ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

Please note that you are viewing an archived section from 2022 and some content may be unavailable. To unlock all content for 2022, please visit the archives.

Abstract: TH-PO508

Kinetics of B Cell Repopulation After Rituximab in ANCA-Associated Vasculitis: Clinical Significance and Predictive Factors

Session Information

Category: Glomerular Diseases

  • 1303 Glomerular Diseases: Clinical‚ Outcomes‚ and Trials

Authors

  • Mescia, Federica, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Salviani, Chiara, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Affatato, Stefania, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Tonoli, Mattia, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Guerini, Alice, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Tedesco, Martina, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Moratto, Daniele, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Gregorini, Gina Alessandra, Independent researcher, Brescia, Italy
  • Chiarini, Marco, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Scolari, Francesco, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
  • Alberici, Federico, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Brescia, Lombardia, Italy
Background

Despite the increasing use of Rituximab (RTX) in ANCA-Associated Vasculitis (AAV), it remains unclear what the optimal dosing is, especially for maintenance. A deeper understanding of post-RTX BC repopulation is needed to better tailor treatment.

Methods

This is a single center, 10-year retrospective study including newly diagnosed, ANCA-positive patients with GPA/MPA receiving RTX induction with no fixed-schedule maintenance. CD19+BC were monitored with flow cytometry. Data were censored after repeat RTX.
Repopulation was defined as CD19+BC>10 cells/μl.

Results

The cohort included 71 AAV patients, with a majority of females (62%), MPA syndrome (75%) and MPO-ANCA positivity (75%). Most had renal involvement (79%), with median eGFR 23 ml/min/1.73m2 (IQR 9-48).
During median follow-up of 55 months, 44 patients (62%) repopulated BCs. Median time to repopulation was 39 months (range 7-102).
Comparing patients with/without repopulation at 12/24/36/48 months, there was a trend for lower flare risk and higher infection risk with ongoing BC depletion, reaching statistical significance only at 48 months (log-rank test).
In exploratory univariate Cox regression, risk of BC repopulation was positively associated with eGFR and female gender, with a trend for negative association with older age, MPA presentation (vs. GPA), and steroid pulses. Among these variables, only eGFR (HR 1.22 per 10 ml/min/1.73m2, 95%CI 1.04-1.43, p=0.016) and gender (HR 2.73 for female, 95%CI 1.39-5.38, p=0.004) were independent predictors of time to BC repopulation in the multivariate model (Figure 1).

Conclusion

A subset of AAV patients develop sustained post-RTX BC depletion, which associates with long-term reduced flare risk and increased infection risk. Renal impairment and male gender are key predictors of delayed BC repopulation. These observations further highlight the need for tailored immunosuppression.

Fig. 1: Expected time to BC repopulation curves across different eGFR groups and gender, according to multivariate Cox model