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Currently filtering by tag: Kappa

Diagnose This (February 25, 2019)

kappa light chain, diagnose this, arkana laboratories, renal pathology
What is your diagnosis?     ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​   ​   ​ ​  ...

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...

Light Chain Deposition Disease

The immunofluorescence in cases of monoclonal immunoglobulin deposition disease is characterized by linear tubular basement membrane staining. In these cases, the positive staining is restricted to the monoclonal immunoglobulin leading to disease. The photomicrographs here show strong staining for kappa compared to lambda in a case of kappa light chain deposition disease. There is also commonly staining of the interstitium, vessels, and glomeruli. When the monoclonal immunoglobulin is a heavy chain, the immunofluorescence shows strong staining for the depositing heavy chain with little to no staining for either light chain.