Which Cells Correspond to the Typical Signals for Fatty and Inflammatory Lesions Seen in Magnetic Resonance Imaging in Ankylosing Spondylitis ? -a Prospective Study Using Biopsy Material Obtained during Spinal Surgery- ACR Meeting Abstracts

Xenofon Baraliakos¹, Heinrich Boehm², Ahmend Samir², Georg Schett³ and Jürgen Braun⁴, ¹Rheumatology, Rheumazentrum Ruhrgebiet, Herne, Germany, ²Clinic for spinal surgery, Bad Berka, Germany, ³Department of Internal Medicine 3 – Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany, ⁴Rheumazentrum Ruhrgebiet, Herne, Germany

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: Ankylosing spondylitis (AS) and magnetic resonance imaging (MRI)

Session Information

Date: Tuesday, November 15, 2016

Title: Spondylarthropathies Psoriatic Arthritis – Pathogenesis, Etiology - Poster II

Session Type: ACR Poster Session C

Session Time: 9:00AM-11:00AM

Background/Purpose: The occurrence of bone marrow edema (BME) and fat metaplasia detected by magnetic resonance imaging (MRI) were shown to be significantly associated with syndesmophyte formation in patients with ankylosing spondylitis (AS). The cell type responsible for the fat signal seen in MRI has not been defined to date. Here we histologically analyze the cells seen in fatty lesions (FL) as detected by MRI in spinal biopsies of AS patients and compare them with controls.

Methods: The occurrence of bone marrow edema (BME) and fat metaplasia detected by magnetic resonance imaging (MRI) were shown to be significantly associated with syndesmophyte formation in patients with ankylosing spondylitis (AS). The cell type responsible for the fat signal seen in MRI has not been defined to date. Here we histologically analyze the cells seen in fatty lesions (FL) as detected by MRI in spinal biopsies of AS patients and compare them with controls.

Results: Biopsies mostly obtained from the lower thoracic and the lumbar spine of 13 AS patients (mean age 56.3 years, mean disease duration 26 years) and 6 controls (mean age 53.4 years) were available. Large proportions of AS patients, (12/13, 92%) and non-AS patients (4/6, 67%) had vital bone marrow. Fat cells were found in all 13 biopsies obtained from AS patients from the area of the fat signal vs. only 2 non-AS patients (33%), while inflammatory cells were found in 9 AS patients (69.2%), all of which also had BME on MRI, vs. 3 non-AS patients (50%). Fibroblasts were seen in 3 AS (23.1%) and 2 non-AS patients (33.3%).

Conclusion: The underlying cell types of FL and BME as detected by MRI in these long standing AS patients were fatty and inflammatory cells. The main difference between AS and non-AS patients was the proportion of biopsies containing fat cells. This suggests that fat cells are responsible for the MRI signal, at least in patients with longstanding ankylosing spondylitis.

Disclosure: X. Baraliakos, None; H. Boehm, None; A. Samir, None; G. Schett, None; J. Braun, None.

To cite this abstract in AMA style:

Baraliakos X, Boehm H, Samir A, Schett G, Braun J. Which Cells Correspond to the Typical Signals for Fatty and Inflammatory Lesions Seen in Magnetic Resonance Imaging in Ankylosing Spondylitis ? -a Prospective Study Using Biopsy Material Obtained during Spinal Surgery- [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/which-cells-correspond-to-the-typical-signals-for-fatty-and-inflammatory-lesions-seen-in-magnetic-resonance-imaging-in-ankylosing-spondylitis-a-prospective-study-using-biopsy-material-obtained-duri/. Accessed .

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