The value of power Doppler ultrasound in patients with rheumatoid arthritis in clinical remission: Reclassifying disease activity?

Optical spectral transmission to assess glucocorticoid therapy response in patients with arthritis: a longitudinal follow-up comparison with joint ultrasound

BACKGROUND

Optical spectral transmission (OST) is a modern diagnostic modality, able to assess the blood-specific absorption of light transmitted through a tissue, promising quantification of inflammation in the finger and wrist joints of patients with arthritis. To date, there are no adequate data regarding the diagnostic value of OST in the evaluation of inflammatory activity changes, during arthritis follow-up. Objectives of this study were therefore to examine the performance of OST in assessing response to anti-inflammatory therapy in patients with active arthritis and to explore OST associations with clinical, laboratory, and ultrasonographic (US) activity markers.

METHODS

1173 joints of 54 patients with arthritides of the wrist and finger joints were examined by OST before and after oral administration of glucocorticoids (GC), during a disease flare. For the same time-points patients underwent clinical, laboratory, and joint US [grayscale (GSUS), power-Doppler (PDUS)] examinations. The distribution of ΔOST-values between the two time-points was compared with the respective distributions of ΔPDUS and ΔGSUS by Bayesian statistical analyses. Moreover, the diagnostic performance of OST compared to a control group (2508 joints of 114 subjects) was examined by receiver operating characteristics and associations of OST values with clinical, laboratory, and arthrosonographic parameters were evaluated by correlation analyses.

RESULTS

OST and US performed similarly in the assessment of inflammatory changes caused by GC (same value-change tendency in 83.2% of the cases). Bayesian statistics revealed no significant differences between ΔOST and ΔPDUS for all 3 examined joint categories (accuracy: metacarpophalangeal (MCP): 68.1%; proximal interphalangeal (PIP): 60.4%; wrists: 50.4%) and between ΔOST and ΔGSUS for MCP and PIP joints (accuracy: 51.1% and 78.7%, respectively). OST diagnostic performance (patients vs. controls) was excellent in both time-points [area under the curve (AUC) before GC=0.883(95%CI=0.83-0.94) and after GC=0.811(95%CI=0.74-0.881); p<0.001]. Furthermore, OST correlated significantly with all examined sonographic activity scores (all; p<0.001) and with swollen joint counts (p<0.01).

CONCLUSIONS

OST was able to assess response to therapy in a similar way to joint US and correlated significantly with arthritis activity markers. Therefore, OST has proved to be a valuable tool to assist disease activity monitoring in the examined cohort.

TRIAL REGISTRATION

German Registry of Clinical Trials, DRKS00016752.

Ultrasound-detected tenosynovitis as a risk factor for flares in rheumatoid arthritis patients in clinical remission

BACKGROUND

Our objective was to investigate the value of ultrasound (US) detected synovitis and tenosynovitis as risk factors for short term flare in rheumatoid arthritis (RA) patients in clinical remission.

METHODS

Consecutive RA patients in clinical remission (DAS28 ERS < 2.6) for at least 3 months underwent Power Doppler ultrasound (PDUS) examination of 1st to 6th extensor compartments at the wrist, 2nd to 5th finger flexor, posterior tibial tendon, and peroneal tendons. To assess synovitis, carpal joints, 1st to 5th metacarpophalangeal (MCP) joints, and 2nd to 5th interphalangeal proximal (IPP) joints were bilaterally examined. Synovitis and tenosynovitis were defined according to OMERACT. Patients were followed for 1 year. Disease flare was defined as an increase in disease activity generating the need for a change in therapy by the attending rheumatologist.

RESULTS

Ninety patients were included. After 1 year of follow-up, 26 patients (29%) experienced a flare. At baseline 39%, 23% and 8% had US-detected synovitis, tenosynovitis or both, respectively. In the 1-year period after the baseline US examination, US-detected tenosynovitis (RR: 4.9; 95% CI: 2.2-10.8) was associated with an increased risk of exacerbation. This association was not shown with US-detected synovitis (RR: 1.3; 95% CI: 0.76-2.2). In the multivariate analysis, only subclinical tenosynovitis (OR: 9.8; 95% CI: 2.5-39.1; p = 0.001) and baseline DAS28 (OR: 5.7; 95% CI: 1.1-31.6; p = 0.047) were significantly associated with an increased risk of having a flare.

CONCLUSION

In our study, subclinical tenosynovitis was associated with disease flare in patients with RA in clinical remission.

KEY POINTS

• Synovitis and tenosynovitis are risk factors for short term flare in RA patients in clinical remission. • Subclinical tenosynovitis, but not synovitis, was associated with disease flare in patients with unstable remission. • Ultrasound-detected tenosynovitis could be useful to predict relapses in RA patients in clinical remission.