Rapidly Progressive Glomerulonephritis (RPGN)

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Last updated: June 19, 2026Bookmark

Rapidly progressive glomerulonephritis (RPGN) is a syndrome characterised by:

Rapid loss of kidney function over days to weeks
Nephritic urine findings (haematuria, dysmorphic RBCs, RBC casts, and proteinuria)
Crescent formation on renal biopsy due to proliferation of parietal epithelial cells in Bowman’s space.

The terms RPGN and crescenteric glomerulonephritis are used interchangeably.

Classification of RPGN

Type	Mechanism	Examples
Type I	Linear anti-GBM antibody deposition	Anti-GBM disease, Goodpasture syndrome
Type II	Granular immune complex deposition	Lupus nephritis, IgA nephropathy, post-infectious GN
Type III	Pauci-immune (minimal/no immune deposits). This is the most common type in adults	ANCA-associated vasculitis
Type IV	Anti-GBM + ANCA positive	Double-positive disease

ANCA Histologic classification

Pattern	Definition
Focal	≥50% normal glomeruli
Crescentic	≥50% cellular crescents
Mixed	No dominant pattern
Sclerotic	≥50% globally sclerotic glomeruli

Immunofluorescence patterns

Disease	Pattern
Anti-GBM disease	Linear IgG deposition
Immune complex disease	Granular deposits
Pauci-immune disease	Minimal/no deposits

Causes
- Anti-GBM disease (Type I)
  - Including Goodpasture syndrome
- Immune complex RPGN (Type II)
  - Post-streptococcal glomerulonephritis
  - Hepatitis B
  - Hepatitis C
  - Lupus nephritis
  - IgA vasculitis (Henoch-Schonlein purpura)
  - Cryoglobulinemia
  - IgA Nephropathy
  - Membranoproliferative glomerulonephritis
  - Membranous nephropathy
  - Fibrillary glomerulonephritis
- Pauci-immune RPGN (Type IIi)
  - Granulomatosis with polyangiitis
  - Microscopic polyangiitis
  - Eosinophilic granulomatosis with polyangiitis
  - Drug-induced ANCA vasculitis
- Double-positive disease (Type IV)
  - ANCA and anti-GBM positive antibodies
Pathophysiology
- Glomerular basement membrane rupture
- Fibrin leakage into Bowman’s space
- Proliferation of parietal epithelial cells
- Influx of macrophages and lymphocytes
- Crescent formation → fibrosis → irreversible kidney damage
  - Once fibrous crescents form renal recovery is unlikely
Signs and symptoms
- Haematuria
- Proteinuria
- Oliguria
- Oedema
- Fatigue
- Nausea
- Vomiting
- Anorexia
- Oliguria
- Other extrarenal symptoms depending on the cause
Investigations
- Urinalysis
  - Dysmorphic RBCs
  - RBC casts
  - Proteinuria
- Urea and creatinine
  - Rapidly rising creatinine
- Serology
  - Anti-GBM antibodies for anti-GBM disease
  - MPO-ANCA (p-ANCA) and PR3-ANCA (c-ANC) for ANCA vasculitis
  - ANA, Anti-dsDNA and Anti-Smith for lupus nephritis
  - ASOT, hepatitis and HIV serology for post-infectious glomerulonephritis
- Low C3/C4 levels in lupus nephritis, cryoglobulinemia, and MPGN
- Renal biopsy is the gold standard test
  - Cellular crescent → fibrocellular crescent → fibrous crescent
Treatment
- Intravenous methylprednisolone
- Oral prednisolone
- Plasmapheresis if there is hemoptysis or goodpasture syndrome is suspected
- Other immunosuppressants, e.g, cyclophosphamide and rituximab
- Other treatments based on the specific disease

