Abstract: TH-PO131

Long Term Outcome of Apparent Treatment Resistant Patients with Idiopathic Membranous Nephropathy

Session Information

Category: Glomerular

  • 1005 Clinical Glomerular Disorders

Authors

  • Vink- van Setten, Coralien, Radboud University Medical Center, Nijmegen, Netherlands
  • van de Logt, Anne-Els, Radboud University Medical Center, Nijmegen, Netherlands
  • Wetzels, Jack F., Radboud University Medical Center, Nijmegen, Netherlands
Background

Cyclophosphamide is effective in idiopathic membranous nephropathy (iMN). Still, some patients do not respond timely, and do not develop remission at the end of therapy. We evaluated the outcome of these “apparent treatment resistant” (ATR) patients.

Methods

We selected patients with iMN, treated with cyclophosphamide (6-12 months), persistent proteinuria (PCR > 3g/10 mmol) at 12 months after start of therapy, and a minimum follow-up of 24 months. Renal failure was defined as > 50% increase in serum creatinine concentration. Remission was defined as PCR of less than 3.0g/10mmol and stable renal function.

Results

Between 1995 and 2016, we evaluated 518 patients with iMN. 219 high risk MN patients were treated with cyclophosphamide. 110 with outcome data were followed for at least 24 months. At 12 months 84 (76.4%) patients achieved partial remission, one (0.9%) patient developed renal failure and 25 (22.7%) patients fulfilled ATR criteria. Of these 25 patients, 20 were males, mean age was 55 (± 12) years, median serum creatinine was 149 umol/L (108.5-195), median PCR 11g/10mmol (6.7-15.3). During follow-up (median 80 months (34.5-126), 16 patients developed partial or complete remission without additional therapy. A relapse has occurred in 4 patients, necessitating a second course of immunosuppressive therapy. Nine patients had persistent proteinuria. Five of these were treated with a second course of immunosuppressive therapy, which resulted in a remission of proteinuria in 4. Two patients with persistent proteinuria and no additional immunosuppressive therapy have developed renal failure after 60 and 237 months respectively.

Conclusion

Persistent proteinuria at 12 months after start of cyclophosphamide therapy is not evidence of treatment resistance. Most patients will develop remission of proteinuria. Patients with persistent proteinuria respond favourably to a second course of therapy. Risk of end stage renal is low.

Funding

  • Government Support - Non-U.S.