gms | German Medical Science

Background: Eosinophilic granulomatosis with polyangiitis (EGPA) forms part of the ANCA associated vasculitides (AAV). To date no consensus exists on induction and maintenance therapy. We recently reported on the efficacy of rituximab (RTX) as induction therapy in EGPA. So far there are no data on RTX in comparison with cyclophosphamide (CYC) in this disease.

Methods: Retrospective analysis in a single-center cohort of 46 EGPA patients. Remission and disease activity were determined by BVAS. Laboratory follow-up included CRP, eosinophils, IgE, IgG, ANCA, and CD19+B-cells.

Results: Eleven patients treated with RTX were compared with twelve age- and sex-matched patients treated with CYC for remission induction. Median disease duration was longer in RTX patients (49months, IQR7-66vs.8.5months, IQR0-7;p=0.0025). Prior to induction therapy there was no significant difference in median BVAS (14vs.12.5) and in FFS (1vs.0.75). Median eosinophil percentages were increased in both RTX (18.4%) and CYC (6.75%) treatment groups (n.s.). 73% of the RTX-treated patients were ANCA-positive compared to only 23% of the CYC-treated patients. Median prednisolone dose per day at induction was significantly higher in CYC-treated patients (35mg/day,IQR26-138) than in RTX-treated patients (17.5mg/day,IQR10-30). After 3 months all patients in both treatment groups were in partial or complete remission. For maintenance therapy all but two patients per group received standard immunosuppressive treatment with a predominance of azathioprine (AZA) (n=7 per group). Median cumulative prednisolone doses during the first treatment year including high doses for remission induction were 3.6 g in RTX- and 3.8 g in CYC-treated patients (p=0.725). Within an observation period of 24 months after remission induction 3 patients in the RTX group and 2 patients in the CYC group had major relapses (n.s.). In two of the 3 relapsing patients after RTX treatment peripheral B-cell counts were evaluated showing a beginning repopulation of the peripheral B-cell compartment. Serum immunoglobulin concentrations remained stable in both treatment groups during follow-up.

Conclusion: RTX was effective in remission induction in EGPA patients. Remarkably this was the fact even in patients refractory to prior CYC treatment and in ANCA negative patients. During follow up the number of major relapses was comparable in both treatment groups. Prior to relapse the peripheral B cell compartment showed beginning repopulation in RTX-treated patients.