Objectives: To determine a potential window of opportunity for retreatment with rituximab in patients with rheumatoid arthritis (RA) from a multicentre longitudinal real-life study based on tight monitoring with ultrasonography (US).
Methods: Thirty RA patients treated with rituximab were included. US parameters were collected at each time (8 visits) of the 18-month follow-up, notably the global score of power Doppler (PD) activity. Clinical relapse was defined as a DAS28 ESR of >3.2 after 6 months in responders while US relapse was defined as an increase of ≥20% of the global score of PD activity. The decision of retreatment was based exclusively on clinical findings.
Results: A total of 29 patients were analysed (mean (SD) age: 57.2 (12.2) years; female gender: 66%). The mean (SD) PD score decreased from 8.8 (5.2) at baseline to 4.9 (4.3) at 6 months (p <0.0001). A clinical response was observed at Month 4 or Month 6 for 93% of patients. A total of 19 patients had a first clinical relapse (with or without US relapse) after Month 6 (18 of them were retreated with rituximab). Among 10 patients without clinical relapse, 3 had US relapse (only one was retreated) and 7 had no US relapse (but 4 were retreated).
Conclusions: This study highlights a great heterogeneity in terms of sequence of clinical relapse, US relapse and retreatment in RA patients receiving rituximab. Therefore, US monitoring does not seem to be relevant to determine the best time for retreatment with rituximab.