Article Text

PDF
Residual inflammation after rituximab treatment is associated with sustained synovial plasma cell infiltration and enhanced B cell repopulation
  1. Y K O Teng1,
  2. E W N Levarht1,
  3. Rene E M Toes1,
  4. Tom W J Huizinga1,
  5. Jacob M van Laar1,2
  1. 1
    Department of Rheumatology, Leiden University Medical Center, The Netherlands
  2. 2
    Musculoskeletal Research Group, Institute of Cellular Medicine, School of Clinical Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
  1. J M van Laar, Musculoskeletal Research Group, Institute of Cellular Medicine, School of Clinical Medical Sciences, Newcastle University, Fourth Floor, Catherine Cookson Building, The Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK; j.m.van-laar{at}ncl.ac.uk

Abstract

Objective: To investigate the clinical effects of rituximab treatment in relation to immunological effects of rituximab on tissue-derived B lineage cells and repopulation of circulating B cells.

Methods: A total of 24 patients with rheumatoid arthritis (RA) were treated with 2×1000 mg rituximab and assessed clinically at 4, 12, 18 and 24 weeks using a 44-joint Disease Activity Score (DAS44). Synovial biopsies were analysed with immunohistochemistry at baseline and 12 weeks after treatment. Peripheral blood mononuclear cells were analysed by high sensitivity flow cytometry at all timepoints.

Results: In this study, a cohort of patients was dichotomised according to those who achieved a low disease activity score (DAS44<2.4: LoA group) and those with persistent disease activity (DAS44>2.4: HiA group) at any time after rituximab treatment. At baseline, the low activity (LoA) group had significantly lower DAS44 scores (median 3.33, range 2.84 to 4.23) than the high activity (HiA) group (median 3.73, range 3.03 to 5.23; p = 0.022) and significantly less histological inflammation in synovium (median 6.7, range 1 to 15 vs 16.6, range 4 to 22; p = 0.036). DAS44 scores before and after rituximab treatment were associated with synovial infiltration of CD79a+ CD20− B cells, morphologically resembling plasma cells. Following treatment with rituximab, the LoA group had significantly reduced repopulation of circulating pre-switched IgD+ B cells (median 0.044%, range 0.002 to 0.66 vs 0.45%, range 0.07 to 9.47; p = 0.006) and post-switched CD27+ B cells (median 0.17%, range 0.04 to 0.39 vs 0.67, range 0.08 to 2.05; p = 0.005) compared to the HiA group.

Conclusion: The present study demonstrated that a low disease activity state following rituximab was associated with reduced infiltration of CD79a+ CD20− plasma cells in synovium and reduced B cell repopulation.

Statistics from Altmetric.com

Footnotes

  • Competing interests: None declared.

  • Funding: The study was supported by an unrestricted grant from Hoffman-Roche and free supplies of rituximab were provided for the patients included in the study. YKOT was supported by an Agiko grant from The Netherlands Organization for Scientific Research.

  • Ethics approval: The study was approved by the Ethics Committee of the Leiden University Medical Center and all patients provided written informed consent.

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.