Background A significant number of rheumatoid arthritis (RA) patients can reach low disease activity (LDA) by using TNF-inhibitors (TNF-i), but this therapy can cause serious side-effects and is expensive. Therefore it could be expedient to stop in case of LDA, especially if relapse can be predicted. Ultrasonography of joints seems to be a predictor in this respect in smaller studies.
The Dutch POET (Potential Optimalisation of Expediency of TNF-i (TNF-inhibitor)) study, is a multicenter randomized prospective cohort study investigating if in patients with RA with LDA on TNF-i and conventional DMARD, the TNF-i can be stopped. Patients were randomized to continue or stop TNF-i. Part of this study is the POET-ultrasonography (US) study.
Objectives To investigate whether US at the time of stopping TNF-i in RA patients with LDA can predict future flare.
Methods Data of patients who stopped TNF-i in the POET study were used for this analysis. Participating patients had RA according to ACR 1987 criteria, >6 months a DAS28 <3.2 (LDA) and treatment with TNF-i > one year next to a conventional DMARD, without dose change in the past six months. Nineteen trained ultrasonographers performed US at baseline of the study, using different US machines, of 20 joints (bilaterally: MCP 1-5 dorsal and volar, wrists and MTP 2-5 dorsal aspect). The joints were graded on grayscale (GS; 0-3) and power doppler (PD; 0-3). US signs of arthritis were defined as GS>1 and/or PD>0. Trial visits were performed every 3 months and when flare was suspected. Flare was defined as DAS28>3.2 and at least >0.6 increase compared to the DAS28 at inclusion. Cox regression was performed to compare TNF-i free LDA between patients with versus those without US signs of arthritis (figure).
Results Nine months data were available for 248 patients. Twenty-one percent was lost to follow-up and censored at last observation. Higher age, longer disease duration, anti-CCP and IgM-RF positivity were all related to flare occurrence. Patients with US signs of arthritis in one or more joints had a greater risk of flare (HR 1.77; 95% CI of 1.16 to 2.70) and shorter relapse-free period compared to patients without US signs of arthritis (see figure). The table shows patient- and US-characteristics at inclusion for patients without flare within 9 months versus patients with flare.
Conclusions On the group level, US can predict flare in RA patients with LDA in whom TNF-i is stopped.
Disclosure of Interest F. Lamers-Karnebeek Grant/research support from: Abbvie, T. Jansen: None declared, P. van Riel: None declared, J. Luime: None declared, J. Jacobs: None declared