To evaluate the efficacy and safety of telitacicept in children with refractory IgA vasculitis with nephritis(IgAVN).

Four children with refractory IgAVN who were hospitalized and treated with telitacicept in the Department of Nephrology, Xi′an Children′s Hospital from August 1, 2024 to March 1, 2025 were enrolled, including 1 boy (case 2) and 3 girls (cases 1, 3, and 4). All 4 children received telitacicept as add-on therapy on the basis of conventional treatment with glucocorticoids and/or immunosuppressants, as well as angiotensin-converting enzyme inhibitors or angiotensin Ⅱ receptor blockers. Telitacicept was administered by subcutaneous injection once weekly at a weight-based dose of 80 mg or 160 mg per dose, with a treatment duration of no less than 24 weeks. Clinical data before and after treatment were retrospectively analyzed, including 24-hour urinary protein excretion, urine protein-to-creatinine ratio (UPCR), routine urinalysis, serum albumin, estimated glomerular filtration rate (eGFR), blood lipid levels, immunoglobulin levels, and B lymphocyte counts. Changes in the doses of glucocorticoids and other immunosuppressants were also recorded. China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, Chinese Medical Journal Full-text Database, and PubMed were searched using" IgAVN" " IgA vasculitis nephritis" and " telitacicept" as search keywords to identify studies on telitacicept in the treatment of pediatric IgAVN. The retrieval period was from March 2021 to March 2025. This study was approved by the Ethics Committee of Xi′an Children′s Hospital (Approval No. 2025-019-01), and written informed consent was obtained from the guardians of all children.

① Among these 4 cases, 1 was male (case 2) and 3 were female (cases 1, 3, and 4). The age at first administration of telitacicept ranged from 10 years and 9 months to 16 years and 3 months. At 24 weeks of follow-up, 24-hour urinary protein excretion decreased from baseline in cases 1, 2, and 4, and the changing trend of urine protein-to-creatinine ratio (UPCR) was generally consistent with that of 24-hour urinary protein excretion. In case 3, proteinuria-related indicators fluctuated markedly, without a sustained decreasing trend. During treatment, estimated glomerular filtration rate (eGFR) remained generally stable in all 4 cases, and serum albumin levels increased from baseline, with an increase ranging from 2.7% to 12.7%. Cases 1, 2, and 4 had hypercholesterolemia before treatment, and their serum total cholesterol levels decreased from baseline after treatment, with a decrease ranging from 8.5% to 43.1%. Case 3 had no obvious abnormality in serum total cholesterol level before treatment, and no obvious change was observed after treatment. At 24 weeks of treatment, serum IgG, IgM, and IgA levels decreased to varying degrees from baseline in all 4 cases, with decreases of 23.5%-45.5%, 53.8%-83.4%, and 35.9%-56.0%, respectively. B lymphocyte counts showed an overall decreasing trend. The median glucocorticoid dose at first administration of telitacicept was 0.29 mg/(kg·d), which decreased to 0.215 mg/(kg·d) at the last follow-up, representing a 25.9% reduction from baseline. Case 2 discontinued glucocorticoids after 24 weeks of treatment. During follow-up, all 4 cases developed infectious events. Cases 1-3 developed upper respiratory tract infections, and case 4 developed gastrointestinal infection. All infections resolved after oral medication and symptomatic treatment. No injection-site reactions or serious adverse events were observed. ② The literature review identified 5 relevant studies involving 24 children. Together with the 4 cases in this study, a total of 28 children were included in the summary analysis. All 28 children received subcutaneous telitacicept once weekly. Among them, 17 children had 24-hour urinary protein excretion reduced to the normal range, gross hematuria improved after treatment in 7 children who had gross hematuria before treatment, and microscopic hematuria was alleviated to varying degrees in 21 children. Immunoglobulin levels decreased after treatment in 16 children, with IgG reduction being the most common. In terms of safety, no serious adverse events or discontinuation of telitacicept due to adverse reactions were reported. The main adverse reactions included upper respiratory tract infection, gastrointestinal infection, and hypogammaglobulinemia.

Telitacicept can improve proteinuria and reduce glucocorticoid dosage in children with refractory IgAVN, with no serious adverse events were observed during short-term follow-up. However, its long-term efficacy and safety need to be further confirmed by large-sample studies with long-term follow-up.