uremic syndrome (HUS). The medical records of patients with HUS hospitalized at the Instituto Nacional de Salud del Niño-Breña (INSN-B) (Lima, Peru) were reviewed. We evaluated 83 patients. The median age was 22 months (interquartile range: 14 to 30 months). Of the sample, 71.1% (59) registered previous use of antibiotics. Seventy-two (86.8%) had oligoanuria and 62 (74.6%) had diarrhea. Five cultures were positive (two enterohaemorrhagic Escherichia coli). Forty-nine (59%) required renal replacement therapy. No patient died during hospitalization. At one year of follow-up, seven patients developed post-HUS nephropathy. In conclusion, in INSN-B, the median age was like previous years and there was a higher frequency of oligoanuria, and renal replacement therapy compared to previous reports.

Síndrome hemolítico urémico secundario a Streptococcus pneumoniae. Reporte de un caso clínico / Streptococcus pneumoniae associated hemolytic uremic syndrome. Case report

El síndrome hemolítico urémico secundario a Streptococcus pneumoniae (SHU-Sp) es una complicación poco frecuente de las enfermedades invasoras por S. pneumoniae. Presenta una alta morbimortalidad, con requerimiento de transfusiones de glóbulos rojos y plaquetas, terapia de sustitución de la función renal de inicio precoz y más prolongada, así como mayores complicaciones a largo plazo, comparado con las formas secundarias a infección entérica por Escherichia coli productora de toxina Shiga. Presentamos el caso clínico de una preescolar de dos años, previamente sana, vacunada con tres dosis de PCV13, que desarrolló una insuficiencia renal aguda, anemia hemolítica y plaquetopenia, en el contexto de una neumonía con empiema y bacteriemia por S. pneumoniae.

Streptococcus pneumoniae associated hemolytic uremic syndrome (Sp-HUS) is an uncommon complication of invasive pneumococcal infections. Patients with Sp-HUS have a higher mortality and long term morbidity than those due to HUS from Shiga toxin-producing Escherichia coli infections (STEC-HUS). They often require more red blood cells and platelet transfusions, and early initiation of renal substitution therapy, presenting a higher rate of arterial hypertension and chronic renal disease in the long term, compared to STEC-HUS. We report a healthy 2 year-old infant, vaccinated with three doses PCV13, that developed acute renal failure, hemolytic anemia and thrombocytopenia in the course of a complicated pneumococcal pneumonia with empyema and bacteremia.

Where are we with haemolytic uremic syndrome? / Síndrome hemolítico urémico: estado actual.

Haemolytic uremic syndrome (HUS) is characterised by microangiopathic haemolytic anaemia with acute kidney injury. It is currently classified into two main categories: Shiga-toxin producing E. coli-hemolytic uremic syndrome (STEC-HUS) and atypical haemolytic uremic syndrome (aHUS). Endothelial cell damage is the common pathway in HUS to developing thrombotic microangiopathy. Atypical HUS includes primary, secondary and aHUS due to metabolic diseases. In the majority of aHUS cases, hyperactivity of the alternative complement pathway plays a central role. Therefore, treatment is based on complement inhibitors like eculizumab, a drug that has revolutionised the natural history of the disease. Relapses are frequent after kidney transplant and thus confer a poor prognosis.

Microangiopatías trombóticas en niños críticamente enfermos. Registro español MATUCIP / Thrombotic microangiopathies in critically ill children: The MATUCIP registry in Spain

