Frequency and characteristics of axial involvement in psoriatic arthritis: results from the International Multicentre AXIS Study

Torgutalp, Murat; Almodovar, Raquel; Azevedo, Valderilio F; Baraliakos, Xenofon; Bosch, Filip Van Den; Braun, Jürgen; Chandran, Vinod; Coates, Laura C; Deodhar, Atul; Diekhoff, Torsten; Fagni, Filippo; Floris, Alberto; Gaalen, Floris A Van; Garcia-Salinas, Rodrigo; Gensler, Lianne S; Goel, Niti; Gottlieb, Alice B; Heijde, Désirée Van Der; Helliwell, Philip S; Hermann, Kay Geert A; Kalyoncu, Umut; Kiltz, Uta; Kynaston-Pearson, Francis; Lambert, Robert Gw; Laxminarayan, Ramasharan; Leung, Ying Ying; Llop, Maria; López-Medina, Clementina; López-Rodríguez, Alejandra; Gentiloni, Michele M Luchetti; Lunteren, Miranda Van; Magrey, Marina; Maharaj, Ajesh B; Maldonado-Ficco, Hernán; Maksymowych, Walter P; Marzo-Ortega, Helena; Massarotti, Marco; Mathew, Ashish J; Mease, Philip; Nash, Peter; Navarro-Compán, Victoria; Østergaard, Mikkel; Proft, Fabian; Protopopov, Mikhail; Ranza, Roberto; Rohekar, Sherry; Salvarani, Carlo; Schiotis, Ruxandra E; Shenker, Nicholas; Sieper, Joachim; Solmaz, Dilek; Soriano, Enrique R; Shan Tam, Lai-; Toledo, Ricardo Acayaba De; Wei, James Cc; Ziade, Nelly; Gladman, Dafna D; Poddubnyy, Denis

doi:10.1016/j.ard.2026.02.025

Objectives: The AxialInvolvementinPsoriaticArthritis(AXIS)cohortaimedatevaluatingthefre- quency ofandclinicalandimagingfeaturesofaxialinvolvementinpsoriaticarthritis(PsA). Methods: AXIS (NCT04434885)isaprospective,multicentre,cross-sectionalstudyconductedin 19 countries,bytheAssessmentofSpondyloArthritisInternationalSocietyandtheGroupfor Research andAssessmentofPsoriasisandPsoriaticArthritis.Participantswithadiagnosisof PsA meetingClASsification criteriaforPsoriaticARthritiswithmusculoskeletalsymptomdura- tion ≤10 yearsandnopriorexposuretobiologicalortargetedsyntheticdisease-modifyinganti- rheumatic drugswereconsecutivelyincluded.Standardisedclinical,laboratory,andimaging assessments (radiographyandmagneticresonanceimagingoftheaxialskeleton,including sacroiliac joints[SIJs]andspine),wereperformed.Imagingwasreviewedlocallyandcentrally to detectaxialinvolvement.Thepresenceofaxialinvolvementwasdeterminedbylocalinvesti- gator judgementbeforeandaftercentral-imagingreview. Results: Among 409participants,axialinvolvementwasidentified in153(37.4%) basedonthe investigator’s initialassessmentandwasdecreasedto112(27.4%) inthe final evaluationafter incorporating central-imagingreview.Participantswithaxialinvolvementwereyounger(45.2 ± 13.8 vs47.6 ± 12.6 years),moreoftenmale(56.3% vs 51.5%), andhadahigherfrequencyof human leukocyteantigen(HLA)-B*27positivity(22.4% vs 10.8%), inflammatory backpain (IBP) (74.7% vs 43.4%), andelevatedC-reactiveprotein(CRP)(52.7% vs 37.4%). Activeinflammatory andstructuralimagingchangeswerehighlydiscriminativebetweenparticipantswith and withoutaxialinvolvement.Thecentralreviewidentified imagingsignsofaxialinvolvement (active inflammation orstructurallesions)in95participants(23.2%). Conclusions: Axial involvementwasidentified in27.4% of participantswithPsAafter final diag- nostic assessment,withassociatedfeaturesincludingHLA-B*27positivity,IBP,elevatedCRP, and imagingchangesinSIJorspine

Frequency and characteristics of axial involvement in psoriatic arthritis: results from the International Multicentre AXIS Study / Torgutalp, M., Almodovar, R., Azevedo, V.F., Baraliakos, X., Bosch, F.V.D., Braun, J., Chandran, V., Coates, L.C., Deodhar, A., Diekhoff, T., Fagni, F., Floris, A., Gaalen, F.A.V., Garcia-Salinas, R., Gensler, L.S., Goel, N., Gottlieb, A.B., Heijde, D.V.D., Helliwell, P.S., Hermann, K.G.A., et al.. - In: ANNALS OF THE RHEUMATIC DISEASES. - ISSN 0003-4967. - STAMPA. - (2026). [Epub ahead of print] [10.1016/j.ard.2026.02.025]