Background: Despite the progressively increased use of the term early axial spondyloarthritis and early peripheral spondyloarthritis in research, no consensual definition has been established. The lack of a standardised definition is leading to a great heterogeneity of arbitrary definitions or non-appropriate definitions employed in new studies by pharmaceutical industry and experts.

Aim: To develop a consensual definition for the terms early axSpA and early pSpA in a research setting under the auspices of the Assessment of SpondyloArthritis international Society (ASAS).

Methodology: An international working group is conducting a project to develop a consensual definition for the terms early axSpA and early pSpA in five consecutive steps:

i) Systematic literature review (SLR) to identify possible definitions of early axSpA/pSpA and to summarize the evidence on the relationship between early treatment (definition based on symptom/disease duration or radiographic damage) and treatment clinical response in patients with SpA;

ii) Discussion of SLR results within the ASAS community;

iii) A three-round Delphi survey to select the items that should be considered for the definition of the terms.

iv) Presentation of Delphi survey results to the ASAS community;

v) Final discussion, voting and endorsement by ASAS members.

Results (ongoing): As a first phase of this project, two SLRs were performed and the results were published. According to these, the term “early SpA” and its subtypes is increasingly used over time. More than one third of the studies did not include a definition of the term and the studies reporting one showed a large heterogeneity. Most of the publications included the term “early axSpA”, whereas only one included “early pSpA”.¹ In addition, the second SLR showed how evidence towards better outcomes in early axSpA is very limited and restricted to nr-axSpA and <5 years symptom duration. When early axSpA is defined based on disease duration or radiographic damage, no differences in response to treatment are found.²  After discussing the results of the SLR with ASAS community the consensus was to proceed for the time being with a definition for early axSpA but not for pSpA.

Conclusions: The process to define early axSpA is currently ongoing. The results of the first phase of the project (SLR) emphasize the need for a standardised definition of early SpA. It is expected that the project will be completed by the end of 2023.

Timelines of the project: 2021-ongoing; expected conclusion 2023

Project Team

PIs: Victoria Navarro Compán (Madrid, Spain) and Sofia Ramiro (Leiden and Heerlen, the Netherlands)

Fellows: Diego Benavent (Madrid, Spain) and Dafne Capelusnik (Tel Aviv, Israel)

Steering committee:

Robert Landewé (Amsterdam and Heerlen, the Netherlands)

Denis Poddubnyy (Berlin, Germany)

Désirée van der Heijde (Leiden, the Netherlands)

Astrid van Tubergen (Maastricht, the Netherlands)

Working group:

Xenofon Baraliakos (Herne, Germany)

Lianne Gensler (San Francisco, USA)

Clementina López Medina (Córdoba, Spain))

Helena Marzo-Ortega (Leeds, UK)

Anna Moltó (Paris, France)

Rodolfo Perez-Alamino (Buenos Aires, Argentina)

Martin Rudwaleit (Bielefeld, Berlin, Germany)

Raj Sengupta (Bath, UK)

Marleen van de Sande (Amsterdam, the Netherlands)

Filip van den Bosch (Ghent, Belgium)

Floris van Gaalen (Leiden, the Netherlands)

Ulrich Weber (Sønderborg, Denmark)

Publications

1. Benavent D, Capelusnik D, van der Heijde D, Landewé R, Poddubnyy D, van Tubergen A, Falzon L, Ramiro S, Navarro-Compán V. How is early spondyloarthritis defined in the literature? Results from a systematic review. Semin Arthritis Rheum 2022;55:152032. doi: 10.1016/j.semarthrit.2022.152032 [published Online First: 20220529]
2. Capelusnik D, Benavent D, van der Heijde D, Landewé R, Poddubnyy D, van Tubergen A, Falzon L, Navarro-Compán V, Ramiro S. Treating spondyloarthritis early: does it matter? Results from a systematic literature review. Rheumatology (Oxford) 2022 doi: 10.1093/rheumatology/keac532 [published Online First: 20220913]