Case Report Fibronectin non-amyloid glomerulopathy
Jim L. Yong, Murray C. Killingsworth, S. Timothy Spicer, Xiao-Juan Wu
Department of Anatomical Pathology, South Western Area Pathology Service, Liverpool NSW, Australia. Affiliated with the University of New South Wales, Faculty of Medicine and the University of Western Sydney, School of Medicine; Renal Medicine, Liverpool Hospital, Liverpool NSW, Australia. Affiliated with the University of New South Wales, Faculty of Medicine; Department of Anatomical Pathology, South Western Area Pathology Service, Liverpool NSW, Australia. Affiliated with the University of Western Sydney, School of Medicine
Received August 19, 2009, accepted September 21, 2009, available online November 20, 2009
Abstract: A 41-year-old Burmese man presented with nephrotic syndrome, a creatinine level of 150 µmol/L and limited clinical history. His renal biopsy demonstrated glomerulopathy with large eosinophilic deposits in the mesangium and capillary loops that were negative for Congo red, slightly positive for periodic acid-Schiff and blue with Masson trichrome stain. Immunofluorescence microscopy with a routine antibody panel was unhelpful. Electron microscopy demonstrated extensive, moderately electron-dense deposits in the subendothelial space, subepithelial space and mesangium that could be differentiated from adjacent basement membrane by their increased electron density. The deposits contained finely granular material and occasional filaments with variable diameter ranging from 9-16 nm. Fibronectin glomerulopathy was suspected from anti-fibronectin immunohistochemistry that showed positive staining of thickened capillary loops. This staining was subsequently confirmed by immunoelectron microscopy demonstrating the presence of cellular fibronectin (cFN) in deposits. Significantly, deposition of fibronectin appeared to have occurred in the absence of thickening or folding of the adjacent basement membrane. The prominent mesangial location of deposits containing a cFN isotype may indicate that retention of local fibronectin produced in the mesangium has contributed to this pathology. (IJCEP908003).
Key words: Kidney, fibronectin, histology, electron microscopy, immunocytochemistry
Address all correspondence to: Murray C. Killingsworth, PhD Department of Anatomical Pathology Locked Bag 7090, Liverpool BC NSW 1871, Australia Tel: +61 2 9828 5392 Fax: +61 2 9828 5328 E-mail: firstname.lastname@example.org