Single‐Cell Level Characterization of B Cell Depletion and Repopulation Following Rituximab in Systemic Lupus Erythematosus

Journal article

Objective: Rituximab, a CD20+ B cell depletion therapy, is frequently used to treat systemic lupus erythematosus (SLE). However, variability in patient response highlights the need for a deeper understanding of the underlying immune cell dynamics of B cell depletion and repopulation. Methods: We conducted longitudinal single‐cell profiling of nine patients with SLE treated with rituximab from pretreatment to up to 15 months post‐treatment. These were compared with eight healthy controls. We profiled 169,513 immune cells via single‐cell RNA, surface protein, B cell receptor (BCR), and T cell receptor sequencing, and bulk BCR repertoire sequencing. Results: Significant depletion of naïve, memory, and age‐associated B cells was observed early post‐treatment, followed by later repopulation of mainly transitional B cells. A fraction of antigen‐experienced B cells, particularly in nonresponders, persisted through the depletion. BCR repertoire analysis revealed reduced diversity and persistent clones in antigen‐experienced cells at early post‐treatment, but these effects were not long‐lasting. Repopulated naïve B cells in rituximab responders exhibited reduced NF‐κB pathway activation, aligning with lower B cell activating factor receptor (BAFF‐R) surface protein levels. In non‐B cells, we identified 27 differentially expressed genes across seven immune cell subtypes post‐rituximab, with regulatory CD4 T cells and double negative (DN) T cells showing the most changes. Responders specifically had increased expression of genes related to cytotoxicity, major histocompatibility complex class II antigen presentation, and T cell activation in CD4 T central memory and DN T cells. Conclusion: Our longitudinal profiling provides single‐cell resolution of the shifts in immune cell dynamics following B cell depletion. image

Authors: Jang, H; Buang, N; Sutherland, C; Lee, W; Overend, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Arthritis & Rheumatology
• Article number: art.70116
• Publication date: 2026-04-20
• Acceptance date: 2026-02-05
• DOI: 10.1002/art.70116
• EISSN: 2326-5205
• ISSN: 2326-5191
• Language: English
• Keywords: Rituximab; B cell; Immune system; Repopulation; Cell; Antibody; Autoimmunity; Cell culture