Chronic glumarulonephritis
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"chronic glomerulonephritis"[MeSH Terms] AND management
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glomerulonephritis AND "chronic kidney disease"
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chronic glomerulonephritis pathogenesis clinical features management 2024
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Chronic Glomerulonephritis
Definition & Overview
Chronic glomerulonephritis (CGN) is not a single disease entity but a final common pathway of diverse glomerular injuries leading to progressive, irreversible glomerular destruction, tubular atrophy, interstitial fibrosis, and ultimately end-stage kidney disease (ESKD). It represents a smoldering, insidious process unfolding over months to years, as opposed to the acute or subacute presentations of postinfectious GN or RPGN.
Etiology & Causes
CGN may arise from almost any primary or secondary glomerular disease. Common precursors include:
| Primary GN | Secondary GN |
|---|---|
| IgA nephropathy (most common worldwide) | Lupus nephritis (SLE) |
| Membranoproliferative GN (MPGN) | Diabetic nephropathy |
| Focal segmental glomerulosclerosis (FSGS) | Henoch-Schönlein purpura |
| Membranous nephropathy | Hepatitis B/C–associated GN |
| Post-infectious GN (minority of cases) | Cryoglobulinemia |
| ANCA-associated vasculitis | Amyloidosis |
In a minority of patients, CGN is discovered at advanced stages with no identifiable antecedent disease. A presumptive diagnosis is then made based on shrunken, scarred kidneys with hypertension and impaired renal function. — Brenner and Rector's The Kidney
Globally, IgA nephropathy is the leading cause; FSGS has become increasingly prevalent, especially in Africa and South Asia, while MPGN has declined in relative frequency.
Pathogenesis
The unifying mechanism is immunologically mediated glomerular injury:
- Immune complex deposition (most common) — circulating antigen-antibody complexes are deposited in the glomerular subendothelial, mesangial, or subepithelial space
- Complement activation — generates C3a and C5a (anaphylatoxins), recruiting neutrophils and monocytes
- Cytokine/growth factor release — TGF-β drives mesangial proliferation and fibrosis; HGF has reno-protective roles that are antagonized in CGN
- Podocyte injury — leads to protein leak and glomerulosclerosis
- Chronic inflammation → sclerosis → fibrosis — sclerosis occurs within the glomeruli, and fibrosis in the tubulointerstitial compartment, reducing nephron mass
Key mediators: TGF-β, PDGF, angiotensin II, endothelin-1 drive progressive glomerulosclerosis and tubulointerstitial fibrosis.
Morphology (Pathology)
Gross Appearance
- Bilaterally shrunken, contracted kidneys with finely granular ("leather-grain") cortical surfaces — this fine, symmetric scarring distinguishes CGN from chronic pyelonephritis (which produces asymmetric, coarse scarring)
- Cortex is thinned; corticomedullary junction is indistinct
Microscopy (Light Microscopy)
- Global glomerulosclerosis — obliteration of glomerular capillaries by fibrous or hyaline material
- Hyalinization of glomerular tufts (replacement by acellular eosinophilic material)
- Tubular atrophy — tubules shrink, with thickened basement membranes
- Interstitial fibrosis with lymphocytic infiltrate
- Vascular changes — hyaline arteriolosclerosis, intimal thickening of arteries
Urinary Sediment ("Telescoped Sediment")
A hallmark of CGN is the "telescoped sediment" — the simultaneous presence of:
- Dysmorphic RBCs and RBC casts (glomerular injury)
- Granular and waxy casts (tubular atrophy)
- Broad casts (indicating dilated, atrophic tubules)
- Heavy proteinuria on dipstick
"With some forms of chronic glomerulonephritis, a 'telescoped' sediment is observed… the presence of the elements of a glomerulonephritis sediment together with waxy or broad casts, the latter indicative of tubular atrophy." — National Kidney Foundation Primer on Kidney Diseases, 8e
Clinical Features
CGN often follows an insidious course. Presentations include:
Asymptomatic Phase
- Detected incidentally: microscopic hematuria, proteinuria, mildly elevated creatinine
- May persist for years
Symptomatic Phase
| Feature | Details |
|---|---|
| Hypertension | Develops early, often severe; may be the presenting complaint |
| Proteinuria | Variable; heavy proteinuria indicates poor prognosis |
| Hematuria | Micro or macroscopic; dysmorphic RBCs on microscopy |
| Edema | Periorbital, dependent; worsens with nephrotic-range proteinuria |
| Oliguria/azotemia | As GFR declines |
| Fatigue, nausea | Uremic symptoms in advanced disease |
Advanced/End-Stage Features
