Purpose of Review
To review current understanding of the prevalence, clinical features, outcome measures and recent therapeutic trials in axial psoriatic arthritis (axPsA).
The prevalence of axPsA is estimated at 40–50%. However, the definition of axPsA remains unclear, therefore these estimates may be inaccurate. Ax PsA appears to be distinct from ankylosing spondylitis in demographic, clinical, genetic and therapeutic features. Because of the lack of widely accepted definition of axPsA it has been difficult to design therapeutic trials for this domain of PsA.
Several studies have demonstrated the uniquness of axPsA. Few recent trials suggest that therapies that work for peripheral arthritis also work for axPsA.
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Moll JMH, Wright V. Psoriatic arthritis. Seminars Athritis Rheum. 1973;3:55–78.
Gladman DD, Shuckett R, Russell ML, Thorne JC, Schachter RK. Psoriatic arthritis - clinical and laboratory analysis of 220 patients. Quart J Med. 1987;62:127–41.
Gladman DD. Axial disease in psoriatic arthritis. Curr Rheumatol Rep. 2007;9:455–60.
•• Chandran V. Psoriatic spondylitis or ankylosing spondylitis with psoriasis: same or different? Curr Opin Rheumatol. 2019;31:329–34 An excellent review of the question posed. Highlights the difficulty in classification of the two conditions.
•• Feld J, Chandran V, Haroon N, Inman R, Gladman D. Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison. Nat Rev Rheumatol. 2018;14:363–71 This is a critical review of the literature addressing the question whether axial disease in psoriatic arthritis is different from that of ankylosing spondylitis and highlights some clinical, imaging, genetic, and therapeutic differences.
Ritchlin CT, Kavanaugh A, Gladman DD, Mease PJ, Helliwell P, Boehncke WH, et al. Treatment recommendations for psoriatic arthritis. Ann Rheum Dis. 2009;68:1387–94.
•• Feld J, Ye JY, Chandran V, et al. Is axial psoriatic arthritis distinct from ankylosing spondylitis with and without concomitant psoriasis? Rheumatology (Oxford). 2020;59:1340–6 This study was triggered by the literature review noted above which identified cross-sectional studies but no longitudinal studies comparing the axial disease in PsA to that of AS with or without psoriasis. Patients with AS and PsA were followed by the same protocol in a single centre. Axial PsA was clearly different from AS with or without psoriasis suggesting that it is a distinct entity.
van der Linden S, Valkenburg HA, Cats A. Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria. Arthritis Rheum. 1984;27:361–8.
Hanly JG, Russell ML, Gladman DD. Psoriatic spondyloarthropathy: a long term prospective study. Ann Rheum Dis. 1988;47:386–93.
Jadon DR, Sengupta R, Nightingale A, Lindsay M, Korendowych E, Robinson G, et al. Axial disease in psoriatic arthritis study: defining the clinical and radiographic phenotype of psoriatic spondyloarthritis. Ann Rheum Dis. 2017;76:701–7.
Ikumi K, Kobayashi S, Tamura N, Tada K, Inoue H, Osaga S, et al. HLA-B46 is associated with severe sacroiliitis in Japanese patients with psoriatic arthritis. Mod Rheumatol. 2019;29:1017–22.
•• Yap KS, Ye JY, Li S, et al. Back pain in psoriatic arthritis: defining prevalence, characteristics and performance of inflammatory back pain criteria in psoriatic arthritis. Ann Rheum Dis. 2018;77:1573–7 This study demonstrated that the definition of inflammatory back pain developed for ankylosing spondylitis may not be appropriate for patients with PsA.
Calin A, Porta J, Fries JF, Schurman DJ. Clinical history as a screening test for ankylosing spondylitis. JAMA. 1977;237:2613–4.
Sieper J, van der Heijde D, Landewé R, et al. New criteria for inflammatory back pain in patients with chronic back pain: a real patient exercise by experts from the Assessment of SpondyloArthritis International Society (ASAS). Ann Rheum Dis. 2009;68:784–8.
