Spondylitis, AnkylosingSpondylitisHLA-B27 AntigenSacroiliac JointSpineSpondylarthritisAntirheumatic AgentsSeverity of Illness IndexSpondylarthropathiesArthritisBlood SedimentationIritisTuberculosis, SpinalArthritis, ReactiveArthritis, PsoriaticRheumatic DiseasesBalneologyTreatment OutcomeUveitis, AnteriorLumbar VertebraeKyphosisArthritis, RheumatoidThoracic VertebraeHLA AntigensBack PainCervical VertebraeImmunoglobulin GAnti-Inflammatory Agents, Non-SteroidalSpinal DiseasesOsteitisSulfasalazineQuestionnairesPseudarthrosisReceptors, Tumor Necrosis FactorSymptom AssessmentAntibodies, MonoclonalFollow-Up StudiesDepressionSacroiliitisQuality of LifeKlebsiellaPsoas Abscess