Swollen, but not tender joints, are independently associated with ultrasound synovitis: results from a longitudinal observational study of patients with established rheumatoid arthritis

Abstract

ObjectivesJoint swelling and tenderness are considered a proxy for inflammation in patients with rheumatoid arthritis (RA). With ultrasound-detected inflammation as reference, our objectives were to explore on patient and joint level the associations between ultrasound synovitis and joint swelling, tenderness and patient-reported joint pain (PRJP).Methods209 patients with established RA were examined six times during 12 months with assessment of 32 joints in upper/lower extremities for joint swelling/tenderness and Grey scale (GS)/power Doppler (PD) synovitis. PRJP was assessed on a manikin. Correlations between different sum scores were at each examination calculated using Spearman’s rho (r), agreement at joint level was examined by Cohen’s kappa and logistic regression models were used to explore the associations between joint assessment and GS/PD scores.ResultsAt patient level, swollen joints were strongly correlated with GS/PD sum scores (r=0.64–0.88), while tender joints were primarily associated with PRJP (r=0.54–0.68). At joint level, GS/PD pathology had higher agreement with swelling (kappa 0.54–0.57) than tenderness (kappa 0.20–0.21) or PRJP (0.23–0.25). Higher percentages of joints were swollen according to increasing GS/PD scores, independently of joint tenderness. However, joints being tender, but not swollen, were not associated with GS/PD scores. Receiver operating curves showed swollen but not tender joints to be associated with GS/PD scores.ConclusionsSwollen joints were strongly associated with ultrasound detected synovitis at both patient and joint level, while this association was not found for tender joints. These results may question if tender joints reflect ongoing inflammation in established RA.

The Relationship between Hematological Markers of Systemic Inflammation (Neutrophil-To-Lymphocyte, Platelet-To-Lymphocyte, Lymphocyte-To-Monocyte Ratios) and Ultrasound Disease Activity Parameters in Patients with Rheumatoid Arthritis

“…However, there is still a debate on how to grade the detected changes, and how to monitor US inflammatory symptoms [20]. Recently, it has been reported that swollen joints were strongly associated with US-detected synovitis (GS/PD score), reflecting ongoing inflammation, while this association was not found for tender joints [23]. Our results are consistent with these data-the significant correlations were confirmed between all the assessed US scores and SJC.…”

Fluorescence optical imaging for treatment monitoring in patients with early and active rheumatoid arthritis in a 1-year follow-up period

“…Recently, Hammer et al showed no association between tender joints and synovitis in GSUS and PDUS, while a strong correlation between swollen joints and US synovitis was calculated. In addition, they found a primary associationn between tender joints and patient-reported joint pain [38]. These findings support that the parameters of DAS28 hardly correlated with the sum scores of FOI also in this present study.…”

Rheumatoid arthritis patients with predominantly tender joints rarely achieve clinical remission despite being in ultrasound remission

“…In addition, low correlations have been shown between PROMs and MRI synovitis in RA patients [ 15 ]. Our findings are supported by a recent study of established RA patients that found swollen but not tender joints to be associated with US synovitis [ 5 ].…”

“…In contrast, swollen joint assessment has a high face validity and is a cornerstone in the clinical evaluation of joint inflammation in patients with RA. Furthermore, swollen joints have been found to be highly associated with disease evaluation by assessors and US synovitis in RA patients [ 5 ].…”