Introducción: Las microangiopatías trombóticas (MAT) son entidades infrecuentes que suelen causar afectación renal, hematológica, neurológica y cardiovascular, con síntomas inespecíficos pero graves. Con la finalidad de mejorar el conocimiento de sus características clínicas, el proceso diagnóstico y el tratamiento en la fase aguda, se ha creado el registro de MAT en las unidades de cuidados intensivos pediátricos (UCIP) de España (Registro MATUCIP). Pacientes y métodos: Estudio observacional, multicéntrico, realizado en 20 UCIP españolas desde enero de 2017 hasta diciembre de 2021 que incluyó niños mayores de 1mes con diagnóstico de MAT y seguimiento hasta el alta de la UCIP. Resultados: Se incluyeron 97 pacientes (51,5% mujeres), con una mediana de edad de 2,6años (RIQ: 1,6-5,7). La clínica inicial fue de tipo gastrointestinal (74,2%), respiratoria (14,4%), cuadro febril (5,2%), neurológica (3,1%) y otras (3,1%). Al ingreso, el 75,3% presentaban anemia hemolítica microangiopática, el 95,9% trombocitopenia y el 94,8% daño renal agudo. Fueron diagnosticados de síndrome hemolítico urémico (SHU) asociado a Escherichia coli productora de toxina Shiga el 57,7%, SHU por Streptococcus pneumoniae el 14,4%, SHU atípico el 15,6%, MAT secundaria el 10,3% y púrpura trombótica trombocitopénica el 2,1%. Desarrollaron hipertensión arterial el 89,7%, manifestaciones digestivas el 49,5%, respiratorias el 22,7%, neurológicas el 25,8% y cardiacas el 12,4%. El 60,8% requirieron depuración extrarrenal y el 2,1%, plasmaféresis. Recibieron eculizumab 20 pacientes. La mediana de estancia en la UCIP fue de 8,5días (RIQ: 5-16,5). Dos niños fallecieron. (AU)

Introduction: Thrombotic microangiopathies (TMA) are rare diseases usually presenting with renal, haematological, neurologic and cardiovascular involvement and nonspecific but severe symptoms. A registry of TMA cases managed in Spanish paediatric intensive care units (the MATUCIP registry) was established with the aim of gaining knowledge on their clinical characteristics, diagnosis and acute-phase treatment. Patients and methods: We conducted a prospective multicentre observational study in 20 paediatric intensive care units (PICUs) in Spain from January 2017 to December 2021 in children aged more than 1month with TMAs, who were followed up through the discharge from the PICU. Results: The sample included 97 patients (51.5% female) with a median age of 2.6years (interquartile range [IQR]: 1.6-5.7). The initial manifestations were gastrointestinal (74.2%), respiratory (14.4%), fever (5.2%), neurologic (3.1%) and other (3.1%). At admission, 75.3% of patients had microangiopathic haemolytic anaemia, 95.9% thrombocytopenia and 94.8% acute kidney injury. Of the total sample, 57.7% of patients received a diagnosis of Shiga toxin-associated haemolytic uraemic syndrome (HUS), 14.4% of Streptococcus pneumoniae-associated HUS, 15.6% of atypical HUS, 10.3% of secondary TMA and 2.1% of thrombotic thrombocytopenic purpura. Eighty-seven patients (89.7%) developed arterial hypertension, and 49.5% gastrointestinal, 22.7% respiratory, 25.8% neurologic and 12.4% cardiac manifestations. Also, 60.8% required renal replacement therapy and 2.1% plasma exchange. Twenty patients received eculizumab. The median PICU stay was 8.5days (IQR: 5-16.5). Two children died. (AU)

[Thrombotic microangiopathy/haemolytic uraemic syndrome. Histopathology update]. / Microangiopatía trombótica/síndrome hemolítico urémico. Actualización de sus características histopatológicas.

Thrombotic microangiopathy (TMA) encompasses different entities known as haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). The histopathological characteristics have remained constant since the initial description and consist in glomerular-type affectation with the presence of double contours, mesangiolysis and microthrombi. It is generally accepted that the vascular damage is related to the prognosis. Ultrastructure, together with conventional histology, shows notable changes in both capillaries and endothelial cells. A comprehensive histopathological study of the renal biopsy, using electronmicroscopy, is useful in the confirmation of a clinical suspicion and demonstrates the pathogenetic mechanisms in the microcirculatory damage. The close resemblance between the ultrastructural appearance and that seen with the light microscope of TMA and transplant glomerulopathy (TG) is precisely what suggests that both entities are subject to the same etiopathogenetic mechanism in which the endothelial cell is targeted. Recent advances in the pathology of atypical HUS, its relation with complement system and the discovery of specific therapeutic targets, has rekindled an interest in the study of TMA and the importance of renal biopsy.

