Arthritis and rheumatism
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Arthritis and rheumatism · Mar 2009
The myeloid-related proteins 8 and 14 complex, a novel ligand of toll-like receptor 4, and interleukin-1beta form a positive feedback mechanism in systemic-onset juvenile idiopathic arthritis.
Fever of unknown origin is a diagnostic challenge in children, especially for differentiation of systemic-onset juvenile idiopathic arthritis (systemic-onset JIA) and infectious diseases. We undertook this study to analyze the relevance of myeloid-related proteins (MRPs) 8 and 14, endogenous activators of Toll-like receptor 4, in diagnosis and pathogenesis of systemic-onset JIA. ⋯ The analysis of MRP-8/MRP-14 in serum is an excellent tool for the diagnosis of systemic-onset JIA, allowing early differentiation between patients with systemic-onset JIA and those with other inflammatory diseases. MRP-8/MRP-14 and IL-1beta represent a novel positive feedback mechanism activating phagocytes via 2 major signaling pathways of innate immunity during the pathogenesis of systemic-onset JIA.
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Arthritis and rheumatism · Mar 2009
Triggering of proteinase-activated receptor 4 leads to joint pain and inflammation in mice.
To investigate the role of proteinase-activated receptor 4 (PAR-4) in mediating joint inflammation and pain in mice. ⋯ This study demonstrates that local activation of PAR-4 leads to proinflammatory changes in the knee joint that are dependent on the kallikrein-kinin system. We also show for the first time that PARs are involved in the modulation of joint pain, with PAR-4 being pronociceptive in this tissue. Thus, blockade of articular PAR-4 may be a useful means of controlling joint inflammation and pain.