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.

Kidney sequelae in 281 Shiga toxin-producing Escherichia coli-hemolytic uremic syndrome patients after a median follow-up of 12 years.

BACKGROUND: A substantial proportion of patients with Escherichia coli-hemolytic uremic syndrome (STEC-HUS) evolve to chronic kidney disease (CKD). The objectives of this study were to evaluate long-term kidney outcomes and to identify CKD predictors. METHODS: In this single-center retrospective study, long-term outcomes of patients were analyzed according to the presence of complete recovery (CR) or CKD at last visit. Then, they were grouped into favorable (CR + CKD1) or poor (CKD2-5) outcome to compare predictors at diagnosis (sex, age, leukocytes, creatinine, hemoglobin, HUS severity score), dialysis duration, and follow-up time between them. RESULTS: Of 281 patients followed up for a median of 12 years, 139 (49%) had CR, 104 (37%) CKD1, 27 (10%) CKD2-4, and 11 (4%) CKD5. Thirty-eight patients progressed to CKD2-5 after a median of 4.8 years, 7% in the first 5 years, increasing to 8%, 10%, and 14% after 5-10 years, 10-15 years, and > 15 years, respectively. They were younger, had higher baseline hemoglobin and leukocytes, and required longer dialysis and follow-up than those with favorable outcome. By multivariate analysis, days of dialysis and follow-up time remained as independent predictors of poor outcome. The best cutoff for days of dialysis was 10 days. After 5 years, 20% of those dialyzed ≥ 10 days evolved to CKD2-5 versus 1% of those non-dialyzed or dialyzed < 10 days. CONCLUSIONS: Fifty-one percent of patients evolved to CKD after 12 years of follow-up and 14% to CKD2-5. Ten days of dialysis was the best cutoff to recognize outcomes. In some cases, kidney damage was evident after 15 years of surveillance, highlighting the need for follow-up until adulthood in all STEC-HUS patients.

Surveillance of Shiga toxin-producing Escherichia coli associated bloody diarrhea in Argentina.

In Argentina, hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli (STEC-HUS) infection is endemic, and reliable data about prevalence and risk factors have been available since 2000. However, information about STEC-associated bloody diarrhea (BD) is limited. A prospective study was performed during the period October 2018-June 2019 in seven tertiary-hospitals and 18 referral units from different regions, aiming to determine (i) the frequency of STEC-positive BD cases in 714 children aged 1-9 years of age and (ii) the rate of progression of bloody diarrhea to HUS. The number and regional distribution of STEC-HUS cases in the same hospitals and during the same period were also assessed. Twenty-nine (4.1%) of the BD patients were STEC-positive, as determined by the Shiga Toxin Quik Chek (STQC) test and/or the multiplex polymerase chain reaction (mPCR) assay. The highest frequencies were found in the Southern region (Neuquén, 8.7%; Bahía Blanca, 7.9%), in children between 12 and 23 month of age (8.8%), during summertime. Four (13.8%) cases progressed to HUS, three to nine days after diarrhea onset. Twenty-seven STEC-HUS in children under 5 years of age (77.8%) were enrolled, 51.9% were female; 44% were Stx-positive by STQC and all by mPCR. The most common serotypes were O157:H7 and O145:H28 and the prevalent genotypes, both among BD and HUS cases, were stx2a-only or -associated. Considering the endemic behavior of HUS and its high incidence, these data show that the rate of STEC-positive cases is low among BD patients. However, the early recognition of STEC-positive cases is important for patient monitoring and initiation of supportive treatment.

Long-term kidney outcomes in non-dialyzed children with Shiga-toxin Escherichia coli associated hemolytic uremic syndrome.

BACKGROUND: Long-term kidney outcomes of non-dialyzed children with Shiga-toxin Escherichia Coli hemolytic uremic syndrome (STEC-HUS) have been scantily studied. Therefore, we aimed to evaluate kidney outcomes and prognostic markers in these patients. METHODS: Non-dialyzed STEC-HUS patients followed for at least 5 years were included. They were grouped and compared according to kidney status at last visit: complete recovery (CR) or chronic kidney disease (CKD). Predictors of CKD evaluated at diagnosis were sex, age, leukocytes, hematocrit, hemoglobin (Hb), and serum creatinine (sCr). Peak sCr and time of follow-up were also analyzed. RESULTS: A total of 122 patients (62 female, median age at diagnosis 1.6 years) with a median follow-up of 11.3 years were included. At last visit, 82 (67%) had CR, 36 (30%) had CKD stage 1, and 4 (3%) had stage 2. No patient developed CKD stage 3-5. Median time to CKD was 5 years (IQR 3.1-8.76 years). Of the 122 patients, 18% evolved to CKD in the first 5 years, increasing to 28% at 10 and 33% at 20 years of follow-up. Serum Cr at diagnosis and peak sCr were significantly higher in patients with CKD than in those with CR. CONCLUSIONS: One third of non-dialyzed STEC-HUS patients evolved to CKD after a median time of 5 years. However, CKD may appear even after 15 years of CR. Serum Cr was significantly higher among patients who evolved to CKD. These data reinforce that all non-dialyzed patients should be followed until adulthood. A higher resolution version of the Graphical abstract is available as Supplementary information.

