ucous membrane pemphigoid (MMP) is a rare subepithelial autoimmune bullous disease typified by predominant mucosal involvement and scarring. 1 It poses a substantial diagnostic challenge owing to the generally lower levels of serum autoantibodies compared with other autoimmune bullous diseases. The heterogeneity of autoantigens targeted in MMP, autoantibody isotypes (immunoglobulin [Ig] IgG, IgA, or both), and the lack of widely available serological assays further hamper early recognition of MMP. Given the rarity of the disease, data about the association of clinical and immunopathological features of the disease are limited. The aim of the current study was to investigate the clinical, immunoserological, and immunopathological characteristics of a large cohort of patients with MMP managed in 2 tertiary centers. MethodsWe performed a retrospective cohort study that included routine data from all patients diagnosed with MMP between January 1, 2007, and February 28, 2020, in 2 referral centers for autoimmune bullous diseases at the

ImportanceMucous membrane pemphigoid (MMP) is a rare and heterogeneous subepithelial autoimmune bullous disease with predominant mucosal involvement. Characteristics associated with the disease course and complications are yet to be delineated.ObjectivesTo evaluate characteristics associated with refractory disease course and blindness among patients with MMP and to estimate the association of different treatment strategies with the prognostic outcome.Design, Setting, and ParticipantsA retrospective cohort study of consecutive patients diagnosed with MMP and followed up for more than 1 year from 2007 to 2020 in 2 tertiary referral centers. Data were analyzed from January 1, 2009, to June 30, 2020.Main Outcomes and MeasuresCharacteristics associated with refractory disease course and blindness were evaluated using multivariable logistic regression model.ResultsThe study encompassed 121 patients with MMP (mean [SD] age, 66.0 [14.0] years; 78 (64.5%) were women), of whom 56 (46.3%) followed a refractory course and 13 (10.7%) developed blindness. Anti–LAD-1 IgA (odds ratio [OR], 3.42; 95% CI, 1.11-10.52; P = .03) and anti–dermal-epidermal/epithelial junction (DEJ) IgG (by indirect immunofluorescence on human salt-split skin; OR, 2.92; 95% CI, 1.26-6.78; P = .01) were significantly associated with refractory course. Development of blindness was associated with older age (≥68 years; OR, 6.38; 95% CI, 1.35-30.16; P = .009), initial presentation with bilateral ocular involvement (OR, 7.92; 95% CI, 2.04-30.68; P = .001), and scarring ocular lesions (OR, 5.11; 95% CI, 1.47-17.79; P = .006). However, 4 (30.8%) and 2 (15.4%) of those experiencing blindness had no ocular scarring lesions and unilateral ocular involvement at the onset of their disease, respectively. Patients progressing to blindness were more likely to be treated by 3 or more immunosuppressive/immunomodulatory drugs (OR, 4.07; 95% CI, 1.17-14.14; P = .02) and by cyclophosphamide (OR, 7.64; 95% CI, 2.24-26.09; P < .001). Patients developing blindness and refractory course were more frequently managed by intravenous immunoglobulin (OR, 7.64; 95% CI, 2.24-26.09; P < .001 and OR, 3.47; 95% CI, 1.42-8.45; P = .005, respectively).Conclusions and RelevanceFindings of this cohort study support that patients with MMP with anti–LAD-1 IgA and anti-DEJ IgG reactivity should be carefully monitored. While initial bilateral ocular disease and scarring ocular lesions were associated with blindness, patients initially presenting with unilateral and nonscarring ocular disease may still develop severe vision impairment.