Ankylosing Spondylitis:
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cases of ankylosing spondylitis
Clinical:
Ankylosing spondylitis occurs in about
0.15%
of white males, is uncommon in blacks, and the male to female ratio is
about
10:1 [3]. The peakk incidence is between the ages of 15-35 years [5].
Up to 95% of patients with ankylosing spondylitis are HLA-B27 (and 2-20% of persons
that are
HLA-B27 positive will develop ankylosing spondylitis) [3]. Symptoms of the disorder and
typically
isolated to the inflammatory spinal disease, but ocular (uveitis
or iritis), cardiovascular (aortic
insufficiency or
dilatation), and pulmonary involvement may also occur [3].
The reported
incidence of pulmonary disease varies, but it probably develops in only
about
1% of patients and it is characterized by upper lobe fibrotic lung
disease
which tends to mimic old TB. The lung disease is usually not evident
until ten
or more years after the onset of bone disease (in patients with
advanced stage disease). In fact, lung disease is
generally identified only in patients with severe bone changes, but
patients
are usually asymptomatic [3]. Lung disease begins unilaterally and then
becomes
bilateral. The cause of the fibrobullous
changes is
not known [3] and it is not felt to be a result of chest wall
immobility.
Secondary superinfection of the cavities
with Aspergillus (i.e.: mycetoma
formation) may also be seen in these patients.
Ankylosing spondylitis is also associated
with aortitis- aortic root disease and
aortic valve
disease can be found in up to 80% of patients [4]. Aortic wall
thickening can
be found at imaging in about 60% of affected patients [4].
X-ray:
Pulmonary
parenchymal findings may mimic those of TB
infection
with apical fibrocavitary changes and cyst
formation.
If fungal superinfection has occurred a mycetoma may be identified.
High-resolution CT can
detect additional abnormalities not identified by plain film
radiographs (2).
REFERENCES:
(1) Semin Arthritis Rheum 1989; Boushea DK, et al. The pleuropulmonary manifestations of ankylosing spondylitis. 18 (4): 277-281 (No abstract available)
(2) AJR 1997; Fenlon HM, et al. Plain radiographs and thoracic high-resolution CT in patients with ankylosing spondylitis. 168: 1067-1072
(3) J Thorac Imaging 1992; Tanoue LT. Pulmonary involvement in collagen vascular disease: A review of the pulmonary manifestations of the Marfan syndrome, ankylosing spondylitis, Sjogren's syndrome, and relapsing polychondritis. 7 (2): 62-77
(4) Radiographics 2011; Restrepo
CS, et al. Aortitis: iimng
spectrum of the infectious and inflammatory conditions of the aorta.
31:
433-451
(5) Radiographics 2012; Capobianco J, et al. Thoracic manifestations of collagen vascular diseases. 32: 33-50
