Axial Disease in Psoriatic arthritis: The presence and progression of unilateral grade 2 sacroiliitis in a psoriatic arthritis cohort

Joy Feld; Justine Y Ye; Vinod Chandran; Robert D Inman; Nigil Haroon; Richard Cook; Dafna D Gladman

doi:10.1016/j.semarthrit.2021.03.007

Axial Disease in Psoriatic arthritis: The presence and progression of unilateral grade 2 sacroiliitis in a psoriatic arthritis cohort

Semin Arthritis Rheum. 2021 Apr;51(2):464-468. doi: 10.1016/j.semarthrit.2021.03.007. Epub 2021 Mar 20.

Authors

Joy Feld¹, Justine Y Ye², Vinod Chandran³, Robert D Inman⁴, Nigil Haroon⁵, Richard Cook⁶, Dafna D Gladman⁷

Affiliations

¹ Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Carmel and Lin Medical Centers, Haifa, Israel.
² Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
³ Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Division of Rheumatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
⁴ Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Division of Rheumatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Department of Immunology, Medical Sciences Building, University of Toronto, Toronto, Ontario, Canada.
⁵ Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Division of Rheumatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
⁶ Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada.
⁷ Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Division of Rheumatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada. Electronic address: dafna.gladman@utoronto.ca.

PMID: 33774593
DOI: 10.1016/j.semarthrit.2021.03.007

Abstract

Background/purpose: A universally accepted definition of axial psoriatic arthritis (axPsA) is lacking. We aimed to 1) assess the presence of axial involvement as defined by "at least unilateral grade 2 sacroiliitis (Uni2SI)" and 2) assess the radiographic progression of Uni2SI and identify risk factors for progression.

Methods: PsA patients participating in a prospective observational cohort were classified according to their highest sacroiliitis grade. The baseline features of patients with Uni2SI were compared to patients meeting the radiographic criteria of the modified New York Ankylosing Spondylitis (mNY AS) criteria. Risk factors were examined for progression from Uni2SI in a sub-group of patients with >1 follow-up radiographs. Logistic regression and a survival analysis were carried out and identified risk factors associated with radiographic mNY AS compared to Uni2SI.

Results: Axial disease defined as ≥Uni2SI was detected in 612/1354 patients (45%). mNY AS sacroiliitis was observed in 477 patients (35%). Radiographic progression of Uni2SI was assessed in 154 patients, 80 (52%) progressed to mNY AS criteria within 5.5 years. At baseline, progressors were diagnosed at a younger age (35.6 vs. 38.9, p = 0.05), had less degenerative disc disease (OR = 0.47, p = 0.02), worse peripheral radiographic damage (OR=1.02, p = 0.03) and worse psoriasis (OR = 1.09, p = 0.01) compared to non-progressors. Patients with an elevated erythrocyte sedimentation rate were more likely to progress (HR = 1.83, p = 0.02), while patients with longer disease duration were less likely to progress (HR = 0.95, p = 0.02).

Conclusion: The radiographic mNY AS criteria appear to be suitable for defining axial PsA according to radiographs. MRI definitions are needed as well for the most appropriate definition of axial PsA.

Keywords: Axial inflammation; Psoriatic arthritis; Sacroiliitis.

Publication types

Observational Study

MeSH terms

Arthritis, Psoriatic* / complications
Arthritis, Psoriatic* / diagnostic imaging
Cohort Studies
Humans
Sacroiliitis* / complications
Sacroiliitis* / diagnostic imaging
Severity of Illness Index
Spondylitis, Ankylosing*