A 35-year-old man with biopsy-proven minimal change disease (MCD) presents with nephrotic syndrome (proteinuria 7 g/day, serum albumin 2.3 g/dL, serum creatinine 0.9 mg/dL). He is started on prednisolone 1 mg/kg/day. After 6 weeks of therapy, proteinuria remains 5.5 g/day and edema persists. What is the most appropriate next step?

Explanation

## Clinical Context This patient has biopsy-proven MCD with nephrotic syndrome who has been on prednisolone 1 mg/kg/day for **6 weeks**. Proteinuria has decreased from 7 g/day to 5.5 g/day, and edema persists. The critical question is whether 6 weeks is sufficient to declare steroid resistance. ## Definition of Steroid Resistance in MCD **Key Point:** Per KDIGO 2021 Glomerulonephritis Guidelines, steroid resistance in MCD is defined as **failure to achieve complete remission after 8–16 weeks** of adequate prednisolone therapy (1 mg/kg/day, maximum 80 mg/day). At 6 weeks, this patient has NOT yet met the criteria for steroid resistance. **High-Yield:** MCD is characteristically steroid-sensitive, but the time to complete remission can range from 4 to 16 weeks. A partial reduction in proteinuria at 6 weeks does not constitute steroid resistance — it may represent a **delayed but ongoing response**. ## Why Continuing Prednisolone is the Correct Next Step | Option | Assessment | |--------|------------| | **Continue prednisolone × 4 more weeks (total 10 weeks)** | ✅ Correct — within the 8–16 week window; allows full therapeutic trial | | Increase prednisolone to 1.5 mg/kg/day | ❌ Not recommended; exceeds standard dosing; increases toxicity without evidence of benefit | | Add cyclophosphamide + taper prednisolone | ❌ Premature at 6 weeks; steroid resistance not yet established | | Switch to MMF monotherapy | ❌ Not evidence-based; MMF monotherapy is not a recognized first-line or second-line strategy for MCD | ## Treatment Algorithm for MCD (KDIGO 2021) ``` MCD diagnosed → Prednisolone 1 mg/kg/day (max 80 mg) ↓ Reassess at 8–16 weeks ↓ Complete remission (proteinuria <0.3 g/day) → Taper steroids ↓ No remission by 16 weeks → Steroid-resistant MCD → Add CYC or CNI ``` **Clinical Pearl:** The most common error in MCD management is premature escalation of therapy. Because MCD is the most steroid-responsive glomerular disease, the standard of care is to complete a full 8–16 week trial before labeling a patient as steroid-resistant and adding second-line agents (Harrison's Principles of Internal Medicine, 21e, Ch. 279; KDIGO Glomerulonephritis Guidelines 2021). **Key Point:** At 6 weeks with some reduction in proteinuria (7 → 5.5 g/day), the most appropriate next step is to **continue prednisolone at the same dose for another 4 weeks** to complete an adequate therapeutic trial before considering escalation. [cite: Harrison 21e Ch 279; KDIGO Glomerulonephritis Guidelines 2021]