Abstract
Spinal new bone formation is a major but incompletely understood manifestation of ankylosing spondylitis (AS). We explored the relationship between spinal new bone formation and ultrasound (US)-determined Achilles enthesophytes to test the hypothesis that spinal new bone formation is part of a generalized enthesis bone-forming phenotype. A multicenter, case control study of 225 consecutive AS patients and 95 age/body mass index (BMI) matched healthy controls (HC) was performed. US scans of Achilles tendons and cervical and lumbar spine radiographs were obtained. All images were centrally scored by one investigator for US and one for radiographs, blinded to medical data. The relation between syndesmophytes (by modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and the number of syndesmophytes) and enthesophytes (with a semi-quantitative scoring of the US findings) was investigated. AS patients had significantly higher US enthesophyte scores than HCs (2.1(1.6) vs. 1.6(1.6); p = 0.004). The difference was significant in males (p = 0.001) but not in females (p = 0.5). The enthesophyte scores significantly correlated with mSASSS scores (ρ = 0.274, p < 0.0001) with the association even stronger in males (enthesophyte scores vs. mSASSS ρ = 0.337, p < 0.0001). In multiple regression analysis, age, BMI, enthesophyte scores and disease duration were significantly associated with syndesmophytes in males, and keeping all other variables constant, increasing US enthesophyte scores increased the odds of having syndesmophytes by 67 %. Male AS patients that have more severe US-determined Achilles enthesophyte also associated spinal syndesmophytes suggesting a bone-forming gender-specific phenotype that could be a useful marker predicting of new bone formation.
References
Ruthoy MK, Schweitzer M, Resnick D (1998) Enthesopathy. In: Klippel JH, Dieppe PA (eds) Rheumatology, 2nd edn. Times-Mirror International Publishers, London, pp 6.13.1–6.13.2
Ball J (1971) Enthesopathy of rheumatoid and ankylosing spondylitis. Ann Rheum Dis 30:213–223
Ramiro S, Stolwijk C, van Tubergen A et al (2015) Evolution of radiographic damage in ankylosing spondylitis: a 12 year prospective follow-up of the OASIS study. Ann Rheum Dis 74:52–59
Poddubnyy D, Haibel H, Listing J et al (2012) Baseline radiographic damage, elevated acute-phase reactant levels, and cigarette smoking status predict spinal radiographic progression in early axial spondylarthritis. Arthritis Rheum 64:1388–1398
Rogers J, Shepstone L, Dieppe P (1997) Bone formers: osteophyte and enthesophyte formation are positively associated. Ann Rheum Dis 56:85–90
Jacques P, Lambrecht S, Verheugen E et al (2014) Proof of concept: enthesitis and new bone formation in spondyloarthritis are driven by mechanical strain and stromal cells. Ann Rheum Dis 73:437–445
van der Linden S, Valkenburg HA, Cats A (1984) Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria. Arthritis Rheum 27:361–368
Creemers MC, Franssen MJ, van’t Hof MA et al (2005) Assessment of outcome in ankylosing spondylitis: an extended radiographic scoring system. Ann Rheum Dis 64:127–129
Baraliakos X, Haibel Listing J et al (2014) Continuous long-term anti-TNF therapy does not lead to an increase in the rate of new bone formation over 8 years in patients with ankylosing spondylitis. Ann Rheum Dis 73:710–715
Haroon N, Inman RD, Learch TJ et al (2013) The impact of tumor necrosis factor α inhibitors on radiographic progression in ankylosing spondylitis. Arthritis Rheum 65:2645–2654
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On behalf of the Turkish Ultrasonography Study Group.
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Aydin, S.Z., Can, M., Alibaz-Oner, F. et al. A relationship between spinal new bone formation in ankylosing spondylitis and the sonographically determined Achilles tendon enthesophytes. Rheumatol Int 36, 397–404 (2016). https://doi.org/10.1007/s00296-015-3360-8
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DOI: https://doi.org/10.1007/s00296-015-3360-8