Supplementary Material for: A decade-long journey of steroid-dependent IgA nephropathy with minimal change disease from immunosuppressants to rituximab and then to obinutuzumab: a case report.

IgA nephropathy with minimal change disease (MCD-IgAN) is a rare subtype of IgAN with a high rate of response to corticosteroids but a poor prognosis in steroid-dependent (SD) patients. Here, we report the case of a young male patient with SD-MCD-IgAN who was treated sequentially with rituximab (RTX) and later with obinutuzumab (OBZ) over a 10-year follow-up period. The patient initially presented with nephrotic syndrome and achieved rapid complete remission (CR) with full-dose corticosteroids. However, during the first 2 years, the patient experienced four relapses despite the addition of various immunosuppressants. These relapses were accompanied by complications such as skin infections, acute kidney injury, and serosal effusions. The initial renal biopsy revealed MCD-IgAN, while a repeat biopsy 8 months later revealed IgAN with focal segmental glomerulosclerosis. RTX (375 mg/m²) was introduced after remission was achieved with full-dose corticosteroids. The patient remained in CR with RTX administered based on CD19+ B cell counts for an initial period of 3 years. Following discontinuation of medication for the subsequent 3 years, the patient experienced a relapse but achieved CR again with low-dose corticosteroids and a single dose of RTX (1.0 g). However, the patient experienced a further relapse after another 3 years of medication cessation. Subsequently, OBZ (1.0 g) was administered along with low-dose corticosteroids, leading to rapid CR and long-term medication-free status.