- Uremia: anorexia, vomiting, encephalopathy, pericarditis
- Anemia of CKD (reduced EPO)
- Renal osteodystrophy (secondary hyperparathyroidism)
- Bilateral small kidneys on imaging
Four Presentations of Glomerulonephritis (Classification)
- Acute GN — sudden onset, usually reversible (e.g., post-streptococcal)
- Rapidly progressive GN (RPGN/Crescentic) — weeks to months, crescents on biopsy
- Recurrent macroscopic hematuria — episodic (classic IgA nephropathy)
- Chronic GN — slow progression over years to ESKD
Investigations
Urine
- Dipstick: protein, blood
- Microscopy: dysmorphic RBCs, RBC casts, granular/waxy/broad casts
- 24-hr urine protein or spot PCR
Blood
- Serum creatinine, BUN, eGFR
- Electrolytes (↑K⁺, ↑phosphate, ↓calcium in advanced CKD)
- Serum albumin (↓ if nephrotic)
- C3 and C4 — C3 low in post-infectious GN, MPGN, lupus nephritis; normal in IgA nephropathy
- ANA, anti-dsDNA (SLE)
- ANCA (p-ANCA, c-ANCA for vasculitis)
- Anti-GBM antibodies (Goodpasture)
- Hepatitis B/C serology
- Cryoglobulins, serum protein electrophoresis
- ASO titre, anti-DNase B (post-streptococcal GN)
Imaging
- Renal ultrasound: small, echogenic, contracted kidneys bilaterally (late CGN)
Renal Biopsy
- Essential for definitive diagnosis and management
- Identifies the specific glomerular lesion, determines activity vs. chronicity
- Guides immunosuppressive therapy decisions
- Harrison's (2025): "Increasing appreciation that patients with IgAN have a more rapid GFR decline to end-stage kidney disease has encouraged greater use of renal pathology to guide a more aggressive management strategy."
Management
General / Conservative Measures
| Intervention | Goal |
|---|---|
| ACE inhibitors or ARBs | First-line; reduce proteinuria, slow progression, control BP (target <130/80 mmHg) |
| Dietary protein restriction | 0.6–0.8 g/kg/day in advanced CKD to reduce hyperfiltration |
| Salt restriction | Control hypertension and edema |
| Lipid-lowering (statins) | Reduce cardiovascular risk (leading cause of death in CKD) |
| Avoid nephrotoxins | NSAIDs, aminoglycosides, IV contrast (use with caution) |
| Treat infections | Especially in infection-related GN |
Disease-Specific Immunotherapy
| Disease | Treatment |
|---|---|
| IgA nephropathy | ACEi/ARB; corticosteroids if progressive; complement blockers (budesonide, sparsentan, avacopan); rituximab |
| Lupus nephritis | Hydroxychloroquine ± mycophenolate mofetil ± steroids; belimumab |
| ANCA vasculitis | Rituximab or cyclophosphamide + steroids; avacopan |
| Anti-GBM disease | Plasmapheresis + cyclophosphamide + steroids |
| Membranous nephropathy | Rituximab (first-line); cyclophosphamide + steroids |
| Minimal change / FSGS | Corticosteroids; calcineurin inhibitors |
Recent advance: The FDA approved sparsentan (dual endothelin-1 and angiotensin II receptor antagonist) for adults with primary IgA nephropathy at high risk of progression (urine PCR >1.5 g/g with decreased GFR). — Harrison's 22E (2025)
Renal Replacement Therapy
When ESKD is reached:
- Hemodialysis
- Peritoneal dialysis
- Kidney transplantation (treatment of choice where feasible)
Prognosis
Prognosis varies by underlying cause and the degree of proteinuria/hypertension at presentation:
| Factor | Unfavorable Prognosis |
|---|---|
| Proteinuria | >1–3 g/day persistently |
| GFR at presentation | Significantly impaired |
| Hypertension | Poorly controlled |
| Histology | >50% globally sclerotic glomeruli, severe interstitial fibrosis |
| Genetics | High-risk APOL1 alleles (African ancestry, rapid FSGS/IgAN progression) |
"Prolonged and persistent heavy proteinuria and abnormal GFR mark patients with an unfavorable prognosis." — Robbins Pathologic Basis of Disease
In women with CGN and normal renal function at baseline, a 30-year study found no significant difference in progression to ESKD between those who became pregnant vs. those who did not — provided blood pressure is well controlled and proteinuria is minimal (<1 g/24 hr). — Creasy & Resnik's Maternal-Fetal Medicine
Histology Image
Light microscopy showing glomerular pathology with mesangial expansion and basement membrane thickening, characteristic of chronic immune-mediated glomerulonephritis.
Key Sources
- Harrison's Principles of Internal Medicine, 22e (2025), Ch. 319
- Robbins, Cotran & Kumar Pathologic Basis of Disease
- Brenner and Rector's The Kidney, 2-Volume Set
- National Kidney Foundation Primer on Kidney Diseases, 8e
- Tintinalli's Emergency Medicine, 9e
- Comprehensive Clinical Nephrology, 7e
- KDIGO 2021 Clinical Practice Guideline for Glomerular Diseases (updated 2024 for lupus nephritis)
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