Abstract
IgA vasculitis (IgAV) is the most prevalent form of vasculitis in children. While most cases of IgAV present with mild clinical symptoms and generally have a favorable prognosis, some children with IgAV nephritis may experience persistent heavy proteinuria, which is at risk of progressing to end-stage renal disease. Despite the administration of various immunosuppressive agents, treatment outcomes for these children are often suboptimal. We report the case of an 8-year-and-four-month-old girl who initially presented with rashes on both lower limbs for a duration of four days and abdominal pain persisting for two days. Renal biopsy subsequently confirmed a diagnosis of IgAV nephritis, specifically type IIIb. Despite undergoing treatment with methylprednisolone sodium succinate, cyclophosphamide, mycophenolate mofetil, leflunomide, rituximab, dapagliflozin, and other medications for over two years, her urinary protein levels remained at least 1000 mg/24 h. One month after initiating treatment with telitacicept, the patient's urinary protein levels decreased, and two months later, they became negative. Notably, even after discontinuing immunosuppressants and glucocorticoids, the girl achieved sustained clinical remission. This case serves as a valuable clinical reference for the use of telitacicept in the treatment of refractory IgAV nephritis.