Re: RESEARCH Anti-Cyclic Citrullinated Peptide Antibody (To )

September 16, 2004

,

As you may be aware, there is no test to say you do or don't have

RA. For obvious reasons, this makes it difficult to diagnose RA or

to rule out RA as a cause of symptoms. This recently new test

described below may be a better way to help identify or rule out RA,

although not 100%. You might want to ask your rheumy if he did this

test. Beyond that, RA is usually diagnosed by watching a patients

symptoms over time, trying RA medications and see how it affects the

symptoms, x-rays to look for damage, and monitoring bloodwork.

Jennie

> Anti-Cyclic Citrullinated Peptide Antibody Assay Effective RA Screen

>

> NEW YORK (Reuters Health) Sept 15 - The highly specific anti-cyclic

> citrullinated peptide antibody (CCP) assay provides useful

additional

> information in the diagnosis of rheumatoid arthritis, according to

a report

> in the September ls of the Rheumatic Diseases.

>

> The first generation of the CCP assay has been shown to provide high

> specificity in the diagnosis of rheumatoid arthritis, the authors

explain.

> " Our study is one of the first to be published using the second

generation

> test, CCP2. "

>

> Dr. Inka Vallbracht of University of Munich, Germany and colleagues

> prospectively evaluated the additional diagnostic and clinical

value of CCP2

> in 295 patients with rheumatoid arthritis, 163 patients with

degenerative or

> other inflammatory joint disease, 103 patients with connective

tissue

> disease or vasculitis, and 154 healthy controls.

>

> The CCP2 assay provided the best specificity for detecting

rheumatoid

> arthritis (97.1%), the authors report, and the highest sensitivity

was

> obtained with the IgM-RF (rheumatoid factor) assay (66.4%). The

sensitivity

> of the CCP2 assay was 64.4%.

>

> Based on a receiver operating characteristic analysis, the CCP2

assay had

> the highest diagnostic value, followed by IgM-RF, IgA-RF, and IgG-

RF assays.

>

> The CCP2 assay was also positive in 30 of 87 rheumatoid arthritis

patients

> in whom all three RF isotypes were negative, the researchers note.

Overall,

> 12.9% of the rheumatoid arthritis patients were IgM-RF-negative but

> CCP2-positive.

>

> Among patients with rheumatoid arthritis of less than 1 year's

duration,

> 14.4% were CCP2-positive but negative for all three RF isotypes.

>

> A higher percentage of patients with high disease activity (81.4%)

were

> CCP2-positive than patients with low disease activity (58.5%), the

> investigators report, and patients with severe joint destruction

were more

> often CCP-2 positive (80.3%) than were patients with minimal joint

damage

> (54.1%).

>

> " ELISA for IgM-RF is still most useful as a screening marker in the

> diagnosis of rheumatoid arthritis, " the researchers

write. " However, the

> second generation CCP ELISA now has a comparable sensitivity, and in

> addition it has proved to be the most specific marker for the

disease. "

>

> " We would recommend the use of CCP in all suspected RA patients,

not only in

> RF negative ones, " Dr. Vallbracht told Reuters Health.

>

> " The presence of CCP (especially high levels) may indicate a more

aggressive

> therapy regime [is indicated] right in the beginning of the

disease, " Dr.

> Vallbracht added.

>

> Ann Rheum Dis 2004;63:1079-1084.

>

> http://www.medscape.com/viewarticle/489323

September 16, 2004