RESEARCH - Ongoing joint damage despite RA remission tied to subclinical inflammation

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Reuters Health Information 2008.

By Baltic

Ongoing joint damage despite RA remission tied to subclinical inflammation

NEW YORK (Reuters Health) Oct 27 - When rheumatoid arthritis (RA) is

in clinical remission yet structural deterioration continues, the

cause appears to be subclinical joint inflammation (synovitis) that

can be detected by ultrasound and by magnetic resonance imaging (MRI),

according to a prospective longitudinal study by U.K. and U.S.

researchers published in the October issue of Arthritis & Rheumatism.

The study is reportedly the first to show both this direct association

and to demonstrate that subclinical inflammation can predict later

results by X-ray examination of clinically asymptomatic joints.

This study used the same cohort of patients who had participated in an

earlier phase of the study, published in 2006. In that phase, the

authors had established that even though most of the patients

fulfilled standard criteria for RA remission, and all were receiving

disease-modifying antirheumatic drugs (DMARDs), sizable majorities of

the patients showed synovial inflammation when imaged with ultrasound

or MRI.

In the current analysis, 90 participants underwent X-rays of hands,

wrists and feet, as well as MRI and ultrasound assessments of the

dominant hand and wrist, at baseline and then 12 months later.

The patients had a mean age of 57 years, two-thirds were female and

91% were taking DMARDs. At baseline, median disease duration was 7

years and median remission was almost 2 years.

During the 12-month study period, there were no statistically

significant changes in measures of RA activity; that is, all patients

were still considered to be in remission, senior researcher Dr.

Emery at the University of Leeds, UK, and colleagues report.

Despite being in remission, 17 of the 90 patients experienced an

overall increase (p = 0.001) in their radiographic joint damage

scores. In addition, baseline scores as determined by the more

sensitive imaging methods were significantly associated with the

likelihood of subsequent structural deterioration in the

metacarpophalangeal joints.

The results, write the researchers, " suggest that, in the majority of

RA patients who are treated with conventional DMARDs, joint damage is

closely related to subclinical inflammation, which in states of low

disease activity, can only be accurately detected by imaging

techniques such as musculoskeletal ultrasound and MRI. "

The authors suggest that the threshold for additional intervention in

such patients might need to be lowered, since they could benefit from

additional therapy even when RA activity is low.

Dr. Emery told Reuters Health that barriers to wider use of ultrasound

and MRI in assessing subclinical manifestations of RA include cost and

training requirements, as well as access.

Arthritis Rheum 2008;58:2958-2967.

http://medgenmed.medscape.com/viewarticle/582629_print

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