Background Little is known about the correlation of rheumatoid nodules and disease activity; in fact, this has been evaluated neither in clinical trials nor in cohort studies.
Objectives The purpose of this study is to correlate the degree of vascularization of rheumatoid nodules measured by a semi-quantitative scale of power Doppler (PD) signal with the degree of disease activity.
Methods We evaluated 36 consecutive patients fulfilling the 1987 ACR criteria for rheumatoid arthritis who had rheumatoid nodules on the extensor aspect of the forearms. In the case the patient had more than one nodule, the largest was chosen for its evaluation. The correlation between the presence and intensity of vascularization of the nodule using a semi-quantitative (0-3) scale of PD signal with disease activity, as measured clinically (DAS28 and RAPID3) and ultrasonographically (German US7 gray scale and PD synovitis scores), were examined by the Mann-Whitney U test and the Spearman’s rank order test. For the latter, a coefficient <0.40 was considered poor, 0.40-0.59 moderate, 0.60-0.79 good and 0.80-1 excellent.
Results Patients were predominantly females (67%) with a median (percentile 25-75) disease duration of 126 (61-261) months. Median PD signal of nodules was 1 (1-2), median DAS 28=4.24 (3.68 – 6.07), median RAPID 3=12.50 (5.48-15.15) and median German US7 gray scale synovitis=12.00 (9.00-19.75) and PD synovitis=9.00 (5.25-12.0). The correlation between the nodules PD vascularization with clinimetric and ultrasonographic indexes are shown in Table 1.
Conclusions In this study, the presence and degree of vascularization of rheumatoid nodules, which can be taken as a surrogate measure of extraarticular inflammation, does not seem to parallel other clinical and ultrasonographic measures of disease activity at both, patient and joint levels. The Rapid3 was the only composite index that showed a moderate level of correlation with the nodule vascularization. Results suggest that different regulatory pathways may exist controlling the expression of rheumatoid nodules and synovitis.
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Disclosure of Interest None Declared