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Currently filtering by tag: IgA nephropathy

Art of Medicine: IgA Nephropathy

The above painting shows glomeruli with mesangial hypercellularity, endocapillary hypercellularity, and crescent formation.  These findings can be seen in IgA nephropathy, and other active glomerulonephritides.  These lesions shown in the painting above are represented in the Oxford Classification for IgA nephropathy.  The Oxford classification is a scoring system on kidney biopsies that  includes mesangial hypercellularity (M0 = <50%, M1 = >50%), endocapillary hypercellularity (E0 = none, E1 = present), segmental sclerosis (S0 = absent, S1 = present), tubular atrophy / interstitial fibrosis (T0 = <25%, T1 25-50%, T2 >50%), and crescents (C0 = absent, C1 = up to 25%, C2...

Twitter Poll (May 22, 2019)

ANSWER: C By the Oxford Classification of IgA nephropathy, the findings present are classified as "M1 E1 S1 T1 C0" (where M=Mesangial hypercellularity; E=Endocapillary proliferation; S=Segmental sclerosis; T=Tubular atrophy & interstitial fibrosis; C=Cellular/fibrocellular crescents). REFERENCE: Trimarchi H, et al. Oxford Classification of IgA Nephropathy 2016: an update from the IgA Nephropathy Classification Working Group. Kidney Int 2017; 91(5):1014-21.    

Crescentic IgA nephropathy

The patient is a 17-year-old white female who presents with 2.85 grams/24 hr proteinuria, microscopic hematuria, and a creatinine of 3.2 mg/dl. She was in her normal state of health and was incidentally found to have abnormal lab values and urinalysis at a routine sport's physical. She reports that she had noticed a little more fatigue the last few months, but had blamed this on being busy at her job after school. Figure 1 shows focal fibrinoid necrosis. Figure 2 shows moderate tubular atrophy and interstitial fibrosis. Figures 3 & 4 show a segmental cellular crescent. Figure 5 shows several...

Disease Week: Renal Manifestations of Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease (IBD) is a condition characterized by chronic inflammation of the gastrointestinal tract with the two most common types Crohn disease and ulcerative colitis.  While renal and urinary involvement in IBD is not uncommon, renal parenchymal disease is rare and most commonly affects the glomerular and tubulointerstitial compartments. The most common findings on renal biopsy of IBD patients are IgA nephropathy and tubulointerstitial nephritis, and this occurrence may represent a common pathogenic mechanism. Although several cases of tubulointerstitial nephritis have been related to drug exposure, there is increasing evidence that this finding may also represent a true extraintestinal...

Twitter Poll (April 3, 2019)

ANSWER: C IgAN is the most frequent diagnosis seen in kidney biopsies from patients with renal failure and history of IBD. In a retrospective study performed by Ambruzs et al., the prevalence of IgAN was 24%, followed by TIN (19%), arterionephrosclerosis, ATI, proliferative GN and MCD. Reference: Ambruzs JM, et al. The histopathologic spectrum of kidney biopsies in patients with inflammatory bowel disease. 2014 Clin J Am Soc Nephrol; 9(2):265-270.

IgA nephropathy with something extra…

The biopsy is from a 61-year-old man with a history of intermittent microscopic hematuria for many years who presents with recent 18-pound weight loss and nephrotic syndrome.  His creatinine is mildly elevated at 1.3 mg/dL.  He has 12.5 g of proteinuria and his serum albumin is 2.6 mg/dL.  The biopsy shows diffuse mild mesangial matrix expansion with no necrosis or proliferative lesions (Fig. 1).  Immunofluorescence microscopy shows extensive granular mesangial IgA deposits (3+) (Fig. 2), compatible with IgA nephropathy.  Interestingly, the Jones methenamine silver stain also shows argyrophilic spikes involving capillary loops, which are most suggestive of spicular amyloid deposits...

DNAJB9 helps uncover dual pathology…

This case illustrates the utility of immunohistochemical staining for DNAJB9, a recently described biomarker for fibrillary glomerulopathy (see reference).  The renal biopsy is taken from a 68-year-old man with a history of cirrhosis (cause unknown) who presents with mild microscopic hematuria, non-nephrotic range proteinuria, and chronic renal failure.  Glomeruli show diffuse mild mesangial matrix expansion.  Immunofluorescence shows granular mesangial IgA (2+) and smudgy mesangial and capillary wall IgG (2+) staining.  Electron microscopy (not shown) shows both immune complex-type and fibrillary deposits involving glomerular capillary basement membranes and mesangium.  Immunohistochemical staining for DNAJB9 shows mesangial staining.  Although IgA immunofluorescence staining may...

IgA Nephropathy Oxford Scoring

The IgA nephropathy Oxford Classification was first published in 2009 by a working group of nephrologists and renal pathologists representing the Renal Pathology Society and International IgA Nephropathy Network. The lesions currently scored include mesangial hypercellularity, endocapillary hypercellularity, segmental sclerosis, tubular atrophy/interstitial fibrosis, and cellular/fibrocellular crescent formation. Two of these lesions, crescent formation (A) and mesangial hypercellularity (B), are shown here.  For the purposes of the Oxford classification, mesangial hypercellularity is defined as >3 mesangial cell nuclei in a mesangial area not adjacent to the vascular pole (in sections cut to 3-micron thickness).