INFO - Damage control in RA: Hard-hitting, early treatment crucial to curbing joint destruction

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Postgraduate Medicine

November 2004

" Damage control in rheumatoid arthritis: Hard-hitting, early treatment

crucial to cubing joint destruction " :

http://www.postgradmed.com/issues/2004/11_04/issa.htm

Excerpts:

" Rheumatoid arthritis, a chronic autoimmune disease characterized by

symmetrical and erosive joint disease, has a prevalence of about 1%

worldwide (1). It is best defined by the clinical descriptors found in the

1987 criteria of the American Rheumatism Association (2) (table 1). Although

these classification criteria may be helpful, they are not always

definitive, and they are not intended for use in diagnosis of the disease in

an individual patient. Moreover, the diagnosis of rheumatoid arthritis may

become obvious only with time, because other causes of synovitis, such as

systemic lupus erythematosus or seronegative spondyloarthropathies, may be

initially indistinguishable from this disease. "

and

" Laboratory evaluation

Laboratory abnormalities that occur in rheumatoid arthritis include the

presence of rheumatoid factor (RF) and anti-cyclic citrullinated peptide

(anti-CCP) antibody. The RF test measures IgM autoantibodies that are

directed against the Fc portion of IgG. Patients who test positive for RF

are described as being seropositive. Although about 85% of patients become

seropositive at some point, this test alone is neither sufficient nor

necessary to make the diagnosis (9).

A patient who has a negative RF test early in the course of disease may

ultimately have a positive one, and thus retesting at 6 months may be

appropriate. However, once a positive result is identified, serial

measurements of RF titer are not helpful in monitoring the course of

disease. A positive RF test may also be seen in association with other

diseases, such as chronic infections and malignancies (9).

Anti-CCP antibodies may be found in some patients with rheumatoid arthritis

and, rarely, in other diseases (9,10). The sensitivity of the anti-CCP

antibody test is comparable to that of the IgM RF test, but the specificity

is 90% to 96%, making it the most specific evaluation for rheumatoid

arthritis (10,11).

Measurement of anti-CCP antibody is not the definitive test for rheumatoid

arthritis. However, it does appear to be a useful tool in diagnosis or

exclusion of this disease in patients with polyarthritis, and it is becoming

more commonly used in clinical practice. Presence of anti-CCP antibody and

RF is associated with greater disease severity, suggesting their usefulness

as markers of prognosis (12).

Other laboratory abnormalities in rheumatoid arthritis include elevations in

test results that are indicative of acute phase reactants, such as increases

in the erythrocyte sedimentation rate and C-reactive protein level. These

indicators are less specific than RF or anti-CCP antibody, but they may be

helpful in distinguishing rheumatoid arthritis from noninflammatory diseases

such as osteoarthritis when physical signs are not prominent. Erythrocyte

sedimentation rate and C-reactive protein level are also used to monitor

therapy; unlike the RF value, these measurements do fluctuate with disease

activity.

Anemia of chronic disease is commonly found in rheumatoid arthritis;

leukocytosis, thrombocytosis, and hypoalbuminemia are often seen in active

disease. Antinuclear antibodies may be detected in about 40% of patients

with rheumatoid arthritis (13). Analysis of fluid aspirated from involved

joints, although not necessary for diagnosis, demonstrates the leukocytosis

typical of inflammatory arthritis. "

Not an MD

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org