Dynamic evolution of kidney function in patients with STEC-hemolytic uremic syndrome followed for more than 15 years: unexpected changes.

BACKGROUND: Most studies regarding kidney outcomes in patients with Shiga toxin-producing Escherichia coli-hemolytic uremic syndrome (STEC-HUS) focus on kidney status at last assessment. We aimed to describe patterns of changes in kidney function during follow-up and investigate associations between kidney function at 1st, 5th, and 10th year after onset and long-term kidney outcomes. METHODS: Data of patients with STEC-HUS followed for at least 15 years were analyzed. Kidney function patterns were constructed considering kidney status at 1st, 5th, 10th, and ≥ 15 years and defined as (1) progressive, if patients changed from complete recovery to any chronic kidney disease (CKD) stage or if CKD worsened; (2) improvement, if they shifted from any CKD stage to complete recovery or to a milder stage; and (3) stable, if remained unchanged. RESULTS: Of 152 patients included, after 1 year of follow-up, 47% had complete recovery, 22% CKD1, and 32% CKD2-5. At last assessment, 46% had complete recovery, 34% CKD1, and 19% CKD2-5. Despite percentages seeming similar, patients differed: 48% were stable, 27% improved, and 25% worsened. Further, 62% of patients with CKD2-4 in the 1st year normalized their glomerular filtration rate (GFR) thereafter. Comparison of kidney function between 1st, 5th, and 10th year to last assessment shows a stable pattern in 48, 59, and 69% respectively. CONCLUSIONS: Changes in kidney function showed a dynamic and complex behavior, with patients moving from one group to another. Consistently, kidney function neither at the 1st, 5th, or 10th year was representative of final outcome. Unexpectedly, two-thirds of patients with CKD2-4 after 1 year achieved normal eGFR later during follow-up.

Hyperuricemia: an unrecognized risk factor for kidney-related sequelae in children with hemolytic uremic syndrome.

BACKGROUND: Chronic kidney-related sequelae after STEC-HUS occur in 20-40% of patients. Hyperuricemia (HU) may cause acute and chronic toxicity involving the kidneys. We retrospectively assessed if there was an association between the presence of HU during the acute illness and that of kidney-related sequelae in children with STEC-HUS. METHODS: Children with STEC-HUS who had clinical and laboratory data at 2 years of follow-up were included in this case-control study. Univariate and multivariate analyses were performed between patients with (cases) or without (controls) kidney-related sequelae to identify factors associated with outcomes, including different measures of serum uric acid (sUA) (baseline level, peak, and duration of HU). HU was defined as sUA > 8 mg/dL. RESULTS: Of 86 patients included, 77.9% had HU. Patients with sequelae (n = 41) had a higher prevalence of HU (41/41 vs. 26/45, p < 0.01), higher baseline leukocyte count, serum creatinine (sCr), and sUA levels as well as lower sodium than controls. During hospitalization, cases also had higher sCr peak, sUA peak and duration of HU, requirement and duration of dialysis, extrarenal complications, and hypertension. By multivariate analysis, after adjusting for length of dialysis, only duration of HU (p = 0.0005; OR 1.7, 95% CI 1.27-2.36) remained as an independent predictor of sequelae, with a best cutoff of 5.5 days (AUC 0.95, specificity 80%, sensitivity 100%). CONCLUSIONS: The presence of HU is a common finding in children with STEC-HUS and its duration during the acute stage was associated with kidney-related sequelae, regardless of the duration of dialysis. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Prevalence of renal involvement among pediatric patients hospitalized due to coronavirus disease 2019: A multicenter study. / Prevalencia de compromiso renal en pacientes pediátricos internados con enfermedad por coronavirus 2019: estudio multicéntrico.

INTRODUCTION: Renal involvement among pediatric patients with coronavirus disease 2019 (COVID-19) ranges between 1.2% and 44%. Given the limited information available locally, the primary objective of this study was to estimate the prevalence of renal involvement in our setting. POPULATION AND METHODS: Cross-sectional study conducted in 13 Argentine sites between March and December 2020. Patients aged 1 month to 18 years hospitalized due to COVID-19 and with at least one measurement of serum creatinine and/or a urinalysis were included. Those with a known kidney disease were excluded. Renal involvement was defined as the presence of acute kidney injury (AKI), proteinuria, hematuria, leukocyturia and/or arterial hypertension (HTN). RESULTS: Among 528 eligible medical records, 423 patients were included (55.0% were males; median age: 5.3 years). The clinical presentation was asymptomatic in 31%; mild, in 39.7%; moderate, in 23.9%; severe, in 1.2%; critical, in 0.7%; and 3.5% had multisystem inflammatory syndrome in children (MIS-C). Two patients (0.47%) died. The prevalence of renal involvement was 10.8% (95% confidence interval: 8.2-14.2); it was described as leukocyturia (16.9%), proteinuria (16.0%), hematuria (13.2%), HTN (3.7%), and AKI (2.3%). No patient required dialysis. Renal involvement was associated with severe forms of disease (p < 0.0001). CONCLUSIONS: The prevalence of renal involvement among pediatric patients hospitalized due to COVID-19 in 13 Argentine sites was 10.8%; severe forms of disease prevailed.

