Successful use of plasma exchange for profound hemolysis in a child with loxoscelism.

We describe a 6-year-old boy who presented with massive hemolysis, shock, disseminated intravascular coagulopathy, and acute renal failure after loxosceles envenomation. In this patient, plasma exchange therapy (PEX) successfully cleared the plasma from an initial hemolytic index of 2000 (equivalent to 2 g/dL hemoglobin, where optimetric laboratory evaluation is impossible) to an index of <50 (no detectable hemolysis). This allowed the PICU team to correct his coagulopathy, assess his degree of organ dysfunction, and provide routine laboratory assessments during continuous venovenous hemodiafiltration. After 9 single volume PEX sessions, his hemolysis and coagulopathy had resolved and his plasma had cleared sufficiently to permit routine laboratory assessments without difficulty. Multiorgan system support with an aggressive transfusion strategy, mechanical ventilation, inotropes, and continuous venovenous hemodiafiltration resulted in complete recovery. We conclude that in the presence of overwhelming hemolysis, plasma can become so icteric that optimetric laboratory evaluation is impossible. In this setting, PEX can be used to clear the plasma, restoring the ability to perform routine laboratory assessments.

Human polyomaviruses in children undergoing transplantation, United States, 2008-2010.

Immunocompromised patients are at risk for disease caused by infection by some polyomaviruses. To define the prevalence of polyomaviruses in children undergoing transplantation, we collected samples from a longitudinal cohort and tested for the 9 known human polyomaviruses. All were detected; several were present in previously unreported specimen types.

Urinary incontinence in the CKiD cohort and health related quality of life.

PURPOSE: Many children with chronic kidney disease have urinary incontinence due to urological disorders and/or a urine concentrating defect. We determined the prevalence and impact of incontinence on health related quality of life in children with chronic kidney disease. MATERIALS AND METHODS: The Chronic Kidney Disease in Children study is a prospective, observational cohort of children recruited from 47 sites in the United States and Canada. Eligibility requirements are age 1 to 16 years and an estimated glomerular filtration rate of 30 to 90 ml per minute per 1.73 m(2). Demographics, continence status, glomerular filtration rate and physical examination were assessed at study entry. Health related quality of life was measured using the parent and child versions of PedsQL. PedsQL scores in participants 5 years old or older were compared among children who were toilet trained and not bed-wetting, bed-wetting or not toilet trained using multivariate linear regression. RESULTS: Overall median age of the 329 participants was 12.5 years, 61.4% were male, 70% were white and 55.5% had a urological disorder. Of participants 71.4% were toilet trained at study enrollment, 23.1% had bed-wetting and 5.5% were not toilet trained. Children who were not yet toilet trained had an average total score that was 13.5 points lower (95% CI -25.2, -1.8) on the PedsQL child report than in those who were toilet trained (p = 0.02). Physical functioning (-15.0, 95% CI -28.2, -1.9) and school functioning (-15.3, 95% CI -29.8, -0.8) were also lower in this group (p = 0.03 and 0.04, respectively). On the PedsQL parent proxy report physical functioning (-14.2, 95% CI -26.7, -1.6) was similarly affected by child incontinence (p = 0.03). CONCLUSIONS: Urinary incontinence is common in pediatric patients with chronic kidney disease and associated with lower health related quality of life on the PedsQL child and parent proxy reports. Early recognition of and treatment for urinary incontinence may improve health related quality of life in this population.

Pediatric nephrolithiasis: does treatment affect renal growth?

OBJECTIVES: The long-term effects of shock wave lithotripsy on the growth of pediatric kidneys are not well defined. Likewise, no long-term data regarding renal growth after ureteroscopy or percutaneous nephrolithotomy have been published. We studied the effect of urolithiasis on renal growth in our pediatric patient population. METHODS: A total of 165 children were treated for urolithiasis at St. Louis Children's Hospital from March 1993 to December 2003. Of these 165 children, 74 were available for long-term follow-up. Four groups were evaluated: those who underwent shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy, and those who received no intervention. The expected renal length was calculated using Chen's nomogram, and the observed renal length was measured using renal ultrasonography. All measurements were performed by one pediatric radiologist. The expected and observed renal growth was determined by subtracting the renal length at baseline from the length at follow-up, divided by the number of months of follow-up. Statistical analysis used paired data for each treatment group, and comparisons were made on a nonparametric single-rank method. RESULTS: Of the 74 children, 39 were boys and 35 were girls, with a mean age at treatment of 9 years (range 9 months to 14 years) and a mean follow-up of 6.2 years (range 1.3 to 13.1). In all groups, the comparison between the treated side and nontreated side for expected and actual kidney size and growth was calculated as described. None of the groups had statistically significant differences in the observed or predicted renal growth rates. CONCLUSIONS: Shock wave lithotripsy, ureteroscopic stone extraction, and percutaneous nephrolithotomy do not appear to impair renal growth.

Histopathology, ultrastructure, and clinical phenotypes in thin glomerular basement membrane disease variants.

Recent genetic studies indicate that Alport syndrome and thin glomerular basement membrane disease (TMD) may both be due to COL4A3, COL4A4, and COL4A5 mutations, but there is continuing uncertainty concerning the diagnosis and management of patients without classic family history and symptoms. We examined kidney pathology and collagen alpha 3 to alpha 5(IV) expression in a series of 16 patients who presented with overlapping signs between TMD and Alport nephritis. All patients presented with hematuria, and 11 also had proteinuria, of whom 5 had nephrotic range proteinuria. Only 9 had family history of hematuria. In 9 of 16 (60%) we found premature glomerulosclerosis in the renal biopsies. Three of 16 had predominantly wide, lamellated glomerullar basement membranes (GBM), and in these, alpha 3 to alpha 5(IV) was absent in glomeruli or skin, diagnostic of Alport nephritis. One patient (12) had a very wide GBM with intramembranous lucencies but no lamellation. Skin biopsy was collagen alpha 5(IV) positive. Nine of 16 patients had predominantly thin GBM by electron microscopy, and 3 had thin and slightly lamellated GBM. Collagen alpha 3 to alpha 5(IV) expression in the kidney or skin biopsy was present in all of the latter 12 patients. Three patients had end-stage renal disease, 7 patients had hypertension, and 1 patient had chronic renal failure. We found that of the 16 patients with presumed TMD, 3 had X-linked Alport nephritis, 2 appeared to have autosomal recessive Alport nephritis, and the remaining patients had either an Alport or a TMD variant. The latter had histologic and/or clinical evidence of progressive renal disease, including premature glomerulosclerosis, hypertension, sustained proteinuria, and either thin or slight GBM lamellation focally, and preserved alpha 3 to alpha 5(IV) expression. These patients have a TMD variant, but an Alport variant with a potentially transmissible severe defect different from benign hematuria cannot be excluded.