Temporal trends in the treatment of relapsing minimal change podocytopathy - a binational cohort study.

Background and hypothesis: While the primary treatment for Minimal Change Disease (MCD) is prednisolone, the immunosuppressive treatment at relapse is less well-defined. More treatment options for MCD have become available and concerns about the adverse effects of prednisolone have been raised. It is unclear to what extent this has influenced the treatment of relapsing disease. Thus, the objective of this study is to characterize the changes in the immunosuppressive treatment of relapse in MCD over the past 35 years.

Methods: A multicentre, retrospective cohort including adult patients with biopsy-proven MCD from 13 hospitals in Denmark and the Netherlands between 1985 and 2022. Patients were identified from pathology registers. Information on treatment and clinical outcomes was retrieved from health records. Treatment before and after 2010 was compared.

Results: The study included 239 patients with a median age of 46 years, 55% female and 64% being diagnosed before 2010. A first relapse was identified in 50% and a second relapse in 28%. The most frequently prescribed treatment at first relapse was prednisolone monotherapy before and after 2010 (67% and 44% of patients, respectively), while the use of calcineurin inhibitors (CNI) increased three-fold after 2010 compared to before 2010. At second relapse CNI was the most frequently prescribed treatment after 2010, while the use of both cyclophosphamide and prednisolone decreased when compared to before 2010. A similar trend was observed at the third to fourteenth relapse with CNI (44% of patients), and rituximab (35% of patients) being the most frequently prescribed treatments after 2010 while the use of cyclophosphamide and prednisolone decreased (0% and 21% of patients, respectively). Regardless of treatment remission rates remained high.

Conclusion: The treatment of relapses in MCD has changed since 2010 with reduced use of prednisolone monotherapy and cyclophosphamide, and increased use of CNI and rituximab.