Síndrome hemolítico urémico atípico secundario a infección neumocócica invasiva / Atypical hemolytic uremic syndrome secondary to invasive pneumococcal infection

Introducción: El síndrome hemolítico urémico (SHU) es una patología infrecuente y grave en pediatría. Se clasifica en SHU “típico” o “atípico” en función de su etiopatogenia. Se caracteriza por la triada: anemia hemolítica microangiopática, trombopenia e insuficiencia renal, siendo característica la presencia de esquistocitos en sangre periférica. Caso clínico: Varón de 13 meses sin antecedentes personales ni familiares de interés. Consulta por fiebre alta de 5 días, sintomatología catarral, astenia, ictericia, vómitos, diarrea y oliguria. Exploración física: mal estado general, HTA estadio I, coloración pálido-ictérica, taquicardia, polipnea, hipoventilación basal pulmonar derecha y edemas pretibiales. Pruebas complementarias: analítica sanguínea: Hb 8,4 g/dl, 20.000/mm3 plaquetas, leucocitosis con desviación izquierda, urea 186 mg/dl, creatinina 3,27 mg/dl [FGe(Schwartz_2009): 10,5 ml/min/1,73 m2], PCR, PCT y LDH elevadas, haptoglobina baja. Sistemático/sedimento urinario: proteinuria 0,95 mg/mg, hematuria glomerular. Frotis sangre periférica: 5% Esquistocitos. Test de Coombs directo: positivo. Radiografía torácica: condensación basal pulmonar derecha. Ante presencia de la triada: anemia hemolítica microangiopática, trombopenia e insuficiencia renal es diagnosticado de SHU en contexto de neumonía, iniciando tratamiento de soporte en UCIP, furosemida y antibioterapia empírica. Actividad ADAMTS13 y determinación de Shiga-toxina: negativas. Hemocultivo: + Streptococcus pneumoniae. Estudio de complemento normal. Empeoramiento funcional renal, precisando hemodialfiltración veno-venosa continua y administración de eculizumab. Presentó mejoría progresiva y alta con diagnóstico final de SHU secundario a sepsis neumocócica. Seguimiento en consulta de Nefrología Pediátrica, actualmente padece enfermedad renal crónica en estadio G3A2. Conclusiones: Es importante realizar un diagnóstico y tratamiento precoces para mejorar su pronóstico vital y funcional renal, estableciendo protocolos de manejo inicial y seguimiento multidisciplinar.(AU)

