Psoriatic Plaques (psoriatic + plaque)

Distribution by Scientific Domains


Selected Abstracts


Identification of differentially expressed genes in psoriasis using expression profiling approaches

EXPERIMENTAL DERMATOLOGY, Issue 9 2005
K. Itoh
Abstract:, To identify differentially expressed genes which play causal roles in pathogenesis and maintenance for psoriasis, we used BodyMapping and introduced amplified fragment length polymorphism approaches. From the BodyMap database, we selected 2007 genes which specifically expressed in epithelial tissues. Among 2007 genes, we surveyed genes which differentially expressed in involved or uninvolved psoriatic lesional skin samples compared with atopic dermatitis, mycosis fungoides, and normal skin samples. As a result of surveying 2007 genes, 241 genes were differentially expressed only in involved psoriatic skin but not in the other samples. Hierarchical cluster analysis of gene expression profiles showed that 13 independent psoriatic-involved skin samples clustered tightly together, reflecting highly similar expression profiles. Using the same 2007 gene set, we examined gene expression levels in five serial lesions from distal uninvolved psoriatic skin to involved psoriatic plaque. We identified seven genes such as alpha-1-microglobulin/bikunin precursor, calnexin, claudin 1, leucine zipper down-regulated in cancer 1, tyrosinase-related protein 1, Yes-associated protein 1, and unc-13-like protein (Coleonyx elegans) which show high-expression levels only in uninvolved psoriatic lesions. These seven genes, which were reported to be related to apoptosis or antiproliferation, might have causal roles in pathophysiology in psoriasis. [source]


Effect of PUVA, narrow-band UVB and cyclosporin on inflammatory cells of the psoriatic plaque

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 3 2007
Gul Erkin
Background:, Because antigen presenting is necessary for T-cell activation, antigen-presenting cells should be involved in the pathogenesis of psoriasis. In this study, our purpose was to evaluate and compare effects of PUVA, cyclosporine A and narrow-band UVB on dendritic cells and activated lymphocytes in the psoriatic lesions. Methods:, Forty-five volunteered patients (15 patients in each treatment group as PUVA, cyclosporin A and narrow-band UVB) were enrolled in this study. Lesional skin biopsies were taken from each patient before and after treatments. Fresh frozen biopsies were studied for the expressions of CD1a, CD68, CD86, CD4, CD8 and HLA-DR proteins by immunohistochemistry. Results:, There was no correlation between severity of the lesions and expressions of the antigens. Only PUVA significantly decreased CD1a+ epidermal Langerhans cells' (LCs) counts. Treatment modalities decreased expression of costimulator CD86, and most of them decrease antigen-presenting capacity of skin by decreasing HLA class-II expression. Conclusions:, All treatment modalities equally reduce lymphocytes, macrophages and dendritic cells. PUVA is the only treatment that decreases epidermal LCs. All treatments effectively diminish expression of CD86 and inhibit this step of inflammation. [source]


Creation of psoriatic plaques: the ultimate tumor suppressor pathway.

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2001
A new model for an ancient T-cell-mediated skin disease.
From an oncological and immunological perspective, the T-cell-mediated induction of psoriatic plaques should be prone to malignant transformation as the phenotype of psoriatic plaques includes: chronic inflammation, epidermal hyperplasia, prolonged survival and elevated telomerase levels in lesional keratinocytes, as well as angiogenesis, exposure to carcinogens and immunosuppressants. However, conversion of a psoriatic plaque to squamous cell carcinoma is exceedingly rare. This paper explores the possible molecular mechanism for the tumor suppressor pathway in psoriatic lesions, with an emphasis on a putative senescence-switch involving p16. [source]


From bench to bedside , translational research in psoriasis

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2010
JC Prinz
Abstract For many years, psoriasis was firmly believed to be a disease of epidermal keratinocytes, but now is attributed to a combination of genetic and environmental factors that promote a T-cell mediated immune response in the skin. Psoriasis is now understood to be a systemic T-cell mediated autoimmune disease with the innate immune system playing an important role. Progress in understanding the pathogenesis of psoriasis has shown that following a stimulus, dendritic and T cell activation leads to the release of cytokines, chemokines and growth factors that initiate the proliferation and altered differentiation of keratinocytes. These factors subsequently lead to continuous activation of T cells and antigen-presenting cells, particularly dendritic cells, within the psoriatic plaque. This vicious cycle of psoriasis, in which the cytokines interleukin 12 (IL-12) and IL-23 play a pivotal role, is a logical target for biological therapy. [source]


