Funding: g Devenir des Spondyloarthropathies Indifférenciées Récentes (DESIR) is financially supported by an unrestricted grant from Pfizer. AS is supported by a doctoral grant from 'Fundação para a Ciência e Tecnologia' (SFRH/ BD/108246/2015). The DESIR study is conducted as a Programme Hospitalier de Recherche Clinique with Assistance Publique Hopitaux de Paris as the sponsor. The DESIR study is also under th...