What is the treatment for IgA (Immunoglobulin A) nephropathy?

Treatment of IgA Nephropathy

The cornerstone of IgA nephropathy treatment is optimized supportive care with renin-angiotensin system (RAS) blockade for patients with proteinuria >0.5 g/day, with additional therapies determined by disease severity, proteinuria level, and kidney function. 1

Risk Stratification and Initial Assessment

• Assess proteinuria level, hematuria, blood pressure, and eGFR at diagnosis
• Evaluate for secondary causes of IgA nephropathy
• Consider kidney biopsy with MEST-C scoring for risk stratification

Treatment Algorithm

Step 1: Supportive Care (All Patients)

• RAS blockade:

  • Mandatory for proteinuria >1 g/day (Grade 1B) 2, 1
  • Recommended for proteinuria 0.5-1 g/day (Grade 2D) 2, 1
  • Titrate upward to achieve proteinuria <1 g/day 2

• Blood pressure targets:

  • <130/80 mmHg for proteinuria <1 g/day
  • <125/75 mmHg for proteinuria >1 g/day 2, 1

• Lifestyle modifications:

  • Sodium restriction (<2 g/day)
  • Smoking cessation
  • Weight control
  • Regular exercise 1

• SGLT2 inhibitors:

  • Consider for reducing CKD progression, even in non-diabetic patients 1, 3

Step 2: Disease-Specific Therapy (Based on Clinical Presentation)

For persistent proteinuria >1 g/day despite 3-6 months of optimized supportive care and eGFR ≥30 ml/min/1.73 m²:

• Consider 6-month course of corticosteroid therapy (Grade 2C) 2, 1
• Contraindications for corticosteroids:
  • eGFR <30 ml/min/1.73 m²
  • Diabetes
  • Obesity (BMI >30 kg/m²)
  • Latent infections
  • Active peptic ulceration
  • Uncontrolled psychiatric disease
  • Severe osteoporosis 1, 4

For crescentic IgA nephropathy (>50% crescents with rapidly progressive deterioration):

• Use steroids and cyclophosphamide (Grade 2D) 2, 5
• Treatment approach similar to ANCA vasculitis 2

For IgA nephropathy with minimal change disease pattern:

• Treat according to minimal change disease guidelines 2, 1

For IgA nephropathy with AKI from macroscopic hematuria:

• Provide general supportive care 2
• Consider repeat kidney biopsy if no improvement after 5 days 2

Special Considerations

Medication Cautions

• Avoid dual RAS blockade (ACE inhibitor + ARB) due to increased risk of hyperkalemia without proven additional benefit 1
• Avoid MMF in general IgA nephropathy (Grade 2C) 2
• Avoid antiplatelet agents (Grade 2C) 2
• Avoid tonsillectomy (Grade 2C) 2

Population-Specific Approaches

• Chinese patients: Consider mycophenolate mofetil as a glucocorticoid-sparing agent 1
• Fish oil: Consider for persistent proteinuria >1 g/day despite optimized supportive care (Grade 2D) 2

Monitoring

• Regular assessment of proteinuria, eGFR, and blood pressure
• Target reduction of proteinuria to <1 g/day as a surrogate marker of improved renal outcome 1

Emerging Therapies

Recent evidence suggests several promising new therapies for IgA nephropathy 6, 3:

• Sparsentan (dual endothelin-1 and angiotensin II receptor blocker)
• Nefecon (targeted release formulation of budesonide)
• Iptacopan (complement factor B inhibitor)

Common Pitfalls to Avoid

• Delaying RAS blockade in patients with normal blood pressure but proteinuria >0.5 g/day
• Using immunosuppression in patients with eGFR <30 ml/min/1.73 m² (except in crescentic disease)
• Failing to assess for secondary causes of IgA nephropathy
• Not monitoring for adverse effects of corticosteroids, particularly in pediatric patients where growth velocity may be affected 4