Sensitive B-cell receptor repertoire analysis shows repopulation correlates with clinical response to rituximab in rheumatoid arthritis.

BACKGROUND: Although B-cell depleting therapy in rheumatoid arthritis (RA) is clearly effective, response is variable and does not correlate with B cell depletion itself. METHODS: The B-cell receptor (BCR) repertoire was prospectively analyzed in peripheral blood samples of twenty-eight RA patients undergoing rituximab therapy. Timepoints of achieved BCR-depletion and -repopulation were defined based on the percentage of unmutated BCRs in the repertoire. The predictive value of early BCR-depletion (within one-month post-treatment) and early BCR-repopulation (within 6 months post-treatment) on clinical response was assessed. RESULTS: We observed changes in the peripheral blood BCR repertoire after rituximab treatment, i.e., increased clonal expansion, decreased clonal diversification and increased mutation load which persisted up to 12 months after treatment, but started to revert at month 6. Early BCR depletion was not associated with early clinical response but late depleters did show early response. Patients with early repopulation with unmutated BCRs showed a significant decrease in disease activity in the interval 6 to 12 months. Development of anti-drug antibodies non-significantly correlated with more BCR repopulation. CONCLUSION: Our findings indicate that rather than BCR-depletion it is repopulation with unmutated BCRs, possibly from naïve B cells, which induces remission. This suggests that (pre-existing) differences in B-cell turnover between patients explain the interindividual differences in early clinical effect.

Low-dose prednisone inclusion in a methotrexate-based, tight control strategy for early rheumatoid arthritis: a randomized trial.

BACKGROUND: Treatment strategies for tight control of early rheumatoid arthritis (RA) are highly effective but can be improved. OBJECTIVE: To investigate whether adding prednisone, 10 mg/d, at the start of a methotrexate (MTX)-based treatment strategy for tight control in early RA increases its effectiveness. DESIGN: A 2-year, prospective, randomized, placebo-controlled, double-blind, multicenter trial (CAMERA-II [Computer Assisted Management in Early Rheumatoid Arthritis trial-II]). (International Standard Randomised Controlled Trial Number: ISRCTN 70365169) SETTING: 7 hospitals in the Netherlands. PATIENTS: 236 patients with early RA (duration <1 year). INTERVENTION: Patients were randomly assigned to an MTX-based, tight control strategy starting with either MTX and prednisone or MTX and placebo. Methotrexate treatment was tailored to the individual patient at monthly visits on the basis of predefined response criteria aiming for remission. MEASUREMENTS: The primary outcome was radiographic erosive joint damage after 2 years. Secondary outcomes included response criteria, remission, and the need to add cyclosporine or a biologic agent to the treatment. RESULTS: Erosive joint damage after 2 years was limited and less in the group receiving MTX and prednisone (n = 117) than in the group receiving MTX and placebo (n = 119). The MTX and prednisone strategy was also more effective in reducing disease activity and physical disability, achieving sustained remission, and avoiding the addition of cyclosporine or biologic treatment. Adverse events were similar in both groups, but some occurred less in the MTX and prednisone group. LIMITATION: A tight control strategy for RA implies monthly visits to an outpatient clinic, which is not always feasible. CONCLUSION: Inclusion of low-dose prednisone in an MTX-based treatment strategy for tight control in early RA improves patient outcomes. PRIMARY FUNDING SOURCE: Catharijne Foundation.