MethotrexateArthritis, RheumatoidArthritisAntirheumatic AgentsArthritis, ExperimentalSynovial MembraneArthritis, InfectiousArthritis, JuvenilePolyglutamic AcidArthritis, PsoriaticRheumatoid FactorSynovial FluidJointsFolic Acid AntagonistsSulfasalazineTetrahydrofolate DehydrogenaseArthritis, ReactiveSynovitisDrug Therapy, CombinationTreatment OutcomeBlood SedimentationOsteoarthritisSeverity of Illness IndexAminopterinAntimetabolites, AntineoplasticReduced Folate Carrier ProteinLeukemia L1210ArthrographyGold Sodium ThiomalateTrimetrexateMetacarpophalangeal JointImmunosuppressive AgentsTumor Necrosis Factor-alphaAntibodies, MonoclonalFolic AcidRheumatologyHydroxychloroquineRheumatic DiseasesImmunoglobulin GIsoxazolesMice, Inbred DBAAutoantibodiesRheumatoid NoduleReceptors, Tumor Necrosis FactorDrug Administration Schedulegamma-Glutamyl HydrolaseLeucovorinDrug ResistanceWrist JointCyclophosphamideTetrahydrofolatesPeptides, CyclicAbortifacient Agents, NonsteroidalHLA-DRB1 ChainsOrganogold CompoundsAnti-Inflammatory AgentsPsoriasisAntineoplastic Combined Chemotherapy ProtocolsDose-Response Relationship, DrugPrednisoloneDouble-Blind MethodSpondylitis, AnkylosingCollagen Type IIDermatologic AgentsFinger JointDeoxyuridineVincristinePrecursor Cell Lymphoblastic Leukemia-LymphomaHLA-DR4 AntigenHLA-DR AntigensFoot JointsTime FactorsPrednisone6-MercaptopurineCitrullinePregnancy, EctopicRemission InductionAntibodies, Monoclonal, HumanizedFluorouracilFormyltetrahydrofolatesGlucocorticoidsInjections, Intra-ArticularAutoimmune DiseasesFollow-Up StudiesFolate Receptors, GPI-AnchoredArthritis, GoutyCells, CulturedLupus Erythematosus, SystemicBiological MarkersPhosphoribosylaminoimidazolecarboxamide FormyltransferaseProspective StudiesAnti-Inflammatory Agents, Non-SteroidalDoxorubicinRats, Inbred LewKnee JointDisability EvaluationHand JointsSpondylarthropathiesOsteosarcomaInjections, Spinal