A 28-year-old woman presents with her fourth episode of gross hematuria, always occurring during upper respiratory tract infections (synpharyngitic hematuria). Urinalysis shows 3+ blood and 2+ protein. Serum creatinine is 1.1 mg/dL. Complement levels are normal. Renal biopsy shows mesangial IgA deposits on immunofluorescence. What is the key prognostic factor that determines initiation of immunosuppressive therapy in IgA nephropathy?
- A Number of macroscopic hematuria episodes per year
- B Presence of mesangial IgA deposits on biopsy
- C Persistent proteinuria >1 g/day despite maximum tolerated renin-angiotensin system blockade ✓
- D Elevated serum galactose-deficient IgA1 levels
Correct answer: C. Persistent proteinuria >1 g/day despite maximum tolerated renin-angiotensin system blockade
Explanation
In IgA nephropathy, persistent proteinuria >1 g/day after 3–6 months of optimized RAS blockade (ACE inhibitor/ARB) is the primary indication for immunosuppressive therapy (systemic corticosteroids), per KDIGO 2021 guidelines. Proteinuria >0.5–1 g/day with declining eGFR despite optimal supportive care is also an indication. Macroscopic hematuria episodes alone do not require immunosuppression. Histological MEST-C scoring (mesangial hypercellularity, endocapillary proliferation, segmental sclerosis, tubular atrophy, crescents) guides prognosis.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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