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Endogenous DNA is released into the bloodstream as cell-free DNA (cfDNA) following cell death and is associated with various pathological conditions. However, their association with therapeutic drugs against rheumatoid arthritis (RA) remains unknown. Therefore, we investigated the significance of cfDNA in RA treated with tocilizumab and tumour necrosis factor inhibitor (TNF-I). Biological DMARDs (bDMARDs), including tocilizumab and TNF-I, were administered to 77 and 59 RA patients, respectively. Plasma cfDNA levels were measured at weeks 0, 4, and 12 by quantitative polymerase chain reaction. Disease activity was evaluated at the same time point using DAS28ESR. cfDNA levels from RA synovial cells treated with tocilizumab or etanercept for 24 h were measured. Human toll-like receptor 9 (hTLR9)-expressing HEK293 cells, which release secreted embryonic alkaline phosphatase (SEAP) upon NF-κB activation, were stimulated by cfDNA from RA patients, and subsequently, SEAP levels were determined. NF-κB translocation was evaluated by immunofluorescence staining with or without tocilizumab. The DAS28ESR significantly improved in both bDMARD groups at week 12. However, plasma cfDNA levels significantly decreased in the tocilizumab group at week 12 compared to that in week 0. cfDNA levels correlated with DAS28ESR in biological treatment-naïve patients administered tocilizumab. cfDNA levels in synovial cells were significantly suppressed by tocilizumab treatment and unaltered with etanercept. HEK293 cells released SEAP upon cfDNA stimulation, and the observed NF-κB nuclear translocation was suppressed by tocilizumab. Tocilizumab suppressed inflammation via the TLR9 pathway by decreasing cfDNA levels. Regulation of cfDNA may be a therapeutic target for RA. Cell-free DNA (cfDNA) from patients with rheumatoid arthritis (RA) activates NF-κB via the toll-like receptor 9 (TLR-9) signalling pathway in vitro. Tocilizumab, but not tumour necrosis factor inhibitors, decreases cfDNA levels in RA patients and RA-associated fibroblast-like synoviocytes. Tocilizumab degrades cfDNA at clinically relevant concentrations, suggesting tocilizumab likely controls inflammation in RA by suppressing TLR-9-dependent NF-κB signalling. [ABSTRACT FROM AUTHOR]

Decoy receptor 3 (DcR3), a member of the tumour necrosis factor receptor (TNFR) superfamily, lacks the transmembrane domain of conventional TNFRs in order to be a secreted protein. DcR3 competitively binds and inhibits members of the TNF family, including Fas ligand (FasL), LIGHT and TL1A. We previously reported that TNFα-induced DcR3 overexpression in rheumatoid synovial fibroblasts (RA-FLS) protects the cells from Fas-induced apoptosis and that DcR3 induces VLA-4 expression in THP-1 macrophages to inhibit cycloheximide-induced apoptosis. Meanwhile, recent studies have suggested that DcR3 acting as a ligand directly induces the differentiation of macrophages to osteoclasts. Therefore, in the present study, we analyzed the direct effects of DcR3 as a ligand in RA-FLS. The experiments showed that DcR3 binds to TL1A expressed in RA-FLS resulting in the negative regulation of cell proliferation induced by inflammatory cytokines. DcR3-TL1A signalling may be involved in the pathogenesis of rheumatoid arthritis (RA).

Laryngeal foreign bodies in children are less common than bronchial foreign bodies, but are more dangerous. We report an 8-month-old boy who accidentally inhaled an open safety pin into his larynx. Anesthesia was induced and maintained with sevoflurane, oxygen. No muscle relaxant was administered during operation. The open safety pin was removed with Jackson's esophagoscope. No complications were observed during the operation.