Background The presence of subclinical inflammation promotes the progression of morphostructural joint damage in RA patients. Currently, clinical remission is based on the count of swollen and painful joints associated with acute phase reactants. Adding an image technique like grey scale (GS) US and power Doppler (PD) increases the capability to detect active synovitis. There are no studies on the association between active synovitis as defined by PD and more specific markers of inflammation like cytokines in patients with RA in clinical remission
Objectives To identify subclinical synovitis in patients with RA in clinical remission using US and to characterize the biological profile of this group of patients by determining inflammatory cytokines
Methods RA patients in clinical remission according to ACR/EULAR criteria were enrolled. Clinical evaluation was performed and DAS28 calculated. Cytokines (IL1b, 10, 6. 5, 2, 4, 8, GMCS, TNFa, IFNg,) were determined using ELISA kit (Human ultrasensitive cytokine 10 -plex panel [Invitrogen, CA, USA]). GS and PD ultrasound was assessed in 7 joints according to Backhaus et al (2). Esaote MyLab ® 25 ultrasound machine with 12-18 MHz linear probe was used.
Results 21 patients were included. Clinical and demographic data are shown in the table.
GS synovitis was found in 95%, and tenosynovitis in 9.5%. PD was detected in 57%. There was no association between DAS28 and duration in clinical remission, disease duration and US-defined active synovitis (p=0.84, 0.309 and 0.762 respectively). Pro-inflammatory cytokines levels were elevated in patients with less than 6 months and in those with 13 to 24 months in clinical remission. Nevertheless, there was no correlation with US-defined synovitis (p=NS)
Conclusions US detected a high percentage of subclinical synovitis in RA patients in clinical remission. Cytokine levels did not correlate with DAS 28 or ultrasound-defined active synovitis.
Brown AK, Conaghan P, Karim Z, et al. An explanation for the apparent dissociation between clinical remission and continues structural deterioration in rheumatoid arthritis. Arthritis Rheum 2008; 58(10): 2958-2967
Backhaus M, Ohrndorf S, Kellner H, et al. Evaluation of a novel 7-joint ultrasound score in daily rheumatologic practice: a pilot project. Arthritis Rheum 2009; 61(9): 1194-1201
Disclosure of Interest None declared