Mastering Nephrotic Syndrome in Adults: MRCP Renal Medicine High‑Yield Guide

Why this topic is exam‑critical

Nephrotic syndrome frequently appears in MRCP Part 2 and workplace‑based assessments. Candidates often lose marks by focusing solely on proteinuria while missing the broader risks and guideline‑aligned management: infection prophylaxis, thrombosis prevention, dyslipidaemia treatment, and safe diuretic use. This high‑yield guide distils current UK consensus (including KDIGO) into exam‑ready steps.

Core definition and diagnostic clues

• Nephrotic syndrome triad:

  • Heavy proteinuria: urine protein/creatinine ratio (uPCR) ≥300 mg/mmol or ≥3.5 g/day

  • Hypoalbuminaemia (serum albumin <30 g/L)

  • Oedema ± foamy urine

• Additional features often present: hyperlipidaemia; increased thrombotic risk.

First‑line work‑up (what you must demonstrate in answers)

• Confirm heavy proteinuria: spot uPCR; 24‑hour collection if needed.

• Baseline labs: U&Es, eGFR, LFTs (albumin), fasting lipids, HbA1c.

• Thrombotic risk markers: baseline coagulation profile if indicated.

• Renal ultrasound: to exclude obstruction or structural disease.

• Immunology screen (when aetiology is unclear or not obvious minimal change/focal segmental glomerulosclerosis [FSGS]): ANA/ENA, dsDNA, ANCA, anti‑GBM, complement (C3/C4), hepatitis B/C and HIV serology, ASO titre if post‑streptococcal is suspected.

• Indication for renal biopsy:

  • Adult with nephrotic syndrome AND atypical features or unclear cause

  • Suspicion of vasculitis/GBM disease or secondary causes

  • Note: in clear‑cut minimal change disease (MCD) in adults, biopsy may be considered; in typical MCD presenting in children, biopsy is often not required—frame this judiciously in answers.

Common causes to mention

• Primary: minimal change disease, FSGS, membranous nephropathy, membranoproliferative GN (MPGN).

• Secondary: diabetes mellitus, amyloidosis, lupus, drugs (e.g., NSAIDs, bisphosphonates, interferon), infections (HBV/HCV/HIV).

Stepwise management to demonstrate competence

1. Oedema control

• Loop diuretic (e.g., furosemide); combine with thiazide for synergy if response is suboptimal.

• Consider IV albumin infusion only when plasma oncotic pressure is critically low or in severe, refractory hypoalbuminaemia—do not use routinely.

• Counsel on daily weights, salt and fluid advice, and monitoring for acute kidney injury (AKI).

2. Infection prophylaxis and vaccination

• Higher risk of spontaneous bacterial peritonitis (SBP) in selected high‑risk patients; consider prophylaxis based on local protocol and risk.

• Encourage pneumococcal and influenza vaccines; ensure patients can recognise early infection.

3. Thrombosis prevention

• Explain increased VTE and renal vein thrombosis risk.

• Risk stratify: presence of additional pro‑thrombotic factors, severe hypoalbuminaemia, immobilisation, recent surgery, known thrombophilia.

• Consider anticoagulation for episodes of VTE or specific high‑risk scenarios; discuss bleeding risk explicitly in the plan.

4. Dyslipidaemia

• Statin therapy is indicated in adults with nephrotic syndrome and raised LDL‑C; use atorvastatin or similar per local lipid guidance.

• Monitor lipids and liver function; counsel on lifestyle and cardiovascular risk reduction.

5. Disease‑specific therapy (anchor to aetiology once confirmed)

• Minimal change disease: high‑dose glucocorticoids (e.g., prednisolone) as first‑line; steroid‑sparing agents for relapses or steroid‑toxicity.

• FSGS: corticosteroids ± calcineurin inhibitors; relapses may require long‑term immunosuppression.

• Membranous nephropathy: risk stratify (proteinuria level, eGFR, phospholipase A2 receptor [PLA2R] antibodies) to choose between conservative care, immunosuppression (e.g., rituximab or cyclophosphamide‑based regimens), and ACE‑I/ARB.

• Lupus/ANCA/GBM: treat according to underlying condition with appropriate induction/immune suppression and plasma exchange where indicated.

• In all cases: optimise BP control, often with ACE‑I or ARB (proteinuria reduction benefit), while monitoring K+ and renal function.

6. Chronic kidney disease (CKD) monitoring and follow‑up

• Track eGFR, proteinuria (uPCR/uACR), lipids, BP, and albumin regularly.

• Address CKD‑related complications (anaemia, bone‑mineral disorders) as they arise.

Safety and monitoring points examiners love

• Counsel on diuretic‑related AKI and hypotension; measure U&Es after initiation/titration.

• Watch for steroid side effects; taper and use protective measures (bone, glucose).

• Monitor for neutropenia with immunosuppressants; arrange regular FBC.

• Discuss thromboembolism symptoms and the need for prompt evaluation.

• Document vaccination status and plan.

High‑yield exam script framework

1. Confirm diagnosis and baseline severity (uPCR, albumin).

2. Rule out secondary causes and assess need for biopsy.

3. Treat the complications: oedema, infection risk, thrombosis, dyslipidaemia.

4. Initiate disease‑specific therapy based on confirmed aetiology.

5. Plan follow‑up with clear monitoring parameters and patient education.

Quick mnemonics

• Think “ALBUM” for nephrotic syndrome work‑up: Albumin low, Lipids high, Blood clots risk, Urine heavy protein, Microscopy (urine) for active sediment to prompt biopsy if atypical.

Top MRCP‑style pitfalls

• Missing indications for biopsy or over‑biopsying classic MCD (frame contextually).

• Forgetting infection prophylaxis in selected patients.

• Omitting thromboprophylaxis counselling and explicit bleeding risk discussion.

• Treating albumin in isolation rather than addressing proteinuria and BP control.

• Not monitoring for CKD progression and cardiovascular risk.

Nephrotic syndrome is a nuanced, high‑stakes topic. Show a structured, guideline‑aligned approach, communicate clearly with the patient, and you’ll score strongly while practising safely.