RESEARCH - Biomarkers may predict the development of RA years before symptoms appear

[Guest guest]

Biomarkers May Predict the Development of RA Years Before Symptoms Appear

NEW YORK (Reuters Health) Mar 12 - Women who develop rheumatoid

arthritis (RA) have evidence of immune activation years before the

onset of symptoms, according to research reported in the March issue

of Arthritis & Rheumatism.

In a nested case-control study, Dr. Karlson of Brigham and

Women's Hospital and Harvard Medical School, Boston, and colleagues

analyzed 170 blood samples obtained up to 12 years prior to symptom

onset in 77 women from the Women's Health Study (WHS) and 93 from the

Nurses' Health Study (NHS) who later developed RA and compared them

with three well-matched randomly chosen controls per case.

Median plasma levels of interleukin-6 (IL-6) and soluble tumor

necrosis factor receptor-II (sTNFR-II) were significantly higher in

preclinical RA cases compared with matched controls in the NHS (p =

0.03 and p = 0.003, respectively) though not in the WHS.

In a pooled analysis of the NHS and WHS cohorts (a total of 170

incident RA cases), the investigators observed a " modest (40%)

increased risk when comparing the top and bottom quartiles of IL-6

concentrations, and a significant 100% increased RA risk comparing the

top and bottom quartiles of sTNFR-II concentrations. "

The researchers also tested for high-sensitivity C-reactive protein

(hsCRP) but were unable to demonstrate any significant association

with this biomarker of inflammation.

" Our finding of elevated levels of sTNFR-II (a surrogate soluble

receptor used to assess potential TNF-alpha levels) among preclinical

RA patients with no documented arthritis symptoms supports the

hypothesis that RA develops in 3 phases: genetic susceptibility, and

preclinical autoimmunity with immune activation followed by clinical

symptoms, " Dr. Karlson and colleagues write.

" These results could have implications with regard to screening for

biomarkers of inflammation of RA risk that could be used for risk

counseling or for targeted interventions to prevent RA, " they

conclude.

Arthritis Rheum 2009;60:641-652.

http://www.medscape.com/viewarticle/589563

Not an MD