Efficacy of rituximab in resistant palindromic rheumatism: First report in literature

Background: Palindromic rheumatism (PR) although often considered as a benign disease can be severe and resistant to DMARDs in some patients. In these patients it can result in almost daily attacks, migrating from joint to joint resulting in poor quality of life. Rituximab has been proven to be effective in treatment of seropositive RA. Objectives: To determine the efficacy and safety of Rituximab in patients with seropositive PR who had an inadequate response toCsDMARDs. Methods: PR was diagnosed based on criteria proposed by Hannonen P et al. Seropositive (ACPA±RF positivity) PR patients who had active disease despite being treated with two Cs DMARDs for >3 months, were treated with Rituximab. Active disease was defined as > 4 attacks per month requiring intake of NSAIDS. All the patients were started on 500mg of rituximab after baseline work up. If complete control of palindromic attacks was not achieved another 500 mg infusion was given after 2 weeks. Results: Thirty three patients with a mean age of 48.15±13.51 years and mean disease duration of6±3.25 years were included. Despite the maximum tolerable dose of combination DMARDs they had mean attack rate of 5.30 ± 2.38 attacks per month and treated with 500 mg of Rituximab. At one month follow up all patients achieved complete control of disease. During a mean follow up of 14.17±8.62 months 12 patients relapsed after a mean duration of 10.33±5.75 months. They were retreated with rituximab and all responded. None of the patients evolved into RA during the study period. No serious adverse events were observed. Conclusions: In seropositive PR, Rituximab not only controls the attacks but also prevents progression to RA. To best of our knowledge this is the first report regarding efficacy of rituximab in PR. Although itneeds to be proved in a larger blinded RCT this early data indicates that Rituximab may be a therapeutic option to preventdevelopment of RA in seropositive patients.