Anti-CD20 (rituximab) treatment improves atopic eczema

Abstract

Atopic eczema (AE) is a chronic inflammatory skin disorder characterized by eczematous skin lesions, pruritus, and typical histopathologic features. We asked whether depletion of B cells by monoclonal anti-CD20 antibody therapy (rituximab) would improve severe AE. Six patients (4 women and 2 men) with severe AE received 2 intravenous applications of rituximab, each 1000 mg, 2 weeks apart. To evaluate the efficacy of rituximab, we monitored clinical parameters (eczema area and severity index, pruritus), total and allergen-specific IgE levels, skin histology, and inflammatory cells and cytokine expression in the skin and peripheral blood before and after therapy. All patients showed an improvement of their skin symptoms within 4 to 8 weeks. The eczema area and severity index significantly decreased (before therapy, 29.4 +/- 4.3; week 8, 8.4 +/- 3.6; P < .001). Histologic alterations such as spongiosis, acanthosis, and dermal infiltrate, including T and B cell numbers, also dramatically improved. However, whereas blood B cells were below detectable levels as a consequence of rituximab administration, skin B cells were reduced by approximately 50% only. Expression of IL-5 and IL-13 was reduced after therapy. Moreover, whereas allergen-specific IgE levels were not altered, we observed a slight reduction in total IgE concentrations in blood. B cells play a major role in AE pathogenesis. Treatment with an anti-CD20 antibody leads to an impressive improvement of AE in patients with severe disease.