[A preliminary exploration of low-dose semicoronal CT of the sacroiliac joints in the diagnosis of ankylosing spondylitis]

Radiologic approach to axial spondyloarthritis: where are we now and where are we heading?

Current emphasis on diagnosing axial spondyloarthritis (axSpA) in early stage enforced the search for sensitive and specific diagnostic algorithms with the use of imaging methods. The aim of this review was to summarise current recommendations concerning the use of imaging techniques in diagnostics and monitoring of axSpA as well as to outline possible future directions of the development in this field. MEDLINE database was searched between March and April 2018. In the first phase, such keywords were applied: ‘ASAS’, ‘EULAR’, ‘ASAS-EULAR’, ‘ASAS/OMERACT’, ‘axial spondyloarthritis’, while in the second step: ‘axial spondyloarthritis’, ‘ankylosing spondylitis’, ‘magnetic resonance imaging’, ‘computed tomography’, and ‘radiography’, ‘imaging’. An up-to-date summary of European League Against Rheumatism (EULAR) recommendations enriched with recent updates of Assessment of Spondyloarthritis International Society (ASAS) diagnostic criteria regarding imaging in axSpA course was created. Moreover, we outlined the role of new in this field, promising imaging techniques, such as diffusion-weighted imaging and dynamic contrast-enhanced sequences in magnetic resonance imaging (MRI) or low-dose computed tomography (CT). As precise monitoring of axSpA activity is vital, we reviewed the most precise methods: semiquantitative scores (e.g., Spondyloarthritis Research Consortium of Canada scores or CT Syndesmophyte Score) and quantitative analysis of MRI-based apparent diffusion coefficient or perfusion maps and enhancement curves. According to EULAR and ASAS recommendations, radiography and MRI still remain basic methods of axSpA diagnostics and monitoring. However, the knowledge of state-of-the-art international guidelines combined with the awareness of emerging imaging methods is the key to effective management of axSpA.

Interleukin-17A-promoted MSC2 polarization related with new bone formation of ankylosing spondylitis

It’s still unknown how over-hyperplasia of tissue such like new bone formation (NBF) developed in ankylosing spondylitis (AS). We found low level of IL-17A promoted TLR4+MSC1 polarization with suppressed osteogenic differentiation through JAK2/STAT3 pathway, while high level of IL-17A promoted TLR3+MSC2 polarization with enhanced osteogenic differentiation through WNT10b/RUNX2 pathway. Furthermore, both proteoglycan-induced spondylitis (PGISp) mouse model and AS patients without NBF showed MSC1 polarization, up-regulated JAK2/STAT3 pathway and high level of IL-17A (peripherally, but not locally), but those with NBF showed MSC2 polarization, up-regulated WNT10b/RUNX2 pathway and high expression of IL-17A at local site. Results showed NBF of AS was induced by MSC2 polarization that was promoted by high level of IL-17A, and may be treated by suppressing local MSC2 polarization.