Effect of Blood Component Coatings of Enosseal Implants on Proliferation and Synthetic Activity of Human Osteoblasts and Cytokine Production of Peripheral Blood Mononuclear Cells.

The study monitored in vitro early response of connective tissue cells and immunocompetent cells to enosseal implant materials coated by different blood components (serum, activated plasma, and plasma/platelets) to evaluate human osteoblast proliferation and synthetic activity and inflammatory response presented as a cytokine profile of peripheral blood mononuclear cells (PBMCs) under conditions imitating the situation upon implantation. The cells were cultivated on coated Ti-plasma-sprayed (Ti-PS), Ti-etched (Ti-Etch), Ti-hydroxyapatite (Ti-HA), and ZrO2 surfaces. The plasma/platelets coating supported osteoblast proliferation only on osteoconductive Ti-HA and Ti-Etch whereas activated plasma enhanced proliferation on all surfaces. Differentiation (BAP) and IL-8 production remained unchanged or decreased irrespective of the coating and surface; only the serum and plasma/platelets-coated ZrO2 exhibited higher BAP and IL-8 expression. RANKL production increased on serum and activated plasma coatings. PBMCs produced especially cytokines playing role in inflammatory phase of wound healing, that is, IL-6, GRO-α, GRO, ENA-78, IL-8, GM-CSF, EGF, and MCP-1. Cytokine profiles were comparable for all tested surfaces; only ENA-78, IL-8, GM-CSF, and MCP-1 expression depended on materials and coatings. The activated plasma coating led to uniformed surfaces and represented a favorable treatment especially for bioinert Ti-PS and ZrO2 whereas all coatings had no distinctive effect on bioactive Ti-HA and Ti-Etch.

The level of fatty acid-binding protein 4, a novel adipokine, is increased in rheumatoid arthritis and correlates with serum cholesterol levels.

OBJECTIVE: To assess the expression of the novel adipokine Fatty Acid Binding Protein-4 (FABP4) in synovial tissues, serum and the synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to study the relationships among FABP4, disease activity and metabolic status. METHODS: FABP4 levels were measured in the serum and synovial fluid of 40 patients with RA and 40 control patients with OA. The disease activity score (DAS28), C-reactive protein (CRP) levels and serum lipids were assessed in patients with RA. Immunohistochemical analysis and confocal microscopy were used to study the expression and cell-specific distribution of FABP4 in synovial tissues. RESULTS: The age, sex and body mass index (BMI) adjusted levels of FABP4 were significantly higher in the serum (p=0.001) and synovial fluid (p=0.005) of patients with RA when compared to OA patients. FABP4 levels were higher in females than in males and correlated positively with body mass index (BMI) in patients with RA. Independent of confounders, FABP4 levels correlated with total cholesterol and LDL cholesterol in patients with RA, but not in OA patients. FABP4 levels were not affected by disease activity. Furthermore, the increased expression of FABP4 that was otherwise restricted to synovial fibroblasts, macrophages and B-cells was noted in RA patients at levels higher than that observed in OA patients. CONCLUSIONS: The observed elevation of FABP4 levels in RA patients and the positive correlation of the adipokine to cholesterol suggest that FABP4 may represent a potential link between RA and the increased risk of atherosclerotic changes.