The combination of the Zenon labeling technique and microscopic image analysis to study cell populations in normal and psoriatic epidermis.

Contains fulltext : 48197.pdf (publisher's version ) (Closed access)BACKGROUND: In order to better characterize epidermal cell populations in psoriatic vs. normal skin, fluorescent immunohistochemical techniques were extended with a new labeling technique. The Zenon technique conjugates primary antibodies rapidly and quantitatively after which they are used in the same manner as covalently labeled primary antibodies. Digital microscopic images of epidermal expression of keratin 10 and keratin 6 (differentiation), Ki-67 antigen (proliferation), and keratin 15 and beta-1 integrin (basal layer) were analyzed in a standardized way. Co-expression of different proteins was demonstrated. METHODS: Sections of normal skin and psoriatic lesions were compared immunohistochemically. Antibodies against keratin 6, 10, and 15 were labeled with the Zenon technique. Antibodies against the Ki-67 antigen and beta-1 integrin were covalently fluorescein isothiocyanate-labeled. Using standardized image analysis, intensity and positive surface area of the different antibodies in the epidermis were measured. RESULTS: The number of Ki-67-antigen positive cells was significantly increased in lesional psoriatic skin. Intensity and positive surface area of keratin 10 and beta-1 integrin were significantly decreased in comparison to normal epidermis. Differential expression of keratin 6 and keratin 15 was demonstrated. CONCLUSIONS: Using Zenon technology and image analysis, a description of morphology, co-expression, and quantification of representative markers for epidermal cell populations is possible

Distribution of dipeptidyl-peptidase IV on keratinocytes in the margin zone of a psoriatic lesion: a comparison with hyperproliferation and aberrant differentiation markers.

Contains fulltext : 70490.pdf (publisher's version ) (Closed access)The inflammation process in psoriatic skin is characterized by influx of leukocytes, hyperproliferation and aberrant differentiation of keratinocytes regulated via cytokines. Dipeptidyl-peptidase IV (DPPIV) is known to be upregulated on keratinocytes in the psoriatic lesion. The objective was to gain insight into dynamics of DPPIV expression and enzyme activity together with keratinocyte proliferation and differentiation markers during development of a psoriatic lesion, in order to investigate coherence in mechanisms behind the upregulation of DPPIV in psoriatic skin. The expression of DPPIV, Ki-67 antigen and keratin-16 (K16) was studied in the dynamic margin zone of the psoriatic lesion, examining skin sections of the clinically uninvolved skin, the early lesion and the chronic lesion of psoriatic patients compared to healthy volunteers using immunohistochemical and enzymehistochemical staining methods. DPPIV-expression and enzyme activity, Ki-67 antigen and K16 are significantly upregulated in the centre and inner margin of the lesion compared to clinically uninvolved skin and the healthy volunteers skin. Mutually between the centre and inner margin, this upregulation did not differ significantly. The clinical symptomless skin proved to have significantly elevated DPPIV enzyme activity compared to the skin of healthy volunteers. We demonstrate that DPPIV is expressed and enzymatically active well before the development of an overt psoriatic lesion. The abnormal DPPIV distribution in psoriatic skin does not coincide with known markers of aberrant growth and differentiation of keratinocytes, which makes DPPIV (expression and enzyme activity) a marker standing on its own

Epidemiology of Chronic Pruritus: Where Have We Been and Where Are We Going?

Between 23 and 44 million Americans are estimated to suffer from chronic pruritus in the setting of both cutaneous and systemic conditions. Patients with chronic pruritus suffer extreme detriment to their ability to function, including but not limited to deranged sleep patterns, mood disturbances, increased levels of anxiety and depression, and reduced levels of overall quality of life. Indeed, chronic pruritus is now known to be as debilitating as chronic pain. For these reasons, chronic pruritus represents a serious public health concern that must be adequately addressed by clinicians. We present an up-to-date summary of the epidemiology of chronic itch in different cutaneous and systemic conditions. While we have endeavored to discuss some of the most common causes of chronic pruritus, this review does not encompass all of the myriad different diseases in which chronic pruritus can occur