Introducción. El compromiso renal (CR) en niños internados con enfermedad por coronavirus 2019 (COVID-19, por su sigla en inglés) varía entre el 1,2 % y el 44 %. Dado que existe limitada información local, el objetivo primario de este estudio fue estimar la prevalencia de CR en nuestro medio. Población y métodos. Estudio transversal realizado en 13 centros de Argentina entre marzo y diciembre de 2020. Se incluyeron pacientes internados con COVID-19, de 1 mes a 18 años y que tuvieran al menos una determinación de creatinina sérica y/o de orina completa. Se excluyeron aquellos con enfermedad renal conocida. Se consideró CR la presencia de lesión renal aguda (LRA), proteinuria, hematuria, leucocituria y/o hipertensión arterial (HTA). Resultados. De 528 historias clínicas elegibles, se incluyeron las de 423 pacientes (el 55,0 % de sexo masculino, mediana de edad 5,3 años). El cuadro clínico fue asintomático en el 31 %, leve en el 39,7 %, moderado en el 23,9 %, grave en el 1,2 %, crítico en el 0,7 %, y el 3,5 % presentó síndrome inflamatorio multisistémico pediátrico (SIMP). Dos pacientes (0,47 %) fallecieron. La prevalencia de CR fue del 10,8 % (intervalo de confianza 95% 8,2-14,2), expresada por leucocituria (16,9 %), proteinuria (16,0 %), hematuria (13,2 %), HTA (3,7 %) y LRA (2,3 %). Ninguno requirió diálisis. Presentar CR se asoció (p <0,0001) con formas graves de enfermedad. Conclusión. La prevalencia de CR en pacientes pediátricos internados con COVID-19 en 13 centros de nuestro país fue del 10,8 % y predominó en las formas clínicas graves.

Prevalencia de compromiso renal en pacientes pediátricos internados con enfermedad por coronavirus 2019: estudio multicéntrico / Prevalence of renal involvement among pediatric patients hospitalized due to coronavirus disease 2019: A multicenter study

Introducción. El compromiso renal (CR) en niñosinternados con enfermedad por coronavirus2019 (COVID-19, por su sigla en inglés) varía entre el 1,2 % y el 44 %. Dado que existe limitada información local, el objetivo primario de este estudio fue estimar la prevalencia de CR en nuestro medio. Población y métodos. Estudio transversalrealizado en 13 centros de Argentina entre marzo y diciembre de 2020. Se incluyeron pacientes internados con COVID-19, de 1 mes a 18 años y que tuvieran al menos una determinación de creatinina sérica y/o de orina completa.Se excluyeron aquellos con enfermedad renal conocida. Se consideró CR la presencia de lesión renal aguda (LRA), proteinuria, hematuria, leucocituria y/o hipertensión arterial (HTA). Resultados. De 528 historias clínicas elegibles, seincluyeron las de 423 pacientes (el 55,0 % de sexo masculino, mediana de edad 5,3 años). El cuadro clínico fue asintomático en el 31 %, leve en el 39,7 %, moderado en el 23,9 %, grave en el 1,2 %, crítico en el 0,7 %, y el 3,5 % presentó síndrome inflamatorio multisistémico pediátrico (SIMP). Dos pacientes (0,47 %) fallecieron. La prevalencia de CR fue del 10,8 % (intervalo de confianza 95% 8,2-14,2), expresada por leucocituria (16,9 %), proteinuria (16,0 %), hematuria (13,2 %), HTA (3,7 %) y LRA (2,3 %). Ninguno requirió diálisis. Presentar CR se asoció (p <0,0001) con formas graves de enfermedad. Conclusión. La prevalencia de CR en pacientes pediátricos internados con COVID-19 en 13 centros de nuestro país fue del 10,8 % y predominó en las formas clínicas graves.

