The JAK inhibitor tofacitinib suppresses synovial JAK1-STAT signalling in rheumatoid arthritis
Ann Rheum Dis. 2014 Nov 14. pii: annrheumdis-2014-206028. doi: 10.1136/annrheumdis-2014-206028. [Epub ahead of print]
Targeting intracellular pathways such as JAK/STAT represents a novel approach to the treatment of RA. Tofacitinib is an oral JAK inhibitor, proven to be effective in the treatment of RA, yet the pathways affected by tofacitinib and the effects on gene expression in situ are unknown. In this study, Boyle et al. tested the hypothesis that tofacitinib targets cytokine signalling critical to the pathogenesis of rheumatoid synovitis by investigating tofacitinib effects on synovial pathobiology.
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March 2014
Features of the synovium of individuals at risk of developing rheumatoid arthritis
Arthritis and Rheumatology March 2014:66;513-522
This study expands on previous findings that synovial inflammation does not coincide with the appearance of rheumatoid arthritis. This was a markedly larger study compared to previous, with 55 individuals assessed. All 55 subjects were positive for IgM rheumatoid factor and/or anti-citrillinated protein antibody as well as possessing no physical evidence of arthritis. 15 of the individuals tested developed arthritis after a median time of 13 months. In these patients the presence of inflammatory...
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Emergence of proinflammaotry autoreactive T-cell responses in preclinical rheumatoid arthritis
The Lancet, Volume 383, Page S22, 26 February 2014
Before the onset of clinically apparent disease, the pathogenesis of RA goes through a number of sequential phases. The presence of autoimmunity through RF and ACPAs can be detected up to 13 years before the onset of clinical synovitis. An important component of the immune system is Treg cells which limit damage caused by excessive immune activity. These cells have been found to be dysfunctional in RA. This study aimed to identify autoreactive T cells to a known RA-associated antigen and determi...
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June 2013
Physiology of cytokine pathways in rheumatoid arthritis
Arthritis Care & Research 2001; 45(1):101-6
This review from 2001 describes the main cytokines involved in the pathophysiology of rheumatoid synovitis, and the redundant and synergistic nature of cytokine pathways in rheumatoid arthritis (RA). The self-regulating nature of cytokines are explained through the actions of anti-inflammatory cytokines, opposing cytokines, cytokine receptor antagonists, and naturally occurring antibodies. The paper explains that as disease often results when an imbalance develops in the cytokine network, therap...
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The pathogenesis of rheumatoid arthritis
The New England Journal of Medicine 2011; 365:2205-19
This review article describes the pathogenic processes involved in rheumatoid arthritis (RA) and discusses the genetic factors and environmental triggers implicated in the disease. Data from twin studies are discussed along with candidate genes with single nucleotide polymorphisms (SNPs) that have been linked to RA. It is now thought a multistep progression to the development of RA occurs via environmental factors, epigenetic modification of susceptible genes that leads to altered post-transcrip...
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Inflammation and bone erosion are suppressed in models of rheumatoid arthritis following treatment with a novel Syk inhibitor
Clinical Immunology 2007; 124:244-57
This study investigated the capacity of the novel oral spleen tyrosine kinase (Syk) inhibitor R406, and its prodrug R788 (fostamatinib), to suppress the reversed passive Arthrus reaction (RPA) and collagen-induced arthritis (CIA) in rats. R406 (0.1, 1, 5 and 10 mg/kg) and R788 (10 and 30 mg/kg) reduced the cutaneous RPA reaction and inflammatory oedema in a dose-dependent manner, with statistically significant reductions in extravascular leakage and tissue swelling (72% reduction with R406 10 mg...
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An oral Syk kinase inhibitor in the treatment of rheumatoid arthritis: a three-month randomized, placebo-controlled, phase II study in patients with active rheumatoid arthritis that did not respond to biologic agents
Arthritis & Rheumatism 2011; 63(2):337-45
This was the first phase 2 study to be published investigating the efficacy and safety of the spleen kinase (Syk) inhibitor R788 (fostamatinib) in patients with refractory rheumatoid arthritis (RA). In this multicentre, randomised, double-blind, placebo-controlled, 3-month trial, patients with active RA on stable background treatment (excluding biologics) were randomised to receive 100 mg R788 or placebo twice daily. Differences in ACR20 responses were significant at week 6 (p=0.003), but not th...