Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Three Phenotype Profiles Are Revealed by Cluster Analysis in Early Inflammatory Back Pain Suggestive of Spondyloarthritis (SPA). Results From the DEvenir Des Spondyloarthropathies Indifferencies Rcentes (DESIR) Cohort.

D'Agostino1,  Maria-Antonietta, Aegerter2,  Philippe, Breban3,  Maxime A., Dougados4,  Maxime

Versailles-Saint Quentin en Yvelines University- APHP, Ambroise-Paré Hospital, Boulogne-Billancourt, France
Versailles-Saint Quentin en Yvelines University- APHP, Ambroise-Paré Hospital,, Boulogne-Billancourt,, France
Hopital Ambroise Pare, Boulogne, France
Paris-Descartes University, Paris, France

Background/Purpose:

SPA spectrum refers to a variety of skeletal and extra-articular inflammatory manifestations that may combine differently among patients. The objective of the study was to examine whether SPA disease manifestations at baseline would combine according to an ordered or random pattern in patients with early inflammatory low back pain (IBP) and suggestive of SPA.

Methods:

Baseline clinical and demographic characteristics, as well as imaging (i.e. pelvic X-rays, pelvic MRI and peripheral entheses ultrasound) and biological data (including HLA-B27) of patients included in the French multicenter DESIR cohort of early (< 3 yrs duration) IBP suggestive of SPA were analysed by multiple correspondence analysis in order to graphically assess the association between the studied manifestations. Several methods of cluster analysis using those variables were then performed to identify subgroups of patients with similar characteristics.

Results:

Seven hundred and eight patients were included into the Cohort. Among the 700 analysed patients cluster analysis allowed us to classify 688 patients in 3 major groups (table 1). Cluster A contained a majority of men, with predominant isolated axial manifestations, and higher frequency of uveitis and positivity of HLA-B27. Cluster B predominantly consisted of women, with higher frequency of peripheral signs (including vascularisation at entheses by power Doppler ultrasound (PDUS)), psoriasis and younger onset of disease symptoms. Cluster C was composed by patients with predominant axial symptoms, equal distribution of sex, highest presence of pelvic X-rays and MRI positivity, and lower prevalence of HLA-B27 positivity.

Table 1.

CharacteristicsCluster A (n = 163)Cluster B (n = 209)Cluster C (n = 316)Global P+
Sex (% of men)61%28%49%<0.0001
Age at onset (<40 ys)76%69%88%0.0027
Duration of symptoms (>24 months)31%24%37%0.007
Arthritis (% of yes)45%95%40%<0.0001
Enthesitis (% of yes)40%82%32%<0.0001
Dactylitis (% of yes)13%31%2%<0.0001
Uveitis (% of yes)14%9%5%0.003
Psoriasis (% of yes)14%32%7%<0.0001
IBD* (% of yes)1.2%4%2%ns
HLA-B27 + (% yes)61%36%28%<0.0001
X Rays sacroiliitis (% of yes)16%21%36%<0.0001
MRI sacroiliitis (% of yes)34%24%47%<0.0001
Vascularized PDUS enthesitis°(% of yes)15.7%23%8.5%0.004
* IBD=inflammatory bowel diseases; °at least one;+Kruskal-Wallis test.

Funding:

The DESIR cohort is supported by an unrestricted grant from PFIZER France

Conclusion:

Cluster analysis of SPA manifestations among patients with early IBP allowed us to clearly identify at baseline 3 different groups of clinical phenotypes. Ongoing follow up will allow to determine whether these clusters may correspond to different severity patterns.

To cite this abstract, please use the following information:
D'Agostino, Maria-Antonietta, Aegerter, Philippe, Breban, Maxime A., Dougados, Maxime; Three Phenotype Profiles Are Revealed by Cluster Analysis in Early Inflammatory Back Pain Suggestive of Spondyloarthritis (SPA). Results From the DEvenir Des Spondyloarthropathies Indifferencies Rcentes (DESIR) Cohort. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :551
DOI:

Abstract Supplement

Meeting Menu

2011 ACR/ARHP