Introduction. Renal involvement among pediatric patients with coronavirus disease 2019 (COVID-19) ranges between 1.2% and 44%. Given the limited information available locally, the primary objective of this study was to estimate the prevalence of renal involvement in our setting. Population and methods. Cross-sectional study conducted in 13 Argentine sites between March and December 2020. Patients aged 1 month to 18 years hospitalized due to COVID-19 and with at least one measurement of serum creatinine and/or a urinalysis were included. Those with a known kidney disease were excluded. Renal involvement was defined as the presence of acute kidney injury (AKI), proteinuria, hematuria, leukocyturia and/or arterial hypertension (HTN). Results. Among 528 eligible medical records, 423 patients were included (55.0% were males; median age: 5.3 years). The clinical presentation was asymptomatic in 31%; mild, in 39.7%; moderate, in 23.9%; severe, in 1.2%; critical, in 0.7%; and 3.5% had multisystem inflammatory syndrome in children (MIS-C). Two patients (0.47%) died. The prevalence of renal involvement was 10.8% (95% confidence interval: 8.2­14.2); it was described as leukocyturia (16.9%), proteinuria (16.0%), hematuria (13.2%), HTN (3.7%), and AKI (2.3%). No patient required dialysis. Renal involvement was associated with severe forms of disease (p < 0.0001). Conclusion. The prevalence of renal involvement among pediatric patients hospitalized due to COVID-19 in 13 Argentine sites was 10.8%; severe forms of disease prevailed.

Erythropoietin in children with hemolytic uremic syndrome: a pilot randomized controlled trial.

BACKGROUND: The efficacy of recombinant human erythropoietin (rHuEPO) in sparing red blood cell (RBC) transfusions in children with hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS) is uncertain. METHODS: We conducted a pilot randomized controlled open trial between December 2018 and January 2021. Children were randomized to the intervention (subcutaneous rHuEPO 50 U/kg three times weekly until discharge + RBC transfusion if hemoglobin ≤ 7 g/dL and/or hemodynamic instability) or to the control arm (RBC transfusion if hemoglobin ≤ 7 g/dL and/or hemodynamic instability). Primary outcome was the number of RBC transfusions received during hospitalization. Secondary outcomes were to explore whether baseline EPO levels were adequate to the degree of anemia, to correlate selected acute phase parameters with the number of RBC transfusions, and to assess possible adverse events. RESULTS: Twelve patients per arm were included; they were comparable at recruitment and throughout the disease course. Median number of RBC transfusions was similar between groups (1.5, p = 0.76). Most patients had baseline EPO levels adequate to the degree of anemia, which did not correlate with the number of transfusions (r = 0.19, p = 0.44). Conversely, baseline (r = 0.73, p = 0.032) and maximum lactic dehydrogenase levels (r = 0.78, p = 0.003), creatinine peak (r = 0.71, p = 0.03) and dialysis duration (r = 0.7, p = 0.04) correlated significantly with RBC requirements. No side effects were recorded. CONCLUSION: In children with STEC-HUS, the administration of rHuEPO did not reduce the number of RBC transfusions. Larger studies addressing higher doses and similar severity of kidney failure at rHuEPO initiation (e.g. at start of dialysis) are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03776851. A higher resolution version of the Graphical abstract is available as Supplementary information.

Evolución en el corto plazo del compromiso renal en niños con enfermedad por el coronavirus 2019 / Course of renal involvement in the short term in children with coronavirus disease 2019

El compromiso renal en los pacientes pediátricos con enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) varía entre el 10 % y el 80 %. Dado que existe limitada información sobre su pronóstico, se realizó este estudio con el objetivo de describir la evolución en el corto plazo de pacientes a quienes se les detectó compromiso renal durante la internación por COVID-19. Estudio observacional y transversal que incluyó pacientes entre 1 mes y 18 años con COVID-19 con compromiso renal. Se excluyeron aquellos con patología renal conocida. Se identificaron 27 pacientes con afectación renal, en 14 de ellos se pudo realizar seguimiento para estudiar la evolución renal luego de 3 meses del diagnóstico. Todos habían normalizado los niveles de creatinina plasmática durante la internación y al momento del control ambulatorio, realizado a los 145 días (92-193), todos se encontraban normotensos y con hallazgos urinarios normales, excepto uno que persistía con microhematuria. La evolución fue favorable; la mayoría de los pacientes presentaron remisión completa del compromiso renal.

