The time-averaged inflammatory disease activity estimates the progression of erosions in MRI of the sacroiliac joints in ankylosing spondylitis

Abstract

A method to estimate the individual ankylosing spondylitis (AS) patient radiological progression of semi-quantitative magnetic resonance imaging (MRI) changes in the sacroiliac joints has not been described yet, which this study examines. Inflammatory disease activity and MRIs of the sacroiliac joints of 38 patients with recent onset established AS were analyzed at baseline and during follow-up. Sacroiliac MRIs were semi-quantitatively assessed using a modification of the "Spondylarthritis Research Consortium of Canada" (SPARCC) method. In each patient, the annual inflammatory disease activity was estimated by the time-averaged C-reactive protein (CRP; mg/l), calculated as the area under the curve. The mean (SD) CRP decreased from 1.3 (1.8) at baseline to 0.5 (0.6) at follow-up MRI (p < 0.04), which has been performed after a mean (SD) disease course of 2.8 (1.5) years. The mean (SD) annual increase (∆) of SPARCC score from baseline to follow-up MRI was 0.4 (0.4). Baseline individual SPARCC sub-score for bone marrow edema did not statistically significantly correlate with individual ∆SPARCC sub-score for erosions (p = N.S.). The individual AS patient correlation between annual time-averaged inflammatory disease activity and each annual ∆SPARCC sub-scores was only statistically significant for erosions (p < 0.01; r = 0.71). Our results show that bone marrow edema and contrast-medium enhancement at baseline do not relate to the progression of erosions but the calculation of the individual patient annual time-averaged inflammatory disease activity allows to estimate the annual progression of erosions in sacroiliac MRIs of patients with AS.

Role of Diffusion-weighted and Contrast-enhanced Magnetic Resonance Imaging in Differentiating Activity of Ankylosing Spondylitis

“…reported that although the role of T2W-STIR and CE-MRI are comparable in identifying the activity of AS, administration of contrast agents may be beneficial for inexperienced MRI readers or detecting early AS with minimal changes. [10] However, some studies using small sample had shown that DWI and CE-MRI had similar diagnostic value, and that CE-MRI does not contribute significant additional information as compared to DWI,[17181920] which is consistent with our results.…”

What Level of Inflammation Leads to Structural Damage in the Sacroiliac Joints? A Four‐Year Magnetic Resonance Imaging Follow‐Up Study of Low Back Pain Patients

“…Structural lesions at the SI joints are also readily detectable on MRI and are considered hallmark signs of manifest SpA, but little is known about the evolution of such lesions over time and their relationship to BME. Most studies that have investigated the association between MRI findings and SpA have been cross‐sectional , and the few longitudinal studies in the field have examined highly selected and mostly small sample sizes of SpA patients without inclusion of patients with non–SpA‐related LBP .…”

Consensus statements on the imaging of axial spondyloarthritis in Australia and New Zealand

“…Similar studies examining ESR are inconsistent . In AS a single study found strong correlation between time‐averaged CRP and spinal erosions but not spinal BMO . There is conflicting evidence of association between sacroiliac BMO and CRP …”

“…37,38 In AS a single study found strong correlation between time-averaged CRP and spinal erosions but not spinal BMO. 41 There is conflicting evidence of association between sacroiliac BMO and CRP. 7,37,40 Symptom-based disease activity scores of axial SpA are not consistently associated with acute inflammation of the spine or SIJ.…”