RESUMO
Psoriasis is a chronic, systemic, inflammatory disorder which accelerates the life process of skin cells, based on a genetically induced deviant immune response. High-frequency ultrasonography (HF-USG) is a painless, non-invasive imaging technique that can be performed and repeated whenever the need arises. We evaluated lesional and non-lesional skin of psoriatic patients with the use of HF-USG, focusing on the immune-induced inflammation and skin thickness. Previous studies suggested that HF-USG, being a non-invasive technique, is useful as an aid to clinical evaluation of the severity of psoriatic plaques. Our goal was to determine whether the skin of psoriatic patients is influenced by the background or habits of the patients. The study included a total of 27 patients affected by psoriasis vulgaris. The thickness of the epidermis and dermis and the skin echogenicity were documented for the active plaques, as well as for the non-affected skin of all the patients included in the study, using a high-frequency ultrasonographic system. The patient's local background, sex, family history of psoriasis, smoking habits and sun exposure were analyzed. HF-USG of the psoriatic plaques exposes a three-band structure that is easily distinguished from the surrounding unaffected skin, due to a hypoechoic band in the upper dermis. Although not specific for psoriasis, it is a strong marker of inflammation. The obtained results confirm that, indeed, skin thickness is greater in lesional skin compared to non-lesional skin, by a mean of 1,180 µm (±340 µm). We consider that skin HF-USG should be used as a quantitative method in the clinical evaluation of the patients with psoriasis and may help as an objective means of assessing inflammation in lesional skin.
RESUMO
Psoriasis vulgaris, a chronic inflammatory skin disorder, is the result of immune mediated processes, genetic background and environmental factors. Prolactin and the vascular endothelial growth factor seem to play a key role in psoriasis pathogenesis regarding hyperproliferation of epidermal keratinocytes and dermal vascular ectasia. The aim of the study was to investigate the expression of tumor necrosis factor-α (TNF-α), vascular endothelial growth factor receptor 2 (VEGFR2) and prolactin receptor (PRLR) in psoriatic skin by immunohistochemical analysis and to evaluate the correlation with disease severity. Two skin biopsies, psoriatic lesion and perilesional skin, obtained by punch biopsy from 19 nontreated psoriasis patients were examined in hematoxylin and eosin staining and immunohistochemistry (IHC) for TNF-α, VEGFR2 and PRLR. The indirect IHC reaction was carried out automatically and visualized by 3,3-diaminobenzidine (DAB) technique. The average number of DAB-positive cells and the intensity of cell staining were quantified on a predefined scale. The results show a significant difference in the quantity and distribution of TNF-α positive cells in the two sample groups. In psoriatic plaque skin, an increased expression of TNF-α was found in the perivascular dermis and epidermic keratinocytes. In perilesional skin the immunostaining was predominant in the basal layer keratinocytes, while in psoriatic plaque, all the layers were positively marked, with stronger expression at the base. A statistically significant difference was found between the intensity of the immunostaining in the two types of tissue. Positive cells for VEGFR2 and PRL were identified in the basal layer keratinocyte cells (VEGFR2), sweat glands and hair outer shaft sheath (PRLR), without significant differences between the two types of samples. Our findings confirm the importance of TNF-α in psoriasis pathogenesis and a positive correlation with lesions severity. No significant differences were found for VEGFR2 and PRLR, but additional studies are necessary to establish their role.