Antibiotic use during E. coli O157:H7 infections is associated with a higher rate of subsequent HUS and should be avoided.

Recently, Schwartz et al. (J Am Soc Nephrol 20:629-637, 2009) used data from the National Institutes of Health-funded Chronic Kidney Disease in Children (CKiD) study to generate new equations for estimating the glomerular filtration rate (eGFR), including an update of the commonly used bedside equation. However, it is unclear if the equation can be generalized to a broader pediatric population. We have used the updated equation on a sample of pediatric patients with less impaired renal function to evaluate the correlation between the new Schwartz equation and measured GFR by iothalamate clearance. We retrospectively analyzed 738 iothalamate clearance tests from 503 patients with a mean serum creatinine of 0.50 mg/dl whose ages ranged from 1 to 16 years. We measured bias, precision, and accuracy and performed a Bland-Altman plot to determine the measure of agreement between the two methods. The mean GFR by iothalamate clearance was 110.6 ml/min/1.73 m(2) and by the new Schwartz estimation 104.7 ml/min/1.73 m(2). The mean difference was 5.84 ml/min/1.73 m(2) (95% CI 4.00-7.67). The newly purposed bedside Schwartz equation therefore demonstrated good agreement with the iothalamate renal clearances in our patient population and appears to be a valid bedside estimating equation for GFR in this sample of children.

Pediatric patients initiating dialysis with hypoalbuminemia are at a higher risk for death. This finding persists after adjusting for glomerular causes for ESRD and other potential confounding variables. Low serum albumin at dialysis initiation is an important marker of mortality risk in pediatric ESRD patients.

No abstract

HUS is a rare but severe complication of invasive pneumococcal infection. Although disseminated intravascular coagulation can also occur in these children, the treatment and follow-up may be different in the 2 conditions. Children with pneumococcal disease and severe hematologic or renal abnormalities should be investigated for evidence of HUS.

Background: Immune responses to vaccination are a known trigger for a new onset of glomerular disease or disease flare in susceptible individuals. Mass immunization against SARS-CoV-2 in the COVID-19 pandemic provides a unique opportunity to study vaccination-associated autoimmune kidney diseases. In the recent literature, there are several case reports demonstrating a temporal association of SARS-CoV-2 immunization and kidney diseases. Methods: Here, we present a series of 29 cases of biopsy-proven glomerular disease in patients recently vaccinated against SARS-CoV-2 and identified patients who developed a new onset of IgA nephropathy, minimal change disease, membranous nephropathy, ANCA-associated glomerulonephritis, collapsing glomerulopathy, and diffuse lupus nephritis diagnosed on kidney biopsies post-immunization, as well as recurrent ANCA-associated glomerulonephritis. This included 28 cases of de novo glomerulonephritis within native kidney biopsies and one disease flare in an allograft. Results: The patients with collapsing glomerulopathy were of African American descent and had two APOL1 genomic risk alleles. A brief literature review of case reports and small series is also provided to include all reported cases to date (n=52). The incidence of induction of glomerular disease in response to SARS-CoV-2 immunization is unknown, however, there was no overall increase in incidence of glomerular disease when compared to the two years prior to the COVID-19 pandemic diagnosed on kidney biopsies in our practice. Conclusions: This suggests that glomerulonephritis in response to vaccination is rare, although should be monitored as a potential adverse event.

The mortality rate in children with ESRD is substantially lower than the rate experienced by adults. However, the risk of death while awaiting kidney transplantation and the impact of transplantation on long-term survival has not been well characterized in the pediatric population. We performed a longitudinal study of 5961 patients under age 19 who were placed on the kidney transplant waiting list in the United States. Of these, 5270 received their first kidney transplant between 1990 and 2003. Survival was assessed via a time-varying nonproportional hazards model adjusted for potential confounders. Transplanted children had a lower mortality rate (13.1 deaths/1000 patientyears) compared to patients on the waiting list (17.6 deaths/1000 patient-years). Within the first 6 months of transplant, there was no significant excess in mortality compared to patients remaining on the waiting list (adjusted Relative Risk (aRR) = 1.01; p = 0.93). After 6 months, the risk of death was significantly lower: at 6-12 months (aRR = 0.37; p < 0.001) and at 30 months (aRR 0.26; p < 0.001). Compared to children who remain on the kidney transplant waiting list, those who receive a transplant have a long-term survival advantage. With the potential for unmeasured bias in this observational data, the results of the analysis should be interpreted conservatively.

The aim of this study was to characterize the 24-h and diurnal variability of urinary protein excretion and identify the prevalence of orthostatic proteinuria (OP) in healthy children. Upright, supine, and 24-h total urinary protein (UrTP) and creatinine clearance (CrCl) were measured in 91 healthy children ages 6–19 years. Urinary protein and creatinine excretions were calculated and examined by gender, age, Tanner stage, and body mass index (BMI). Orthostatic proteinuria (OP) was defined as a 24-h UrTP >100 mg/m2 with a normal supine UrTP (<4 mg/m2/h). There exists a marked diurnal variability in UrTP. The upright UrTP rate was three to four-times greater than the supine rate. UrTP, adjusted for body surface area, is higher in boys than girls and increases with age and BMI. There is a similar increase in upright CrCl compared with supine. Urinary protein to creatinine ratio (UPcr) is strongly correlated with UrTP. OP is common, being found in 20% of children in this cohort, and is more common in boys and associated with age >10 years and BMI >85%. In children with OP, a first morning UPcr shows a value in the normal range, whereas a random daytime UPcr is elevated. There exists a diurnal variability in urinary protein excretion that is exaggerated in participants with OP. UPcr reliably estimates 24-h UrTP. Using current pediatric criteria, OP is very common, particularly in boys. A normal first morning UPcr ratio indicates that a child with elevated random urinary protein has OP.