A scanning electron microscope study of isolated glomeruli in glomerulonephritis

Area of Science:

• Nephrology
• Pathology
• Electron Microscopy

Background:

• Glomerulonephritis (Gn) encompasses a group of kidney diseases affecting the glomeruli.
• Understanding the ultrastructural changes in podocytes is crucial for diagnosing and classifying Gn.
• Light microscopy has limitations in visualizing fine podocyte morphology.

Purpose of the Study:

• To investigate the utility of scanning electron microscopy (SEM) in characterizing glomerular changes in diverse forms of glomerulonephritis.
• To correlate SEM findings of podocyte alterations with light microscopic observations.
• To assess the diagnostic and differential diagnostic value of SEM in specific Gn subtypes.

Main Methods:

• Isolation of glomeruli from 48 cases of glomerulonephritis.
• Examination of isolated glomeruli using scanning electron microscopy (SEM).
• Correlation of SEM-identified podocyte changes with light microscopy findings.

Main Results:

• SEM provided good preservation of glomerular structure with minimal processing loss (2.4%).
• Distinct SEM features were observed in various Gn types, including podocyte necrosis, foot process fusion, cell body swelling, microvilli, and spherical bodies.
• Specific patterns were noted for IgA nephropathy, minimal change Gn, membranous Gn, focal sclerosing Gn, membranoproliferative Gn, and lupus nephritis.

Conclusions:

• While individual SEM changes are not diagnostic, their combination, type, and severity are indicative of light microscopic findings.
• SEM is a valuable tool that aids in differentiating between specific glomerulonephritis subtypes, such as idiopathic minimal change Gn and focal sclerosing Gn.
• SEM offers complementary ultrastructural insights into podocyte pathology in glomerulonephritis.