Renal involvement among pediatric patients with coronavirus disease 2019 (COVID-19) ranges between 10 % and 80 %.Given the limited information about its prognosis, the objective of this study was to describe the short-term course of patients in whom renal involvement was detected during hospitalization due to COVID-19. This was an observational, cross-sectional study in patients aged 1 month to 18 years who had COVID-19 and renal involvement. Those with a known kidney disease were excluded. A total of 27 patients with renal involvement were identified; 14 of them were followed-up to study their disease course for 3 months after diagnosis. All of the patients had achieved normal plasma creatinine levels during hospitalization and, at the time of outpatient follow-up, which took place 145 days (92-193) later, all had normal blood pressure and urinary values, except for 1 patient who continued with microscopic hematuria. Course was favorable; in most patients, renal involvement had fully resolved.

Course of renal involvement in the short term in children with coronavirus disease 2019. / Evolución en el corto plazo del compromiso renal en niños con enfermedad por el coronavirus 2019.

Renal involvement among pediatric patients with coronavirus disease 2019 (COVID-19) ranges between 10% and 80%. Given the limited information about its prognosis, the objective of this study was to describe the short-term course of patients in whom renal involvement was detected during hospitalization due to COVID-19. This was an observational, cross-sectional study in patients aged 1 month to 18 years who had COVID-19 and renal involvement. Those with a known kidney disease were excluded. A total of 27 patients with renal involvement were identified; 14 of them were followed-up to study their disease course for 3 months after diagnosis. All of the patients had achieved normal plasma creatinine levels during hospitalization and, at the time of outpatient follow-up, which took place 145 days (92-193) later, all had normal blood pressure and urinary values, except for 1 patient who continued with microscopic hematuria. Course was favorable; in most patients, renal involvement had fully resolved.

El compromiso renal en los pacientes pediátricos con enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) varía entre el 10 % y el 80 %. Dado que existe limitada información sobre su pronóstico, se realizó este estudio con el objetivo de describir la evolución en el corto plazo de pacientes a quienes se les detectó compromiso renal durante la internación por COVID-19. Estudio observacional y transversal que incluyó pacientes entre 1 mes y 18 años con COVID-19 con compromiso renal. Se excluyeron aquellos con patología renal conocida. Se identificaron 27 pacientes con afectación renal, en 14 de ellos se pudo realizar seguimiento para estudiar la evolución renal luego de 3 meses del diagnóstico. Todos habían normalizado los niveles de creatinina plasmática durante la internación y al momento del control ambulatorio, realizado a los 145 días (92-193), todos se encontraban normotensos y con hallazgos urinarios normales, excepto uno que persistía con microhematuria. La evolución fue favorable; la mayoría de los pacientes presentaron remisión completa del compromiso renal.

Nefropatía por inmunoglobulina M: características histopatológicas y clínicas. Serie de casos / Immunoglobulin M nephropathy: histopathological and clinical characteristics. Case series

La nefropatía por inmunoglobulina M (NIgM) es una glomerulopatía idiopática caracterizada por depósitos mesangiales globales y difusos de IgM. Se realizó un estudio retrospectivo de las características clínicas e histopatológicas de los pacientes con NIgM atendidos en nuestro servicio. De 241 biopsias renales, 21 correspondieron a NIgM (8,7 %). Se incluyeron 18 pacientes (14 de sexo femenino, mediana de edad: 3,08 años). Se excluyó a 1 paciente por enfermedad sistémica asociada y a 2 por seguimiento menor a 1 año. Catorce pacientes se manifestaron con síndrome nefrótico (SN) y 4 con proteinuria aislada o asociada a hematuria. En la microscopia óptica, 13 presentaron hiperplasia mesangial, y 5 esclerosis focal y segmentaria. De los pacientes con SN, 7 fueron corticorresistentes, 4 corticodependientes y 3 presentaban recaídas frecuentes. Todos los pacientes con SN y 1 con proteinuria-hematuria recibieron inmunosupresores; los 18 pacientes recibieron, además, antiproteinúricos. Luego de 5,2 años (2-17,5) de seguimiento, 6 pacientes evolucionaron a enfermedad renal crónica

Immunoglobulin M nephropathy (IgMN) is an idiopathic glomerulopathy characterized by diffuse global mesangial deposits of IgM. We retrospectively studied the clinical and histopathological characteristics of the patients with IgMN seen in our service. Of 241 renal biopsies, 21 corresponded to IgMN (8.7 %). One patient was excluded due to associated systemic disease and 2 due to follow-up less than 1 year, 18 were included (14 girls, median age 3.08 years). Fourteen manifested with nephrotic syndrome (NS) and the remaining with proteinuria (isolated or associated with hematuria). On light microscopy, 13 had hyperplasia with mesangial expansion and 5 had focal and segmental sclerosis. Of the patients with NS, 7 were steroid-resistant, 4 steroid-dependent, and 3 frequent relapsers. All patients with NS and 1 with proteinuria-hematuria received immunosuppressants; the 18 patients also received antiproteinuric drugs. After 5.2 years (2-17.5) of follow-up, 6 patients developed chronic kidney disease.

