Rapidly Progressive (Crescentic) Glomerulonephritis
Content of This Page
1- Definition & Types
2- Causes (Aetiology)
3- Pathophysiology
4- Clinical Features & Examination
5- Investigations
6- Management
7- Complications
8- Core Concepts
Definition & Types
Definition:
RPGN is a syndrome characterized by rapid decline in renal function (within days to weeks), typically with:
Severe glomerular injury
Crescent formation on renal biopsy
Features of nephritic syndrome (e.g. haematuria, hypertension)
Types (by immunopathology):
Anti-GBM disease (linear IgG deposition) → Goodpasture’s syndrome if lung involvement
Immune complex GN (granular IF): e.g. post-infectious GN, lupus nephritis, IgA nephropathy
Pauci-immune GN (little or no immune deposits): ANCA-associated vasculitis (e.g. GPA, MPA)
Causes (Aetiology)
| Category | Examples |
|---|---|
| Anti-GBM disease | Goodpasture’s syndrome (renal + lung) |
| Vasculitis | ANCA-positive: GPA (Wegener’s), MPA |
| Immune complex | Post-streptococcal GN, lupus nephritis, IgA nephropathy |
| Others | SLE, cryoglobulinaemia |
Pathophysiology
Severe immune-mediated injury leads to breaks in the glomerular capillary wall.
Plasma leaks into Bowman’s space, recruiting macrophages → formation of crescents (accumulation of cells in the glomerular capsule).
Leads to rapid obliteration of glomerular tuft → acute renal failure.
Key histological feature:
Crescentic GN: semicircular accumulation of cells (epithelial + inflammatory) compressing glomerular tuft
Often associated with necrosis and fibrin deposition
Clinical Features & Examination
| Feature | Description |
|---|---|
| Timing | Acute/subacute (days to weeks) deterioration |
| Symptoms | Fatigue, anorexia, oliguria, haematuria |
| Signs | Hypertension, oedema, pulmonary signs if alveolar haemorrhage |
| Pulmonary–renal syndrome | In anti-GBM or vasculitis (e.g. haemoptysis + AKI) |
Investigations
| Test | Key Finding |
|---|---|
| Urinalysis | Dysmorphic RBCs, red cell casts, proteinuria |
| U&E | Rising creatinine, AKI |
| Serology |
|
Management
General:
Urgent nephrology referral
Control BP and fluid status
Avoid nephrotoxins
Specific treatment depends on type:
| Disease | Treatment |
|---|---|
| Anti-GBM disease | Plasma exchange + high-dose glucocorticoids + cyclophosphamide |
| ANCA vasculitis | Glucocorticoids + rituximab or cyclophosphamide |
| Lupus nephritis | Steroids + MMF or cyclophosphamide |
| Post-infectious GN | Supportive (diuretics, dialysis if needed) + antibiotics if infection ongoing |
Complications
End-stage renal disease (ESRD) if untreated
Pulmonary haemorrhage (in Goodpasture’s or GPA)
Hypertensive crisis
Treatment-related toxicity: infection, leukopenia, infertility (cyclophosphamide)
Core Concepts
| Core Feature | RPGN (Crescentic GN) |
|---|---|
| Key histology | Crescents (Bowman’s space) |
| Progression | Rapid—AKI within days to weeks |
| Classic signs | Haematuria, red cell casts, ↓ GFR, oedema |
| Biopsy role | Essential to define cause and guide treatment |
| Treat early | Delayed therapy → irreversible ESRD |