Use of rituximab in the treatment of mucous membrane pemphigoid: An analytic review

Mucous Membrane Pemphigoid (MMP) is a potentially fatal mucocutaneous autoimmune blistering disease. Autoantibodies are produced against various components of the dermo-epidermal or mucosal-submucosal junction are referred to as basement membrane zone (BMZ). The hallmark is deposition of of Ig and C3 on the perilesional tissues and in some patients detection of anti-BMZ autoantibodies. A unique characteristic of MMP is that as the blisters or erosions heal, they leave irreversible scarring. This scarring results in serious and catastrophic sequelae that affect the quality of life. Conventional therapy consists of anti-inflammatory and immunosuppressive agents (ISA). In patients who fail conventional therapy or develop significant side effects to them, rituximab (RTX) has been used off label. In this review, the clinical outcomes of patients with MMP treated with RTX were studied. 124 patients were identified, 47.58% being male. 72 patients were treated by the Lymphoma Protocol and 51 by Rheumatoid Arthritis (RA) protocol. Follow up for the entire cohort was 36 months (range 0.5–72). On follow-up 64 patients (51.61%) achieved complete clinical remission (CR) off therapy, 25 patients (20.16%) were in CR on therapy, 5 patients (4.03%) were non-responders, and 9 patients (7.25%) were failures. 52 patients (41.93%) experienced a relapse, after 36 months follow-up. Duration between last RTX infusion and relapse was 10.5 months (range 1–30). Most patients with relapses were treated with additional RTX. A statistically significant better outcome was observed in patients treated with RTX as monotherapy compared to those who received RTX with ISA. Clinical outcomes in patients treated with Lymphoma protocol were better than RA protocol at a statistically significant level. Data on CD20+ B cell depletion and repopulation was limited. Interestingly relapses were seen in patients with CD20+ B cell depletion and after repopulation. In the final analysis, 89 patients (71.77%) were in complete remission. Data in this review indicated that RTX was a useful agent to treat MMP. While a randomized control trial may not be practically possible, better and disease specific protocols need to be developed. When publishing, authors should attempt to provide complete and detailed information. In doing so, they will benefit their colleagues and the patients with MMP they treat with RTX.