Yuichi Teraki

Intraepidermal T lymphocytes found in psoriatic skin lesions are involved in the development and maintenance of lesional pathology. It has become clear that differential expression of homing and chemokine receptors determines the specific migration of T cells to distinct tissues and microenvironments, including psoriasis lesions. The aim of the present study was to clarify expression of homing (CLA, VLA-4, and LFA-1) and chemokine (CCR4, CCR6, CCR7, and CXCR3) receptors on intraepidermal T cells in psoriatic lesions using flow cytometry. The vast majority of intraepidermal T cells in psoriatic lesions expressed CLA and LFA-1, whereas 58% of CD4+ and 85% of CD8+ T cells expressed VLA-4. The majority of CD4+ T cells and about half of the CD8+ T cells expressed CCR4 and CCR6, whereas less than one-third of CD4+ and CD8+ T cells expressed CXCR3 or CCR7. In patients with psoriasis the percentages of T cells expressing CLA, CCR4, and CCR6 were much higher in the epidermis of psoriatic plaques than in the peripheral blood. Thus, CLA, CCR4, and CCR6 may play a more important role in the migration of T cells to psoriatic epidermis.

Summary Background Intraepidermal T lymphocytes are a critical element for sustaining the lesional pathology of psoriasis. Integrin αEβ7 (CD103), a ligand for E‐cadherin, may play a role in the l...

We describe here a case of a 33-year-old man who had lichen amyloidosus associated with Kimura’s disease. In this case, treatment with cyclosporine dramatically improved the lesions of both Kimura’s disease and lichen amyloidosus. Although Kimura’s disease and lichen amyloidosus are both rare distinct entities, to our knowledge, 11 cases of association of Kimura’s disease and lichen amyloidosus have been described previously.

Background Skin‐homing T cells are characterized by expression of cutaneous lymphocyte‐associated antigen (CLA). Few data are available on the frequency of circulating CLA+ cytokine‐producing T cell...

In multicellular organisms, homeostasis is maintained by a balance between cell proliferation and cell death. Two common forms of cell death, called apoptosis and necrosis, have been described. Apoptosis, which is often equated with programmed cell death, is a physiological form of cell death that is responsible for the deletion of cells. Apoptosis is morphologically and biochemically characterized by cell shrinkage, dense chromatin condensation, cellular budding, fragmentation, rapid phagocytosis by nearby cells, and DNA fragmentation into units of approximately 200 base pairs. Apoptosis can be triggered by a wide variety of stimuli such as cytokines, hormones, drugs, and viruses, and their signal transduction tightly regulated by genes such as Bcl-2. Effector caspases are finally activated, resulting in apoptotic cell death. In the skin, there is considerable evidence that apoptosis plays an important role in the pathogenesis of a wide variety of skin diseases. In lichenoid tissue reactions, the Civatte body or colloid body is a form of apoptotic keratinocytes which is mediated by T lymphocytes via Fas-FasL interaction or through the perforin-granzyme B pathway. In several skin tumors, Bcl-2 or FasL expression is involved in the proliferation or regression of the tumors, or in the escape from immune attack by T cells. Moreover, apoptosis is also responsible for the homeostasis of skin, such as the keratinocyte differentiation and hair cycle. In this review, we describe the basic concept of apoptosis and its relevance to skin diseases.

Eosinophilic pustular folliculitis is a distinctive dermatosis that was first described in Japan. Although the histopathologic feature of eosinophilic pustular folliculitis is characterized by follicular infiltrates with numerous eosinophils, its pathophysiology remains unclear. The lesional skin of five patients with eosinophilic pustular folliculitis was examined using several monoclonal antibodies including a variety of anti-leukocyte adhesion molecules: endothelial cell adhesion molecule 1, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1, by means of immunohistochemical techniques. Intercellular adhesion molecule 1 expression by keratinocytes was observed on follicular epithelium, but not on epidermis. The migration of eosinophils and lymphocytes, which were intensely positive for antilymphocyte function-associated antigen 1, was limited to follicular epithelium. Endothelial cell adhesion molecule 1 and vascular cell adhesion molecule 1 expression of vascular endothelium was more often observed around hair follicles. There was no reactivity for interleukin 8 in follicular epithelium. These findings may explain the selective migration of eosinophils and lymphocytes to the hair follicles in eosinophilic pustular folliculitis.