Imaging Biomarkers in Crohn's Associated Spondyloarthritis

Study Summary

In patients with Crohn's Disease, symptoms of inflammatory back pain (IBP) precede changes on plain X-rays by years, and MRI changes of axial inflammation precede development of X-ray changes. Sacroiliitis on MRI without x-ray changes (i.e.Non radiographic SpA) is a valid diagnostic criterion for Spondyloarthritis (SpA) and leads to earlier diagnosis of SpA in patients with IBP. It is unclear when MRI changes occur, and if they precede clinical symptoms of IBP. There are reports of asymptomatic sacroiliitis noted on MRI in Crohn's patients. This is important, as MRI evidence of inflammation may be the first sign of incipient SpA. Inflammation in other regions of the axial skeleton in SpA patients has also been documented, but its significance is unknown. The prospect of undiagnosed and untreated inflammation is concerning, as it can lead to significant morbidity. Moreover, relationship between MRI evidence of axial inflammation-likely a proxy for systemic inflammation- and patient reported outcomes (e.g. ASDAS-CRP= Ankylosing Spondylitis Disease Activity Score- C reactive protein, BASDAI= Bath Ankylosing Spondylitis Disease Activity Index, SF-12 = Short Form- 12, HBI= Hervey Bradshaw Index and PROMIS-29= Patient Reported Outcome Measurement Information System-29), has not been reported. Recent unpublished data from Dr. Longman's lab (collaborator) suggest a distinct intestinal dysbiosis in Crohn's associated SpA. But relationship between this microbiome and MRI changes is yet to be determined. Identifying inflammation earlier on MRI- in the absence of clinical symptoms will provide an opportunity to intervene early with available therapies, such as- biologics etc. Asymptomatic MRI changes could be a marker of underlying systemic inflammation- which is a risk factor for poor outcomes in Crohn's associated SpA. Studying association between whole spine MRI changes with patient reported outcomes) may facilitate informed clinical decision making to initiate targeted the

Primary Outcome

MRIs were independently read and scored by 2 expert rheumatologists and 1 newly trained rheumatologist reader, blinded to any clinical information. MRIs were evaluated and scored for presence of bone marrow edema (BME) and structural lesions (erosion, fat metaplasia, backfill and ankylosis) using a validated scoring method originally derived from the Spondyloarthritis Research Consortium of Canada SIJ module. MRI was considered "positive" for presence of sacroiliitis if it met global evaluation,

Interventions

• OTHER No intervention