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Currently filtering by tag: Hepatitis C

Twitter Post (August 30, 2018)

ANSWER: B Type II (mixed) cryoglobulinemia is characterized by immune-complexes containing a monoclonal Ig (usually IgM) that have an RF activity and polyclonal Ig (usually IgG). It’s most commonly caused by HCV, with some cases caused by lymphoproliferative or autoimmune disorders. References: Zaidan M, et al. Spectrum and prognosis of noninfectious renal mixed cryoglobulinemic GN. J Am Soc Nephrol 2016; 27:1-12. Fabrizi F, et al. Hepatitis C virus infection, mixed cryoglobulinemia, and kidney disease. Am J Kidney Dis 2013; 61(4): 623-637.  

Hep C-Associated Cryoglobulinemic Glomerulonephritis

This biopsy was performed on a 66-year-old Caucasian male with a history of hepatitis C, who presented with nephrotic range proteinuria (UPC 4.2 g/g), hematuria and increased creatinine (2.5 mg/dl). C3 is 7 mg/dl and C4 <2 mg/dl. The glomerulus shows a membranoproliferative pattern of glomerular injury characterized by mesangial matrix expansion and hypercellularity, associated with endocapillary proliferation, segmental capillary loop double contour formation and accentuation of the lobular architecture (Fig 1&2).  Furthermore, the capillary lumens show frequent, large, PAS-positive pseudothrombi (Fig 1). Immunofluorescence (not shown) is positive in a mesangial and global capillary wall pattern for IgG (1+), IgM...

Diagnose This! (November 20, 2017)

What is your diagnosis?     ​   ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​   ​   ​...

Cryoglobulinemic Deposits by EM

Electron microscopy can be helpful in the diagnosis of cryoglobulinemic glomerulonephritis. This renal biopsy (Fig. 1) shows a membranoproliferative pattern glomerulonephritis in which the extent of endocapillary hypercellularity and glomerular capillary double contour formation is nicely highlighted with a Jones silver stain. The patient had a long history of hepatitis C infection, and you can clearly see intraluminal hyaline thrombi – “pseudothrombi” – in some capillary lumens, which are a helpful clue in diagnosing cryoglobulinemic glomerulonephritis. Some cases of cryoglobulinemic glomerulonephritis show electron dense deposits with organized substructure (Fig. 2), including tubular, fibrillar, crystalloid, or even fingerprint-like patterns. Early work...

Fibrillary Glomerulopathy

Commonly heard after we give the diagnosis: “I heard about this in Fellowship”… This 62-year-old African-American just completed treatment for hepatitis C with HARVONI® (ledipasvir 90 mg/sofosbuvir 400 mg). He was found to have an elevated creatinine of 1.8 mg/dl (baseline 1.1 mg/dl). Urinalysis showed 3+ protein with no blood and no casts. He also has well-controlled hypertension for more than 10 years. 1. Glomerulus with diffuse mesangial expansion (PAS x400) 2. IgG predominantly mesangial but with extension into loops (200x) 3. Mesangial and loop fibrillary deposits (EM 4,000x) 4. Mesangial and loop fibrillary deposits (EM 12,000x.) Diagnosis: Fibrillary Glomerulopathy

Pushing Glass (April 18, 2017)

A 45 year-old man received renal transplantation for HCV-associated end stage renal disease. He is currently treated with Sofobuvir, Tacrolimus and ACEI. He developed renal function impairment (Serum Cr increased to 2.3 mg/dL) with mild proteinuria. Based on the renal biopsy images, which is the most likely diagnosis? A. Severe acute tubular injury due to Sofobuvir B. Calcineurin inhibitor toxicity C. Polyomavirus nephropathy D. Tubular injury secondary to cryoglobulinemia E. Diabetic nephropathy     The answer is B. The light microscopic examination demonstrates isometric vacuolization of tubular epithelial cells, severe hyaline arteriolopathy and a striped pattern of fibrosis. These features...