Form of glomerulonephritis that constitutes one of the most severe organ manifestations of the autoimmune disease systemic lupus erythematosus (SLE)
- Occurs in 60% lupus cases
- First clinical manifestation of SLE in 15-20% cases
Classification
International Society of Nephrology/Renal Pathology Society (ISN/RPS) histological classification:
- Class I: Minimal mesangial LN (20%)
- Class II: Mesangial proliferative LN
- Class III: Focal LN (<50% glomeruli)
- III(A): Active lesions
- III(A/C): Active and chronic lesions
- III(C): Chronic lesions
- Class IV: Diffuse LN (>50% glomeruli) (M/C form)
- Diffuse segmental (IV-S) or global (IV-G)
- IV(A): Active lesions
- IV(A/C): Active and chronic lesions
- IV(C): Chronic lesions
- Class V: Membranous LN
- Class VI: Advanced sclerotic LN (≥90% globally sclerosed glomeruli without residual activity)
Pathophysiology
Glomerular immune complex accumulation, which leads to glomerular inflammation and, if unchecked, also involves the renal interstitium.
Clinical features
- Proteinuria (characteristic feature) (100%)
- Nephrotic range proteinuria/nephrotic syndrome (45-65%)
- Microscopic hematuria (80%), invariably associated with proteinuria
- Macroscopic hematuria (rare, < 5%)
- Urinary RBC casts (30%)
- Other urinary cellular casts (30%)
- Hypertension (30%)
- Renal insufficiency (60%)
- Acute kidney injury (uncommon, 15%)
- Tubular abnormalities (70%)
- Disturbed renal tubular function:
Diagnosis
24-hour urine collection:
- Proteinuria (100%)
- Microscopic hematuria (80%), invariably associated with proteinuria
- Macroscopic hematuria (rare, < 5%)
- Urinary RBC casts (30%)
- Other urinary cellular casts (30%)
- ↓ Glomerular filtration rate (GFR) (50%)
- Disturbed tubular function: Tamm-Horsefall proteins, light chains and β2-microglobulin
Renal biopsy (GOLD STANDARD):
- “Full house” staining pattern: Positive staining for immunoglobulin G, A, and M with C1q, C3, and C4
- “Wire loop” structures: Circumferential thickening of the capillary wall
Management
Summary:
Related