Global Molecular Effects of Tocilizumab Therapy in Rheumatoid Arthritis Synovium. Issue 1 (January 2014)

• Record Type: Journal Article
• Authors: Ducreux, Julie; Durez, Patrick; Galant, Christine; Nzeusseu Toukap, Adrien; Van den Eynde, Benoît; Houssiau, Frédéric A.; Lauwerys, Bernard R.
• Is Part Of: Arthritis & rheumatology. Volume 66:Issue 1(2014)
• Page Start: 15
• Page End: 23
• Publication Date: 2014-01
• Subjects: Arthritis -- Periodicals; Rheumatism -- Periodicals; 616.72
• DOI: 10.1002/art.38202
• Languages: English
• ISSNs: 2326-5191

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="art38202-sec-0001" sec-type="section"> <title>Objective</title> <p>To investigate the global molecular effects of tocilizumab (TCZ) in comparison with methotrexate (MTX) treatment in synovial biopsy tissue obtained from patients with previously untreated rheumatoid arthritis (RA) before therapy (T0) and 12 weeks after the initiation of therapy (T12), and to compare the results with previous gene expression data obtained in synovial biopsy tissue from adalimumab (ADA)– and rituximab (RTX)–treated patients with RA.</p> </sec> <sec id="art38202-sec-0002" sec-type="section"> <title>Methods</title> <p>Paired synovial biopsy samples were obtained at T0 and T12 from the affected knee of TCZ‐treated RA patients and MTX‐treated RA patients. Gene expression studies were performed using GeneChip Human Genome U133 Plus 2.0 microarrays, and confirmatory quantitative real‐time reverse transcription–polymerase chain reaction experiments were performed on selected transcripts. The effects of TCZ and MTX on synovial cell populations and histologic characteristics were assessed by immunohistochemistry.</p> </sec> <sec id="art38202-sec-0003" sec-type="section"> <title>Results</title> <p>Gene expression studies showed that blockade of the interleukin‐6 receptor (IL‐6R) gene (<italic>IL6R</italic>) using TCZ induced a significant decrease in the expression of numerous chemokine and T cell activation genes in the RA synovium. These effects strongly correlated with the molecular effects of MTX and RTX therapy on RA synovial tissue, but differed from the molecular changes induced by ADA (decreased expression of genes involved in cell proliferation).</p> </sec> <sec id="art38202-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The molecular similarities between the effects of TCZ, RTX, and MTX therapies in the RA synovium indicate that B cell– and <italic>IL‐6</italic>–dependent pathways play synergistic roles in the pathogenesis of the disease, in particular through activation of T cell responses. Moreover, these results open perspectives for the individualization of therapeutic decisions, based on a better knowledge of the synovial molecular effects of each type of RA therapy.</p> </sec> </abstract>