Sensibilidad diagnóstica de la ampliación de los criterios hematológicos y renales para la definición de síndrome urémico hemolítico / Diagnostic sensitivity of extended renal and hematologic criteria to define hemolytic uremic syndrome

Introducción. La definición habitual de síndrome urémico hemolítico causado por Escherichia coli productora de toxina Shiga (STEC-SUH) se basa en la presencia de anemia, plaquetopenia y elevación de los niveles séricos de creatinina, acompañadas o no de proteinuria y/o hematuria. La definición estricta solo acepta como criterio renal el aumento de la creatinina sérica. La definición amplia mantiene criterios renales flexibles, aunque reemplaza la anemia por hemólisis y acepta la caída brusca del recuento plaquetario como indicador de consumo plaquetario. El objetivo de este estudio fue estimar y comparar la sensibilidad diagnóstica de dichas definiciones en pacientes con STEC-SUH como diagnóstico de egreso hospitalario. Población y métodos. Revisión retrospectiva de las historias clínicas de pacientes con SUH. Se calculó la sensibilidad y el valor predictivo positivo con sus intervalos de confianza 95 % (IC95 %) de las tres definiciones en función del diagnóstico de egreso de STEC-SUH (diagnóstico de referencia). Se utilizó la prueba de McNemar. Resultados. De 208 pacientes, 107 (51,4 %) fueron identificados con la definición estricta, 133 (63,9 %) con la habitual; y 199, con la amplia (95,6 %). La sensibilidad resultó menor para la definición estricta (51,4 %; IC 95 %: 44,8-58,3), intermedia para la habitual (63,9 %; IC 95 %: 56,9-70,4) y mayor para la amplia (95,6 %; IC 95 %: 91,6-97,8); (p < 0,001). Conclusión. Las distintas definiciones de STEC-SUH presentaron diferencias significativas en la sensibilidad diagnóstica. Dado que la definición amplia alcanzó una sensibilidad superior al 95 %, su uso generalizado podría disminuir la demora diagnóstica

Introduction. The usual definition of Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (STEC-HUS) is based on the presence of anemia, thrombocytopenia, and elevated serum creatinine levels, with or without proteinuria and/or hematuria. The strict definition only considers elevated serum creatinine levels as a renal criterion. The extended definition maintains flexible renal criteria, although it replaces anemia with hemolysis and considers a sharp drop in platelet count as an indicator of platelet consumption. The objective of this study was to estimate and compare the diagnostic sensitivity of these definitions in patients with STEC-HUS as hospital discharge diagnosis. Population and methods. Retrospective review of medical records of HUS patients. Sensitivity and positive predictive value, with their corresponding 95 % confidence intervals (CIs), were estimated for the 3 definitions based on a discharge diagnosis of STEC-HUS (reference diagnosis). The McNemar test was used. Results. Out of 208 patients, 107 (51.4 %), 133 (63.9 %), and 199 (95.6 %) were identified with the strict, usual, and extended definition, respectively. Sensitivity was lower for the strict definition (51.4 %; 95 % CI: 44.8-58.3), intermediate for the usual definition (63.9 %; 95 % CI: 56.9-70.4), and higher for the extended one (95.6 %; 95 % CI: 91.6-97.8); (p < 0.001). Conclusion. The different STEC-HUS definitions showed significant differences in diagnostic sensitivity. The extended definition reached a sensitivity above 95 %, so its generalized use may help to reduce diagnostic delays

Diagnostic sensitivity of extended renal and hematologic criteria to define hemolytic uremic syndrome. / Sensibilidad diagnóstica de la ampliación de los criterios hematológicos y renales para la definición de síndrome urémico hemolítico.

INTRODUCTION: The usual definition of Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (STEC-HUS) is based on the presence of anemia, thrombocytopenia, and elevated serum creatinine levels, with or without proteinuria and/or hematuria. The strict definition only considers elevated serum creatinine levels as a renal criterion. The extended definition maintains flexible renal criteria, although it replaces anemia with hemolysis and considers a sharp drop in platelet count as an indicator of platelet consumption. The objective of this study was to estimate and compare the diagnostic sensitivity of these definitions in patients with STEC-HUS as hospital discharge diagnosis. POPULATION AND METHODS: Retrospective review of medical records of HUS patients. Sensitivity and positive predictive value, with their corresponding 95% confidence intervals (CIs), were estimated for the 3 definitions based on a discharge diagnosis of STEC-HUS (reference diagnosis). The McNemar test was used. RESULTS: Out of 208 patients, 107 (51.4%), 133 (63.9%), and 199 (95.6%) were identified with the strict, usual, and extended definition, respectively. Sensitivity was lower for the strict definition (51.4%; 95% CI: 44.8-58.3), intermediate for the usual definition (63.9%; 95% CI: 56.9-70.4), and higher for the extended one (95.6%; 95% CI: 91.6-97.8); (p< 0.001). CONCLUSION: The different STEC-HUS definitions showed significant differences in diagnostic sensitivity. The extended definition reached a sensitivity above 95%, so its generalized use may help to reduce diagnostic delays.