Ocular involvement in STEC-associated hemolytic uremic syndrome.

BACKGROUND: Hemolytic uremic syndrome (HUS) is a systemic thrombotic microangiopathy characterized by hemolytic anemia, thrombocytopenia, and variable kidney involvement. Extrarenal thrombotic microangiopathy occurs in central nervous system (CNS), colon, and other organ systems, but ocular involvement is rarely recognized. This study aimed to analyze frequency and severity of ocular involvement in STEC-HUS, and the relationship between ocular involvement and disease severity, with emphasis on CNS, kidney, and colonic disease. METHODS: Prospective, longitudinal, observational study. INCLUSION CRITERIA: STEC-HUS patients September 2014-January 2019. Funduscopic examination (FE) was performed within 48 h of admission. We evaluated severity of CNS disease, kidney involvement, and presence of hemorrhagic colitis (HC). RESULTS: Ninety-nine patients were included (female 52), mean age 39.4 months (DE: 29.8; range 9-132). Thirteen patients (13.1%) had abnormal FE, 10 showing variable degrees of hemorrhagic exudates and 2 with typical Purtscher-like retinopathy. Other findings included tortuous vascularity, cotton wool spots, and transient retinal edema. CNS involvement was present in 16/99 patients, severe in 12 (75%). Abnormal FE occurred in 5/12 (31%) patients with severe CNS involvement vs. 8/87 (9.2%) with mild, moderate, or no CNS disease (p = 0.0191). Abnormal FE was present in 2/33 (6%) patients without dialysis vs. 11/66 (16.6%) requiring dialysis (p = 0.20). Finally, there were FE abnormalities in 6/20 patients with HC vs. 7/79 without HC (p = 0.012). CONCLUSIONS: FE abnormalities were present in 13% of HUS patients. Abnormal FE significantly associated with more severe disease, including severe CNS involvement and HC. We suggest FE should be performed in severe HUS, especially in cases with severe CNS disease. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli infection in Argentina: update of serotypes and genotypes and their relationship with severity of the disease.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) infection is the most common cause of hemolytic uremic syndrome (HUS). Only few studies correlated serotypes and stx genotypes with disease severity. This study aimed to update STEC serotypes, stx genotypes, and virulence factors (eae and ehxA) in a cohort of patients with STEC-HUS and investigate whether they influence the severity of disease. METHODS: In this multicentric study, children hospitalized between 2005 and 2016 with STEC-HUS confirmed by the National Reference Laboratory were included. Serotypes (O157, O145, O121, and others), stx genotypes (stx1a, stx2a, stx2c, stx2d, and others), and virulence factors were analyzed, and their association with dialysis requirement (>10 days); severe neurological, cardiovascular, and/or bowel involvement; and death was assessed. RESULTS: The records of 280 patients were reviewed; 160 females, median age 21 months (IQR18m). STEC O157 was isolated in 206 (73.6%) patients, O145 in 47 (16.8%), O121 in 15 (5.4%), and other serotypes in 12 (4.2%). The stx2a/2c genotype was carried by 179 (63.9%) strains, stx2a by 94 (33.6%), stx1a/stx2a by five (1.8%), and stx1a only by two (0.7%). All strains except six harbored eae and ehxA genes. Fifty-nine (21.1%) patients had severe neurological involvement, 29 (10.4%) severe bowel injury, 14 (5%) cardiovascular involvement, 53 (18.9%) required > 10 days of dialysis, and 12 (4.3%) died. Neither serotypes nor stx genotypes detected were significantly linked to severity. CONCLUSIONS: Serotype O157 and virulence stx2a/2c, eae, ehxA genotype are prevalent in Argentina, and no relationship was found between severity and serotypes and genotypes of STEC detected.

