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 the current manifestations of the disease, level of symptoms, and patient's wishes and expectations, 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 have a genetic component, with the HLA-B27 gene being a significant risk factor 1. Risk factors include:

• Male gender (more common in men)
• Age (typically develops in late adolescence or early adulthood)
• Family history of AS
• Presence of HLA-B27 gene

Preventive Measures

Preventive measures for AS include:

• Regular exercise, especially stretching and posture exercises
• Maintaining good posture
• Quitting smoking
• Healthy diet and weight management

Signs and Symptoms

Signs and symptoms of AS include:

• Lower back pain and stiffness, especially in the morning
• Pain in the buttocks, hips, and other joints
• Fatigue
• Limited spine flexibility
• Chest pain or difficulty breathing (in advanced cases)

Treatment

Treatment for AS includes:

1. Medications:
   • NSAIDs (e.g., naproxen, ibuprofen) for pain and inflammation, as recommended by the American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 recommendations 1
   • 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 long-term complications and maintain quality of life. Patients should work closely with a rheumatologist to develop an individualized treatment plan. Regular monitoring and adjustments to the treatment regimen may be necessary as the disease progresses or responds to therapy 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, progressive, inflammatory disease of the spine and SI joints 4
• The inherited nature of AS is linked to a genetic factor, HLA-B27 4
• AS can lead to osteoporosis, and patients with AS tend to have spinal fractures due to limited mobility and osteoporosis 5
• The disease process promotes extensive remodeling of the spinal axis via ligamentous ossification, vertebral joint fusion, osteoporosis, and kyphosis, resulting in a weakened vertebral column with increased susceptibility to fractures and spinal cord injury (SCI) 6

Preventive Measures

• Primary prevention strategies for SCI in patients with AS are essential to avoid vertebral column fractures and SCI 6
• Early recognition and management of AS and its complications, such as Andersson lesions, are critical to preventing progressive kyphotic deformities and associated complications 7

Signs and Symptoms

• AS is characterized by pain, stiffness, and progressive thoracolumbar kyphotic deformity 7
• Andersson lesions can cause significant mechanical pain, often mistaken for the chronic discomfort associated with AS 7
• Patients with AS may experience limited mobility, osteoporosis, and spinal fractures 5
• AS can lead to spinal cord injury, which is often exacerbated by the highly unstable nature of vertebral column fractures in AS 6

Treatment Options

• Diagnostic criteria for AS have undergone a series of changes, and earlier diagnosis and multiple treatment options have facilitated efficient and more effective treatment 4
• Medical management, including methotrexate, sulfasalazine, non-steroidal anti-inflammatory drugs, and corticosteroids, can lead to significant pain reduction and improved mobility 7
• Surgical intervention may be required in cases of severe pain, deformity, or neurological involvement 7
• Anti-tumor necrosis factor agents have resulted in improved symptoms and functions for many patients with AS, and clinical research suggests that effective therapy can also prevent destruction in the spine and other structures 8