Arthritis, Rheumatoid/metabolism; Synovial Fluid/chemistry; Synovial Membrane/metabolism; Tumor Necrosis Factor Ligand Superfamily Member 14/metabolism; Aged; Apoptosis/drug effects; Arthritis, Rheumatoid/immunology; Arthritis, Rheumatoid/pathology; CD4-Positive T-Lymphocytes/chemistry; CD4-Positive T-Lymphocytes/metabolism; Cell Proliferation; Cell Survival; Cells, Cultured; Female; Fibroblasts/metabolism; Fibroblasts/pathology; Flow Cytometry; Humans; Immunohistochemistry; Intercellular Adhesion Molecule-1/analysis; Interleukin-6/analysis; Leukotriene B4/analysis; Leukotriene B4/metabolism; Male; Matrix Metalloproteinase 9/analysis; Middle Aged; NF-kappa B/analysis; NF-kappa B/metabolism; Osteoarthritis/immunology; Osteoarthritis/metabolism; Osteoarthritis/pathology; RNA, Messenger/analysis; Receptors, Tumor Necrosis Factor, Member 14/analysis; Receptors, Tumor Necrosis Factor, Member 14/metabolism; Recombinant Proteins/pharmacology; Reverse Transcriptase Polymerase Chain Reaction; Statistics, Nonparametric; Synovial Fluid/immunology; Synovial Fluid/metabolism; Synovial Membrane/immunology; Synovial Membrane/pathology; Tumor Necrosis Factor Ligand Superfamily Member 14/analysis; Tumor Necrosis Factor Ligand Superfamily Member 14/genetics