Abstract:

Objective To study the efficacy of rituximab in the treatment of pemphigus vulgaris （PV） and its underlying mechanism. Methods A 38-year-old female with PV presented with refractory, painful oral ulcers and erosions. Since she was poorly responsive to prednisone 80 mg daily, intravenous ritu- ximab of 500 mg once a week was given for successive 3 weeks followed by 5 successive days of intravenous gamma globulin at a dose of 400 mg/kg per day, and a total of two treatment sessions were conducted. ELISA was used to detect the serum titer of anti-Dsg3 antibodies and their IgG subtypes （IgG1 and IgG4） as well as serum level of interferon-gamma （IFN-gamma）, interleukin-4 （IL-4）, interleukin-10 （IL-10）. Results Three months after the end of two treatment sessions, the symptom was obviously improved, and lesions subsided; after another 1 month, clinical symptom fully disappeared. During the 1-year follow-up, no lesions recurred. The anti-Dsg3 antibody titer was 253.33 U/mL before treatment, plateaued at 250 U/mL within 4 weeks after the initial infusion, decreased till 3 months after the withdrawal, and reached 26.06 U/mL 7 months after the withdrawal, and remained within normal range till the time of this writing. The serum titer of IgG1 subclass of anti-Dsg3 antibodies dropped dramatically right after the first infusion, but that of IgG4 subclass remained at a high level at early stage of medication, began to decline until 3 months after the withdrawal, and finally reached the normal range following clinical remission. Also, serum level of IFN-gamma and IL-10 correlated with the severity of PV. Conclusions Combined rituximab is effective for the control of PV, likely by eliminating Dsg3-specific antibodies, especially IgG4 subclass of them.

Key words: Pemphigus;Rituximab;Treatment outcome