Abstract: 【Abstract】 Objective To assess the long-term effectiveness and safety of rituximab （RTX） for the treatment of pemphigus, and to evaluate the effect of RTX on immune indices. Methods A retrospective study was conducted, and patients with pemphigus who received monotherapy or combination therapy with RTX （375 mg/m2 body surface area, once a week for 4 consecutive weeks） were collected from the Department of Dermatology, Peking University First Hospital from February 2008 to July 2017. Levels of autoantibodies and proportion of B cells in patients were determined at baseline and different follow-up time points, and their changes and relationship with therapeutic effect were analyzed. Time-to-event outcomes （disease control, complete remission and relapse） were estimated using the Kaplan-Meier method. The median （M） as well as 25th （P25） and 75th （P75） percentile values were calculated for repeatedly measured immune indices （autoantibodies and B cells）, and the median level of immune indice-time curve was drawn. Results A total of 53 patients of Han nationality with pemphigus were included, including 40 with pemphigus vulgaris and 13 with pemphigus foliaceus. The male to female ratio was 0.96∶1, the median age was 37.4 years, and the median duration of disease was 13.4 months at baseline. The median follow-up duration （P25, P75） was 37.5 （25.0, 54.7） months. Forty-eight （90.6%） patients achieved disease control, and the time to disease control was 1.7 （1.1, 3.2） months. Thirty-eight （71.7%） patients achieved complete remission, and the time to complete remission was 13.1 （9.6, 27.5） months. During the follow up, 12 of the 38 （31.6%） patients who had complete remission experienced recurrence, with the time to recurrence being 12.4 （4.8, 19.8） months. The median immune indice level-time curve showed that anti-Dsg1 and Dsg3 autoantibody levels decreased when skin lesions resolved, but increased when skin lesions relapsed. The most common severe adverse reaction was pulmonary infection, with a mortality rate of 3.8% （2/53）. Conclusions RTX shows marked long-term effectiveness for the treatment of pemphigus. Pulmonary infection during treatment is worthy of the highest attention. The autoantibody levels can serve as an index for evaluating the effectiveness of RTX in the treatment of pemphigus.

Key words: Pemphigus, Antigens, CD20, Biological agents, Treatment outcome, Drug toxicity, Rituximab