Prognostic value of the clinical and imaging arm of the ASAS criteria for progression of structural sacroiliac joint lesions

OBJECTIVE

To investigate the prognostic value of the two arms of the Assessment of SpondyloArthritis international Society (ASAS) criteria regarding the progression of structural lesions in the sacroiliac joints (SIJs).

METHODS

Information on baseline fulfilment of the ASAS criteria and baseline and follow-up magnetic resonance imaging of the SIJ in 603 patients aged 18-40 years referred with low back pain to an outpatient spine were collected. Magnetic resonance imaging positivity was defined as bone marrow oedema (BMO) in two or more consecutive slices or two or more lesions in one slice, as described in the ASAS definition of sacroiliitis.

RESULTS

Of 71 participants fulfilling the ASAS criteria at baseline, 66 (93%) fulfilled the 'imaging arm' and 14 (20%) fulfilled the 'clinical arm'. The 'clinical arm' predicted the progression of erosions with an odds ratio of 55 (compared with not fulfilling the ASAS criteria), while the 'imaging arm' predicted the progression of erosions with an odds ratio of 8. Moreover, in 24% of the patients in the 'imaging arm', all having BMO at the SIJ at baseline, the BMO disappeared without neither erosions nor ankylosis emerging.

CONCLUSION

We found that the 'clinical arm' was a strong predictor for the progression of SIJ erosion, while the 'imaging arm' had a more modest prognostic value for structural progression.

Prevalence of sacroiliitis among patients referred for hip MR arthrography

OBJECTIVE

To determine the prevalence of sacroiliitis among patients who have been referred for MR arthrography.

MATERIALS AND METHODS

A retrospective search identified 130 consecutive MR arthrograms of the hip performed on a 1.5T Siemens Avanto at our institution from August 2013 to August 2014. Four studies were excluded due to the absence of a coronal short tau inversion recovery sequence of the pelvis, leaving 126 studies for analysis. A musculoskeletal radiology fellow and three attending musculoskeletal radiologists reviewed the images for the presence of bone marrow edema affecting the sacroiliac joints. Only cases of bone marrow edema meeting the Assessment of SpondyloArthritis international Society definition were considered positive. The two-tailed Fisher's exact test was used to compare the prevalence of positive MRI findings among age and gender groups. GraphPad InStat (GraphPad Software) was used for statistical calculations.

RESULTS

Patients less than 40 years of age demonstrated a statistically higher prevalence of positive MRI findings of sacroiliitis when compared to patients older than 40 (p = 0.0082). No difference in prevalence was found between genders. Overall prevalence of MRI signal alteration suggestive of sacroiliitis as defined by the Assessment of SpondyloArthritis international Society was 4.8%. Among the six patients with positive findings, two were subsequently diagnosed with spondyloarthritis.

CONCLUSION

Hip pain may be a presenting symptom of spondyloarthritis and attention should be paid to the sacroiliac joints during screening examinations, particularly in patients less than 40 years of age.

Update on the Safety Profile of Tofacitinib in Rheumatoid Arthritis from Clinical Trials to Real-World Studies: A Narrative Review

Tofacitinib is approved for the treatment of moderate to severe active rheumatoid arthritis (RA) in adult patients who do not respond adequately or are intolerant to one or more disease-modifying anti-rheumatic drugs. The tofacitinib RA clinical development program included randomized controlled trials of 6-24-month duration and long-term extension studies with > 7061 patients and 22,875 patient-years of exposure. To date, there are no data from other randomized studies in patients with cardiovascular risk factors comparing the long-term safety of a JAK inhibitor versus an anti-TNF. Real-world studies are necessary to complete the body of evidence supporting the effectiveness and safety of a therapeutic agent. In the case of tofacitinib, real-world data derive from health insurance claims databases, registries (US Corrona Registry, Swiss Registry, and others), national pharmacovigilance programs, and hospital databases (case series). The present article provides complete and up-to-date information on the safety profile of tofacitinib in RA, from clinical trials to real-world studies. Tofacitinib has demonstrated a consistent safety profile during up to 9.5 years of experience in randomized controlled trials and long-term extension studies. Real-world evidence has not added new safety issues with respect to those found in the clinical program. In general, the safety profile of tofacitinib is consistent with that of biologic disease-modifying anti-rheumatic drugs, with an increased risk of herpes zoster that seems to be a class effect of Janus kinase inhibitors. The continuous follow-up of therapeutic agents to treat rheumatoid arthritis is needed to adequately establish the safety profile for new mechanisms of action and potential risks associated with their longer term use.

