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|Acute Kidney Injury (AKI) / Acute Renal Failure
|Renal/Kidney Physiology
|Chronic Kidney Disease (CKD)
|Anaemia in Chronic Kidney Disease
|Analgesic Nephropathy
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|IgA Nephropathy (Berger's disease)
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๐งพ Key Point: Minimal Change Disease (MCD) is the commonest cause of nephrotic syndrome in children.
โ
Prognosis is excellent โ only ~1% progress to end-stage renal failure.
About ๐ถ
- MCD = most common cause of nephrotic syndrome in children, especially boys under 5 years.
- Can occur in adults, but far less common.
- Strong steroid responsiveness โ good long-term outcome.
Causes & Triggers โก
- ๐น Idiopathic in most cases (~80โ90%).
- ๐น Secondary causes (10โ20%):
- ๐ Drugs: NSAIDs, rifampicin.
- ๐ฆ Infections: EBV (infectious mononucleosis).
- ๐ Malignancies: Hodgkinโs lymphoma, NHL, thymoma.
Aetiology & Pathophysiology ๐ฌ
- ๐ Electron microscopy: shows fusion/effacement of podocyte foot processes.
- โก Loss of the negative charge of the GBM โ selective albuminuria.
- ๐ Associations: atopy, HLA-DR7, Hodgkinโs disease, NSAIDs.
Clinical Features ๐ค
- ๐ง Oedema: periorbital โ peripheral โ anasarca.
- ๐บ Frothy urine: due to heavy proteinuria.
- ๐งช Nephrotic syndrome triad: proteinuria, hypoalbuminaemia, hyperlipidaemia.
- โ Hypertension and haematuria are uncommon (contrast with other GN).
Investigations ๐
- ๐งช U&E: usually normal.
- ๐ง Urinalysis: highly selective proteinuria (>3 g/day, mainly albumin).
- ๐ Serum albumin: low (<25 g/L typical).
- โฌ๏ธ Cholesterol/lipids: elevated.
- ๐ฌ Renal biopsy: not needed if classic presentation, but shows podocyte effacement on EM.
Management ๐ฉบ
- ๐ Steroids: Prednisolone 8 weeks then taper โ remission in ~90% children.
- ๐ Relapses: occur in ~50% โ may require cyclophosphamide or ciclosporin.
- ๐ง Supportive: fluid/salt restriction, diuretics for oedema, infection prophylaxis (pneumococcal vaccine >2yrs).
Prognosis ๐
- ๐ Excellent with treatment โ most achieve remission.
- โ ๏ธ Relapsing course common, but ESRF progression is very rare (~1%).
- ๐ฆ Infection (due to immunoglobulin loss) remains the main serious risk.
โจ Exam Pearl:
Child with sudden oedema, frothy urine, hypoalbuminaemia + hyperlipidaemia = MCD until proven otherwise.
๐ If hypertension + haematuria present, think other causes (e.g., FSGS, membranous GN).
Cases โ Minimal Change Disease (MCD)
- Case 1 โ Childhood nephrotic syndrome ๐ง: A 5-year-old boy presents with periorbital swelling, frothy urine, and ankle oedema. Urine dip: 4+ protein, no blood. Serum albumin: 16 g/L, cholesterol elevated. Renal function normal. Diagnosis: nephrotic syndrome due to minimal change disease. Managed with high-dose oral corticosteroids; biopsy often deferred unless atypical features develop.
- Case 2 โ Relapsing disease in adolescence ๐: A 14-year-old girl with a history of childhood nephrotic syndrome presents again with oedema after a viral URTI. Urine: heavy proteinuria. Previous biopsy: minimal change disease. Diagnosis: relapsing MCD. Managed with repeat steroid therapy, with consideration of calcineurin inhibitor if frequent relapses.
- Case 3 โ Adult secondary MCD ๐: A 42-year-old man develops sudden-onset nephrotic syndrome while being treated with NSAIDs for chronic back pain. Renal biopsy: minimal change disease. Diagnosis: secondary MCD due to NSAID use. Managed by stopping NSAID, starting steroids, and nephrology follow-up.
Teaching Point ๐ฉบ: Minimal change disease is the commonest cause of nephrotic syndrome in children, but can also affect adults. It is usually steroid-responsive. Secondary forms may be triggered by NSAIDs, lymphoma, or infections. Electron microscopy shows podocyte foot process effacement.