Class-switched B cells display response to therapeutic B-cell depletion in rheumatoid arthritis

Arthritis Res Ther. 2009;11(3):R62. doi: 10.1186/ar2686. Epub 2009 May 6.


Introduction: Reconstitution of peripheral blood (PB) B cells after therapeutic depletion with the chimeric anti-CD20 antibody rituximab (RTX) mimics lymphatic ontogeny. In this situation, the repletion kinetics and migratory properties of distinct developmental B-cell stages and their correlation to disease activity might facilitate our understanding of innate and adaptive B-cell functions in rheumatoid arthritis (RA).

Methods: Thirty-five 'RTX-naïve' RA patients with active arthritis were treated after failure of tumour necrosis factor blockade in an open-label study with two infusions of 1,000 mg RTX. Prednisone dose was tapered according to clinical improvement from a median of 10 mg at baseline to 5 mg at 9 and 12 months. Conventional disease-modifying antirheumatic drugs were kept stable. Subsets of CD19+ B cells were assessed by flow cytometry according to their IgD and CD27 surface expression. Their absolute number and relative frequency in PB were followed every 3 months and were determined in parallel in synovial tissue (n = 3) or synovial fluid (n = 3) in the case of florid arthritis.

Results: Six of 35 patients fulfilled the European League Against Rheumatism criteria for moderate clinical response, and 19 others for good clinical response. All PB B-cell fractions decreased significantly in number (P < 0.001) after the first infusion. Disease activity developed independently of the total B-cell number. B-cell repopulation was dominated in quantity by CD27-IgD+ 'naïve' B cells. The low number of CD27+IgD- class-switched memory B cells (MemB) in the blood, together with sustained reduction of rheumatoid factor serum concentrations, correlated with good clinical response. Class-switched MemB were found accumulated in flaring joints.

Conclusions: The present data support the hypothesis that control of adaptive immune processes involving germinal centre-derived, antigen, and T-cell-dependently matured B cells is essential for successful RTX treatment.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arthritis, Rheumatoid / immunology*
  • Arthritis, Rheumatoid / therapy*
  • B-Lymphocytes / classification
  • B-Lymphocytes / cytology*
  • B-Lymphocytes / immunology*
  • Cell Count / methods
  • Cell Separation / methods
  • Female
  • Flow Cytometry / methods
  • Humans
  • Immunoglobulin Class Switching / immunology*
  • Immunoglobulins / biosynthesis
  • Immunoglobulins / classification*
  • Lymphocyte Depletion*
  • Male
  • Middle Aged
  • Prospective Studies


  • Immunoglobulins