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: 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.

The final definition that has been endorsed by the ASAS members is published³  and can be found below.

Timelines of the project: 2021-2023

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 Aug;55:152032. doi: 10.1016/j.semarthrit.2022.152032 
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) 2023 Apr 3;62(4):1398-1409. doi: 10.1093/rheumatology/keac532
3. Navarro-Compán V, Benavent D, Capelusnik D, van der Heijde D, Landewé RB, Poddubnyy D, van Tubergen A, Baraliakos X, Van den Bosch FE, van Gaalen FA, Gensler L, López-Medina C, Marzo-Ortega H, Molto A, Pérez-Alamino R, Rudwaleit M, van de Sande M, Sengupta R, Weber U, Ramiro S. ASAS consensus definition of early axial spondyloarthritis. Ann Rheum Dis. 2023 Jun 15:ard-2023-224232. doi: 10.1136/ard-2023-224232. [Epub ahead of print].