Glomerulonephritis

Related Subjects: |Metabolic acidosis |Lactic acidosis |Acute Kidney Injury (AKI) / Acute Renal Failure |Renal/Kidney Physiology |Chronic Kidney Disease (CKD) |Anaemia in Chronic Kidney Disease |Analgesic Nephropathy |Medullary Sponge kidney |IgA Nephropathy (Berger's disease) |HIV associated nephropathy (HIVAN) |Balkan endemic nephropathy (BEN) |Autosomal Dominant Polycystic kidney disease

⚡ Rapid diagnosis, especially in rapidly progressive GN, is crucial. 🧪 Measuring ANCA and Anti-GBM antibodies allows early detection and improves outcomes.

About 📖

• Glomerulonephritis (GN): Inflammation of the glomerulus due to immune-mediated injury.
• Involves changes to the basement membrane, mesangium, or capillary endothelium.
• Mechanisms: antibody-mediated, complement activation, or cell-mediated injury.

Classifications 🧩

• Clinical: Nephritic ⚠️ vs. Nephrotic 💧 syndrome.
• Treatment Response: Steroid-responsive vs. Non-responsive.
• Aetiology: e.g., Post-streptococcal GN.
• Histology: Focal, diffuse, segmental, or with basement membrane changes/sclerosis.

Primary GN 🔬

• Minimal Change Disease (MCD)
• Focal Segmental Glomerulosclerosis (FSGS)
• Membranous Nephropathy
• IgA Nephropathy (Berger’s disease)
• Rapidly Progressive GN (Anti-GBM, pauci-immune GN)
• Post-Streptococcal GN
• Membranoproliferative GN (MPGN)

Secondary GN 🌍

• Lupus Nephritis (SLE-associated)

Clinical Features 🚨

• Acute haematuria (tea-coloured urine), proteinuria, red cell casts.
• Hypertension + oedema.
• Impaired renal function (AKI features).
• ⚠️ Severe hypertension with headache / neuro signs = poor prognostic marker.

Investigations 🔍

• FBC: Anaemia.
• Urinalysis: Haematuria, proteinuria, RBC casts.
• U&E: Check creatinine, urea, K⁺, calcium.
• ESR/CRP: Raised in inflammation.
• Blood gases: Look for metabolic acidosis.
• Immunology: ANA, ENA, ANCA, Anti-GBM, cryoglobulins, complement (C3/C4), ASOT.
• SPEP: For plasma cell disorders.
• 24-hr proteinuria: Quantify protein loss.
• USS + Biopsy: Assess kidney size, histology confirms diagnosis.

Complement Levels 🧬

• Low: Cryoglobulinaemia, SLE, endocarditis, shunt nephritis, MPGN, post-strep GN.
• Normal: Polyarteritis nodosa, Goodpasture’s, IgA nephropathy, HSP, idiopathic RPGN.

Management 🛠️

• 🏥 Admit if: anuria, nephrotic syndrome, massive proteinuria, severe hypertension, pulmonary features.
• 💧 Fluid restriction if overloaded.
• 💊 Loop diuretics for oedema / proteinuria.
• ⚡ Severe hypertension + neuro signs → urgent therapy (CCBs, IV nitroprusside).

Indications for Steroids 💊

• Vasculitis: Steroids = mainstay.
• SLE: High-dose steroids.
• HSP: May help renal involvement.
• Granulomatosis with Polyangiitis: Steroids + cyclophosphamide.
• Idiopathic RPGN: IV methylprednisolone pulses.
• Goodpasture’s: Steroids + cyclophosphamide + plasmapheresis (esp. pulmonary haemorrhage).

Exam Pearl ✨

🔑 Complement levels guide diagnosis: - Low C3 = post-strep GN, MPGN, SLE. - Normal C3 = IgA nephropathy, Goodpasture’s. 👉 Always ask for a renal biopsy if diagnosis uncertain or rapidly progressive GN suspected.

Cases — Glomerulonephritis

• Case 1 — Post-infectious GN 🦠: A 9-year-old boy presents with cola-coloured urine, periorbital oedema, and hypertension 2 weeks after a sore throat. Urine: proteinuria and red cell casts. Bloods: low C3 complement, raised ASO titre. Diagnosis: post-streptococcal glomerulonephritis. Managed with supportive care and BP control.
• Case 2 — IgA nephropathy (Berger’s disease) 🩸: A 22-year-old man develops visible haematuria 24 hours after an upper respiratory infection. Exam: mild ankle oedema. Urine: haematuria, proteinuria. Renal biopsy: mesangial IgA deposition. Diagnosis: IgA nephropathy. Managed with ACE inhibitor for proteinuria and nephrology follow-up.
• Case 3 — Rapidly progressive GN (crescentic) ⚡: A 35-year-old woman presents with oedema, hypertension, and oliguria progressing over days. Urine: haematuria, proteinuria. Bloods: creatinine rapidly rising. Biopsy: crescentic GN. Serology: ANCA positive. Diagnosis: RPGN secondary to ANCA-associated vasculitis. Managed with high-dose corticosteroids, cyclophosphamide, and plasma exchange if severe.

Teaching Point 🩺: Glomerulonephritis is a spectrum ranging from post-infectious nephritic syndromes to immune-mediated diseases like IgA nephropathy and rapidly progressive crescentic GN. Key features: haematuria, proteinuria, oedema, and hypertension. Biopsy is often needed for definitive diagnosis and guiding therapy.