Tiempo de excreción fecal de Escherichia coliproductora de toxina Shiga en niños con síndrome urémico hemolítico / Duration of fecal shedding of Shiga toxin-producing Escherichia coli among children with hemolytic uremic syndrome

Introducción. Conocer el tiempo de excreción fecal de Escherichia coli productora de toxina Shiga (Shiga toxin-producing Escherichia coli; STEC, por sus siglas en inglés) en pacientes con síndrome urémico hemolítico sería útil para controlar la transmisión de la enfermedad.Objetivos. 1) Analizar las características del tiempo de excreción de STEC. 2) Evaluar la asociación con las variables sexo, edad, necesidad de diálisis, antibióticos y serotipos de STEC.Población y métodos. Estudio prospectivo, observacional, longitudinal y analítico. Período 2013-2019. Se realizaron coprocultivos al ingresar y cada 5-7 días hasta obtener 2 negativos. Se definió tiempo de excreción desde el inicio de la diarrea hasta el primer negativo. Se confirmó STEC por detección de los genes stx1, stx2 y rfbO157 por reacción en cadena de la polimerasa. Se calculó la media (IC 95 %) y percentilos del tiempo de excreción de STEC, y se compararon las variables estudiadas mediante el test de t.Resultados. Se incluyeron 43 pacientes. La media de tiempo de excreción fue 10,2 días (IC 95 %: 8,92-11,59), rango: 3-22 días. El 90 % de los pacientes negativizaron el coprocultivo a los 15 días. No hubo diferencias según sexo (p = 0,419), edad (p = 0,937), necesidad de diálisis (p = 0,917), antibióticos (p = 0,147) ni serotipos (p = 0,231).Conclusión. El 90 % de los pacientes negativizó el coprocultivo a los 15 días del inicio de la diarrea, y todos, al día 22. No se encontró asociación entre el tiempo de excreción y las variables estudiadas.

Introduction. Knowing the duration of fecal shedding of Shiga toxin-producing Escherichia coli(STEC) among patients with hemolytic uremic syndrome would be useful to control disease transmission.Objectives. 1) To analyze the characteristics of STEC shedding duration. 2) To assess the association with sex, age, need of dialysis, antibiotics, and STEC serotypes.Population and methods. Prospective, observational, longitudinal, and analytical study in the 2013-2019 period. Stool cultures were done upon admission and every 5-7 days until 2 negative results were obtained. Shedding duration was defined as the period from diarrhea onset to the first negative result. STEC was confirmed with polymerase chain reaction detection of stx1, stx2, and rfbO157 genes. The mean (95 % CI) and percentile values of the STEC shedding duration were estimated, and the studied outcome measures were compared using the t test.Results. A total of 43 patients were included. The mean duration of shedding was 10.2 days (95 % CI: 8.92-11.59), range: 3-22 days. After 15 days, 90 % of patients had a negative stool culture. There were no differences in terms of sex (p = 0.419), age (p = 0.937), need of dialysis (p = 0.917), antibiotics (p = 0.147) or serotype (p = 0.231).Conclusion. Fifteen days after the onset of diarrhea, 90 % of patients had a negative stool culture, and all patients had one after 22 days. No association was observed between the duration of shedding and studied outcome measures.

Acute peritoneal dialysis, complications and outcomes in 389 children with STEC-HUS: a multicenter experience.

BACKGROUND: Management of acute kidney injury (AKI) in children with hemolytic uremic syndrome induced by a Shiga toxin-producing Escherichia coli infection (STEC-HUS) is supportive; however, 40 to 60% of cases need kidney replacement therapy (KRT). The aim of this study was to analyze procedure complications, especially peritonitis, and clinical outcomes in children with AKI secondary to STEC-HUS treated with acute PD. METHODS: This is a multicenter retrospective study conducted among thirty-seven Argentinian centers. We reviewed medical records of 389 children with STEC-HUS hospitalized between January 2015 and February 2019 that required PD. RESULTS: Complications associated with PD were catheter malfunction (n = 93, 24%), peritonitis (n = 75, 19%), fluid leaks (n = 45, 11.5%), bleeding events (n = 23, 6%), and hyperglycemia (n = 8, 2%). In the multivariate analysis, the use of antibiotic prophylaxis was independently associated with a decreased risk of peritonitis (hazard ratio 0.49, IC 95% 0.29-0.81; p = 0.001), and open-surgery catheter insertion was independently associated with a higher risk (hazard ratio 2.8, IC 95% 1.21-6.82; p = 0.001). Discontinuation of PD due to peritonitis, severe leak, or mechanical complications occurred in 3.8% of patients. No patient needed to be transitioned to other modality of KRT due to inefficacy of the technique. Mortality during the acute phase occurred in 2.8% patients due to extrarenal complications (neurological and cardiac involvement), not related to PD. CONCLUSIONS: Acute PD was a safe and effective method to manage AKI in children with STEC-HUS. Prophylactic antibiotics prior to insertion of the PD catheter should be considered to decrease the incidence of peritonitis.

