The significance of endocan immunohistochemical expression in chronic plaque psoriasis

Background Psoriasis is a chronic inflammatory skin disease with immune-mediated mechanism. Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelium of blood vessels. Aims The present study aims to evaluate immunohistochemical localization of endocan in psoriatic skin in comparison with normal skin and to correlate its expression with the clinical and pathological data of psoriasis. Patients/Methods Skin biopsies from 36 psoriatic patients and 40 normal subjects were taken and processed for immunohistochemical staining of endocan. Results Endocan was expressed in 63.9% and in 36.1% of epidermal keratinocytes and dermal endothelial and inflammatory cells of psoriatic skin, respectively, compared with its expression in 30% of epidermis of normal skin. Diffuse epidermal expression of endocan was in favor of cases with more angiogenesis and its intense expression was in favor of marked acanthosis and with cases affecting trunk as main presentation. Positive dermal endocan expression was significantly associated with marked parakeratosis and with more angiogenesis. Conclusion Endocan is over-expressed in psoriatic skin from epidermal keratinocytes and dermal endothelial and inflammatory cells. Endocan enhances angiogenesis and proliferation of psoriatic skin contributing to pathogenic mechanisms of psoriasis.