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Purpose: We aimed to assess osteoclastogenic potential of peripheral blood mononuclear cells (PBMC) and synovial fluid-derived mononuclear cells (SFMC) in different forms of arthritis and to correlate it with inflammatory mediators within intra-articular and circulatory compartments., Methods: Paired PBMC and SFMC samples of patients with rheumatoid arthritis (RA; n = 10) and psoriatic arthritis (PsA; n = 10), and PBMC of healthy controls were cultured to assess osteoclastogenic potential by the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts (OCs) and expression of OC-related genes (receptor activator of nuclear factor-κΒ (RANK), cFMS, and TRAP). Osteoclastogenesis was correlated with the arthritis-related inflammatory indicators in serum and synovial fluid (SF)., Results: Number of OCs differentiated from PBMC was significantly higher in RA and PsA compared with control, with RA having more OCs compared with PsA. There was no difference in SFMC OC number between arthritic patients, but RANK expression in OCs differentiated from SFMC was higher in PsA compared with RA. SF of PsA patients more potently induced OC differentiation from control CD3(-)CD19(-)CD56(-)CD11b(+)CD115(+) PBMC compared with RA, paralleled with higher RANK-ligand expression in PsA SFMC. Positive correlations of OC number with erythrocyte sedimentation rate, serum level of CCL2, and PBMC gene expression of interleukin-18 and Fas-ligand were observed., Conclusion: Osteoclastogenic potential is systemically enhanced in patients with RA, paralleled by disordered systemic and local expression of proinflammatory mediators, whereas PsA involves specific deregulation in RANKL/RANK axis. Our study reveals arthritis-specific mediators associated with the form of arthritis, indicating clinical relevance for diagnosis and treatment.

Objectives: Receptor for advanced glycation end products (RAGE) ligands/RAGE interactions have been proposed to have a pathogenic role in neuroinflammatory disorders. Our study aimed to assess changes in high-mobility group box (HMGB)1 and its receptor RAGE in peripheral blood (PBL) and cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) at the disease onset compared with control subjects. Methods: PBL and CSF were collected from control subjects (n = 30) and MS patients (n = 27) at clinical onset. Soluble RAGE (sRAGE), HMGB1, S100 calcium-binding protein A12 (S100A12), interleukin (IL)-1β and tumor necrosis factor (TNF)-α were measured in the CSF and plasma by enzyme-linked immunosorbent assay. Gene expression in PBL mononuclear cells (PBMCs) was detected by quantitative PCR for RAGE, HMGB1, S100A12 and several proinflammatory/immunoregulatory cytokines. Results: We found a significantly lower expression of IL-10 (p = 0.031) in the PBMCs of MS patients. The level of sRAGE in the CSF of MS patients was lower (p = 0.021), with the ability to discriminate between MS patients and control subjects. Moreover, PBMC gene expression for HMGB1 and S100A12 positively correlated with IL-6. Conclusions: Our study confirmed that the cytokine network is disturbed in PBL and CSF at MS clinical onset. The deregulated HMGB1/RAGE axis found in our study may present an early pathogenic event in MS, proposing sRAGE as a possible novel therapeutic strategy for MS treatment. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]