Duration of fecal shedding of Shiga toxin-producing Escherichia coli among children with hemolytic uremic syndrome. / Tiempo de excreción fecal de Escherichia coli productora de toxina Shiga en niños con síndrome urémico hemolítico.

INTRODUCTION: Knowing the duration of fecal shedding of Shiga toxin-producing Escherichia coli (STEC) among patients with hemolytic uremic syndrome would be useful to control disease transmission. OBJECTIVES: 1) To analyze the characteristics of STEC shedding duration. 2) To assess the association with sex, age, need of dialysis, antibiotics, and STEC serotypes. POPULATION AND METHODS: Prospective, observational, longitudinal, and analytical study in the 2013-2019 period. Stool cultures were done upon admission and every 5-7 days until 2 negative results were obtained. Shedding duration was defined as the period from diarrhea onset to the first negative result. STEC was confirmed with polymerase chain reaction detection of stx1, stx2, and rfbO157 genes. The mean (95 % CI) and percentile values of the STEC shedding duration were estimated, and the studied outcome measures were compared using the t test. RESULTS: A total of 43 patients were included. The mean duration of shedding was 10.2 days (95 % CI: 8.92-11.59), range: 3-22 days. After 15 days, 90 % of patients had a negative stool culture. There were no differences in terms of sex (p = 0.419), age (p = 0.937), need of dialysis (p = 0.917), antibiotics (p = 0.147) or serotype (p = 0.231). CONCLUSION: Fifteen days after the onset of diarrhea, 90 % of patients had a negative stool culture, and all patients had one after 22 days. No association was observed between the duration of shedding and studied outcome measures.

Introducción. Conocer el tiempo de excreción fecal de Escherichia coli productora de toxina Shiga (Shiga toxin-producing Escherichia coli; STEC, por sus siglas en inglés) en pacientes con síndrome urémico hemolítico sería útil para controlar la transmisión de la enfermedad. Objetivos. 1) Analizar las características del tiempo de excreción de STEC. 2) Evaluar la asociación con las variables sexo, edad, necesidad de diálisis, antibióticos y serotipos de STEC. Población y métodos. Estudio prospectivo, observacional, longitudinal y analítico. Período 2013-2019. Se realizaron coprocultivos al ingresar y cada 5-7 días hasta obtener 2 negativos. Se definió tiempo de excreción desde el inicio de la diarrea hasta el primer negativo. Se confirmó STEC por detección de los genes stx1, stx2 y rfbO157 por reacción en cadena de la polimerasa. Se calculó la media (IC 95 %) y percentilos del tiempo de excreción de STEC, y se compararon las variables estudiadas mediante el test de t. Resultados. Se incluyeron 43 pacientes. La media de tiempo de excreción fue 10,2 días (IC 95 %: 8,92- 11,59), rango: 3-22 días. El 90 % de los pacientes negativizaron el coprocultivo a los 15 días. No hubo diferencias según sexo (p = 0,419), edad (p = 0,937), necesidad de diálisis (p = 0,917), antibióticos (p = 0,147) ni serotipos (p = 0,231). Conclusión. El 90 % de los pacientes negativizó el coprocultivo a los 15 días del inicio de la diarrea, y todos, al día 22. No se encontró asociación entre el tiempo de excreción y las variables estudiadas.

Enfermedad invasiva asociada a neumococo y síndrome urémico hemolítico, nuevo serotipo / Invasive pneumococcal disease and hemolytic uremic syndrome: new serotype

El síndrome urémico hemolítico asociado a Streptococcus pneumoniae (SUH-Sp) se define como anemia hemolítica microangiopática, plaquetopenia y lesión renal aguda, en un paciente con infección invasiva por Streptococcus pneumoniae (Sp). Varón de 2 años, con neumonía con derrame pleural por Sp aislado en hemocultivos y líquido pleural. A las 72 h, presentó palidez, decaimiento, quejido respiratorio y oliguria. En el análisis de laboratorio se encontró anemia, plaquetopenia, aumento de la urea, la creatinina y la lactato deshidrogenasa en sangre; coombs directa +; esquistocitos en frotis; fibrinógeno; coagulograma normal; dímero D aumentado. Orina con proteinuria y hematuria. En Terapia Intensiva requirió asistencia respiratoria mecánica y transfusión con glóbulos rojos lavados; se recuperó progresivamente. El Instituto Malbrán informó serotipo 38 de Sp. Es el primer paciente comunicado con este serotipo

