Arthritis, PsoriaticArthritisArthritis, RheumatoidPsoriasisArthritis, ExperimentalAntirheumatic AgentsArthritis, InfectiousSpondylitis, AnkylosingJointsArthritis, JuvenileArthritis, ReactiveSynovial MembraneNail DiseasesSynovial FluidHand JointsRheumatic DiseasesSeverity of Illness IndexSynovitisSpondylitisToe JointSpondylarthropathiesReceptors, Tumor Necrosis FactorRheumatoid FactorDermatologic AgentsTumor Necrosis Factor-alphaSpondylarthritisFinger JointFoot JointsPeriostitisArthrographyMethotrexateAntibodies, MonoclonalBlood SedimentationOsteoarthritisHLA-C AntigensImmunoglobulin GTreatment OutcomeAntibodies, Monoclonal, HumanizedSacroiliac JointHLA-B27 AntigenRheumatologyIritisGenetic Predisposition to DiseaseDouble-Blind MethodAnti-Inflammatory AgentsKnee JointEtretinateDisability EvaluationHLA-B39 Antigen