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.

Transient early-childhood hyperkalaemia without salt wasting, pathophysiological approach of three cases.

Two types of early childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis (MA) due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present 3 patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia (TECHH) without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In 3 children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion (FE) of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic MA with FE of bicarbonate 0.58%-2.2%, positive urinary anion gap during MA and normal ability to acidify the urine. Based on these findings a diagnosis of TECHH without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that TECCH without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children.

Hiperpotasemia transitoria del lactante sin pérdida salina, enfoque fisiopatológico de tres casos / Transient early-childhood hyperkalemia without salt wasting, physiopathological approach of three cases

Se reconocen 2 variedades de hiperpotasemia temprana de la infancia (del inglés Early childhood hyperkalemia) según la presencia o no de pérdida salina urinaria. Se trata de una entidad atribuida a un desorden madurativo en los receptores de aldosterona caracterizada por hiperpotasemia, acidosis metabólica hiperclorémica por diminución de la eliminación de amonio y bicarbonaturia, y creatinina normal con retraso de crecimiento. Presentamos 3 pacientes de la forma con ausencia de pérdida salina, a la que denominaremos hiperpotasemia transitoria del lactante sin pérdida salina, y discutimos su fisiopatología con relación a los nuevos conocimientos en el manejo tubular del sodio y el potasio por la aldosterona. En 3 pacientes de entre 30 y 120 días de edad con bronquiolitis y retraso de crecimiento se encontró hiperpotasemia en laboratorio de rutina. Presentaban creatinina normal, excreción fraccionada de potasio disminuida o inapropiadamente normal junto a niveles de aldosterona y renina plasmática inadecuadamente normales para el estado de hiperpotasemia, pero sin pérdida salina. También cursaban con acidosis metabólica hiperclorémica con bicarbonaturia (excreción fraccionada de bicarbonato 0,58-2,2%), anión restante urinario positivo durante acidosis metabólica y capacidad normal para acidificar la orina. En base a estos hallazgos se diagnosticó hiperpotasemia transitoria del lactante sin pérdida salina y se trataron con bicarbonato de sodio e hidroclorotiazida con buena respuesta. El cuadro fue transitorio permitiendo la suspensión del tratamiento. Dado que la hiperpotasemia transitoria del lactante sin pérdida salina es un desorden tubular transitorio con síntomas leves debe tenerse presente en el diagnóstico diferencial de hiperpotasemia en niños pequeños. (AU)

Two types of early-childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present three patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In three children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic metabolic acidosis with fractional excretion of bicarbonate 0.58–2.2%, positive urinary anion gap during metabolic acidosis and normal ability to acidify the urine. Based on these findings a diagnosis of transient early-childhood hyperkalemia without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that transient early-childhood hyperkalemia without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children. (AU)

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.

Eliglustat prevents Shiga toxin 2 cytotoxic effects in human renal tubular epithelial cells.

BACKGROUND: Shiga toxin-producing Escherichia coli is responsible for post-diarrheal (D+) hemolytic uremic syndrome (HUS), which is a cause of acute renal failure in children. The glycolipid globotriaosylceramide (Gb3) is the main receptor for Shiga toxin (Stx) in kidney target cells. Eliglustat (EG) is a specific and potent inhibitor of glucosylceramide synthase, first step of glycosphingolipid biosynthesis, actually used for the treatment of Gaucher's disease. The aim of the present work was to evaluate the efficiency of EG in preventing the damage caused by Stx2 in human renal epithelial cells. METHODS: Human renal tubular epithelial cell (HRTEC) primary cultures were pre-treated with different dilutions of EG followed by co-incubation with EG and Stx2 at different times, and cell viability, proliferation, apoptosis, tubulogenesis, and Gb3 expression were assessed. RESULTS: In HRTEC, pre-treatments with 50 nmol/L EG for 24 h, or 500 nmol/L EG for 6 h, reduced Gb3 expression and totally prevented the effects of Stx2 on cell viability, proliferation, and apoptosis. EG treatment also allowed the development of tubulogenesis in 3D-HRTEC exposed to Stx2. CONCLUSIONS: EG could be a potential therapeutic drug for the prevention of acute kidney injury caused by Stx2. IMPACT: For the first time, we have demonstrated that Eliglustat prevents Shiga toxin 2 cytotoxic effects on human renal epithelia, by reducing the expression of the toxin receptor globotriaosylceramide. The present work also shows that Eliglustat prevents Shiga toxin 2 effects on tubulogenesis of renal epithelial cells. Eliglustat, actually used for the treatment of patients with Gaucher's disease, could be a therapeutic strategy to prevent the renal damage caused by Shiga toxin.

Uncommon Presentation of Atypical Hemolytic Uremic Syndrome: A Case Report.

Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia and renal damage. Its presentation as nephrotic syndrome (NS) during first year of life is uncommon; we describe a child with clinical and laboratory findings of NS whose renal biopsy revealed thrombotic microangiopathy (TMA). A previously healthy 4-month-old male was admitted with severe dehydration, diarrhea and anuria. Laboratory results showed electrolyte disturbances, increased serum creatinine, anemia without schistocytes, thrombocytosis, normal lactic dehydrogenase (LDH) levels, hypoalbuminemia hypercholesterolemia and decreased C3 levels. After rehydration hematuria and massive proteinuria were also documented and an initial diagnosis of NS of the first year was established. Studies seeking for infectious agents were negative. During hospitalization he continued to be oligo-anuric needing dialysis and a renal biopsy was performed, which showed TMA findings. We here considered the diagnosis of aHUS and started plasma infusions as a bridge until starting eculizumab. After two infusions urine output improved leading to discontinuation dialysis. The diagnoses of STEC infection and thrombocytopenic thrombotic purpura were ruled out. Factor B, H, I and properdin levels were normal. Antibodies against CFH negative were negative. Screening for genes causative of aHUS detected a heterozygous variant in CFHR3 of uncertain significance. On day 20, treatment was switched to eculizumab, which induced a progressive remission of the NS. This case outlines the need for a heightened diagnosis suspicion of this already rare disease since early initiation of eculizumab therapy improves its prognosis.

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.

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

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.

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.