Efficacy of rituximab in resistant palindromic rheumatism: first report in literature.

Background: Rituximab (RTX) provides significant clinical benefits in active rheumatoid arthritis (RA) patients with inadequate response to DMARDs and anti-TNF. There is no data regarding efficacy of RTX in seropositive Palindromic Rheumatism (PR), a forerunner of RA.

Aim: To determine the efficacy and safety of RTX treatment in active PR patients exhibiting inadequate response to conventional synthetic DMARDs (csDMARDs).

Methods: The retrospective study, over a period of 3 years, included seropositive (RF ± antiCCP) PR patients with inadequate control of PR (> 4 attacks per months) despite combination csDMARDs and were treated with RTX. All the patients were treated with an initial dose of 500 mg RTX and later with a second infusion after 2 weeks' period in those who did not achieve adequate/ complete disease control. Patients were continued on csDMARDS and retreated with RTX on relapse of symptoms.

Results: Thirty-three seropositive PR patients with a mean age of 48.15 ± 14.2 years, mean disease duration of 68.4 ± 68.2 months, mean follow up period of 24.3 ± 10.8 months, were treated with RTX. 88% patients were on combination DMARDS and 79% patients were females. All patient achieved rapid and complete control of palindromic attacks with RTX. Fifteen patients had a relapse after a mean duration of 10.4 ± 5.5 months and needed repeat RTX infusions following which remission was achieved. None of the patients progressed to RA till the end of the follow-up. No serious adverse effects were recorded.

Conclusion: RTX treatment could be effective in achieving disease control in active palindromic rheumatism not responding to csDMARDs.

Key Points: • PR is thought to be a forerunner of RA and rituximab (RTX) has been found to be effective in RA. • Our study supports the hypothesis that B cells play an important role in the pathophysiology of PR and that the combination (RTX+ conventional drugs) can prevent the disease evolution into RA. • This 3-year retrospective study showed that rituximab was found to be effective in those who responded poorly to conventional drugs and remission was achieved in all patients. • Although it is a rare disease, we see palindromic rheumatism patients in India more often. As the symptoms are very debilitating in these patients, in those patients, not controlled on conventional drugs, rituximab offers newer promise in controlling the attacks and prevents further progression to RA.