B-cell phenotype and IgD-CD27- memory B cells are affected by TNF-inhibitors and tocilizumab treatment in rheumatoid arthritis

PLoS One. 2017 Sep 8;12(9):e0182927. doi: 10.1371/journal.pone.0182927. eCollection 2017.

Abstract

Background: The use of TNF-inhibitors and/or the IL-6 receptor antagonist, tocilizumab, in rheumatoid arthritis (RA) have pleiotropic effects that also involve circulating B-cells. The main goal of this study was to assess the effect of TNF-inhibitors and tocilizumab on B-cell phenotype and gene expression in RA.

Methods: Blood samples were collected from untreated early RA (ERA) patients, established RA patients under methotrexate treatment, established RA patients before and after treatment with TNF-inhibitors and tocilizumab, and healthy donors. B-cell subpopulations were characterized by flow cytometry and B-cell gene expression was analyzed by real-time PCR on isolated B-cells. Serum levels of BAFF, CXCL13 and sCD23 were determined by ELISA.

Results: The frequency of total CD19+ B cells in circulation was similar between controls and all RA groups, irrespective of treatment, but double negative (DN) IgD-CD27- memory B cells were significantly increased in ERA and established RA when compared to controls. Treatment with TNF-inhibitors and tocilizumab restored the frequency of IgD-CD27- B-cells to normal levels, but did not affect other B cell subpopulations. TACI, CD95, CD5, HLA-DR and TLR9 expression on B-cells significantly increased after treatment with either TNF-inhibitors and/ or tocilizumab, but no significant changes were observed in BAFF-R, BCMA, CD69, CD86, CXCR5, CD23, CD38 and IgM expression on B-cells when comparing baseline with post-treatment follow-ups. Alterations in B-cell gene expression of BAFF-R, TACI, TLR9, FcγRIIB, BCL-2, BLIMP-1 and β2M were found in ERA and established RA patients, but no significant differences were observed after TNF-inhibitors and tocilizumab treatment when comparing baseline and follow-ups. Serum levels of CXCL13, sCD23 and BAFF were not significantly affected by treatment with TNF-inhibitors and tocilizumab.

Conclusions: In RA patients, the use of TNF-inhibitors and/ or tocilizumab treatment affects B-cell phenotype and IgD-CD27- memory B cells in circulation, but not B-cell gene expression levels.

MeSH terms

  • Antibodies, Monoclonal, Humanized / pharmacology
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Arthritis, Rheumatoid / diagnosis
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / immunology*
  • Arthritis, Rheumatoid / metabolism
  • B-Lymphocyte Subsets / drug effects
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / metabolism
  • Biomarkers
  • Chemokine CXCL13 / blood
  • Follow-Up Studies
  • Gene Expression Profiling
  • Gene Expression Regulation / drug effects
  • Humans
  • Immunoglobulin D / metabolism
  • Immunologic Memory*
  • Immunophenotyping
  • Lymphocyte Count
  • Methotrexate / pharmacology
  • Methotrexate / therapeutic use
  • Phenotype
  • Receptors, CXCR5 / metabolism
  • Receptors, IgE / blood
  • Treatment Outcome
  • Tumor Necrosis Factor Receptor Superfamily, Member 7 / metabolism
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*

Substances

  • Antibodies, Monoclonal, Humanized
  • Biomarkers
  • Chemokine CXCL13
  • Immunoglobulin D
  • Receptors, CXCR5
  • Receptors, IgE
  • Tumor Necrosis Factor Receptor Superfamily, Member 7
  • Tumor Necrosis Factor-alpha
  • tocilizumab
  • Methotrexate

Grants and funding

RAM was funded by Fundação para a Ciência e a Tecnologia (FCT, www.fct.pt) (SFRH/BPD/81936/2011), Portugal. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.