Arthritis, PsoriaticPsoriasisRheumatologyArthritis, RheumatoidArthritisArthritis, ExperimentalArthritis, InfectiousArthritis, JuvenileAntirheumatic AgentsRheumatic DiseasesJointsArthritis, ReactiveSpondylitis, AnkylosingSynovial MembraneDermatologic AgentsSeverity of Illness IndexSynovial FluidNail DiseasesSynovitisMethotrexateRheumatoid FactorHand JointsReceptors, Tumor Necrosis FactorSpondylarthropathiesTumor Necrosis Factor-alphaOsteoarthritisArthrographyBlood SedimentationAntibodies, MonoclonalHLA-C AntigensTreatment OutcomeSpondylitisSpondylarthritisImmunoglobulin GFinger JointToe JointFoot JointsAntibodies, Monoclonal, HumanizedPeriostitisGenetic Predisposition to DiseaseArthritis, GoutyHLA-B27 AntigenBiological ProductsSkinPUVA TherapyAnti-Inflammatory AgentsUltraviolet TherapyAutoantibodiesDouble-Blind MethodSacroiliac JointDisability EvaluationInjections, Intra-ArticularMice, Inbred DBAKnee JointImmunosuppressive AgentsLupus Erythematosus, SystemicBiological MarkersCase-Control StudiesImmunologic FactorsCohort StudiesDrug Therapy, CombinationIritisAge of OnsetAutoimmune DiseasesJoint DiseasesQuality of LifeAnti-Inflammatory Agents, Non-SteroidalQuestionnairesCollagen Type IICornified Envelope Proline-Rich ProteinsEtretinateProspective StudiesFibromyalgiaAntibodies, AntinuclearGene FrequencyNailsHealth StatusSulfasalazineFollow-Up StudiesMetacarpophalangeal JointCytokinesPrevalenceRats, Inbred LewReproducibility of ResultsGreat BritainDisease ProgressionHLA Antigens