Assessing the construct validity of clinical tests to identify sacroiliac joint inflammation in patients with non‐radiographic axial spondyloarthritis

Interobserver Reliability of Magnetic Resonance Imaging of Sacroiliac Joints in Axial Spondyloarthritis

Introduction: Axial spondyloarthritis (axSpA) is characterized by damage to the axial skeleton and entheses, and is often associated with extra-articular manifestations, in the presence of the human leukocyte antigen (HLA) B27. The aim of our study is to assess the performance of rheumatologists in interpreting the inflammatory and structural damage to sacroiliac joints, in comparison to radiologists. Material and Methods: The present study included a total of 34 patients diagnosed with axSpA, according to the Assessment of SpondyloArthritis International Society (ASAS) criteria for axSpA, examined from January 2021 to November 2021 in the Departments of Rheumatology and Radiology and Medical Imaging of the University of Medicine and Pharmacy of Craiova. All patients underwent physical examination, laboratory tests, and magnetic resonance imaging (MRI) of the sacroiliac joints. The images were interpreted by a senior radiologist (SR), a junior radiologist (JR), a senior rheumatologist (SRh), and a junior rheumatologist (JRh), who were blinded to the clinical and paraclinical data. Results: The overall κ was 0.7 for the JR (substantial agreement), 0.707 for the SRh (substantial agreement), and 0.601 for the JRh (moderate agreement), in comparison with the SR. Regarding the overall inflammatory changes, the SRh and JR were proven to have substantial agreement (κ = 0.708 and 0.742, respectively) with the SR, while the JRh was proven to have moderate agreement (κ = 0.607). The structural damage observed by the JR showed substantial agreement (κ = 0.676) with the SR, while the SRh and JRh had substantial and moderate agreement (κ = 0.705 and 0.596, respectively) with the SR. Conclusions: Our study showed substantial agreement between the senior radiologist, senior rheumatologist, and junior radiologist, and moderate agreement with the junior rheumatologist.

Australian Consensus Statements for the Assessment and Management of Non-radiographic Axial Spondyloarthritis

Background

The understanding of non-radiographic axial spondyloarthritis (nr-axSpA) has accelerated over the last decade, producing a number of practice-changing developments. Diagnosis is challenging. No diagnostic criteria exist, no single finding is diagnostic, and other causes of back pain may act as confounders.

Aim

To update and expand the 2014 consensus statement on the investigation and management of non‐radiographic axial spondyloarthritis (nr-axSpA).

Methods

We created search questions based on our previous statements and four new topics then searched the MEDLINE and Cochrane databases. We assessed relevant publications by full-text review and rated their level of evidence using the GRADE system. We compiled a GRADE evidence summary then produced and voted on consensus statements.

Results

We identified 5145 relevant publications, full-text reviewed 504, and included 176 in the evidence summary. We developed and voted on 22 consensus statements. All had high agreement. Diagnosis of nr-axSpA should be made by experienced clinicians, considering clinical features of spondyloarthritis, blood tests, and imaging. History and examination should also assess alternative causes of back pain and related conditions including non-specific back pain and fibromyalgia. Initial investigations should include CRP, HLA-B27, and AP pelvic radiography. Further imaging by T1 and STIR MRI of the sacroiliac joints is useful if radiography does not show definite changes. MRI provides moderate-to-high sensitivity and high specificity for nr-axSpA. Acute signs of sacroiliitis on MRI are not specific and have been observed in the absence of spondyloarthritis. Initial management should involve NSAIDs and a regular exercise program, while TNF and IL-17 inhibitors can be used for high disease activity unresponsive to these interventions. Goals of treatment include improving the frequent impairment of social and occupational function that occurs in nr-axSpA.

Conclusions

We provide 22 evidence-based consensus statements to provide practical guidance in the assessment and management of nr-axSpA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00416-7.

Imaging in Axial Spondyloarthritis: What is Relevant for Diagnosis in Daily Practice?

PURPOSE OF REVIEW

To explore how imaging may assist diagnosing axial spondyloarthritis in rheumatology practice.

RECENT FINDINGS

A diagnosis of axial spondyloarthritis is based on pattern recognition by synthesizing clinical, laboratory, and imaging findings. In health care settings providing low threshold access to advanced imaging, sacroiliac joint MRI is the preferred imaging modality in clinically suspected axial spondyloarthritis. In daily routine, the optimum protocol to assess suspected inflammatory back pain combines sacroiliac joint and spine MRI fitting a 30-min slot. Contextual assessment of concomitant structural and active MRI lesions is key to enhance diagnostic utility. In women with postpartum back pain suggestive of axial spondyloarthritis, recent reports advocate waiting 6-12 months after delivery before acquiring sacroiliac joint MRI. Major unmet needs are consistent MRI protocols, standardized training modules on how to evaluate axial MRI, and timely dissemination of imaging advances into mainstream practice both in rheumatology and in radiology. In rheumatology practice, MRI has become indispensable to help diagnose early axial spondyloarthritis. However, major gaps in training and knowledge transfer to daily care need to be closed.