Rituximab-induced T cell depletion in patients with rheumatoid arthritis: association with clinical response

Arthritis Rheum. 2013 Nov;65(11):2783-90. doi: 10.1002/art.38107.


Objective: Rituximab, a monoclonal antibody specifically targeting CD20, induces B cell depletion and is effective in the treatment of rheumatoid arthritis (RA). This study was undertaken to evaluate whether routine monitoring of lymphocyte subpopulations, especially T cells, may be useful in patients receiving rituximab for RA.

Methods: We examined data on all RA patients receiving rituximab between July 2007 and November 2012 in our center. Peripheral blood CD3+, CD4+, CD8+, CD3-CD56+, and CD19+ lymphocyte counts before and during the first course of rituximab were measured by flow cytometry. The Mann-Whitney nonparametric test was used to compare lymphocyte subpopulation counts before and during treatment.

Results: Data on 52 patients were examined. Rituximab induced unexpected and substantial depletion of T cells, mainly CD4+ cells, in most patients. The CD4+ cell count decreased by a mean ± SD of 37 ± 33% as compared to baseline at week 12, reaching <200 cells/μl in 3 patients. Importantly, lack of CD4+ cell depletion was associated with no clinical response. Therefore, the mechanism of action of rituximab may depend at least in part on T cells.

Conclusion: Rituximab induces substantial T cell depletion, mainly of CD4+ cells, which is associated with the clinical response in RA. Routine monitoring of T cells may be useful in the clinical setting of RA.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal, Murine-Derived / pharmacology*
  • Antirheumatic Agents / pharmacology
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / immunology*
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / cytology
  • CD4-Positive T-Lymphocytes / drug effects*
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / drug effects*
  • CD8-Positive T-Lymphocytes / immunology
  • Drug Monitoring / methods
  • Female
  • Flow Cytometry
  • Humans
  • Male
  • Middle Aged
  • Rituximab


  • Antibodies, Monoclonal, Murine-Derived
  • Antirheumatic Agents
  • Rituximab