Clinical response of severe mechanobullous epidermolysis bullosa acquisita to combined treatment with immunoadsorption and rituximab (anti-CD20 monoclonal antibodies)

Background: Epidermolysis bullosa acquisita (EBA) is an autoimmune bullous disorder with mucocutaneous involvement, skin fragility, and tendency to scarring. The mechanobullous form of EBA has a chronic relapsing course and is difficult to treat. We describe herein the therapeutic response of 2 patients with recalcitrant mechanobullous EBA to combined treatment with immunoadsorption and rituximab, an anti-CD20 monoclonal antibody that induces depletion of B cells in vivo. Observations: Two patients with mechanobullous EBA received combined treatment with immunoadsorption and rituximab, resulting in an almost complete clinical remission in one patient and stable disease in the other patient. In the patient with complete remission, prolonged B-cell depletion and clinical improvement with disappearance of mucocutaneous erosions paralleled the decline in titers of circulating anti-basement membrane zone autoantibodies. In the other patient, combined treatment with immunoadsorption and rituximab reduced the de novo appearance of blisters but did not lead to significant improvement of gingivitis, despite depleted B cells for 6 months that remained at 5% 12 months after the last administration of rituximab, as well as a reduction in autoantibody titers. Conclusion: The patients' response suggests that combined treatment with immunoadsorption and rituximab may be a valuable adjuvant treatment regimen for severe mechanobullous EBA, which is in line with recently observed beneficial effects in inflammatory EBA.