Perforin expression is upregulated in the epidermis of psoriatic lesions

BRITISH JOURNAL OF DERMATOLOGY, Issue 4 2004
M. Ka, telan
Summary Background, There are currently very few data regarding the role of cell-mediated cytotoxicity in psoriasis. Both cytotoxic T lymphocytes and natural killer (NK) cells mediate cytotoxicity reactions, mainly by two distinct pathways, the perforin/granzyme and the Fas/Fas ligand pathway. Objectives, To study the expression and distribution of perforin, T- and NK-cell subsets in psoriatic lesional and nonlesional skin. Methods, Skin biopsy specimens from both lesional and nonlesional skin of 11 patients with chronic plaque psoriasis and eight healthy controls were analysed by immunohistochemistry. Results, We found a significant increase in CD4+ and CD8+ cells in psoriatic lesions compared with nonlesional and healthy skin. The expression of CD16+ NK cells was significantly lower in lesions compared with healthy skin. Perforin expression was significantly enhanced in the epidermis of psoriatic lesions. Conclusions, Perforin expression is upregulated in the epidermis of psoriatic lesions, suggesting a potential role for perforin in the creation of the psoriatic plaque. [source]


Correlation of psoriasis activity with abundance of CD25+CD8+ T cells: conditions for cloning T cells from psoriatic plaques

EXPERIMENTAL DERMATOLOGY, Issue 10 2004
Wayan M. Kohlmann
Abstract:, The role of T cells in the pathogenesis of psoriasis is widely acknowledged. However, key aspects of their precise function in the disease as well as the relative pathogenic contribution of T-cell subsets are still unknown. T-cell clones have been isolated from psoriatic plaques but a study of conditions affecting the isolation and expansion of T-cell clones from psoriatic skin has not been reported to date. Here, we observe a correlation of disease activity with the frequency of the CD3+CD8+CD25+ subset. We show that prolonged in vitro culture changes the phenotypic subset distribution of T-cell lines derived from psoriatic skin and that T-cell clones can be isolated by sorting of CD25+ cells emigrated from skin fragments after 7 days. We evaluate various conditions affecting expansion of psoriatic T-cell clones in vitro and show that blocking apoptosis can facilitate proliferation of activated T-cell clones in vitro. Our results indicate a prominent role of the CD8+CD25+ T-cell subset in disease pathogenesis and should be useful in the design of experiments aiming at a systematic analysis of the specificity of clones present in psoriatic plaques. [source]


Basis of occlusive therapy in psoriasis: correcting defects in permeability barrier and calcium gradient

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2001
Sang Min Hwang MD
Background Although occlusive dressings have great potential in the management of psoriasis vulgaris, the therapeutic mechanism is not completely understood. Occlusion artificially restores and corrects the defective barrier in psoriasis plaques. Additionally, occlusion is know to normalize the epidermal calcium gradients in hyperproliferative murine skin models. Methods To investigate the basis of the therapeutic effect of occlusion on psoriatic plaques, we investigated the ultrastructural morphology of intercorneocyte lipid layers, lamellar bodies, and calcium gradient in chronic plaque-type psoriasis after occlusion with a water vapor-impermeable membrane. The specimens were processed for electron microscopy using: (i) ruthenium tetroxide postfixation; and (ii) ion-capture cytochemistry for calcium localization. Results Occlusion for 7 days resulted in a nearly mature pattern of intercellular multilamellar structures, re-establishment of the near-normal epidermal calcium gradient, and disappearance of calcium precipitates from the stratum corneum interstices. Conclusions The normalization of the permeability barrier and epidermal calcium gradient may play important roles in the therapeutic effects of occlusive dressings in chronic plaque-type psoriasis. [source]


Creation of psoriatic plaques: the ultimate tumor suppressor pathway.