Streptococcus pneumoniae associated hemolytic uremic syndrome (Sp-HUS) is defined as microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury, in a patient with Streptococcus pneumoniae (Sp) invasive infection. A 2-year-old boy was admitted with pneumonia and empyema. Sp was isolated from blood and pleural fluid cultures. After 72 h, the patient showed paleness, asthenia, respiratory whining and oliguria. Laboratory showed anemia, low platelets, increased blood urea, creatirnina, lactate dehdrogenase, direct Coombs +, schistocytes, fibrinogen, normal coagulogram and increased D-dimer. Proteinuria and hematuria were detected in urine. Mechanical ventilatory assistance and transfusions of washed red blood cells were required. The patient recovered progressively. Sp serotype 38 was isolated in the National Reference Laboratory "Malbran". This is the first report associated to this serotype

Hyponatremia: a new predictor of mortality in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome.

OBJECTIVES: (1) Evaluate mortality rate in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, (2) determine the leading causes of death, and (3) identify predictors of mortality at hospital admission. METHODS: We conducted a multicentric, observational, retrospective, cross-sectional study. It included patients under 18 years old with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome hospitalized between January 2005 and June 2016. Clinical and laboratory data were obtained from the Argentine National Epidemiological Surveillance System of Hemolytic Uremic Syndrome. Clinical and laboratory variables were compared between deceased and non-deceased patients. Univariate and multivariate analyses were performed. ROC curves and area under the curve were obtained. RESULTS: Seventeen (3.65%) out of the 466 patients died, being central nervous system involvement the main cause of death. Predictors of death were central nervous system involvement, the number of days since the beginning of diarrhea to hospitalization, hyponatremia, high hemoglobin, high leukocyte counts, and low bicarbonate concentration on admission. In the multivariate analysis, central nervous system involvement, sodium concentration, and hemoglobin were independent predictors. The best cut off for sodium was ≤ 128 meq/l and for hemoglobin ≥ 10.8 g/dl. CONCLUSIONS: Mortality was low in children with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, being central nervous system involvement the main cause of death. The best mortality predictors found were central nervous system involvement, hemoglobin, and sodium concentration. Hyponatremia may be a new Shiga toxin-producing Escherichia coli hemolytic uremic syndrome mortality predictor.

Comparación entre algoritmos de imágenes tras una primera infección urinaria febril en niños / Algorithms imaging tests comparison following the first febrile urinary tract infection in children

Objetivos. Comparar la sensibilidad diagnóstica, los costos y las dosis de radiación entre algoritmos de imágenes de la Sociedad Argentina de Pediatría de 2003 y 2015, y las guías británicas y americanas luego de una primera infección urinaria (IU) febril. Población y métodos. Los criterios de inclusión fueron niños ≤ 2 años con primera IU febril con ecografía normal, cistouretrografía miccional y centellografía con ácido dimercaptosuccínico según el algoritmo de la Sociedad Argentina de Pediatría de 2003, asistidos entre los años 2003 y 2010. Las comparaciones entre algoritmos se realizaron por simulación retrospectiva. Resultados. 80 pacientes cumplieron con los criterios de inclusión; 51 (63%) presentaron reflujo vesicoureteral (RVU); 6% de alto grado; escaras en 6 (7,5%); costo: 404 000 $; radiación: 160 milisievert. Aplicando el algoritmo de la Sociedad Argentina de Pediatría de 2015, se hubiera omitido el diagnóstico de 4 RVU y 2 escaras, con un costo de 301 800 $ y 124 milisievert de radiación. Las guías británicas y americanas hubieran omitido los diagnósticos de todos los RVU y escaras con costos de 23 000 $ y 40 000 $, respectivamente, y 0 de radiación. Conclusión. Los protocolos intensos tienen alta sensibilidad para detectar RVU y escaras, pero conllevan altos costos y dosis de radiación con beneficios cuestionables.

