What is the treatment for Berger's disease (IgA nephropathy)?

Treatment of Berger's Disease (IgA Nephropathy)

The cornerstone of IgA nephropathy treatment is long-term ACE inhibitor or ARB therapy for patients with proteinuria >1 g/day, with blood pressure targets of <125/75 mmHg, and consideration of a 6-month course of corticosteroids for persistent proteinuria despite optimized supportive care. 1, 2

Initial Assessment and Risk Stratification

• Assess risk of progression through:
  • Proteinuria level (key prognostic factor)
  • Blood pressure
  • eGFR at diagnosis and during follow-up
  • Pathological features (Oxford MEST-C score)

Treatment Algorithm

1. Optimized Supportive Care (First-Line for All Patients)

• Antiproteinuric therapy:

  • For proteinuria >1 g/day: ACE inhibitors or ARBs (Grade 1B) 1, 2
  • For proteinuria 0.5-1 g/day: ACE inhibitors or ARBs (Grade 2D) 1, 2
  • Titrate to maximum tolerated dose to achieve proteinuria <1 g/day 1

• Blood pressure targets:

  • Proteinuria <1 g/day: <130/80 mmHg 1
  • Proteinuria ≥1 g/day: <125/75 mmHg 1

• Lifestyle modifications:

  • Dietary sodium restriction (<2 g/day)
  • Weight normalization
  • Smoking cessation 2

2. Second-Line Therapy (For Persistent Proteinuria)

• Corticosteroid therapy:

  • Indication: Persistent proteinuria ≥1 g/day despite 3-6 months of optimized supportive care AND eGFR ≥50 ml/min/1.73 m² 1, 2
  • Regimen options:
    • IV methylprednisolone 1g for 3 days at months 1,3, and 5, plus oral prednisone 0.5 mg/kg every other day for 6 months 1
    • Oral prednisone 0.8-1 mg/kg/day for 2 months, then reduced by 0.2 mg/kg/day per month for the next 4 months 1

• Fish oil supplementation:

  • Consider for persistent proteinuria ≥1 g/day despite optimized supportive care (Grade 2D) 1, 3

3. Special Scenarios

• Crescentic IgA nephropathy (>50% crescents with rapidly progressive deterioration):

  • Steroids plus cyclophosphamide, similar to ANCA vasculitis treatment 1

• IgA nephropathy with minimal change disease:

  • Treat as for minimal change disease with standard steroid regimen 1, 2

• IgA nephropathy with AKI and macroscopic hematuria:

  • Supportive care
  • Consider kidney biopsy if no improvement after 5 days 1, 2

Treatments to Avoid

• Do not use:
  • Corticosteroids combined with cyclophosphamide or azathioprine (unless crescentic IgA nephropathy) 1
  • Immunosuppressive therapy in patients with eGFR <30 ml/min/1.73 m² (unless crescentic IgA nephropathy) 1
  • Mycophenolate mofetil (MMF) 1
  • Antiplatelet agents 1
  • Tonsillectomy (except possibly in cases of recurrent tonsillitis) 1, 3, 4

Monitoring and Follow-up

• Regular assessment of:
  • Proteinuria (target: reduction to <1 g/day)
  • Renal function (serum creatinine, eGFR)
  • Blood pressure
  • Hematuria 2

Important Caveats

• Despite being historically considered benign, IgA nephropathy leads to end-stage renal disease in 20-30% of patients after 20 years 3, 5
• The antiproteinuric effect of ACE inhibitors/ARBs is crucial for long-term renal protection 6
• Consider dual ACE inhibitor-ARB therapy for enhanced antiproteinuric effect in selected patients with persistent proteinuria 6
• Early intervention is critical - patients with preserved renal function respond better to treatment 7
• Recurrence after kidney transplantation is possible, suggesting a systemic disorder 4, 5