Upregulation of interleukin-33 in the epidermis of two Japanese patients with Netherton syndrome.

Netherton syndrome (NS) is a rare autosomal recessive disorder which is caused by mutations in the SPINK5 gene encoding the serine-protease inhibitor LEKTI. Characteristic symptoms of NS include erythroderma with diffuse desquamation, hair abnormalities and atopic manifestations. Here, we report two Japanese patients with NS, one of whom had a novel mutation in the SPINK5 gene which leads to p.C367Lfs*3. The upregulation of interleukin-33 (IL-33) was evident in basal and thickened lower spinous layers of the epidermis in those cases. This suggests that IL-33 may be involved in the pathophysiology of NS as well as in atopic dermatitis.