Ab0882 Spine and Sacroiliac Joint Involvement in Newly Diagnosed Patients With Inflammatory Bowel Disease: Symptoms, Clinical and Magnetic Resonance Imaging Findings

Background: Inflammatory bowel disease (IBD) related spondyloarthritis (SpA) is associated with poor outcomes and substantial impact on quality of life. Hence, early detection is important to optimally tailor treatment and prevent future structural damage of sacroiliac joints (SIJs) and the spine. However, the prevalence and pattern of involvement are poorly described as systematic rheumatological characterisation in early IBD is lacking. Objectives: To determine the prevalence and distribution of axial symptoms, clinical findings and MRI-determined inflammatory and structural lesions in the spine and the SIJs of newly diagnosed IBD patients. Methods: Patients with newly diagnosed IBD from a prospective population-based inception cohort were consecutively included. Data on peripheral and axial symptoms were collected by questionnaires and by a structured rheumatological interview. MRI assessment for SIJ and spine inflammation and structural lesions was based on Spondyloarthritis Research Consortium of Canada (SPARCC) method for SIJs and Canada-Denmark scoring system (CANDEN) for the spine. Further, an expert assessment of the MRIs as±indicative of axial SpA applying standardized definitions was performed 1,2. Results: Of 110 included patients (mean age 42 years, 40% male, 70 with ulcerative colitis (UC), 40 with Crohn's disease (CD)), 74 had active IBD. At the time of evaluation, 4 patients received systemic glucocorticoid and one biological treatment. Two patients had a history of psoriasis, 5 of uveitis and none of previously diagnosed SpA. Back and/or buttock pain was reported by 48(44.9%) patients and inflammatory back pain (by ASAS definition) by 10(9.1%). In 23(21.5%) the pain could not (according to the assessing rheumatologist) be better explained by competing conditions such as degenerative disc disease, nerve root compression, osteoporosis or fibromyalgia. The axial symptoms were accompanied by peripheral joint and/or entheseal symptoms in 30(62.5 %) patients and 33(68.8%) had tender and/or swollen joints and/or entheses. According to the MRI expert, MRIs of 17(16.7%) patients were indicative of axial SpA (SIJs and spine evaluated together), while 13(12.7%) of the SIJs MRIs and 11(10.8%) of the spine MRIs were indicative of axSpA (Table 1). There was no difference in symptoms or MRI findings between patients with UC and CD, or between patients with active and inactive IBD. SIJ bone marrow oedema (BME) in ≥1 slice was found in 27(26.5%) patients and definite BME in ≥3 slices 2 in 12(11.8%). Location of BME and structural lesions in the different SIJ segments is shown in Figure 1D-E. Erosion in the SIJs was present in 24(23.5%) patients, fat degeneration in 12(11.8%) and ankylosis in 3(2.9%). Definite structural lesions typical of axSpA were present in 17(16.7%) patients 2. Mean SPARCC inflammation score was 1.38(SD 4.1). Spine BME in ≥1 slice was present in 30(30.3%) patients and vertebral corner inflammation in 27(27.3%). Mean CANDEN spine total inflammation score was 3.13(SD 4.44). Spine MRI structural lesions, i.e. fat, erosion and new bone formation, were found in 34(34.3%), 10(10.1%) and 11(11.1%) patients, respectively. Figure 1A-C shows location of inflammatory and structural lesions by type and anatomical location in the spine. The ASAS definition of positive MRI for sacroiliitis 1 was fulfilled in 12(11.8%) patients and half of them had axial symptoms. MRI findings were more frequent in symptomatic than in asymptomatic patients (Table 1). Among the 9 HLA-B27 positive patients, 7(78%) were symptomatic; 3 (33%) had MRI sacroiliitis. The ASAS classification criteria for axSpA were met in 11 cases. Conclusion: At the time of IBD diagnosis 17% of the patients had findings indicative of axSpA on SIJs and spine MRI, while only ̴60% of these were symptomatic, suggesting that axSpA is underdiagnosed condition among IBD patients. Our results indicate a need for multidisciplinary collaboration to ensure early detection of axial involvement to enable an optimal therapeutic strategy and prevent future structural damage and disability. REFERENCES: 1 Lambert et al., Ann Rheum Dis 2016 2 Maksymowych et al., Rheumatology 2021 Acknowledgements: NIL. Disclosure of Interests: Nora Vladimirova MSD, Novartis, Mohamed Attauabi: None declared, Gorm Madsen: None declared, Flemming Bendtsen Ferring and Tillotts, Jakob Seidelin Research grants from Takeda and the Capital Region Denmark, national coordinator of studies from AbbVie, Arena Pharmaceuticals, Ely, Johan Burisch AbbVie, Janssen-Cilag, Celgene, MSD, Pfizer, Takeda, Tillotts Pharma, Samsung Bioepis, Bristol Myers Squibb, Novo Nordisk, Pharmacosmos, Ferring, Galapagos, Janssen-Cilag, MSD, Pfizer, Takeda, Tillots Pharma, Bristol Myers, Squibb, Novo Nordisk, Mikkel Østergaard Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Galapagos, Gilead, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Galapagos, Gilead, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Galapagos, Gilead, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB.