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.

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.

Wilms tumor: 15 years of experience at a children's hospital in Córdoba, Argentina. / Tumor de Wilms: experiencia de 15 años en un Hospital de niños, Córdoba, Argentina.

The objective of this study was to describe the epidemiology, clinical presentation, treatment and nephrology follow-up of children with Wilms tumor. Data from 46 patients were collected. The clinical presentation occurred at a young age (< 40 months old), with initial symptoms of pain, abdominal mass, and fever. The prevalent histology type was mixed nephroblastoma. All patients received pre-surgery chemotherapy followed by, in most cases, unilateral nephrectomy. Patients with a high histological risk had a 7.2 relative risk of death (75 % confidence interval: 1.5-33.7) compared to the rest, and a 2.5 relative risk of recurrence (75 % confidence interval: 1.0-6.4). Disease-free survival at 5 years was 70 %. Once cancer treatment was completed, 80 % of patients maintained a stage-I kidney function. The most important prognostic factor was histology. These patients required a long-term nephrology follow-up.

El objetivo de este trabajo fue describir la epidemiología, la presentación, el tratamiento y el seguimiento nefrológico de niños con tumor de Wilms. Se recopilaron datos de 46 pacientes. Se encontró baja edad de presentación (< 40 meses), con síntomas iniciales de dolor, masa abdominal y fiebre. La histología prevalente fue nefroblastoma tipo mixto. Todos los pacientes recibieron quimioterapia prequirúrgica seguida, en la mayoría de los casos, de nefrectomía unilateral. Los pacientes con alto riesgo histológico tuvieron un riesgo relativo de morir de 7,2 (IC 75 %: 1,5-33,7) con respecto al resto y de recidiva de 2,5 (IC 75 %: 1,0-6,4). La sobrevida libre de enfermedad a 5 años fue del 70 %. El 80 % mantuvo la función renal en estadio I al completar el tratamiento oncológico. El factor pronóstico más importante fue la histología. Estos pacientes requieren seguimiento nefrológico prolongado.

Tumor de Wilms: experiencia de 15 años en un Hospital de niños, Córdoba, Argentina / Wilms tumor: 15 years of experience at a children's hospital in Córdoba, Argentina

El objetivo de este trabajo fue describir la epidemiología, la presentación, el tratamiento y el seguimiento nefrológico de niños con tumor de Wilms. Se recopilaron datos de 46 pacientes. Se encontró baja edad de presentación (< 40 meses), con síntomas iniciales de dolor, masa abdominal y fiebre. La histología prevalente fue nefroblastoma tipo mixto. Todos los pacientes recibieron quimioterapia prequirúrgica seguida, en la mayoría de los casos, de nefrectomía unilateral. Los pacientes con alto riesgo histológico tuvieron un riesgo relativo de morir de 7,2 (IC 75 %: 1,5-33,7) con respecto al resto y de recidiva de 2,5 (IC 75 %: 1,0-6,4). La sobrevida libre de enfermedad a 5 años fue del 70 %. El 80 % mantuvo la función renal en estadio I al completar el tratamiento oncológico. El factor pronóstico más importante fue la histología. Estos pacientes requieren seguimiento nefrológico prolongado.

The objective of this study was to describe the epidemiology, clinical presentation, treatment and nephrology follow-up of children with Wilms tumor. Data from 46 patients were collected. The clinical presentation occurred at a young age (< 40 months old), with initial symptoms of pain, abdominal mass, and fever. The prevalent histology type was mixed nephroblastoma. All patients received pre-surgery chemotherapy followed by, in most cases, unilateral nephrectomy. Patients with a high histological risk had a 7.2 relative risk of death (75 % confidence interval: 1.5-33.7) compared to the rest, and a 2.5 relative risk of recurrence (75 % confidence interval: 1.0-6.4). Disease-free survival at 5 years was 70 %. Once cancer treatment was completed, 80 % of patients maintained a stage-I kidney function. The most important prognostic factor was histology. These patients required a long-term nephrology follow-up.