From the Guidelines
Screening for spondylitis should start with a combination of clinical assessment, laboratory tests, and imaging studies, prioritizing the use of conventional radiography of the sacroiliac joints as the first imaging method, followed by MRI of the sacroiliac joints if clinical suspicion remains high and radiography is normal, as recommended by the European League Against Rheumatism (EULAR) 1.
Key Steps in Screening for Spondylitis
- Evaluate patients for key symptoms including chronic low back pain lasting more than three months, morning stiffness that improves with activity, and pain that wakes patients at night.
- Perform physical examination focusing on spinal mobility tests such as the Schober test, chest expansion, and occiput-to-wall distance.
- Include laboratory tests for inflammatory markers like C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and consider HLA-B27 genetic testing, especially in patients with suggestive symptoms.
- Use imaging studies, starting with plain X-rays of the sacroiliac joints and spine to look for sacroiliitis, and consider Magnetic Resonance Imaging (MRI) for detecting early inflammatory changes when clinical suspicion is high but X-rays are normal, as supported by the American College of Radiology Appropriateness Criteria 1.
Importance of Early Detection
Early detection of spondylitis is crucial as prompt treatment with NSAIDs and potentially biologics like TNF inhibitors can prevent disease progression and structural damage, improving patient outcomes and quality of life, as emphasized in recent guidelines and studies 1.
Considerations for Imaging
- Conventional radiography is recommended as the first imaging method for diagnosing sacroiliitis as part of axial SpA.
- MRI of the sacroiliac joints is an alternative first imaging method, especially in young patients or those with short symptom duration, and is recommended if the diagnosis cannot be established based on clinical features and conventional radiography.
- Imaging modalities other than conventional radiography and MRI are not generally recommended for the diagnosis of axial SpA, with the exception of CT in specific cases where conventional radiography is negative and MRI cannot be performed.
From the Research
Screening for Spondylitis
To screen for spondylitis, the following methods can be used:
- Comprehensive history taking
- Physical examination
- Laboratory studies 2
- Monitoring of disease activity using measures such as the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) 3, 4, 5, 6
- Assessment of inflammatory markers such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum amyloid A (SAA) 4, 5, 6
Inflammatory Markers
Inflammatory markers can be used to monitor disease activity and response to treatment:
- ESR and CRP can be used to assess disease activity, but neither is superior to the other 5, 6
- SAA may be a useful marker for monitoring response to anti-tumor necrosis factor (anti-TNF) treatment 4
- Elevated baseline levels of CRP and SAA may be associated with a higher predictive value for response to treatment 4
Disease Activity Assessment
Disease activity can be assessed using various measures, including: