Successful Management of Membranoproliferative Glomerulonephritis with Repository Corticotropin Injection

Introduction: Membranoproliferative glomerulonephritis (MPGN) is a pattern of glomerular injury subdivided by light microscopy into immune complex/monoclonal immunoglobulin-mediated, complement-mediated, and MPGN without immunoglobulin or complement deposition. Treating underlying causes is ideal, but idiopathic immune complex MPGN is often managed with immunosuppressive medications. Repository corticotropin injection shows promise in hard-to-treat cases, as illustrated in a successful treatment involving significant psychiatric side effects from steroids. Case Description: A 30-year-old female with MPGN diagnosed at age 16, presented to hospital with lower extremity edema and AKI. Before the presentation she was treated with prednisone 20 mg daily for many years and any attempt to taper prednisone resulted in MPGN flares. She was previously also trialed on mycophenolate with lower dose prednisone, but gastrointestinal side effects led to discontinuation of mycophenolate. She was then treated with repository corticotropin injection with prednisone 5 mg and was stable for two years until she had another flare with urine protein creatinine ratio (UPCR) rising to 3.2 g/g. Increasing prednisone to 50 mg/day temporarily improved UPCR, but severe depression with suicidal ideation prompted cessation of steroids. Subsequently, her renal function declined, with creatinine rising and UPCR reaching 4 g/g. After discontinuing all her medications for six months, severe deterioration ensued, with creatinine at 3.19 and UPCR at 12 g/g. She was admitted to hospital and renal biopsy was done which showed MPGN immune complex. Despite induction therapy with cyclophosphamide and rituximab her UPCR remained at 8.5 g/g after three months. Repository corticotropin injection was initiated at 80 mg biweekly, reducing UPCR to 4.35 g/g in a month and further to 0.75 g/g over three months. Discussion: Our case of difficult-to-treat idiopathic immune complex MPGN responded only to high steroid doses, which were discontinued due to steroid-induced suicidal ideation. Repository corticotropin injection, which stimulates endogenous steroid production, offered lower steroid exposure and fewer side effects. This may be a good option to avoid systemic side effects of steroids in other hard to treat cases.