Background Subcutaneous nodules (SCN) are easily identifiable extra-articular manifestation of rheumatoid arthritis (RA) with characteristic histopathology. Identifying clinical characteristics associated with SCN may lead to better pathophysiological understanding of RA, and may enhance its utility as clinical marker of RA outcomes.
Objectives To assess prevalence and associations of SCN in a large multinational cohort of RA patients.
Methods A cross-sectional study of 8549 patients in the Quantitative Standard Monitoring of Patients with RA (QUEST-RA) database who received usual care from rheumatologists in 33 countries was done. Physicians recorded SCN presence. Multivariable logistic regression (MLR) was used to identify association of SCN with demographic and health characteristics [age, gender, race, smoking status, body mass index (BMI), co-morbidity burden by an index derived from 10 co-morbidities], RA characteristics [RA duration, rheumatoid factor (RF) titer (low <25 IU/ml, moderate 25-100 IU/ml, high >100 IU/ml), radiographic erosions, current RA activity by disease activity score 28 (DAS28), functional status by health assessment questionnaire (HAQ)], and RA treatment [corticosteroids, methotrexate, other disease modifying agents (DMARDs), and biologics].
Results 1787 (20.9%) had SCN. The SCN prevalence varied from 5.1% to 30.3% in different countries. The Table shows the patient characteristics independently associated with SCN. Men, white race, and current smoking were more likely to have SCN. RA duration, presence of erosive disease, high titer RF, but not the current RA activity increased likelihood of SCN. Use of methotrexate and biologics were associated with SCN presence. Patients with SCN had higher comorbidity burden, and were more likely to have higher BMI.
Conclusions We confirm previously reported patient characteristics associated with SCN (race, gender, smoking, RA duration, erosive disease, RF titer, methotrexate use), and also report several new associations (biologics use, higher comorbidity burden, BMI). Further studies are needed to determine whether there is true biological basis for these associations.
Ann Rheum Dis 2006;65:601
Scand J Rheumatol 2011;40:81
Disclosure of Interest None Declared