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Archive: November 2017

Collapsing Glomerulopathy

Collapsing glomerulopathy is characterized by glomerular tuft collapse with overlying epithelial hypertrophy and hyperplasia in Bowman’s space. This pattern of glomerular injury is most commonly seen in African Americans and has been shown to be strongly associated with the presence of APOL1 risk variants in a number of associated diseases including HIV infection, lupus nephritis, interferon therapy, PLA2R-positive membranous glomerulopathy, and idiopathic cases.

IgA with Crescents, MEST-C

This biopsy is from a young adult patient with IgA nephropathy (the immunofluorescence image in Fig. 2 shows 2+ mesangial IgA deposits). While both glomeruli show endocapillary hypercellularity, the arrow indicates one glomerulus with a cellular crescent (Fig. 1). The recently updated Oxford classification of IgA nephropathy recommends that the frequency of crescents (cellular and/or fibrocellular) be added as the “C” in the MEST-Cscore (see reference). Although randomized clinical trials are still needed to determine optimal therapy, a C1 score (crescents in <25% of glomeruli) identifies patients at risk for poor renal outcome if not treated with immunosuppression, and a...

Calcium Phosphate Deposits

Calcium phosphate deposits within the kidney may be seen in the setting of hypercalcemia/ hypercalciuria or hyperphosphatemia/ hyperphosphaturia. Regardless of the etiology, the result is the formation of hydroxyapatite crystals within the tubular lumens (Fig 1 and 2), tubular epithelium, tubular basement membranes or within the interstitium. The term nephrocalcinosis is usually reserved to describe the presence of tubulointerstitial calcium phosphate deposits in patients with hypercalcemic disorders. These include, among others, hyperparathyroidism, sarcoidosis, underlying malignancies of various types, milk-alkali syndrome, hypervitaminosis A or D, Dent disease and other tubulopathies. On the other hand, phosphate nephropathy is predominantly seen in patients...

Diagnose This! (November 27, 2017)

What is your diagnosis (IgG stain shown)?     ​   ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​  ...


It's a bird! It's a plane! IT'S SUPERNEPH!!! We'd like to thank all of the nephrologists who are spending this Thanksgiving Day caring for their patients! What heroes!

Vascular Staining in Membranous

This immunofluorescence (IF) image shows extensive granular glomerular capillary wall IgG deposits, consistent with membranous glomerulopathy. The glomerular staining pattern as seen by IF is not specific for either primary or secondary membranous glomerulopathy. However, the prominent IgG deposits also involving the associated arteriole in this case are an important clue that helps argue for a secondary etiology. This patient, in fact, was found to have systemic lupus erythematosus.

Renal Vein Obstruction

This biopsy is from a 60-year-old female, status post renal transplant 5 days prior, who was found to have mechanical obstruction of the renal vein during the surgical revision of the transplanted kidney, without evidence of thrombosis. The biopsy shows marked congestion of the glomerular capillary loops (Fig 1), peritubular capillaries and arterioles, along with margination of neutrophils (Fig 2), interstitial hemorrhage and severe acute tubular injury. C4d is negative and there are no other clinical or morphologic findings suspicious for hyperacute or acute antibody-mediated rejection. Renal vein or artery obstruction is a rare complication of renal transplantation which is...