IgA-dominant infection-associated glomerulonephritis in the pediatric population.

BACKGROUND: IgA-dominant infection-associated glomerulonephritis is well-documented in adults but has not been studied in depth in children. We assessed the incidence of pediatric IgA-dominant infection-associated glomerulonephritis and clinical and kidney biopsy findings. METHODS: Pediatric native kidney biopsies over a 10-year period with IgA dominance, strong C3, and findings indicative of infection-associated etiology were identified. RESULTS: We identified 9 cases of IgA-dominant infection-associated glomerulonephritis, 0.8% of pediatric native kidney biopsies. Seven patients presented with elevated creatinine. All had hematuria and proteinuria. Eight patients had clinical evidence of infection: one each with central port infection by methicillin-sensitive Staphylococcus aureus, recurrent streptococcal pharyngitis and recent otitis media, streptococcal pharyngitis demonstrated 8 months after biopsy, suspected streptococcal scalded skin syndrome, and viral gastroenteritis, and three with serologic evidence of Streptococcal infection but no identified site of infection. All but one patient experienced short-term normalization of creatinine and resolution of proteinuria, though two eventually progressed to kidney failure: one 3 years later due to progressive disease and one 11 years later due to focal segmental glomerulosclerosis without concurrent immune deposits. CONCLUSIONS: Pediatric IgA-dominant infection-associated glomerulonephritis is rare, and generally has a favorable prognosis, contrasting that seen in adults with severe comorbidities. A higher resolution version of the Graphical abstract is available as Supplementary.

Evaluation of morphologically unclassified renal cell carcinoma with electron microscopy and novel renal markers: implications for tumor reclassification.

Despite progress in the classification of renal cell carcinomas (RCC), a subset of these carcinomas remains unclassified (RCC-U). Patients with RCC-U usually present at a late stage and have a poor prognosis. Several studies have attempted to extract new classifications of newly recognized renal carcinomas from the group of RCC-U. However, to date, no studies in the literature have attempted to characterize the RCC-U with unrecognizable cell types beyond the morphologic evaluation on H&E-stained sections. The purpose of this study was to evaluate this group of RCC-U using electron microscopy and novel renal markers. Ten cases of such RCC-U were identified for this study. At the ultrastructural level, they did not show typical morphology that resembled any of the well-studied, recognizable subtypes of RCC. However, they did reveal features of renal tubular epithelial differentiation. The histologic, ultrastructural, and immunophenotypic features indicated that these tumors are poorly differentiated renal epithelial tumors, possibly derived from the proximal nephron, with an immunohistochemical profile similar to high-grade clear cell RCC. It is, therefore, proposed that this group of renal carcinomas be renamed "poorly differentiated renal cell carcinoma, not otherwise specified." The current study showed that PAX-8 and carbonic anhydrase IX are reliable markers for this novel group of renal carcinoma, and that electron microscopy is an important adjunct in the evaluation of new and unusual renal entities.

Web-based nephropathology teaching modules and user satisfaction: the nephrology on-demand experience.

Nephropathology is an integral component of nephrology education. Online teaching sites provide valuable educational materials to learners, but learner satisfaction has not been measured. We developed a nephropathology website and measured learners' satisfaction. The Nephrology On-Demand Histopathology website (http://blog.ecu.edu/sites/nephrologyondemand/?page_id=4502) provided nephropathologic specimens with explanations. Users were asked to complete a Likert-based survey (1-strongly agree . . . 5-strongly disagree) regarding four key areas of content quality: accuracy, currency, objectivity, and usefulness. Learners of all training levels perceived the content quality favorably. The mean (±SD) for accuracy was 1.70 (0.89), currency 1.62 (0.90), objectivity 1.80 (1.01), and usefulness 1.72 (0.95). Nephrology On-Demand Histopathology is a well-received teaching tool to learners of all training levels. Educators may consider using it, as well as other online nephropathology sites, as adjunctive teaching tools.