Introduction. Hemolytic uremic syndrome (HUS) is a rare and serious pathology in pediatrics. It is classified as “typical” or “atypical” HUS depending on its etiopathogenesis. It is characterized by the triad: microangiopathic hemolytic anemia, thrombopenia and renal failure, with the presence of schistocytes in peripheral blood being characteristic. Case report: 13-month-old male with no personal or family history of interest. Consultation due to high fever for 5 days, catarrhal symptoms, asthenia, jaundice, vomiting, diarrhea and oliguria. Physical examination: Poor general condition, Stage-I arterial hypertension, pale-jaundiced muco-cutaneous, tachycardia, polypnea, hypoventilation at the right lung base and pretibial edema. Complementary tests: Blood analysis: Hb 8.4 g/dl, platelets 20,000/mm3, leukocytosis with left deviation, urea 186mg/dl, creatinine 3.27 mg/dl [eGFR(Schwartz_2009): 10.5 ml/min/1.73 m2], elevated CRP, PCT and LDH, low haptoglobin. Systemic/urinary sediment: proteinuria 0.95 mg/mg, glomerular hematuria. Peripheral blood smear: 5% Schistocytes. Direct Coombs test: positive. Chest x-ray: right pulmonary basal condensation. In the presence of the triad: microangiopathic hemolytic anemia, thrombopenia and renal failure, HUS was diagnosed in the context of pneumonia, initiating supportive treatment in the PICU, furosemide and empirical antibiotic therapy. ADAMTS13 activity and Shiga-toxin determination: negative. Blood culture: + Streptococcus pneumoniae. Worsening renal function, requiring continuous veno-venous hemodiafiltration and administration of eculizumab. He showed progressive improvement and was discharged with diagnosis of HUS secondary to pneumococcal sepsis. Follow-up in Pediatric Nephrology consultation, currently suffering from chronic kidney disease (stage G3A2). Conclusions: It is important to carry out early diagnosis and treatment to improve vital and renal functional prognosis, establishing initial management protocols and multidisciplinary follow-up.(AU)

[The pathology of renal transplants]. / Anatomía patológica del trasplante renal.

In order to make an objective assessment of the histopathology of a renal biopsy during a kidney transplant, all the various elements involved in the process must be understood. It is important to know the characteristics of the donor organ, especially if the donor is older than 65. The histopathological features of the donor biopsy, especially its vascular status, are often related to an initial poor function of the transplanted kidney. The T lymphocyte inflammatory response is characteristic in acute cellular rejection; the degree of tubulitis, together with the amount of affected parenchyme, are important factors. The proportion of cellular sub-populations, such as plasma cells and macrophages, is also important, as they can be related to antibody-mediated humoral rejection. Immunofluorescent or immunohistochemical studies are necessary to rule out C4d deposits or immunogloblulins. The presence of abundant deposits of C4d in tubular basement membranes supports a diagnosis of humoral rejection, as does the presence of capillaritis, glomerulitis which, together with vasculitis, are typical diagnostic findings in C4d negative cases. Interstitial fibrosis, tubular atrophy and glomerular sclerosis, although non-specific, imply a chronic phase. Transplant glomerulopathy and multilamination in more than 6 layers of the tubular and glomerular basement membranes are quasi-specific characteristics of chronic humoral rejection. Electron microscopy is essential to identify of these pathologies as well as to demonstrate the presence of other glomerular renal diseases.

Manejo de síndrome hemolítico urémico atípico en la paciente gestante / Management of atypical uremic hemolytic syndrome in pregnant patient

El síndrome hemolítico urémico atípico es una variante de la microangiopatía trombótica caracterizada por presentar anemia hemolítica no autoinmune, trombocitopenia y fallo renal agudo como consecuencia de una excesiva activación del Sistema del complemento. Hasta en un 60% de los pacientes presentan mutaciones en los genes que codifican el sistema del complemento. Se requiere un factor desencadenante para su manifestación, entre los que se encuentra la gestación. Es una entidad que presenta una elevada morbimortalidad, que puede disminuir de forma relevante si se realiza un diagnóstico precoz y se inicia tratamiento adecuado. La administración de eculizumab ha demostrado la interrupción rápida del proceso, con reducción de la necesidad de terapias de depuración extrarrenal y mejoría de la función renal y pronóstico de las pacientes.(AU)

Atypical uremic haemolytic syndrome is a variant of thrombotic micro-andiopathy characterized by non-autoimmune hemolytic anemia, thrombocytopenia and acute renal failure as a result of excessive activation of the complement. Up to 60% of patients have mutations in the genes that encode the complement system. A disensing factor is required for its manifestation, including gestation. It is an entity with a high morbidity, which can decrease drastically if an early diagnosis is made and appropriate treatment is initiated. Administration of ecuilizumab has demonstrated rapid process disruption, reducing the need for extrarenal purification therapies and improving renal function and patient prognosis.(AU)