Page 810 - Clinical Immunology_ Principles and Practice ( PDFDrive )

CHaPtEr 57 Spondyloarthritis 781

TABLE 57.6 Measurements of Disease Radiographic Imaging of Spondyloarthritis
Outcome in spondyloarthritis Axial Spondyloarthritis
The bottom line in the diagnosis of AS is the demonstration of
ankylosing spondylitis radiographic sacroiliitis (Fig. 57.5). Two outcome instruments
4
1) Disease activity have been introduced in the assessment of disease damage and
(a) Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) progression in AS: the Bath Ankylosing Spondylitis Radiographic
(b) Ankylosing Spondylitis Disease Activity Score (ASDAS) Index (BASRI) and the modified Stokes Ankylosing Spondylitis
(c) Patient and Physician Global Assessments 31
2) Function Scoring System (mSASSS). As a rule, these instruments have
(a) Bath Ankylosing Spondylitis Functional Index (BASFI) a low sensitivity to change (7.5% over 2 years), have been validated
(b) Dougados Functional Index in long-duration disease only, and their predictive effect for
3) Quality of Life disease activity is not yet ascertained.
(a) SF-36 One problem with radiographic imaging is the average decade-
(b) Ankylosing Spondylitis Quality of Life Index (ASQOL) long interval from the onset of inflammatory back pain to the
(c) ASAS Health Index 5
4) Metrometry appearance of radiographic sacroiliitis. The introduction of MRI
(a) Schober test (lumbar flexion) imaging of the spine and entheses has allowed not only correct
(b) Chest expansion anatomical description of spinal structures but also differentiation
(c) Occiput-to-wall distance of AS-related and unrelated inflammatory spinal lesions earlier
(d) Lateral bending than is possible with standard radiography. MRI of the sacroiliac
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(e) Bath Ankylosing Spondylitis Metrology Index (BASMI) lateral joints and spine is currently the only imaging tool to localize
ending
5) Imaging and quantify spinal inflammation accurately (Fig. 57.6) and is
(a) Standard radiography being developed as a measure of disease activity and treatment
(b) Computed tomography response.
(c) Magnetic resonance imaging
6) Assessment in Ankylosing Spondylitis (ASAS) 20 Psoriatic Arthritis
(a) An improvement of 20% and absolute improvement of 10 units PsA has some characteristic radiographic manifestations, including
on a 0–100 scale in three of the following four domains:
i. Patient global assessment (by visual analogue scale [VAS] asymmetrical involvement, involvement of the DIP joints, and
global assessment) the classic “pencil-in-cup” deformities. Also seen are periostitis,
ii. Pain assessment (the average of VAS total and nocturnal pain bony ankylosis, and bony erosions with new bone formation.
scores) Radiographic severity is quantitated by the modified Sharp scoring
iii. Function (represented by BASFI) method used in RA.
iv. Inflammation (the average of the BASDAI’s last two VAS The measures used in PsA to assess disease severity include
concerning morning stiffness, intensity, and duration) the ACR response criteria, the Psoriatic Arthritis Response Criteria
v. Absence of deterioration in the potential remaining domain
(deterioration is defined as 20% worsening) (PsARC), which entail improvement in at least two of the fol-
lowing four criteria: (i) physician; and (ii) patient global assess-
Psoriatic arthritis ments (on 0–5 visual analogue scales); (iii) tender and swollen
1) Arthritis joint scores (>30% improvement), with improvement in at least
(a) ACR response criteria one of these two joint scales; and (iv) no worsening in any criteria.
(b) Psoriatic Arthritis Response Criteria (PsARC) The Ritchie Articular Index is also used. The Psoriasis Area and
(c) Ritchie Articular Index Severity Index (PASI) is used to assess the extent of skin involve-
2) Skin response ment, as well as general measures, such as the target lesion score,
(a) Psoriasis Area and Severity Index (PASI)
(b) Target lesion score and the static global assessment. The PASI is a composite index
(c) Static global assessment of skin disease severity, including an overall evaluation and
3) Quality of life (HAQ, SF-36, DLQI) quantitation of the extent of scaling, erythema, and induration
4) Radiographic weighted: (i) by severity; and (ii) by body surface area. A target
lesion is a single lesion >2 cm in diameter that is evaluated over
time by a dermatologist and is graded for size, elevation, erythema,
CLiNiCaL rELEVaNCE and scaling.
Utility of Human Leukocyte Antigen (HLA)-B27 DISEASE COURSE AND PROGNOSIS
Testing in the Evaluation of Inflammatory Back
Pain and Spondyloarthritis Ankylosing Spondylitis
AS significantly impacts the lives of those affected. Recent data
• Not indicated where the diagnosis is unquestionable, as it has little suggest that patients with AS are more likely to be work disabled or
value in prognosis. even not participate in the labor force compared with population
• Although patients with spondyloarthritis of African and Middle Eastern
ancestry are more likely to be HLA-B27 negative, the finding of HLA-B27 controls, especially in older patients and in those with longer
in these patients has higher predictive value. disease duration. Moreover, in the same study, patients with AS
• Most useful in patients with either inflammatory back pain without were more likely to have never married or to be divorced. Women
radiographic changes or with other features of spondyloarthritis with AS were less likely than expected to have had children. 32
(unexplained lower extremity arthritis in a young adult, uveitis, etc.). Although AS is a chronic condition that can frequently have
• If serological testing is used to ascertain HLA-B27, it must be ensured an unpredictable course, some studies suggest that those with
that the blood sample arrives in the laboratory within 24 hours of
being drawn (false negatives will be caused by cell death). higher levels of disease activity early in the course of the disease
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are more likely to have active disease in the future (Fig 57.7).