Sustained post-rituximab B-cell depletion is common in ANCA-associated vasculitis and is affected by sex and renal function

• Published in: Nephrology, dialysis, transplantation dialysis, transplantation, 2024-03, Vol.39 (4), p.683-693
• Main Authors: Mescia, Federica, Salviani, Chiara, Tonoli, Mattia, Affatato, Stefania, Moratto, Daniele, Tedesco, Martina, Guerini, Alice, Gemmo, Alessia, Camoni, Marta, Delbarba, Elisa, Zubani, Roberto, Garrafa, Emirena, Chiarini, Marco, Gregorini, Gina, Scolari, Francesco, Alberici, Federico
• Format: Article
• Language: English
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfad197

ABSTRACT Objective Despite the increasing use of rituximab in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), it remains unclear what the optimal dosing is, especially for maintenance of remission. A deeper understanding of post-rituximab B-cell repopulation patterns may aid better-tailored treatment. Methods This is a monocentric, retrospective study including ANCA-positive AAV patients receiving a single course of rituximab induction. CD19+ B cells were longitudinally monitored with flow cytometry. B-cell repopulation was defined as CD19+ >10 cells/μL. Results Seventy-one patients were included, the majority with microscopic polyangiitis (75%), myeloperoxidase-ANCA positivity (75%) and with renal involvement (79%). During a median follow-up of 54 months since the first rituximab infusion, 44 patients (62%) repopulated B cells, with a median time to repopulation of 39 months (range 7–102). Patients experiencing B-cell depletion lasting longer than the overall median time to repopulation (39 months) exhibited a lower risk of flare and higher risk of serious infection. In multivariate Cox regression, higher estimated glomerular filtration rate (eGFR) [hazard ratio (HR) 1.84, 95% confidence interval (CI) 1.13–2.98 per 30 mL/min/1.73 m2 eGFR] and female sex (HR 2.70, 95% CI 1.37–5.31) were independent predictors of increased rate of B-cell repopulation. Conclusion A subset of AAV patients develop sustained post-rituximab B-cell depletion, which associates with reduced risk of flare and increased risk of serious infection in the long term. Preserved renal function and female sex are associated with faster B-cell repopulation. These observations further highlight the need to personalize immunosuppression to improve clinical outcomes. Graphical Abstract Graphical Abstract Video 10.1093/ndt/gfad197 Video Watch the video of this contribution at https://academic.oup.com/ndt/pages/author_videos gfad197Media1 6341386414112