Page 744 - Clinical Immunology_ Principles and Practice ( PDFDrive )

716 Part SIX Systemic Immune Diseases

A C

D

B
FIG 52.5 Photomicrographs and Radiographs of the Rheumatoid Hand. Chronic, severe, and
erosive RA, refractory to treatment and showing joint swelling and classical deformities (A and
B), is compared with erosive disease whose progression has been attenuated by combination
and biological therapy (C and D). White arrows indicate major areas of bone and cartilage destruc-
tion. Reproduced with kind permission from the patients.

weighted score around four domains, including distribution and Laboratory Findings
type of joint involvement (tender as well as swollen joints are Until the late 1990s, IgM RFs, autoantibodies that recognize the
included, scoring 0–5 points), serology (0–3) that includes RF Fc subunit of IgG, remained one of the few parameters of value
or ACPAs and is weighted according to antibody levels, duration in the clinical setting, forming the basis of the seropositive versus
of synovitis (0–1), and acute-phase reactants erythrocyte sedi- seronegative RA stratification and identifying those patients more
mentation rate or C-reactive protein (0–1). A score of 6 or above likely to progress to erosive disease with or without extraarticular
is indicative of an early disease state requiring initiation of features. Nevertheless, RF can be detected in up to 5% of the
disease-modifying antirheumatic drugs (DMARDs) such as healthy population and in 10–20% of the elderly population
43
methotrexate (Table 52.2), and so these criteria are thought to (>65 years of age); RF is found in a range of rheumatic conditions
better reflect an intention to treat on the part of the supervising including Sjögren syndrome, SLE, and cryoglobulinemia as well
physician. Although the presence of synovitis in at least one joint as in acute infectious and neoplastic disease entities, influencing
is required (in the absence of an alternative diagnosis that better its diagnostic utility. In general RF is not of value for monitoring
explains the synovitis), there remains debate as to whether responses to therapy.
subclinical synovitis of specific joints, defined by magnetic reso- The discovery of ACPAs, which can be detected very early in
nance imaging (MRI) or high-resolution ultrasonography the disease process, has had a major impact on diagnostic practice
30
(HRUS), should be included in the joint score. as the assays have become more widely available. They also