Ankylosing spondylitis
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Ankylosing spondylitis (AS) is a chronic, progressive inflammatory arthritis primarily affecting spine and sacroiliac joints, causing eventual fusion of the spine; it is a member of the group of the spondylarthropathies. Complete fusion results in a complete rigidity of the spine, a condition known as bamboo spine.
Treatment is with physiotherapy and medication. Some cases remain mild, while other result in marked disability.
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Signs and symptoms
The typical patient is a young man of 15-30 years old (although women are also affected) with pain and stiffness in the spine. It is also associated with iridocyclitis (anterior uveitis), ulcerative colitis, psoriasis and Reiter's disease, through HLA-B27 (see below).
Organs affected by AS, other than the axial spine, are the hips, heart, heels, and other areas (peripheral).
Diagnosis
The diagnosis is by X-ray studies of the spine, which show characteristic spinal changes and sacroiliitis. A normal X-ray does not exclude the disease.
HLA-B27 (demonstrated in a blood test) is occasionally used, but does not distinguish AS from other diseases and is therefore not of real diagnostic value.
Pathophysiology
AS is a systemic rheumatic disease, and about 90% of the patients are HLA-B27 positive. HLA-DR and IL1ra are also implicated in ankylosing spondylitis. Although specific autoantibodies cannot be detected, its response to immunosuppresive medication has prompted its classification as an autoimmune disease.
Hypotheses on its pathogenesis include a cross-reaction with antigens of the Klebsiella bacterial strain (Tiwana et al. 2001). Particular authorities argue that elimination of the prime nutrients of Klebsiella (starches) would decrease antigenemia and improve the musculoskeletal symptoms. On the other hand, Khan (2002) argues that the evidence for a correlation between Klebsiella and AS is circumstantial so far, and that the efficacy of low-starch diets has not yet been scientifically evaluated.
Epidemiology
The sex ratio is 3:1 for men:women. In the USA, the prevalence is 0.25%, but as it is a chronic condition, the number of new cases (incidence) is fairly low.
Therapy
Physical therapy and exercise, along with medication, are at the heart of therapy for ankylosing spondylitis.
There are four major types of medications used to treat ankylosing spondylitis:
- NSAIDs such as aspirin, ibuprofen, naproxen and COX-2 inhibitors, which reduce inflammation and pain;
- Steroids;
- DMARDs such as methotrexate and sulfasalazine, which are immunosuppressants; and
- TNFα receptors such as etanercept and infliximab, also known as biologics.
Alternative therapies are:
- Diet - starch free diet (Ebringer et al 1996), london diet, Paleolithic diet
- Stretching - yoga, pilates
- Exercise - swimming, jogging, etc.
Prognosis
AS can range from mild to progressively debilitating, and from medically controlled to refractive.
See also
- NASC, the AS patients' federation
- NIAMS, the National Institute of Arthritis and Musculoskeletal and Skin Diseases
Reference
- Ebringer A, Wilson C. The use of a low starch diet in the treatment of patients suffering from ankylosing spondylitis. Clinical Rheumatology 1996 Jan;15 Suppl 1:62-66. PMID 8835506.
- Khan MA. 2002. Ankylosing spondylitis: The facts. Oxford University Press. ISBN 0192632825.
- Tiwana H, Natt RS, Benitez-Brito R, Shah S, Wilson C, Bridger S, Harbord M, Sarner M, Ebringer A. Correlation between the immune responses to collagens type I, III, IV and V and Klebsiella pneumoniae in patients with Crohn's disease and ankylosing spondylitis. Rheumatology (Oxford) 2001;40:15-23. PMID 11157137.
External links
National organizations
- National Ankylosing Spondylitis Society (http://www.nass.co.uk/) (UK)
- Spondylitis Association of America (http://www.spondylitis.org/) (USA)
Support groups
- KickAS.org (http://www.kickas.org/) (online community; support and information)de:Morbus Bechterew