Glomerular Involvement in Systemic Diseases

Lupus Nephritis: Classification and Pathophysiology

Lupus nephritis is a serious complication of systemic lupus erythematosus (SLE) affecting the kidneys. It results from immune-mediated damage to the glomeruli, leading to proteinuria, hematuria, and progressive renal dysfunction.

Classification of Lupus Nephritis

• Class I: Minimal mesangial lupus nephritis
• Class II: Mesangial proliferative lupus nephritis
• Class III: Focal lupus nephritis
• Class IV: Diffuse lupus nephritis
• Class V: Membranous lupus nephritis
• Class VI: Advanced sclerotic lupus nephritis

Pathophysiology

Lupus nephritis occurs due to autoantibody deposition and immune complex formation in glomerular capillaries, causing inflammation and fibrosis. Key mechanisms include:

• Autoantibodies targeting nuclear components
• Immune complex deposition leading to complement activation
• Inflammatory cytokine release and glomerular damage
• Progressive renal dysfunction with nephrotic or nephritic manifestations

Early diagnosis using renal biopsy, serological markers (ANA, anti-dsDNA, complement levels), and prompt immunosuppressive therapy are critical in managing lupus nephritis.