Objectives. To compare the diagnostic sensitivity, costs and radiation doses of imaging tests algorithms developed by the Argentine Society of Pediatrics in 2003 and 2015, against British and American guidelines after the first febrile urinary tract infection (UTI). Population and Methods. Inclusion criteria: children < 2 years old with their first febrile UTI and normal ultrasound, voiding cystourethrography and dimercaptosuccinic acid scintigraphy, according to the algorithm established by the Argentine Society of Pediatrics in 2003, treated between 2003 and 2010. The comparisons between algorithms were carried out through retrospective simulation. Results. Eighty (80) patients met the inclusion criteria; 51 (63%) had vesicoureteral reflux (VUR); 6% of the cases were severe. Renal scarring was observed in 6 patients (7.5%). Cost: ARS 404,000. Radiation: 160 millisieverts. With the Argentine Society of Pediatrics' algorithm developed in 2015, the diagnosis of 4 VURs and 2 cases of renal scarring would have been missed. The cost of this omission would have been ARS 301,800 and 124 millisieverts of radiation. British and American guidelines would have missed the diagnosis of all VURs and all cases of renal scarring, with a related cost of ARS 23,000 and ARS 40,000, respectively and 0 radiation. Conclusion. Intensive protocols are highly sensitive to VUR and renal scarring, but they imply high costs and doses of radiation, and result in questionable benefits.

Algorithms imaging tests comparison following the first febrile urinary tract infection in children. / Comparación entre algoritmos de imágenes tras una primera infección urinaria febril en niños.

OBJETIVES: To compare the diagnostic sensitivity, costs and radiation doses of imaging tests algorithms developed by the Argentine Society of Pediatrics in 2003 and 2015, against British and American guidelines after the first febrile urinary tract infection (UTI). POPULATION AND METHODS: Inclusion criteria: children ≤ 2 years old with their first febrile UTI and normal ultrasound, voiding cystourethrography and dimercaptosuccinic acid scintigraphy, according to the algorithm established by the Argentine Society of Pediatrics in 2003, treated between 2003 and 2010. The comparisons between algorithms were carried out through retrospective simulation. RESULTS: Eighty (80) patients met the inclusion criteria; 51 (63%) had vesicoureteral reflux (VUR); 6% of the cases were severe. Renal scarring was observed in 6 patients (7.5%). Cost: ARS 404,000. Radiation: 160 millisieverts. With the Argentine Society of Pediatrics' algorithm developed in 2015, the diagnosis of 4 VURs and 2 cases of renal scarring would have been missed. The cost of this omission would have been ARS 301,800 and 124 millisieverts of radiation. British and American guidelines would have missed the diagnosis of all VURs and all cases of renal scarring, with a related cost of ARS 23,000 and ARS 40,000, respectively and 0 radiation. CONCLUSION: Intensive protocols are highly sensitive to VUR and renal scarring, but they imply high costs and doses of radiation, and result in questionable benefits.

OBJETIVOS: Comparar la sensibilidad diagnóstica, los costos y las dosis de radiación entre algoritmos de imágenes de la Sociedad Argentina de Pediatría de 2003 y 2015, y las guías británicas y americanas luego de una primera infección urinaria (IU) febril. POBLACIÓN Y MÉTODOS: Los criterios de inclusión fueron niños ≤ 2 años con primera IU febril con ecografía normal, cistouretrografía miccional y centellografía con ácido dimercaptosuccínico según el algoritmo de la Sociedad Argentina de Pediatría de 2003, asistidos entre los años 2003 y 2010. Las comparaciones entre algoritmos se realizaron por simulación retrospectiva. RESULTADOS: 80 pacientes cumplieron con los criterios de inclusión; 51 (63%) presentaron reflujo vesicoureteral (RVU); 6% de alto grado; escaras en 6 (7,5%); costo: 404 000 $; radiación: 160 milisievert. Aplicando el algoritmo de la Sociedad Argentina de Pediatría de 2015, se hubiera omitido el diagnóstico de 4 RVU y 2 escaras, con un costo de 301 800 $ y 124 milisievert de radiación. Las guías británicas y americanas hubieran omitido los diagnósticos de todos los RVU y escaras con costos de 23 000 $ y 40 000 $, respectivamente, y 0 de radiación. CONCLUSIÓN: Los protocolos intensos tienen alta sensibilidad para detectar RVU y escaras, pero conllevan altos costos y dosis de radiación con beneficios cuestionables.

