RESEARCH - Quantifying anti-CCP titer: clinical utility and association with tobacco exposure in patients with RA

[Guest guest]

Ann Rheum Dis. Published Online First: 7 April 2008. doi:10.1136/ard.2007.084509

--------------------------------------------------------------------------------

Extended Report

Quantifying Anti-CCP titer: clinical utility and association with

tobacco exposure in patients with rheumatoid arthritis

M. Lee 1*, Roxanne 2, M. Hagan 2, Lori B

Chibnik 2, H Costenbader MD, MPH2 and H Schur 3

1 Brigham and Women's Hospital/Harvard Medical School, United States

2 Brigham and Women's Hospital, United States

3 Brigham & Women's Hospital-Harvard Med School, United States

Abstract

Objectives: To determine the significance of quantitative levels of

antibodies to cyclic citrullinated peptides (anti-CCP) in a population

of patients with rheumatoid arthritis (RA).

Methods: 241 consecutive sera from patients with RA sent from a large

rheumatology clinic for laboratory testing were selected for precisely

quantifying anti-CCP antibody titers with the anti-CCP2 assay. Patient

charts were reviewed for demographic information, smoking history,

clinical diagnosis, RF titer, radiographic information and other

laboratory information (ESR and CRP). Correlations with anti-CCP titer

and RF titer, disease parameters and smoking history were assessed.

Results: We confirm previous findings that anti-CCP seropositivity is

associated with a higher incidence of erosions in patients with RA

(56% vs 20% CCP+ vs CCP-, kappa=0.297, P<0.0001). We also find a

moderate correlation between anti-CCP titer and RF titer. However, we

failed to find association between anti-CCP titer and presence of

erosions, between anti-CCP titer and CRP or ESR level or between

anti-CCP titer and age or disease duration. Interestingly, we did find

a significantly higher anti-CCP titers in patients with a history of

smoking (452 units/ml vs 229 units/ml, smoker vs. non-smoker

respectively. P=0.02).

Conclusions: Although anti-CCP titers were not associated with

clinical parameters of disease, they are increased in RA patients with

exposure to tobacco. In contrast, no elevation in RF was noted in

patients with history of smoking. These observations are consistent

with a pathogenic contribution of smoking to RA and suggest the immune

stimulus for anti-CCP is distinct from that for RF.

http://ard.bmj.com/cgi/content/abstract/ard.2007.084509v1?papetoc

--

Not an MD