Paraneoplastic pemphigus associated with metastatic lymphoepithelioma‐like carcinoma originating from the thyroid gland

13 months). One patient with BP achieved a partial remission and one patient with antilaminin-c1 pemphigoid, both treatment refractory, achieved full remission after one cycle of rituximab. Two patients with MMP improved after CD20depleting therapy: one showed a full remission after two cycles, the other patient showed a partial remission after one cycle of therapy. Three patients had a further progression of the disease with a continued inflammation of the ocular mucous membranes despite therapy. A follow-up assessment of B-cell levels was performed in six patients by detecting CD19+ and CD20+ in peripheral blood via fluorescence-activated cell sorting analysis. We observed a B-cell depletion after rituximab treatment for 9 7 7 3 months. Tolerability was good in the majority of patients (20 of 22). Two adverse events were observed during B-cell-depleting therapy. One patient developed a rituximab-induced alveolitis 4 days after the second infusion of rituximab, which was treated with intravenous antibiotics and resolved during therapy. In another patient, the second infusion was stopped due to the development of a metallic taste in the mouth. Our data show that B-cell ablative treatment is safe and effective in controlling recalcitrant courses of autoimmune blistering skin diseases. Moreover, we observed long-term remission in 15 of 22 patients, with an observational followup phase of up to 48 months, which is longer than the follow-up phase used in previous studies (Kanwar and Vinay up to 37 months and Gregoriou et al. up to 42 months). Our small data series suggests that patients with PV and PF seem more likely to respond to B-cell depletion than patients with MMP. Furthermore, B-cell depletion can also be considered as a treatment option for patients diagnosed with treatmentrefractory BP and antilaminin-c1 pemphigoid, as we observed good clinical efficacy in these patients as well. Cumulatively, our data support previous reports on clinical efficacy of a B-cell-targeted treatment in different subsets of autoimmune bullous skin disease. Our findings also support the need for a prospective clinical trial to prove that such treatment is not only efficacious and tolerable but also longlasting. The long remission period strongly suggests that rituximab therapy is a possible curative approach, as the concomitant immunosuppressive medication was reduced and even stopped for several patients. Apparently long-lived plasma cells, which are thought to play a role in many immunological diseases and are not affected by immunosuppressive agents, do not seem to play a central role in the pathogenesis of autoimmune blistering diseases.