Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


Reduced IL-7 Serum Titres in Relation with Symptom Duration Are Associated with Progression towards Rheumatoid Arthritis in Less Than 6 Months Inflammatory Arthritis

Goeb1,  Vincent, Cuthbert1,  Rich, Horner1,  Elizabeth, Churchman1,  Sarah, Coates2,  Laura C., Marzo-Ortega2,  Helena, Nam1,  Jackie

Leeds University, Leeds, United Kingdom
University of Leeds, Leeds, United Kingdom
LIMM, Leeds, United Kingdom
CHU d'Amiens, France
CHU Rouen - INSERM U 905, France
Leeds General Infirmary, Leeds, United Kingdom
Rouen, France

Purpose:

Early diagnosis of RA is crucial for initiation of therapy in order to obtain sustained remission. IL-7 is a pleiotropic cytokine that play a central role in the development and maintenance of T cells, and has recently been associated with RA. Injection of IL-7 in a collagen induced arthritis model aggravated the disease and the therapeutic value of IL-7 blocking antibodies has also been reported in two separate animal models. We showed that serum circulating levels of IL-7 are reduced in established RA patients. We hypothesised that this reduction may have predictive diagnostic value. Our objectives are to determine whether IL-7 titres in serum will distinguish patients who will evolve into RA from early inflammatory arthritis (EIA), and whether they are correlated with clinical parameters of disease activity, structural radiographic damage, shared epitope or autoantibody status and titres.

Method:

359 patients with EIA (<6 months duration) were followed up for 2 years and diagnosed according to ACR criteria. 31 were lost to follow up and 77 diagnosed with other forms of musculoskeletal disease (reactive arthritis, osteoarthritis, lupus, connective tissue diseases etc...). 65 controls and 183 patients with established disease were also assessed. IL-7 levels in serum were determined by ELISA.

Results:

Patients with EIA were diagnosed as having RA (n=162,), undifferentiated arthritis (UA, n=61), ankylosing spondylitis (AS n=12) or psoriatic arthritis (PsA n=16). IL-7 levels at recruitment were reduced coared to healthy controls (n=67, median 13.8 pg/ml) in RA (median 11.5 P<0.001), PsA (P=0.012 median 11.1) and UA (median 11.8P=0.003) but not in AS or osteoarthritis patients (n=19). We also confirmed reduction in IL-7 levels between healthy controls and established RA (n=106 median 7.9 p<0.001), AS (n=56 median 10.1 p=0.001) or PsA (n=21 median 7.8 p=0.001). There was no correlation between IL-7 titres and disease activity score (DAS), CRP, rheumatoid factor (RF), anti-CCP and HLA-SE status at recruitment. The presence of erosions at recruitment was also not associated with IL-7 in early RA. Importantly, IL-7 levels were inversely correlated with symptoms duration at presentation in less than 6 months RA (R=-0.513, P<0.001), but not in AS or PsA.

Conclusion:

Our data demonstrate decrease levels of IL-7 across the inflammatory disease continuum. furthermore, no relationship between IL-7 titres and disease activity, blood inflammation, HLA-SE and auto-antibodies in early RA was observed. Further analysis is needed to establish the added value of IL-7 over other parameters in predicting evolution to RA, particularly in CCP negative patients.

To cite this abstract, please use the following information:
Goeb, Vincent, Cuthbert, Rich, Horner, Elizabeth, Churchman, Sarah, Coates, Laura C., Marzo-Ortega, Helena, et al; Reduced IL-7 Serum Titres in Relation with Symptom Duration Are Associated with Progression towards Rheumatoid Arthritis in Less Than 6 Months Inflammatory Arthritis [abstract]. Arthritis Rheum 2009;60 Suppl 10 :1334
DOI: 10.1002/art.26408

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