Background: Munro’s microabscesses are a characteristic histopathologic feature of psoriasis vulgaris; however, the pathomechanisms underlying the migration of transepidermal leukocytes (PMNs) have not been fully elucidated yet. Objective and Methods: Since the lesional scale extracts contain potent chemoattractants , such as IL-8 and C5a fragments, we studied their location in the lesions of p soriasis vulgaris and PPP with immunohistochemical techniques. Results: Localiza tion of IL-8 was not detected in the subcorneal keratinocytes but was demonstra ted only in the basal keratinocytes together with migrating PMNs. In contrast, t he presence of a complement fragment, C3b, was observed on the cell membranes of subcorneal keratinocytes, suggesting that these were the sites of complement ac tivation. Conclusion: Such distinct localization of IL-8 and complement compone nts suggests that the intraepidermal migration of PMNs takes place first accordi ng to the concentration gradient of IL-8, and thereafter they are guided by com plement components to the final destination, the subcorneal portion of the lesional skin.
展开▼
