Background Ultrasound (US) is a sensitive and reliable method for the assessment of inflammatory activity in rheumatoid arthritis (RA). Many reduced scores have been proposed for measuring disease activity in an attempt to optimize time expended during US evaluation. Validity and responsiveness of these scores varies according to the number of joints examined; for example, some of them only assess the dominant hand. It is possible, nevertheless, that not examining the non-dominant hand would mislead the interpretation of the patients' clinical status.
Objectives To compare the number of joints with synovial hypertrophy (SH) and power Doppler (PD) signal in the dominant vs. the non-dominant hand
Methods We evaluated 62 patients with diagnosis of RA (1987 ACR criteria). The presence and intensity of SH and PD signal was assessed in the wrist, metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of both hands. SH and PD signal were graded semi-quantitative from 0 to 3, according to OMERACT. An 11 index for both, SH and PD signal of each hand, were also obtained by the sum of the scores of the individual joints. The total number of joints with SH and PD signal and their respective indexes of the dominant hand were compared to those of the non-dominant hand using the Spearman's rank order correlation coefficient. Two further sub-analysis were also performed, the first including a reduced joint assessment (wrist, second and third MCP's) and the second including only patients in clinical remission and per the DAS28-ESR.
Results Patients were predominantly females (81%) and they had a mean (SD) age of 55.6 (13.6) years and a median (IQR) disease duration of 83.5 (100.5) months. Median DAS28-ESR score was 3.1 (2.2). The Table below depicts total number of joints with SH and PD signal and their respective indexes in the dominant and non-dominant hand.
Conclusions In this study, we found that both, SH and PD signal, are highly correlated in both hands independently of the number of joints evaluated (complete vs. reduced assessment). When examining patients in clinical remission, theses correlations drop to moderate and poor. However, the dominant hand still displays more SH and PD signal compared to the non-dominant hand and, therefore, suitable to be used in reduced US scores even in patients in clinical remission.
Mandl P, Naredo E et al. A Systematic Literature Review Analysis of Ultrasound Joint Count and Scoring Systems to Assess Synovitis in Rheumatoid Arthritis According to the OMERACT Filter J Rheumatol 2011; 38:2055–62.
Disclosure of Interest None declared