Israel Medical Association Journal

Background: Clinical research is needed to identify patients with axial spondyloarthritis (axSpA) who are more likely to be responsive to interleukin (IL)-17 inhibition.

Objectives: To evaluate short-term efficacy of secukinumab in the management of axSpA.

Method: Twenty-one patients (7 males, 14 females) with axSpA were consecutively treated with secukinumab. Laboratory and clinical assessments were based on erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP, and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Data were recorded at baseline and at a 3 month follow-up visit.

Results: The study was comprised of 21 patients. Both BASDAI and ASDAS-CRP showed a statistically significant reduction between the baseline and the 3 month visit (P < 0.0001 and P = 0.0005, respectively). During the laboratory assessment, ESR showed a significant decrease (P = 0.008) while CRP improvement did not reach statistical significance (P = 0.213). No statistical significance was observed between patients treated with secukinumab 150 mg vs. 300 mg in BASDAI (P=0.99), ASDAS-CRP (P = 0.69), ESR (P = 0.54), and CRP (P = 0.56). No significant differences emerged between the BASDAI (P = 0.15), ASDAS-CRP (P = 0.09), and CRP (P = 0.15) rates in biologic-naïve patients and those previously failing tumor necrosis factor-α inhibition. Conversely, ESR decrease was significantly higher in the biologic-naïve subgroup (P = 0.01). No adverse events were reported.

Conclusions: Secukinumab has proven remarkable short-term effectiveness, regardless of the biologic treatment line. A dosage of 150 mg proved to be appropriate in the clinical and laboratory management of axSpA.

Background: Magnetic resonance imaging (MRI) is the most sensitive imaging modality for the detection of sacroiliitis. Diagnosing sacroiliitis on MRI is not always straightforward and can be challenging in some cases.

Objectives: To evaluate the prevalence of alternative diagnoses suggested by MRI and characterize the MR appearance of the most common ones.

Methods: Consecutive MRI examinations of the sacroiliac joints (SIJ) performed between 2005 and 2012 were retrospectively evaluated for the presence of structural and active sacroiliitis findings according to the Assessment of SpondyloArthritis International Society guidelines. Alternative diagnoses, including degenerative changes, diffuse idiopathic skeletal hyperostosis (DISH), Osteitis condensans ilii (OCI), septic sacroiliitis/discitis, stress reaction as well as anatomic variants, were registered

Results: We evaluated 281 MRI examinations, 116 males, 165 females, average age 44 ± 15 years. Sacroiliitis was found in 71 examinations (25%) and alternative diagnoses were suggested in 87 (31%) (OCI 8.9%, anatomic variants 5.3%, septic sacroiliitis 5.3%, degenerative findings 4.3%, diffuse idiopathic skeletal hyperostosis [DISH] 1.5%, stress reaction 0.7%, tumor 0.3%). A normal examination was found in the remaining 123 examinations. Patients with alternative diagnoses were older than those with sacroiliitis (62 vs. 47 years of age, respectively, P > 0.05). Alternative pathologies in the SIJ were significantly more common in females (66) than males (21), P < 0.05.

Conclusions: A substantial proportion of patients with suspected sacroiliitis had normal SIJ while the rest were more commonly diagnosed with other pathologies. A referral by an experienced rheumatologist may improve the sensitivity and specificity of this important examination.

Axial spondyloarthritis (axSpA) covers the stage of non-radiographic axial spondyloarthritis (nr-axSpA) and classic ankylosing spondylitis. The pathognomonic findings of axSpA are mainly inflammatory and osteoproliferative changes in the sacroiliac joints (SIJ) and the spine. Various imaging techniques are being used in daily practice for assessment of disease-specific changes, such as periarticular bone marrow edema, erosions, sclerosis, fat metaplasia and ankylosis in the SIJ or spondylitis, spondylodiscitis, facet joint involvement, or syndesmophytes in the spine of patients with axSpA. Conventional radiographs are still considered the gold standard for assessment of structural changes, while the method of for detection of inflammatory changes is magnetic resonance imaging (MRI).

A result for an MRI in the SIJ is considered positive for axSpA when more than one lesion is present on one MRI slice, If there is one lesion only, this should be present on at least two consecutive slices. For the spine, inflammatory lesions should preferably be located in the corner of the vertebral bodies, while occurrence of spondylitis in three or more vertebral corners is considered highly suggestive of axSpA.

This review gives a detailed overview about the benefits and limitations of all available imaging techniques in patients with axSpA, explains the usage of imaging techniques in the context of diagnosis and differential diagnosis of the disease, and reports on the potential future trends in the area of imaging of the axial skeleton in patients who are suspicious for this diagnosis.

The term non-radiographic axial spondyloarthritis (nrAxSpA) was coined for patients who have a clinical picture of ankylosing spondylitis (AS) but do not exhibit radiographic sacroiliitis. The ASAS classification criteria for nrAxSpA, ensuring the recruitment of homogenous study cohorts, were accepted in 2009, although the respective diagnostic criteria for daily clinical practice have not yet been developed. The clinical diagnosis should be based on the composite of clinical symptoms and signs of the disease, HLA B27 status, and magnetic resonance imaging (MRI) of sacroiliac joints. Notably, a negative MRI or HLA B27 does not exclude the diagnosis in patients with a high clinical suspicion for nrAxSpA. The prevalence of nrAxSpA is similar to that of AS, but the former has a higher female preponderance. The rate of progression of nrAxSpA to the radiographic stage of disease (AS) ranges from 10% to 20% over 2 years. Current treatment strategies for nrAxSpA are the same as for AS and include non-steroidal anti-inflammatory drugs and inhibitors of tumor necrosis factor-alpha. While this review summarizes the current achievements in the field of nrAxSpA, further understanding of the epidemiology and natural history of the disease and, particularly, mechanisms of inflammation and subsequent new bone formation is essential for the development of new treatment strategies for nrAxSpA patients.