Rudwaleit M, Metter A, Listing J, Sieper J, Braun J. Inflammatory back pain in ankylosing spondylitis: a reassessment of the clinical history for application as classification and diagnostic criteria. Arthritis Rheum. 2006;54:569–78.
• Haroon M, Gallagher P, FitzGerald O. Inflammatory back pain criteria perform well in a subset of patients with active axial psoriatic arthritis but not among patients with established axial disease. Ann Rheum Dis. 2019;78:1003–4 This study looked specifically at patients with axial PsA who had spinal pain and in them the inflammatory back pain criteria developed for AS worked.
• Mease PJ, Palmer JB, Liu M, Kavanaugh A, Pandurengan R, Ritchlin CT, et al. Influence of axial involvement on clinical characteristics of psoriatic arthritis: analysis from the Corrona psoriatic arthritis/Spondyloarthritis registry. J Rheumatol. 2018;45:1389–96 In this report from the Corrona registry axial involvement defined by physician without any specific criteria imparted a greater disease burden among patients with PsA.
Aydin AZ, Kucuksahin O, Kilic L, et al. Axial psoriatic arthritis: the impact of underdiagnosed disease on outcomes in real life. Clin Rheumatol. 2018;37:3443–8.
• Nas K, Erkan K, Tekeoglu I, et al. The effect of gender on disease activity and clinical characteristics in patients with axial psoriatic arthritis. Mod Rheumatol. 2020. https://doi.org/10.1080/14397595.2020.1812870This is one of few studies addressing the effect of gender on the expression of axial psoriatic arthritis. It demonstrates that women have more pain and higher scores on patients reported outcomes while men have more severe sacroiliitis.
Benavent D, Plasencia-Rodriquez C, Franco-Gómez K, et al. Axial spondyloarthritis and axial psoriatic arthritis: similar or different disease spectrum? Ther Adv Muscoloskel Dis. 2020;12:1–8.
Liu V, Fong W, Kwan YH, Leung YY. Residual disease burden in axial spondyloarthritis and psoriatic arthritis patients despite low disease activity states in a multi-ethnic Asian population. J Rheumatol. 2020.
• Coates LC, Baraliakos X, Blanco FJ, et al. The phenotype of axial spondyloarthritis: is it dependent on HLA-B27 status? Arthritis Care Res. 2020. This study investigated the phenotype of axial Spondyloarthritis as it relates to HLA-B27. Patients who were HLA-B27 positive had higher radiographic scores than those who were negative.
Gladman DD, Inman R, Cook R, van der Heijde D, Landewé RB, Braun J, et al. International Spondyloarthritis Inter-Observer Reliability Exercise – the INSPIRE Study: I. Assessment of Spinal Measures. J Rheumatol. 2007;34:1733–9.
Chandran V, O'shea FD, Schentag CT, et al. Relationship between spinal mobility and radiographic damage in ankylosing spondylitis and psoriatic spondylitis: a comparative analysis. J Rheumatol. 2007;34:2463–5.
Wakhlu A, Chandran V, Phumethum V, Shen H, Cook RJ, Gladman D. Comparison between INSPIRE and Domjan method for measuring lumbar lateral flexion in patients with psoriatic arthritis (PsA) and correlation with radiographic damage. Clin Rheumatol. 2019;38:1063–6.
Biagioni B, Gladman DD, Cook RJ. Reliability of radiographic scoring methods in axial psoriatic arthritis. Arthritis Care Res. 2014;66:1417–22.
Ibrahim A, Gladman DD, Thavaneswaran A, Eder L, Helliwell P, Cook RJ, et al. Radiographic scoring instruments have moderate sensitivity but high specificity for detecting change in axial psoriatic arthritis. Arthritis Care Res. 2017;69:1700–5.
Sieper J, Rudwaleit M, Baraliakos X, et al. The assessment of spondyloarthritis international society (ASA) hand book: a guide to assess Spondyloarthritis. Ann Rheum Dis. 2009;68:ii1–44.
Taylor WJ, Harrison AA. Could the Bath ankylosing spondylitis disease activity index (BASDAI) abe a valid measure of disease activity in patients with psoriatic arthritis? Arthritis Rheum (Arthritis Care Res). 2004;51:311–5.
