Disease Relapse After Drug-Free Remission in Ocular Mucous Membrane Pemphigoid

Purpose: To quantitate the risk of relapse of ocular and extraocular disease among patients with mucous membrane pemphigoid (MMP) who had undergone drug-free remission. Design: Retrospective, comparative, interventional case series. Methods: There were 167 patients with biopsy-proven MMP who were seen at the Wilmer Eye Institute between November 1984 and December 2019. Among the 167 patients, 119 patients had ocular involvement and 103 of those patients received systemic treatment for MMP. The main outcome measures were the incidence of ocular remission, incidence rate of disease relapse after remission, and risk factors for disease relapse. Results: Over a median follow-up time of 7 years, 74 of 103 treated patients (71.8%) experienced drug-free remission (incidence rate = 0.28/person-year [PY], 95% confidence interval [CI] 0.22–0.35/PY). Most patients (80/103, 77.7%) received cyclophosphamide therapy. Thirteen of the 74 patients (17.6%) had disease relapse after remission: 4 with ocular disease only, 4 with extraocular disease only, and 5 with both. The rate relapse of ocular MMP was 0.020/PY (95% CI 0.009–0.038/PY), and the rate of relapse of MMP at any site (ocular or extraocular site) was 0.029/PY (95% CI 0.015–0.050/PY). The use of cyclophosphamide was associated with a greater chance of remission (hazard ratio [HR] = 3.84, P < .0001) and a lower risk of relapse (HR = 0.32, P = .05) compared with other immunosuppressive drugs except for rituximab. Five patients experienced drug-free remission after rituximab therapy and none of them had relapse (median follow-up after remission = 3.6 years). When use of cyclophosphamide or rituximab was compared with all other treatments, the risk of MMP relapse at any site (HR = 0.17, P = .02) and of ocular MMP (HR = 0.11, P = .007) were significantly lower. Conclusions: Rates of relapse of MMP after drug-free remission are low but not zero; therefore, monitoring of patients remains necessary. Relapses were not observed among those patients treated with rituximab who had remission; however, follow-up duration in those patients was shorter than the whole MMP cohort and the sample size was small.