Cytokine Profiling of Erythroderma Biopsies Reveals Types 2 and 17 Immune Activation Status

Erythroderma is a dermatologic condition characterized by widespread red and scaly skin. The causes include, but are not limited to, psoriasis, eczema, drug eruptions, pityriasis rubra pilaris (PRP), and cutaneous T-cell lymphoma. Most of these are typified by Type 2 (e.g., eczema) or Type 17 (e.g., psoriasis) immune activation. However, since the clinicopathologic features of erythroderma can be nonspecific, assays that determine the underlying immune activation status are desirable.

IL-13 RNA in situ hybridization and IL-36 immunohistochemistry were performed on 30 specimens of erythroderma, to ascertain Type 2 and Type 17 immune signatures, respectively.

Specimens of erythrodermic psoriasis and PRP showed strong expression of IL-36 and less than one IL-13-positive cell per millimeter. Conversely, those of spongiotic dermatitis showed low expression of IL-36 and greater than one IL-13-positive cell per millimeter. Most specimens of spongiotic, psoriasiform dermatitis demonstrated low IL-36 expression and greater than one IL-13-positive cell per millimeter, but a subset showed high IL-36 expression and greater than one IL-13-positive cell per millimeter.

We developed a Type 2/17 immune signature classifier based on cytokine profiling, which showed that cases of erythroderma fall within distinct categories of immune activation. This categorization may have utility in guiding clinical decisions.