Introducción. La definición habitual de síndrome urémico hemolítico causado por Escherichia coli productora de toxina Shiga (STEC-SUH) se basa en la presencia de anemia, plaquetopenia y elevación de los niveles séricos de creatinina, acompañadas o no de proteinuria y/o hematuria. La definición estricta solo acepta como criterio renal el aumento de la creatinina sérica. La definición amplia mantiene criterios renales flexibles, aunque reemplaza la anemia por hemólisis y acepta la caída brusca del recuento plaquetario como indicador de consumo plaquetario. El objetivo de este estudio fue estimar y comparar la sensibilidad diagnóstica de dichas definiciones en pacientes con STECSUH como diagnóstico de egreso hospitalario. Población y métodos. Revisión retrospectiva de las historias clínicas de pacientes con SUH. Se calculó la sensibilidad y el valor predictivo positivo con sus intervalos de confianza 95% (IC95%) de las tres definiciones en función del diagnóstico de egreso de STEC-SUH (diagnóstico de referencia). Se utilizó la prueba de McNemar. Resultados. De 208 pacientes, 107 (51,4%) fueron identificados con la definición estricta, 133 (63,9%) con la habitual; y 199, con la amplia (95,6%). La sensibilidad resultó menor para la definición estricta (51,4%; IC 95%: 44,8-58,3), intermedia para la habitual (63,9%; IC 95%: 56,9- 70,4) y mayor para la amplia (95,6%; IC 95%: 91,6-97,8); (p< 0,001). Conclusión. Las distintas definiciones de STECSUH presentaron diferencias significativas en la sensibilidad diagnóstica. Dado que la definición amplia alcanzó una sensibilidad superior al 95%, su uso generalizado podría disminuir la demora diagnóstica.

[Immunoglobulin M nephropathy: histopathological and clinical characteristics. Case series]. / Nefropatía por inmunoglobulina M: características histopatológicas y clínicas. Serie de casos.

Immunoglobulin M nephropathy (IgMN) is an idiopathic glomerulopathy characterized by diffuse global mesangial deposits of IgM. We retrospectively studied the clinical and histopathological characteristics of the patients with IgMN seen in our service. Of 241 renal biopsies, 21 corresponded to IgMN (8.7 %). One patient was excluded due to associated systemic disease and 2 due to follow-up less than 1 year, 18 were included (14 girls, median age 3.08 years). Fourteen manifested with nephrotic syndrome (NS) and the remaining with proteinuria (isolated or associated with hematuria). On Nefropatía por inmunoglobulina M: características histopatológicas y clínicas. Serie de casos Immunoglobulin M nephropathy: histopathological and clinical characteristics. Case series light microscopy, 13 had hyperplasia with mesangial expansion and 5 had focal and segmental sclerosis. Of the patients with NS, 7 were steroid-resistant, 4 steroid-dependent, and 3 frequent relapsers. All patients with NS and 1 with proteinuria-hematuria received immunosuppressants; the 18 patients also received antiproteinuric drugs. After 5.2 years (2-17.5) of follow-up, 6 patients developed chronic kidney disease.

La nefropatía por inmunoglobulina M (NIgM) es una glomerulopatía idiopática caracterizada por depósitos mesangiales globales y difusos de IgM. Se realizó un estudio retrospectivo de las características clínicas e histopatológicas de los pacientes con NIgM atendidos en nuestro servicio. De 241 biopsias renales, 21 correspondieron a NIgM (8,7 %). Se incluyeron 18 pacientes (14 de sexo femenino, mediana de edad: 3,08 años). Se excluyó a 1 paciente por enfermedad sistémica asociada y a 2 por seguimiento menor a 1 año. Catorce pacientes se manifestaron con síndrome nefrótico (SN) y 4 con proteinuria aislada o asociada a hematuria. En la microscopia óptica, 13 presentaron hiperplasia mesangial, y 5 esclerosis focal y segmentaria. De los pacientes con SN, 7 fueron corticorresistentes, 4 corticodependientes y 3 presentaban recaídas frecuentes. Todos los pacientes con SN y 1 con proteinuria-hematuria recibieron inmunosupresores; los 18 pacientes recibieron, además, antiproteinúricos. Luego de 5,2 años (2-17,5) de seguimiento, 6 pacientes evolucionaron a enfermedad renal crónica.