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2001
A new model for an ancient T-cell-mediated skin disease.
From an oncological and immunological perspective, the T-cell-mediated induction of psoriatic plaques should be prone to malignant transformation as the phenotype of psoriatic plaques includes: chronic inflammation, epidermal hyperplasia, prolonged survival and elevated telomerase levels in lesional keratinocytes, as well as angiogenesis, exposure to carcinogens and immunosuppressants. However, conversion of a psoriatic plaque to squamous cell carcinoma is exceedingly rare. This paper explores the possible molecular mechanism for the tumor suppressor pathway in psoriatic lesions, with an emphasis on a putative senescence-switch involving p16. [source]


Disappointing results and low tolerability of photodynamic therapy with topical 5-aminolaevulinic acid in psoriasis.

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2006
A randomized, double-blind phase I/II study
Abstract Background, Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. Objective, A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. Methods, In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm2 and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). Results, The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. Conclusion, Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile. [source]


Psoriasis confined strictly to vitiligo areas , a Koebner-like phenomenon?

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2 2006
TG Berger
Abstract Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-,) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-, and interferon-, (IFN-,), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis. [source]


The immunological basis of psoriasis

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2003
C E M Griffiths
ABSTRACT Evidence that psoriasis is an immune-mediated disorder comes from laboratory studies, clinical observation, and use of targeted therapies. Immunohistochemical studies have shown that the majority of T cells in psoriatic plaques are CD45RO+ memory-effector T cells that migrate into skin in recognition of an as yet undetermined antigen. There is also a predominance of Th1 cytokines, namely interferon gamma, in psoriatic plaques, in contrast to the predominance of Th2 cytokines found in atopic dermatitis. The efficacy of therapeutic agents that target T cells, such as anti-CD4+ monoclonal antibodies, cyclosporin, and interleukin-2 fusion toxin, has provided further substantial evidence that psoriasis is a T-cell-mediated disease. New T-cell targeted approaches and cytokine modulation are advancing basic science in providing an understanding of the evidence for the importance of the immune process in the biology of psoriasis. [source]


Erythema measurements may allow early diagnosis of diabetes mellitus in adult psoriatics

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2003
O Avci
ABSTRACT Background ,We have observed that the erythema in subjects with psoriasis vulgaris associated with non-insulin-dependent diabetes mellitus (NIDDM) presents a mostly deep-red to purple hue instead of the typical pink to red tones. We carried out a descriptive clinical study, including 141 patients with psoriasis vulgaris to quantify these colour differences. Methods, Mean erythema index values were established for the psoriatic plaques of adult subjects using an optoelectronic method. Non-diabetic psoriatics underwent an oral glucose tolerance test (OGTT), and based on the results of the oral OGTTs, the subjects were divided into three groups: 18 psoriatics with NIDDM, 16 psoriatics with impaired glucose tolerance (IGT) and 107 psoriatics with normal glucose tolerance. The mean erythema index value was calculated for each group and the findings were compared. Results, The differences in the erythema were found to be highly significant between the group of subjects with psoriasis having normal glucose tolerance and both those with IGT and those with NIDDM (P < 0.01 and P < 0.01). The differences in the erythema were also highly significant between the psoriatic group with normal glucose tolerance and the group of 34 psoriatics with IGT and NIDDM all together (P < 0.01). Conclusions, Individuation of the various hues of erythema in psoriatics by careful dermatological examination or routine measurements of lesional erythema may alert the physician to possible IGT in the presenting subject, and this may affect disease severity. [source]


The effects of phototherapy on the numbers of circulating natural killer cells and T lymphocytes in psoriasis

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 2 2009
A. M. Tobin
The innate immune system is believed to be important in the pathogenesis of psoriasis and natural killer (NK) have been found in increased numbers in psoriatic plaques. Alterations in the numbers of NK cells in peripheral blood have been reported. We investigated the effect of phototherapy on levels of peripheral NK cells and lymphocytes in patients with psoriasis. In nine patients whom we followed before, during and after narrowband ultraviolet B (UVB) treatment there were no differences in the numbers of circulating lymphocytes, lymphocyte subsets or cells expressing NK markers and controls. Treatment with narrowband UVB did, however, significantly lower circulating CD4 counts which gradually recovered posttreatment. [source]


Interleukin-20 plays a critical role in maintenance and development of psoriasis in the human xenograft transplantation model

BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2009
K. Stenderup
Summary Background, Interleukin (IL)-20 is a recently discovered cytokine displaying increased levels in psoriatic lesions. Interestingly, IL-20 levels decrease with antipsoriatic treatment, correlating with clinical improvement. However, the role of IL-20 in the aetiology of psoriasis is unknown. Objectives, In this study, we investigate the effects both of blocking IL-20 signalling in psoriatic plaques and of adding IL-20 to nonlesional psoriasis skin. Methods, We employed the human skin xenograft transplantation model in which psoriatic plaques and nonlesional keratome skin biopsies obtained from donors with moderate to severe plaque psoriasis were transplanted on to immuno-deficient mice. The transplanted mice were treated with anti-IL-20 antibodies or recombinant human IL-20. Results, We demonstrate that blocking IL-20 signalling with anti-IL-20 antibodies induces psoriasis resolution and inhibits psoriasis induction. We also demonstrate that continuous IL-20 infusion, together with injection of additional nonactivated leucocytes, promotes induction of psoriasis in nonlesional skin from patients with psoriasis. Conclusions, The results suggest that IL-20 plays a critical role in the induction and maintenance of psoriasis, and IL-20 is suggested as a new possible specific target in psoriasis treatment. [source]


Topical aminolaevulinic acid-based photodynamic therapy as a treatment option for psoriasis?

BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2005
Results of a randomized, observer-blinded study
Summary Background, Topical aminolaevulinic acid-based photodynamic therapy (ALA-PDT) has recently been tried in small open studies for several inflammatory dermatoses including psoriasis. Objectives, The purpose of this randomized, within patient comparison study was to investigate whether topical ALA-based PDT using a range of light doses can induce a satisfactory response in localized psoriasis. Patients and methods, Twenty-nine patients with chronic plaque type psoriasis were enrolled in the study. After keratolytic pretreatment three psoriatic plaques in each patient were randomly allocated to PDT with 1% ALA and a light dose of 5 J cm,2, 10 J cm,2 or 20 J cm,2, respectively. Treatment was performed twice weekly until complete clearance or for a maximum of 12 irradiations. As a measure of clinical response the psoriasis severity index (PSI) of the three target plaques was assessed separately by an observer blinded to the treatment at baseline, before each PDT treatment and 3,4 days after the last irradiation. Results, Eight patients withdrew prematurely from the study. Keratolytic pretreatment alone reduced the baseline PSI in all three dose groups by about 25%. Subsequent PDT with 20 J cm,2 resulted in a final reduction of PSI by 59%, PDT with the lower doses of 10 J cm,2 and 5 J cm,2 decreased the baseline PSI by 46% and 49%, respectively. The difference in clinical efficacy between 20 J cm,2 and 10 J cm,2 or 5 J cm,2 was statistically significant (P = 0·003; P = 0·02), whereas no difference was found between 10 J cm,2 and 5 J cm,2 (P = 0·4). All patients reported some degree of PDT-induced stinging or burning during irradiation. Conclusions, The unsatisfactory clinical response and frequent occurrence of pain during and after irradiation renders topical ALA-based PDT an inadequate treatment option for psoriasis. [source]


Calcipotriol induces apoptosis in psoriatic keratinocytes

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 8 2009
R. Tiberio
Summary In recent years, vitamin D3 analogues have become one of the most widely prescribed topical treatments for mild or moderate chronic plaque psoriasis. These molecules are effective and safe, but their exact mechanism of action is not completely understood. In vitro studies have shown that D3 analogues decrease proliferation and induce differentiation of keratinocytes, and have strong immunomodulating effects, but there are no conclusive data about apoptosis. The aim of this study was to evaluate differences in apoptotic response between lesional and perilesional keratinocytes of patients with psoriasis before and after treatment with calcipotriol, a synthetic vitamin D3 analogue. Keratinocytes were isolated from psoriatic plaques including lesional and perilesional skin, and cultured. Cells were treated with calcipotriol for 20 h and examined under confocal microscopy after staining with propidium iodide. The number of apoptotic cells after incubation with calcipotriol was significantly higher in lesional than in perilesional keratinocytes (P < 0.05) or non-treated psoriatic keratinocytes (P < 0.05). In conclusion, calcipotriol seems to induce apoptosis in psoriatic keratinocytes. [source]