IgM Nephropathy: A Steroid-Dependent Case with Management Challenges

OBJETIVE: Describe the case of a patient with steroid-dependence immunoglobulin M nephropathy treated with multiple immunosuppressant, levamisole, cyclophosphamide, cyclosporine, mycophenolate mofetil and rituximab, with frequent relapses and poor response to second line treatment, in an attempt to encourage the study this pathology and its treatment. CASE DESCRIPTION: A 18 months-old female presented with edema, high blood pressure, diarrhea, and perineal candidiasis. Investigations revealed significant proteinuria, hypertriglyceridemia, hypoalbuminemia, and positive Epstein-Barr virus serology. Initial treatment with dietary changes, diuretics, antihypertensives, and prednisolone led to partial remission but steroid dependence and relapses. Steroid-sparing agents, including levamisole, cyclophosphamide and rituximab showed limited benefit. A renal biopsy indicated mesangioproliferative nephritis with mild activity, chronicity and an immune pattern for immunoglobulin M at immunofluorescence. Treatment with mycophenolate mofetil and cyclosporine resulted in temporary improvement. Despite attempts to reduce steroids, patient continues with fluctuating proteinuria and recurrent nephrotic syndrome. COMMENTS: This case highlights challenges in managing steroid-dependent immunoglobulin M nephropathy despite multiple immunosuppressants, underscoring the need for more effective treatments and long-term studies to guide therapy. Further research on steroid-sparing options and their efficacy in immunoglobulin M nephropathy is critical for improving patient outcomes.