A prospective study comparing patients with early and late relapsing pemphigus treated with rituximab.

BACKGROUND: Rituximab (RTX) is an effective therapy for patients with pemphigus; however, the therapy does not prevent relapse.

OBJECTIVES: To compare early relapsing patients (before 12 months) and late relapsing patients (after 24 months) following RTX therapy.

METHOD: In this prospective study, 19 patients were enrolled (14 with pemphigus vulgaris and 5 with pemphigus foliaceus). The baseline disease score, autoantibody levels, and percentage of CD20+ cells of patients with pemphigus were measured. Patients received 1 cycle of RTX and were followed for 26 months.

RESULTS: Among early relapsing patients (n = 5), the time to relapse was 6 to 11 months. Among late relapsing patients (n = 6), the time to relapse was 24 to 26 months. A significant difference was observed in the mean baseline anti-desmoglein 1 (DSG1) index between early relapsing (705.72) and late relapsing patients (210.4) (P = .0014). A significant negative correlation was found between the baseline anti-DSG1 index and time to relapse (r = -0.777, P = .00009).

LIMITATIONS: The small number of patients with pemphigus foliaceus.

CONCLUSIONS: Because patients with high baseline anti-DSG1 indices relapsed earlier, it may be important to follow these patients closely for the initial 12 months after RTX therapy. These patients may require a maintenance RTX dose during the first 12 months after RTX therapy.