Fernandez-Sueiro JL, Willisch A, Pertega-Diaz S, et al. Validity of the bath ankylosing spondylitis disease activity index for the evaluation of disease activity in axial psoriatic arthritis. Arthritis Care Res. 2010;62:78–85.
Eder L, Chandran V, Shen H, Cook RJ, Gladman DD. Is ASDAS better than BASDAI as a measure of disease activity in Axial Psoriatic Arthritis? Ann Rheum Dis. 2010;69:2160–4.
Kilic G, Kilic E, Nas K, et al. Comparison of ASDAS and BASDAI as a measure of disease activity in axial psoriatic arthritis. Clin Rheumatol. 2015;34:515–21.
Coates LC, Kavanaugh A, Mease PJ, et al. Group for research and assessment of psoriasis and psoriatic arthritis: treatment recommendations for psoriatic arthritis 2015. Arthritis Rheum. 2016;68:1060–71.
Gossec L, Baraliakos X, Kerschbaumer A, de Wit M, McInnes I, Dougados M, et al. EULAR recommendations for the management of psoriatic arthritis with pharmacological therapies: 2019 update. Ann Rheum Dis. 2020;79:700–12.
• Helliwell PS, Gladman DD, Chakravarty SD, et al. Effects of ustekinumab on spondylitis-associated endpoints in TNFi-naive active psoriatic arthritis patients with physician-reported spondylitis: pooled results from two phase 3, randomised, controlled trials. RMD Open. 2020;6(1):e001149 This analysis of patients including in the PSUMMIT 1 and 2 studies investigating the effect of ustekinumab in PsA demonstrated improvement in spinal endpoint in the subgroup of patients who had axial disease defined by a physician. The study is relevant since it suggests that IL-12/23 inhibition may work in axial PsA although it did not work in AS.
• Helliwell PS, Gladman DD, Poddubnyy D, et al. Efficacy of guselkumab, a monoclonal antibody that specifically binds to the p19-subunit of IL-23, on endpoints related to axial involvement in patients with active PsA with imaging-confirmed sacroiliitis: week-24 results from two phase 3, randomized, double-blind, placebo-controlled studies. Ann Rheum Dis. 2020;79(supplement 1):36 (Submitted for publication). This analysis of patients including in the DISCOVER 1 and 2 studies investigating the effect of guselkumab in PsA demonstrated improvement in spinal endpoint in the subgroup of patients who had axial disease confirmed by imaging. The study is relevant since it suggests that IL-23 p19 inhibition may work in axial PsA although it did not work in AS.
•• Baraliakos X, Gossec L, Poumara E, et al. Secukinumab improves clinical and imaging outcomes in patients with psoriatic arthritis and axial manifestations with inadequate response to NSAIDs: week 52 results from the MAXIMISE trial. Ann Rheum Dis. 2020;79(supplement 1):36 (Submitted for publication). This is the first study designed specifically to assess axial disease in PsA. Although the patient selection was based on physician definition of axial disease, at least half the patients had inflammatory changes on MRI. Both clinical and imaging responses were noted with secukinumab.
Availability of Data and Material
Dr. Gladman’s research is supported by the Krembil Foundation, the Canadian Institutes of Health Research, and the National Psoriasis Foundation.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Conflict of Interest
Dr. Gladman has received trial grants and or consulting fees from AbbVie, Amgen, BMS, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB.
• Ankylosing spondylitis and axial psoriatic arthritis are both part of the spectrum of spondyloarthritis and have overlapping features but also differ in their genetic, clinical, radiographic, and prognostic characteristics.
• HLA-B*27 occurs less frequently in axial psoriatic arthritis than in ankylosing spondylitis but is a genetic risk factor for both diseases.
• Axial psoriatic arthritis develops at an older age, is less symptomatic, and is associated with distinct radiographic features compared with ankylosing spondylitis.
• The majority of comparative studies to date have had a cross-sectional design, which captures patients at different stages of disease and hampers the true comparison of these two diseases.
• The lack of a universally accepted definition of axial psoriatic arthritis needs to be addressed.
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This article is part of the Topical Collection on Spondyloarthritis