What is the concise workup and management plan for membranous glomerulonephritis in a pediatric patient?

Membranous Glomerulonephritis in Pediatrics: Concise Workup & Management

Initial Workup

Pediatric membranous nephropathy (MN) is fundamentally different from adult disease—aggressively search for secondary causes before assuming it's primary. 1

Essential Diagnostic Steps

• Rule out secondary causes first (critical in children): 1

  • Lupus (especially in young females, even with negative ANA) 1
  • Hepatitis B (HBV markers—high association in endemic areas) 1, 2
  • Hepatitis C 1
  • Medications (NSAIDs, D-penicillamine) 1
  • In children <5 years: Consider bovine serum albumin (BSA) exposure—test immune deposits for BSA and eliminate cow's milk/beef if positive 1
  • CMV in young children with fever/rash 3

• Anti-PLA2R antibodies: Can occur in adolescents ≥12 years but less common than adults 1

• Baseline labs: Albumin, creatinine, proteinuria quantification, complement levels 1

Biopsy Findings to Note

• Stage on light microscopy 4, 5
• Presence of chronic histological changes (predicts worse outcomes) 4

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Management Algorithm

Non-Nephrotic Proteinuria

Conservative management only—avoid immunosuppression 1

• ACE inhibitors/ARBs for proteinuria reduction 1
• Monitor closely for progression 1

Nephrotic Syndrome

Start with supportive care in all cases: 1

• RAAS blockade (ACE-I/ARB) 1
• Sodium restriction <2 g/day 1
• Consider anticoagulation if albumin <2.5 g/dL (warfarin preferred) 1
• Pneumococcal vaccine, influenza vaccine 1
• Consider PCP prophylaxis with TMP-SMX if using immunosuppression 1

Immunosuppression indications: 1

• Persistent nephrotic-range proteinuria
• Severe/disabling symptoms
• Rising creatinine (≥30% increase over 6-12 months)

Preferred pediatric regimen (if immunosuppression needed): 1

• Cyclophosphamide 2 mg/kg/day + alternate-day steroids for 12 weeks (total cumulative cyclophosphamide dose 200 mg/kg) 1
• This provides less cyclophosphamide exposure than adult protocols 1
• Give only ONE course of cyclophosphamide in children (never repeat cyclical regimens) 1

Alternative options: 1

• Calcineurin inhibitors (cyclosporine or tacrolimus) 1
• Trial of corticosteroid monotherapy (though ineffective in adults) 1

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Monitoring

• Proteinuria (primary marker of response) 1, 4
• Albumin levels (thrombosis risk assessment) 1
• Renal function (eGFR—watch for ≥40% decline over 2-3 years) 1
• Weekly CBCs during cyclophosphamide (watch for leukopenia) 1

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Key Pitfalls

• Don't automatically apply adult MN protocols to children—pediatric disease behaves differently 1
• Never give more than one course of cyclophosphamide in children (cumulative toxicity) 1
• Don't miss secondary causes—especially lupus in young females and HBV in endemic areas 1, 2
• In very young children (<5 years), always consider BSA-related MN and test for it 1
• Anticoagulation threshold is albumin <2.5 g/dL, not <2.0 g/dL 1
• Avoid immunosuppression if eGFR <30 mL/min/1.73m² or kidney size <8 cm 1

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Prognosis

• Good overall prognosis with treatment: 75% complete remission, 17% partial remission with steroids + cyclophosphamide 4
• Absence of chronic histological changes predicts complete remission (p=0.03) 4
• Progressive renal failure is rare in pediatric MN 2, 5