Hemolytic uremic syndrome due to Shiga toxin­producing Escherichia coli and hypocomplementemia with favorable response to eculizumab: a case report / [Síndrome urémico hemolítico por Escherichia Coli e hipocomplementemia con respuesta favorable a eculizumab: comunicación de un caso]

Introduction: Neurologic involvement in hemolytic uremic syndrome related to Shiga toxin­producing Escherichia coli (STEC-HUS) is the main cause of death. In last years has been demonstrated that activation of complement alternative pathway also contributes to organ damage. This finding led to the recognition of decreased C3 levels at admission as a marker of poor prognosis as well as the evaluation of the use of eculizumab in cases with neurologic compromise. Objective: to report a patient with STEC-HUS and hypocomplementemia with neurological involvement treated with eculizumab. Clinical case: A 17-month-old male was admitted due to seizures and anuria for last 24 h with a history of 48 h of bloody diarrhea. He presented a laboratory profile compatible with STEC-HUS and severe hyponatremia, results of brain tomography were normal. Also there was complement activation: C3 73 mg/dl (normal > 90 mg/dL) and C5b-9 778.9 ng/ml (normal 135.8-385.3 ng/ml). Initial treatment includes normal saline solution and anticonvulsants drugs, sodium correction and peritoneal dialysis. On third day of hospitalization, because of progression of the neurologic involvement a dose of eculizumab (300 mg) was given, showing at 24 h a markedly neurologic improvement along with and increasing platelet count and a descending lactic dehydrogenase levels. He was discharged after 14 days in a good condition. Later a STEC O157:H7 infection was confirmed and he also normalized the C3 level. Conclusion: This case shows that decreased C3 level at admission was associated to neurologic involvement and suggests that eculizumab might be a favorable therapeutic option.

Introducción: En compromiso neurológico en el síndrome urémico hemolítico producido por Eschericha coli productor de Shiga toxina (STEC-SUH) es la primera causa de mortalidad. En los últimos años se ha demostrado que también contribuye al daño de órgano la activación de la vía alterna del complemento. Este hallazgo dio lugar al reconocimiento del descenso de C3 como marcador de mal pronóstico así como a la evaluación del uso de eculizumab ante compromiso neurológico severo. Objetivo: Comunicar un paciente con STEC-SUH e hipocomplementemia con compromiso neurológico tratado con eculizumab. Caso clínico: Varón de 17 meses que ingresa por síndrome convulsivo y 24 horas de anuria con antecedente de diarrea con sangre de 48 horas de evolución. Presentaba al ingreso laboratorio compatible con STEC-HUS e hiponatremia severa, con tomografía de cerebro normal. Además presentaba activación del complemento: C3 73 mg/dl (normal > 90 mg/dL) y C5b-9 778,9 ng/ml (normal 135,8-385,3 ng/ml). Se administró solución fisiológica y anticonvulsivantes, se corrigió la natremia y comenzó diálisis peritoneal. Al tercer día, por progresión del compromiso neurológico, se administró eculizumab (300 mg) experimentando una notable recuperación neurológica a las 24 horas junto a aumento de plaquetas y descenso de láctico deshidrogenasa. El paciente fue dado de alta luego de 14 días en buen estado general. Posteriormente se confirmó aislamiento de STEC O157:H7 y normalización de C3. Conclusión: este caso demuestra que el descenso de C3 al ingreso se asoció con daño neurológico y sugiere que la administración de eculizumab podría ser una alternativa terapéutica favorable.

Prodromal Phase of Hemolytic Uremic Syndrome Related to Shiga Toxin-Producing Escherichia coli: The Wasted Time.