Axial spondyloarthritis: new advances in diagnosis and management

Axial spondyloarthritis (axSpA) is an inflammatory disease of the axial skeleton associated with significant pain and disability. Previously, the diagnosis of ankylosing spondylitis required advanced changes on plain radiographs of the sacroiliac joints. Classification criteria released in 2009, however, identified a subset of patients, under the age of 45, with back pain for more than three months in the absence of radiographic sacroiliitis who were classified as axSpA based on a positive magnetic resonance imaging or HLAB27 positivity and specific clinical features. This subgroup was labeled non-radiographic (nr)-axSpA. These patients, compared with those identified by the older New York criteria, contained a larger percentage of women and demonstrated less structural damage. However, their clinical manifestations and response to biologics were similar to radiographic axSpA. The discovery of the interleukin (IL) IL-23/IL-17 pathway revealed key molecules involved in the pathophysiology of axSpA. This discovery propelled the generation of antibodies directed toward IL-17A, which are highly effective and demonstrate treatment responses in axSpA that are similar to those observed with anti-TNF agents. The finding that agents that block IL-23 were not effective in axSpA came as a surprise and the potential underlying mechanisms underlying this lack of response are discussed. New agents with dual inhibition of the IL-17A and F isoforms and some oral small molecule agents that target the Jak-STAT pathway, have also shown efficacy in axSpA.

Immunogenicity of biologic agents in rheumatology

Biologic agents have become a core component of therapeutic strategies for many inflammatory rheumatic diseases. However, perhaps reflecting the specificity and generally high affinity of biologic agents, these therapeutics have been used by rheumatologists with less consideration of their pharmacokinetics than that of conventional synthetic DMARDs. Immunogenicity was recognized as a potential limitation to the use of biologic agents at an early stage in their development, although regulatory guidance was relatively limited and assays to measure immunogenicity were less sophisticated than today. The advent of biosimilars has sparked a renewed interest in immunogenicity that has resulted in the development of increasingly sensitive assays, an enhanced appreciation of the pharmacokinetic consequences of immunogenicity and the development of comprehensive and specific guidance from regulatory authorities. As a result, rheumatologists have a greatly improved understanding of the field in general, including the factors responsible for immunogenicity, its potential clinical consequences and the implications for everyday treatment. In some specialties, immunogenicity testing is becoming a part of routine clinical management, but definitive evidence of its cost-effectiveness in rheumatology is awaited.

MRI of the sacroiliac joints in athletes: recognition of non-specific bone marrow oedema by semi-axial added to standard semi-coronal scans

OBJECTIVE

Assessment of combined semi-axial and semi-coronal SI joint MRI in two cohorts of young athletes to explore frequency and topography of non-specific bone marrow oedema (BMO), its association with four constitutional SI joint features, and potential restriction of false-positive assignments of Assessment of SpondyloArthritis International Society-defined sacroiliitis on standard semi-coronal scans alone.

METHODS

Combined semi-axial and semi-coronal SI joint MRI scans of 20 recreational runners before/after running and 22 elite ice-hockey players were evaluated by three blinded readers for BMO and its association with four constitutional SI joint features: vascular partial volume effect, deep iliac ligament insertion, fluid-filled bone cyst and lumbosacral transitional anomaly. Scans of TNF-treated spondyloarthritis patients served to mask readers. We analysed distribution and topography of BMO and SI joint features across eight anatomical SI joint regions (upper/lower ilium/sacrum, subdivided in anterior/posterior slices) descriptively, as concordantly recorded by ⩾2/3 readers on both MRI planes. BMO confirmed on both scans was compared with previous evaluation of semi-coronal MRI alone, which met the Assessment of SpondyloArthritis International Society definition for active sacroiliitis.

RESULTS

Perpendicular semi-axial and semi-coronal MRI scans confirmed BMO in the SI joint of every fourth young athlete, preferentially in the anterior upper sacrum. BMO associated with four constitutional SI joint features was observed in 20-36% of athletes, clustering in the posterior lower ilium. The proportion of Assessment of SpondyloArthritis International Society-positive sacroiliitis recorded on the semi-coronal plane alone decreased by 33-56% upon amending semi-axial scans.

CONCLUSION

Semi-axial combined with standard semi-coronal scans in MRI protocols for sacroiliitis facilitated recognition of non-specific BMO, which clustered in posterior lower ilium/anterior upper sacrum.

Imaging in axial spondyloarthritis: Changing concepts and thresholds

Imaging is key to recognition of axial spondyloarthritis (SpA) because clinical and laboratory examinations have limited diagnostic utility. Only MRI can capture both inflammation and bone remodeling by simultaneous depiction of active and structural lesions and their anatomic location. Bone marrow edema of limited extent on the sacroiliac joint (SIJ) MRI is often nonspecific and should be interpreted along with the clinical context. Contextual interpretation of the SIJ lesion signature viewed simultaneously on fluid- and fat-sensitive MRI sequences enhances confidence in the recognition of disease. A critical re-appraisal of using pelvic radiographs in clinically suspected early spondyloarthritis is warranted because of substantial limitations. In health care settings with low threshold access to advanced imaging, MRI is the preferred modality in early SpA. CT has recently advanced spinal outcome research, but substantial radiation exposure in young patients with spondyloarthritis and limited evidence on its relevance in practice do not advocate its use in daily routine.