Electrone Microscopy finding in Common Kidney Disease

Electron microscopy is a part of routine pathologic assessment of kidney biopsies. Although it has a confirmatory role in many diseases,it is an essential tool for the diagnosis of some other disorders. In this brief review, we summarize some diagnostic ultrastructural findings in common glomerular diseases.Minimal change disease and focal and segmental glomerulosclerosis (FSGS)are podocytopathic disorders ultrastructurally diagnosed by extensive effacement of Visceral Foot Processes and absence of immune-type deposits. Distinction between unsampled FSGS and minimal change disease could be challenging on electron microscopy as the light microscopy.For accurate staging of membranous glomerulopathy, electron microscopy is necessary. Presence of small sparsesubepithelial deposits without GBM thickening is indicative of stageI. On stage II, GBM thickening and subepithelialspikes would be obvious. When the new basement membrane surrounds the deposits,stage III could be suggested, and finally stage IV shows extensive resorption of intramembranous deposits and foci of sclerosis. Dense deposit disease is a type of C3 glomerulopathy which is characterized by deposition of mesangial and intramembranous extremely dense deposits. Electron microscopy is crucial to make the diagnosis. In problematic situations, presence of subepithelial humps are supportive of post-infectious glomerulonephritis. Electron microscopy is necessary for the diagnosis of Alport syndrome and thin membrane disease (Benign familial hematuria).Irregular GBM with alternating foci of thickening, thinning and multilayering of lamina densa are diagnostic findings forAlport syndrome. In some patients, widespread thinning of the GBM is the only pathologic finding, a situation that is reminiscent of thin basement membrane disease. So, thin GBM is a structural abnormality observed in several progressive or benignnonprogressivehematuric disorders. Further investigations including IHC or molecular study for α chains of collagen type IV are required in these patients. Diagnosis of some other rare disorders such asFabrydisease, LCAT deficiency, Pierson syndrome, Collagen III glomerulopathy, Nail-patella syndrome and…. is demonstrated on Electron microscopy as well