Factores de riesgo asociados a infección en pacientes con hidronefrosis antenatal de alto grado / Risk factors associated to urinary infection in patients with high grade antenatal hydronephrosis

Introducción: la elevada incidencia de infección urinaria en pacientes con hidronefrosis antenatal de alto grado ha llevado a la recomendación de profilaxis antibiótica. Objetivos: Determinar la incidencia de infección urinaria en pacientes con hidronefrosis antenatal aislada de alto grado y posibles factores de riesgo asociados. Material y métodos: Diseño observacional, analítico, retrospectivo. Criterios de inclusión: recién nacidos con hidronefrosis antenatal de alto grado aislada (moderadas y severas, diámetro antero-posterior de la pelvis >15 mm) con más de 12 meses de seguimiento en aquellos tratados conservadoramente y hasta la cirugía en los que la requirieron. No se incluyeron recién nacidos con hidronefrosis de alto grado debida a reflujo vesicoureteral, mega uréteres, válvula de uretra posterior, ureterocele. Se realizó análisis de regresión logística múltiple, variables independientes: género, grado de hidronefrosis y profilaxis antibiótica. Se aplicó prueba exacta de Fisher, p≤0,05 fue considerada significativa. Resultados: Se evaluaron 68 pacientes, 51 con hidronefrosis antenatal moderada (parénquima normal) y 17 con severa (parénquima afinado). Dieciséis pacientes (23,5%) tuvieron infección urinaria. Ni el género, ni el grado de hidronefrosis fueron factores de riesgo para infección urinaria. El 57% (12/21) de los pacientes con profilaxis presentaron IU, contra el 8,5% (4/47) sin profilaxis. La profilaxis incrementó el riesgo de IU (OR crudo 14,3; IC 95% 3,7-54,7; y ajustado por género y grado de hidronefrosis 25; IC 95% 5- 125; p<0.001). Conclusiones: La incidencia de infección urinaria fue 23,5%. Nuestro estudio muestra un mayor riesgo de infección urinaria en pacientes con profilaxis antibiótica.

Introduction: the high incidence of urinary infection in patients with high-grade antenatal hydronephrosis has led us to recommend antibiotic prophylaxis. Objectives: To determine the incidence of urinary infection in patients with high grade isolated antenatal hydronephrosis and its possible associated risk factors. Methods: Observational retrospective analytic design. Inclusion criteria: new born with isolated high grade antenatal hydronephrosis (moderate and severe, anterior-posterior pelvis diameter >15mm) monitored for more than 12 months, conservatively treated until surgical intervention on those that required it. New born with high-grade hydronephrosis due to vesicoureteral reflux, megaureters, posterior urethral valve, ureterocele, were not included. Multiple logistic regression analyses were performed, independent variables: gender, grade of hydronephrosis and antibiotic prophylaxis. FisherÆs exact test was used, p<0.05 was considered significant. Results: 68 patients were evaluated, 51 with moderate antenatal hydronephrosis (normal parenchyma) and 17 with severe antenatal hydroneprohosis (thin parenchyma). Sixteen patients (23.5%) had urinary infection. Neither gender nor hydronephrosis grade were risk factors for urinary infection. 57% (12/21) of the patients with prophylaxis presented UI, compared to 8.5% (4/47) in those without prophylaxis. Prophylaxis increased risk of IU: OR crude 14.3 (CI 95% 3.7-54.7) and adjusted by gender and hydronephrosis grade OR 25 (CI 95%5-125; p<0.001). Conclusions: Urinary infection incidence was 23.5%. Our study shows a major risk of urinary infection in patients with antibiotic prophylaxis.

Could prophylactic antibiotics be stopped in patients with history of vesicoureteral reflux?

OBJECTIVE: To compare the incidence and type of urinary tract infection (UTI) in patients with primary vesicoureteral reflux (VUR) diagnosed after a febrile UTI while they were on prophylactic antibiotics (PA) and after stopping PA. MATERIALS AND METHODS: Criteria to discontinue PA were: no UTI during 12+ or more months on PA, old enough to communicate UTI symptoms, potty trained and absence of risk factors for UTI. Patients with at least 1 year of follow up without PA were included (n=77). We recorded: age at which PA was indicated and stopped, time on and off PA, incidence and type of UTI (cystitis vs acute pyelonephritis (APN)), and renal scan results. RESULTS: PA was started and stopped at a mean age of 18.5 and 61 months, respectively. Mean time on PA was 39 months (range 12-95): 25 patients had 44 UTI episodes (0.17 episodes/patient/year), and 31 (70%) of them were APN. Mean time of antibiotics was 44.5 months (range 12-162): 13 patients had 24 UTI episodes (0.08 episodes/patient/year), eight (33%) of which were APN (P<0.05). A renal scan was performed in 71 patients after the index infection and repeated in 12. Two patients lost renal function while still on PA. CONCLUSION: Discontinuing PA in patients with history of VUR is a safe practice and should be considered as a management option.

Long-term follow-up of Argentinean patients with hemolytic uremic syndrome who had not undergone dialysis.