OBJECTIVES: This study aimed to evaluate practice patterns during prodromal phase of hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS). METHODS: Trajectories of children from first symptoms until STEC-HUS admitted consecutively at our center (period 2000-2017) were retrospectively reviewed. Early recommended practices include identification of STEC infections, antibiotics and antiperistaltic avoidance, and administration of anticipatory intravenous fluids; therefore, implementation and changes over time (before and after 2011) of such interventions were assessed. In addition, early management was correlated with acute disease outcomes. RESULTS: Of 172 patients, 98 (57%) had early consults, 75 of them visit the pediatric emergency department. Those seen with watery diarrhea (n = 74) were managed as outpatients, whereas 27 of the 45 assisted with bloody diarrhea were hospitalized for diagnosis other than STEC-HUS. Stool cultures were performed in 13.4% (23/172), 18% (31/172) received antibiotics, and 12.8% (22/172) received endovenous fluids; none received antiperistaltic agents. Shiga toxin-producing E. coli infection was proven in 4% (7/172) before HUS. Rate of cultured patients and treated with intravenous fluids remained unchanged over time (P = 0.13 and P = 0.48, respectively), whereas antibiotic prescription decreased from 42.8% to 16.6% (P = 0.005). Main acute outcomes (need for dialysis, pancreatic compromise, central nervous system involvement, and death) were similar (P > 0.05) regardless of whether they received antibiotics or intravenous fluids. CONCLUSIONS: During the diarrheal phase, 57% of patients consulted; three-quarters of them consulted to the pediatric emergency department. Shiga toxin-producing E. coli detection was poor, antibiotic use remained high, and anticipatory volume expansion was underused. These findings outline the critical need to improve the early management of STEC-HUS.

Correction to: C3 levels and neurologic involvement in hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli.

The original version of the letter unfortunately contained a mistake.

Rasburicase in hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli: a report of nine cases.

BACKGROUND: Hyperuricemia might induce additional renal damage in children with hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS). A few case reports have shown rasburicase to be effective in decreasing serum uric acid (UA) and improving renal function. However, there is only one report on the use of rasburicase in a child with STEC-HUS, which shows satisfactory results. We describe here the safety and efficacy of rasburicase in nine additional cases. CASE-DIAGNOSIS/TREATMENT: Data from 9 children (5 females, median age 2 years) who received rasburicase were reviewed. At admission, 6 were dehydrated and 3 euvolemic. Dehydrated patients received saline solution and afterwards, as well as for those initially euvolemic, we aimed to keep a neutral fluid balance. Despite this, urine output did not increase. Baseline creatinine was 3.35 mg/dL (1.47-9.1) and UA 11.4 mg/dL (8.3-19.2). A single dose of rasburicase (0.2 mg/kg) was given 6-8 h after admission, which reduced UA levels to 1.8 mg/dL (0.3-5, p = 0.009) on the next day. However, renal parameters worsen and dialysis had to be initiated. Then, while still on dialysis, a UA rebound occurred in all cases reaching a peak of 8.9 mg/dL (4.5-13.8). Just after a steady increase in urine output, a sustained decline in UA levels concomitantly occurred with an improvement in renal function. At discharge, all patients reached normal UA levels. No side effects were recorded. CONCLUSIONS: Administration of rasburicase in children with STEC-HUS was safe but failed to provide any significant benefit despite fall in serum UA levels.

Correction to: C3 levels and acute outcomes in Shiga toxin-related hemolytic uremic syndrome.

Due to an unfortunate error during the processing of the article, the spelling of the second author name was incorrect.

Blood urea nitrogen to serum creatinine ratio as a prognostic factor in diarrhea-associated hemolytic uremic syndrome: a validation study.

Identifying those children with complicated forms of diarrhea-associated hemolytic uremic syndrome (D+HUS) on admission can optimize their management. Recently, the blood urea nitrogen to serum creatinine ratio (BCR) at admission has been proposed as a novel and accurate predictor of complicated clinical outcome in D+HUS; therefore, we performed this retrospective study aimed to validate such observation in a larger series of patients. A complicated course was defined as developing one or more of the following: severe neurological or bowel injury, pancreatitis, cardiac or pulmonary involvement, hemodynamic instability, hemorrhage, and death. Data from 161 children were reviewed, 50 of them with a complicated disease including five deaths. Those with worse evolution presented a lower admission BCR than those with good outcome (22.5 vs. 30.8; p = 0.005). BCR at admission showed a limited ability to identify children at risk of a complicated course, with an AUC of 0.63 (95% CI 0.58-0.71) and an optimal cutoff point of ≤ 26.7, which achieves a sensitivity of 70% (95% CI 55.2-81.7) and a specificity of 56.7% (95% CI 47-66). CONCLUSION: In this validation study, the BCR at admission provided a limited value to predict severe forms of D+HUS. What is Known: • BCR at admission has been proposed as an accurate predictor of complicated clinical course in children with D+HUS. What is New: • In a larger series of children with D+HUS, we were unable to confirm the usefulness of the admission BCR to early identify those at risk of complicated forms of the disease. • Further research is warranted to improve the optimal detection of these high-risk patients.