234. PREDICTORS OF FLARE IN RHEUMATOID ARTHRITIS PATIENTS TREATED PREVENTIVELY WITH RITUXIMAB: A PROSPECTIVE STUDY USING ULTRASOUND AND PATIENT-REPORTED OUTCOMES

Abstract

Background: Rituximab (RTX) is an effective and relatively safe treatment for rheumatoid arthritis (RA). Following treatment, controversy remains on optimizing further retreatment while limiting risks of cumulative immunosuppression and cost. The aim of this study was to identify predictors of flare in patients with RA 1 month prior to RTX retreatment. Methods: A prospective study of 33 RA patients provisionally booked for RTX retreatment with RTX preventively was undertaken. Initial assessment 4 weeks prior to scheduled RTX retreatment (week 0) included clinical and laboratory assessment, and US of wrists and hands. Patient reported outcomes (PROs) (HAQ, Facit, SF-36, EuroQol-5D-3L) were completed weekly until RTX retreatment 4 weeks later. At this time point (week 4) clinical assessment and US were repeated. Results: 22/33 patients were female, 11/33 male, with a mean age of 62.2 years. The patients were assessed at mean 6.9 months after their previous RTX treatment. The patients had received a mean 8.2 RTX cycles (range 2-18) previously. At week 0, 66.7% (22/33) of patients remained depleted (CD19 count ≤ 0.005) while 33.3% (11/33) had already started repopulating. From week 0 to week 4 ESR increased in 36.7%, decreased in 40%, no change 23.3. CRP increased in 42.4%, decreased 51.5%, no change 6.1%. The number of joints with synovial hypertrophy (SH) on US increased in 70.4% (19/27), and decreased in 29.6% (8/27). The number of joints showing power Doppler (PD) increased in 40.7% (11/ 27), reduced in 29.6% (8/27), no change in 29.6%. Worsening of symptoms from week 0 to week 4 was reported in 13/28 patients, whereas 15/28 were the same/better. Of the patients with increased PD (11), only 3 reported worsening of the symptoms. The remainder were the same/better. Surprisingly, the general VAS and DAS28 scores decreased by 38.6% and 21.7% respectively in the majority of patients (36.4% and 60.6% respectively) from week 0 to week 4. 18/33 patients completed the weekly PROs. HAQ, Facit-F and SF-36 scores showed similar changes. 50% of EuroQol-5D-3L scores remained the same. Conclusion: The data of this study do not show any consistent pattern of variation within 4 weeks prior to RTX provisional retreatment, and baseline assessments at week 0 did not seem to predict stability or worsening of symptoms in the following 4 weeks. The variables increased, decreased or remained the same in almost similar patient numbers. SH and to a lesser extent PD on US showed an increase over the 4-week period. Only a small number of patients (3/11) who had increased PD during the study period reported worsening of symptoms before retreatment. Assessment of patients 1 month before preventive retreatment with RTX does not seem to be able to predict which patients are likely to start flaring shortly.