[What to call glomerulonephritis: controversial problems of classification]

Area of Science:

• Nephrology
• Pathology
• Immunology

Context:

• Current morphologic classifications of glomerulonephritis are analyzed.
• Distinguishing between glomerulonephritis and primary nephrotic syndrome is crucial for accurate diagnosis and treatment.
• Understanding the diverse morphologic forms of glomerulonephritis is essential for patient management.

Purpose:

• To propose a revised morphologic classification of glomerulonephritis.
• To exclude specific conditions from the glomerulonephritis group and categorize them under primary nephrotic syndrome.
• To highlight the relationship between morphologic forms, etiology, pathogenesis, clinical presentation, and prognosis of glomerulonephritis.

Summary:

• Minimal changes (lipoid nephrosis), membranous glomerulopathy, and focal segmental glomerular hyalinosis are proposed for exclusion from the glomerulonephritis classification.
• These excluded conditions are suggested to form a distinct group: primary nephrotic syndrome.
• Glomerulonephritis is redefined to encompass proliferative (endocapillary, extracapillary, mesangioproliferative, mesangiocapillary) and sclerosing (fibroplastic) forms.

Impact:

• This reclassification provides a clearer definition of glomerulonephritis, aiding in more precise diagnosis and research.
• It facilitates a better understanding of the distinct pathologies of glomerulonephritis and primary nephrotic syndrome.
• The revised classification emphasizes the correlation between specific morphologic features and the clinical trajectory of kidney diseases.