Reference Intervals ›

Biochemistry

ACTH	P: <80 ng/L
ALT	P: 5–35 U/L
Albumin	P: 35–50 g/L
Aldosterone	P: 100–500 pmol/L
Alk. phosphatase	P: 30–130 U/L
α-Amylase	P: 0–180 IU/dL
α-Fetoprotein	S: <10 kU/L
Angiotensin II	P: 5–35 pmol/L
ADH	P: 0.9–4.6 pmol/L
AST	P: 5–35 U/L
Bicarbonate	P: 24–30 mmol/L
Bilirubin	P: 3–17 μmol/L
BNP	P: <50 ng/L
CRP	P: <10 mg/L
Calcitonin	P: <0.1 mcg/L
Calcium (ionized)	P: 1.0–1.25 mmol/L
Calcium (total)	P: 2.12–2.60 mmol/L
Chloride	P: 95–105 mmol/L
Cholesterol	P: <5.0 mmol/L
VLDL	P: 0.128–0.645 mmol/L
LDL	P: <2.0 mmol/L
HDL	P: 0.9–1.93 mmol/L
Cortisol AM	P: 450–700 nmol/L
Cortisol Midnight	P: 80–280 nmol/L
CK ♂	P: 25–195 U/L
CK ♀	P: 25–170 U/L
Creatinine	P: 70–100 μmol/L
Ferritin	P: 12–200 mcg/L
Folate	S: 2.1 mcg/L
FSH	P: 2–8 U/L ♂; >25 menopause
GGT ♂	P: 11–51 U/L
GGT ♀	P: 7–33 U/L
Glucose (fasting)	P: 3.5–5.5 mmol/L
Growth hormone	P: <20 mu/L
HbA1C (DCCT)	B: 4–6%
HbA1C (IFCC)	B: 20–42 mmol/mol
Iron ♂	S: 14–31 μmol/L
Iron ♀	S: 11–30 μmol/L
Lactate (venous)	P: 0.6–2.4 mmol/L
Lactate (arterial)	P: 0.6–1.8 mmol/L
LDH	P: 70–250 U/L
LH	P: 3–16 U/L
Magnesium	P: 0.75–1.05 mmol/L
Osmolality	P: 278–305 mosmol/kg
PTH	P: 0.8–8.5 pmol/L
Potassium	P: 3.5–5.3 mmol/L
Prolactin ♂	P: <450 U/L
Prolactin ♀	P: <600 U/L
PSA	P: 0–4 mcg/mL
Protein (total)	P: 60–80 g/L
Red cell folate	B: 0.36–1.44 μmol/L
Renin (erect)	P: 2.8–4.5 pmol/mL/h
Renin (recumbent)	P: 1.1–2.7 pmol/mL/h
Sodium	P: 135–145 mmol/L
TBG	P: 7–17 mg/L
TSH	P: 0.5–4.2 mU/L
T4	P: 70–140 nmol/L
Free T4	P: 9–22 pmol/L
TIBC	S: 54–75 μmol/L
Triglycerides	P: 0.50–2.3 mmol/L
T3	P: 1.2–3.0 nmol/L
Troponin T	P: <0.1 mcg/L
Urate ♂	P: 210–480 μmol/L
Urate ♀	P: 150–390 μmol/L
Urea	P: 2.5–6.7 mmol/L
Vitamin B12	S: 0.13–0.68 nmol/L
Vitamin D	S: 50 nmol/L

Arterial Blood Gases

pH	7.35–7.45
PaCO₂	4.7–6.0 kPa
PaO₂	>10.6 kPa
Base excess	±2 mmol/L

Urine

Cortisol (free)	<280 nmol/24h
Hydroxyindole acetic acid	16–73 μmol/24h
Hydroxymethylmandelic acid	16–48 μmol/24h
Metanephrines	0.03–0.69 μmol/mmol cr.
Osmolality	350–1000 mosmol/kg
17-Oxogenic steroids ♂	28–30 μmol/24h
17-Oxogenic steroids ♀	21–66 μmol/24h
17-Oxosteroids ♂	17–76 μmol/24h
17-Oxosteroids ♀	14–59 μmol/24h
Phosphate (inorganic)	15–50 mmol/24h
Potassium	14–120 mmol/24h
Protein	<150 mg/24h
Protein/creatinine ratio	<3 mg/mmol
Sodium	100–250 mmol/24h

Haematology

WCC	4.0–11.0 ×10⁹/L
RBC ♂	4.5–6.5 ×10¹²/L
RBC ♀	3.9–5.6 ×10¹²/L
Hb ♂	130–180 g/L
Hb ♀	115–160 g/L
PCV ♂	0.4–0.54 L/L
PCV ♀	0.37–0.47 L/L
MCV	76–96 fL
MCH	27–32 pg
MCHC	300–360 g/L
RDW	11.6–14.6%
Neutrophils	2.0–7.5 ×10⁹/L (40–75%)
Lymphocytes	1.0–4.5 ×10⁹/L (20–45%)
Eosinophils	0.04–0.44 ×10⁹/L (1–6%)
Basophils	0–0.10 ×10⁹/L (0–1%)
Monocytes	0.2–0.8 ×10⁹/L (2–10%)
Platelets	150–400 ×10⁹/L
Reticulocytes	0.8–2.0% / 25–100 ×10⁹/L
Prothrombin time	10–14 s
APTT	35–45 s

Paediatric

Pulse Rate (bpm)
Neonate	140–160
Infant <1yr	120–140
1–5 years	110–130
5–12 years	80–120
>12 years	70–100
Respiratory Rate (tachypnoea)
0–2 months	≥60/min
2–12 months	≥50/min
1–5 years	≥40/min
>5 years	≥30/min
Blood Pressure (mmHg)
Term	65/45
1 year	75/50
4 years	85/60
8 years	95/65
10 years	100/70
Weight Formulas
3–12 months	(a + 9)/2 kg
1–6 years	2a + 8 kg
>6 years	(7a − 5)/2 kg
Haemoglobin (g/dL)
Term newborn	13–20
1 month	11–18
2 months	10–15
1–2 years	10–13
>2 years	11–14
MUAC (6 months–5 years)
Obese	>17.5 cm
Normal	13.5–17.4 cm
At risk	12.5–13.4 cm
Moderate malnutrition	11.5–12.4 cm
Severe malnutrition	<11.5 cm
Developmental Milestones
Social smile	1.5 months
Head control	4 months
Sits unsupported	7 months
Crawls	10 months
Stands unsupported	10–12 months
Walks	12–13 months
Talks	18 months
CSF WBC (/mm³)
Term newborn	0–25
>2 weeks	0–5

Calculator ›

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