Ulrike Wehkamp, Marion Jost, Kai Wehkamp, Jürgen Harder
DOI: 10.2340/00015555-3372

Mycosis fungoides and Sézary syndrome belong to the group of primary cutaneous T-cell lymphomas. Because of the inflammatory appearance of the skin lesions, we hypothesized that antimicrobial peptides might be dysregulated in these conditions, similar to in inflammatory skin conditions. Samples from 20 patients with cutaneous T-cell lymphoma were analysed using immunohistochemistry and enzyme-linked immunoassay (ELISA) of skin washing fluids of hBD-2, hBD-3, RNase 7 and psoriasin. Immunohistochemistry results were compared with previous analyses of healthy and psoriatic skin. ELISA and immunohistochemistry revealed a higher expression of psoriasin in lesional cutaneous T-cell lymphoma compared with non-lesional and healthy samples. Immunohistochemistry showed an increase in hBD-2 in lesional cutaneous T-cell lymphoma skin compared with healthy skin. The expression profile of antimicrobial peptides in cutaneous T-cell lymphoma appears to be dysregulated, indicating a potential role of antimicrobial peptides in cutaneous T-cell lymphoma. A larger prospective study and functional studies are needed to improve our understanding of the role of antimicrobial peptides in cutaneous T-cell lymphoma.

Antimicrobial peptides are important for infection control and are known to be dysregulated in inflammatory skin conditions. In early stages of cutaneous T-cell lymphoma the lesions resemble inflammatory skin conditions. In later stages, patients often die due to infections. These clinical facts have led to an increased interest in the potential involvement of antimicrobial peptides. The current study shows that antimicrobial peptides are dysregulated in lesional cutaneous T-cell lymphoma skin. It is likely that antimicrobial peptides play a critical role in cutaneous T-cell lymphoma disease pathogenesis and maintenance. Furthermore, the antimicrobial peptide dysregulation potentially contributes to the infection risk with fatal outcome in higher disease stages.