We examined the records of patients with hemolytic uremic syndrome, who had not undergone dialysis during the acute stage, with the aims of evaluating: (1) the outcome after at least 5 years of follow-up; (2) the value of peak serum creatinine as a prognostic marker; (3) the relationship between outcome and time to normalization of renal function. From 1968 to 2000, 1,179 patients were assisted. Forty-two patients (3.6%) died during the acute stage, 478 patients (40.5%) required dialysis and 659 patients (55.9%) did not undergo dialysis; 529 non-dialysis patients were lost to follow-up. The remaining 130 patients were classified into four groups: group I, complete recovery; group II, with two subgroups, IIa, microalbuminuria, and IIb, proteinuria and/or high blood pressure, both with normal renal function; group III, chronic renal failure; and group IV, end-stage renal disease. We analyzed the relationship between final outcome and: (1) peak creatinine (the highest of at least two determinations) during the acute stage and (2) time to normalization of urea and/or creatinine after the acute stage. After a mean follow-up time of 147.1 months (range 60-362 months), group I had 83 patients (63.9%), group IIa had 27 (20.8%), group IIb had 15 (11.5%) and group III had 5 (3.8%). The value of peak serum creatinine concentration was available for 57 patients. On the last clinical visit, eight out of 26 (30.7%) patients with peak serum creatinine equal to or higher than 1.5 mg/dl were in groups IIb and III versus one out of 31 (3.2%) patients with lower values (P < or = 0.007). Finally, six out of 28 patients (21%) whose renal function had normalized after 15 days from diagnosis were in groups IIb-III versus 8/82 (9.7%) whose renal function had normalized within 15 days (P = 0.18). After a mean period of follow-up of 12 years, 15% of a selected patient group had developed proteinuria, high blood pressure or chronic renal failure, and 21% had developed microalbuminuria. Peak serum creatinine during the acute stage was useful as a prognostic indicator. Patients whose renal function required more time to normalize did not have a worse outcome.

Anormalidades del tracto urinario: Detección con ecografía renal en lactantes sanos / Ultrasound screening of healthy infants for urinary tract abnormalities

Introducción.Se determinó la incidencia de anomalías del tracto urinario que pueden ser detectadas mediante ecografía renal en lactantes sanos.Se estudiaron trescientos niños con edades entre uno y doce meses que concurrieron a su control mensual de salud.Resultados.Doscientos setenta y ocho lactantes tuvieron estudios normales.veinte,marginales(pelvis renal menor o igual a 5mn)y dos mostraron anormalidades del tracto urinario.Un paciente tuvo una estenosis pielouretral congénita que requirió cirugía y el otro,un riñon ectópico pelviano.En sólo veinte niños con exámenes marginales se demostró un reflujo vesicouretral.La incidencia de anomalías del tracto urinario fue del 1 por ciento.Conclusiones.Este estudio indica que:1)Las dilataciones de la pelvis renal menores o iguales a 5 mn pueden ser transitorias y no implicar patología,a menos que persitan o se agraven en sucesivos controles.2)La baja incidencia de anomalías severas del tracto urinario encontradas sugiere que en la actualidad en nuestro medio,la evaluación sonográfica de rutina no es un método eficiente,en relación al costo,para prevenir,la progresión de la enfermedad renal

Anormalidades del tracto urinario: Detección con ecografía renal en lactantes sanos / Ultrasound screening of healthy infants for urinary tract abnormalities

Introducción.Se determinó la incidencia de anomalías del tracto urinario que pueden ser detectadas mediante ecografía renal en lactantes sanos.Se estudiaron trescientos niños con edades entre uno y doce meses que concurrieron a su control mensual de salud.Resultados.Doscientos setenta y ocho lactantes tuvieron estudios normales.veinte,marginales(pelvis renal menor o igual a 5mn)y dos mostraron anormalidades del tracto urinario.Un paciente tuvo una estenosis pielouretral congénita que requirió cirugía y el otro,un riñon ectópico pelviano.En sólo veinte niños con exámenes marginales se demostró un reflujo vesicouretral.La incidencia de anomalías del tracto urinario fue del 1 por ciento.Conclusiones.Este estudio indica que:1)Las dilataciones de la pelvis renal menores o iguales a 5 mn pueden ser transitorias y no implicar patología,a menos que persitan o se agraven en sucesivos controles.2)La baja incidencia de anomalías severas del tracto urinario encontradas sugiere que en la actualidad en nuestro medio,la evaluación sonográfica de rutina no es un método eficiente,en relación al costo,para prevenir,la progresión de la enfermedad renal