What are the causes, risk factors, preventive measures, signs and symptoms, and treatment options for Ankylosing Spondylitis (AS), a type of Spondyloarthritis (SpA)?

From the Guidelines

Ankylosing spondylitis (AS) is a chronic inflammatory arthritis primarily affecting the spine and sacroiliac joints, and its treatment should be tailored according to current manifestations of the disease, level of symptoms, and patient wishes, with a focus on reducing symptoms, maintaining spinal flexibility, and reducing functional limitations, as recommended by the American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 recommendations 1.

Cause and Risk Factors

The exact cause of AS is unknown, but it's believed to be a combination of genetic and environmental factors. Risk factors include:

• Genetic predisposition (HLA-B27 gene)
• Male gender (more common in men)
• Age (typically onset between 15-45 years)
• Family history of AS

Preventive Measures

Preventive measures for AS include:

• Regular exercise, especially stretching and posture exercises
• Maintaining good posture
• Not smoking
• Balanced diet and healthy weight

Signs and Symptoms

Signs and symptoms of AS include:

• Chronic lower back pain and stiffness, especially in the morning
• Pain in the buttocks, hips, and other large joints
• Fatigue
• Limited spinal mobility
• Eye inflammation (uveitis)
• In severe cases, fusion of spinal vertebrae

Treatment

Treatment for AS includes:

1. Medications:
   • NSAIDs (e.g., naproxen, ibuprofen) for pain and inflammation
   • Disease-modifying antirheumatic drugs (DMARDs) like sulfasalazine or methotrexate
   • Biologic drugs (TNF inhibitors) such as adalimumab, etanercept, or infliximab
   • JAK inhibitors (e.g., tofacitinib) for some cases
2. Physical therapy:
   • Regular exercises to maintain flexibility and posture
   • Stretching routines
   • Posture training
3. Lifestyle modifications:
   • Quitting smoking
   • Maintaining a healthy weight
   • Using proper ergonomics at work and home
4. Surgery (in severe cases):
   • Joint replacement
   • Corrective osteotomy for severe spinal deformities

Early diagnosis and treatment are crucial to prevent spinal fusion and maintain quality of life, and patients should work closely with a rheumatologist to develop an individualized treatment plan and monitor disease progression, as recommended by the Assessment of SpondyloArthritis international Society (ASAS) and the European League Against Rheumatism 1.

From the FDA Drug Label

Ankylosing Spondylitis (AS) (1. 4): reducing signs and symptoms in adult patients with active AS. The FDA drug label indicates that Ankylosing Spondylitis (AS) is a condition for which the medication is prescribed, but it does not provide information on the causes, risk factors, preventive measures, signs and symptoms, and treatment options for AS.

• Causes: Not specified in the label
• Risk factors: Not specified in the label
• Preventive measures: Not specified in the label
• Signs and symptoms: Not specified in the label
• Treatment options: The label only mentions that the medication is indicated for reducing signs and symptoms in adult patients with active AS, but does not provide a comprehensive overview of treatment options 2, 3, 2.

From the Research

Causes and Risk Factors

• Ankylosing Spondylitis (AS) is a chronic inflammatory condition primarily affecting the axial bone and sacroiliac joints, with a complicated etiology involving genetic variables, demographic factors, and environmental variables 4
• The human leukocyte antigen B27 (HLA-B27) variation is currently the most significant gene associated with AS susceptibility, accounting for around 20% of the genetic risk 4
• Over 100 genes have been connected to AS susceptibility, and the disease typically manifests in males in their third decade 4
• Family history, age of onset, gender, and ethnicity are also demographic factors that contribute to the risk of developing AS 4

Preventive Measures

• Primary prevention strategies for spinal cord injury (SCI) in patients with AS include measures to reduce the incidence of vertebral column fractures, such as maintaining a healthy lifestyle and avoiding traumatic injuries 5
• Early diagnosis and treatment of AS can also help prevent long-term complications, such as spinal fusion and disability 6, 4

Signs and Symptoms

• Clinical signs of AS include stiffness and inflammation in the back, eye inflammation, aortitis, and spinal ankylosis that impacts posture and fatigue 4
• The dagger sign and sacroiliitis on radiographs are crucial for diagnosis, and modern diagnostic tools such as MRI can help identify early inflammatory alterations 4
• Elevated inflammatory markers, such as C-reactive protein and erythrocyte sedimentation rate, can also provide supporting evidence for diagnosis 4

Treatment Options

• Treatment paradigms for AS have seen significant change over time, with first-line treatments including non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying anti-rheumatic drugs (DMARDs) 4, 7
• Biologics, such as tumor necrosis factor blockers, have also been developed and can be effective in managing AS 4, 7
• Physical therapy, emphasizing consistent exercise, stretches, and posture maintenance, is extremely helpful in managing AS, and surgical interventions may be required in extreme situations 4
• Recent research has also highlighted the significance of the interleukin 23/17 axis in the disease cascade, and a deeper comprehension of the genetic landscape may open the door for more specialized therapies 4, 8