Untreated Plaques Research Articles

Fixed-combination halobetasol propionate and tazarotene topical lotion decreases TNF-α and IL-17A levels in psoriatic lesions

ObjectiveFixed-combination halobetasol propionate (0.01%) and tazarotene (0.045%) lotion (HP/TAZ) is approved for the treatment of plaque psoriasis in adults, with a demonstrated efficacy and safety profile in phase 3 trials. This study examined the effect of HP/TAZ on the reduction of tumor necrosis factor alpha (TNF-α) and interleukin 17 A (IL-17A) and its correlation to psoriasis improvement.Materials and methodsTen adults with mild-to-moderate plaque psoriasis and 2 symmetrical plaques self-applied HP/TAZ (treated plaque) or vehicle lotion (untreated plaque) for 12 weeks. At baseline and each study visit (weeks 2, 4, 8, and 12), Investigator’s Global Assessment (IGA) score and erythema, scaling, and induration were assessed. Additionally, D-squame tape strips were utilized to quantify TNF-α and IL-17A in target lesions by enzyme-linked immunosorbent assay.ResultsSignificant improvements in mean IGA score in HP/TAZ–treated compared with untreated plaques were evident at week 2 and maintained through week 12 (p < 0.003). HP/TAZ significantly reduced TNF-α levels at weeks 4 through 12 (p < 0.03) and IL-17A levels at weeks 2 through 8 (p < 0.05) in treated compared with untreated plaques.ConclusionsHP/TAZ was highly effective in treating psoriasis plaques and, although HP/TAZ is not a biologic, effectively reduced cytokine-associated inflammatory markers that drive psoriatic disease.

Investigation of the effects of Bipolar Radiofrequency Energy on the Structural Morphology of Dental Plaque.

To investigate the effects of radiofrequency (RF) energy, applied through a power toothbrush, on the structural morphology of dental plaque and its bacteria components. Previous studies showed that a toothbrush powered by RF (ToothWave) effectively reduces extrinsic tooth stains, plaque, and calculus. However, the mechanism by which it reduces dental plaque deposits is not fully established. Multispecies plaques at sampling time points of 24, 48, and 72 hours were treated with the application of RF using ToothWave with the toothbrush bristles 1 mm above the plaque surface. Groups that underwent the same protocol but without RF treatment served as paired controls. Confocal laser scanning microscope (CLSM) was used to determine cell viability at each time point. Plaque morphology and bacteria ultrastructure were viewed using scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. Data were analyzed statistically using analysis of variance (ANOVA) and Bonferroni post-tests. At each time, RF treatment significantly (p < 0.05) reduced the viable cells in plaque and caused a substantial disruption of plaque morphology, while the untreated plaque had intact morphology. Cells in treated plaques showed disrupted cell walls, cytoplasmic material, huge vacuoles, and heterogeneity in electron density, while these organelles remained intact in untreated plaques. The application of RF via a power toothbrush can disrupt plaque morphology and kill bacteria. These effects were enhanced by the combined application of RF and toothpaste.

Everolimus-eluting stents stabilize plaque inflammation in vivo: assessment by intravascular fluorescence molecular imaging.

Inflammation drives atherosclerosis complications and is a promising therapeutic target for plaque stabilization. At present, it is unknown whether local stenting approaches can stabilize plaque inflammation in vivo. Here, we investigate whether everolimus-eluting stents (EES) can locally suppress plaque inflammatory protease activity in vivo using intravascular near-infrared fluorescence (NIRF) molecular imaging. Balloon-injured, hyperlipidaemic rabbits with atherosclerosis received non-overlapping EES and bare metal stents (BMS) placement into the infrarenal aorta (n = 7 EES, n = 7 BMS, 3.5 mm diameter x 12 mm length). Four weeks later, rabbits received an injection of the cysteine protease-activatable NIRF imaging agent Prosense VM110. Twenty-four hours later, co-registered intravascular 2D NIRF, X-ray angiography and intravascular ultrasound imaging were performed. In vivo EES-stented plaques contained substantially reduced NIRF inflammatory protease activity compared with untreated plaques and BMS-stented plaques (P = 0.006). Ex vivo macroscopic NIRF imaging of plaque protease activity corroborated the in vivo results (P = 0.003). Histopathology analyses revealed that EES-treated plaques showed reduced neointimal and medial arterial macrophage and cathepsin B expression compared with unstented and BMS-treated plaques. EES-stenting stabilizes plaque inflammation as assessed by translational intravascular NIRF molecular imaging in vivo. These data further support that EES may provide a local approach for stabilizing inflamed plaques.

Kv1.3 in psoriatic disease: PAP-1, a small molecule inhibitor of Kv1.3 is effective in the SCID mouse psoriasis – Xenograft model

Kv1.3 channels regulate the activation/proliferation of effector memory T cells and thus play a critical role in the pathogenesis of autoimmune diseases. Using a combination of immunohistochemistry, confocal microscopy, flow cytometry and electrophysiology methods we observed a significant enrichment of activated Kv1.3+ memory T cells in psoriasis plaques and synovial fluid from patients with psoriasis/psoriatic arthritis (PsA) compared to non-lesional psoriatic skin, normal skin or peripheral blood lympho-mononuclear cells. In in vitro studies performed with lesional mononuclear cells or T cells derived from skin and joints of psoriatic disease, the small molecule Kv1.3 blocker PAP-1 dose-dependently inhibited proliferation and suppressed IL-2 and IFN-γ production. To further substantiate the pathologic role of Kv1.3 high TEM cells in psoriatic disease we tested whether PAP-1 is able to improve psoriatic disease pathology in the SCID mouse-psoriasis skin xenograft model. Following four weeks of daily treatment with 2% PAP-1 ointment we noticed about 50% reduction in the epidermal thickness (rete peg length) and the number of CD3+ lymphocytes/mm2 of dermis decreased by 85%. Vehicle treated and untreated plaques in contrast remained unchanged and showed no reduction in epidermis thickness and infiltrating CD3+ T cells and HLA-DR+ T cells. Based on these results we propose the development of Kv1.3 targeted topical immunotherapy for psoriasis and possibly for other inflammatory skin conditions, where effector memory T cells are involved in the pathogenesis.

Optical coherence tomography imaging of psoriasis vulgaris: correlation with histology and disease severity

Epidermal thickness (ET) has been suggested as a surrogate measure of psoriasis severity. Optical coherence tomography (OCT) is a recent imaging technology that provides real-time skin images to a depth of 1.8 mm with a micrometre resolution. OCT may provide an accurate in vivo measure of ET. It is, therefore, speculated that OCT may be used in the assessment of psoriasis vulgaris. A total of 23 patients with psoriasis vulgaris were systematically evaluated by OCT imaging and skin biopsy during treatment. Biopsies were graded for disease severity, and additional evaluation was done by the physician via psoriasis area and severity index (PASI) score, and by the patient through measures such as self-administered PASI, psoriasis life stress inventory index and dermatology life quality index. ET was calculated from OCT images. In comparison to normal skin, psoriasis appeared with a more irregular surface with a stronger entrance signal, a serrated dermo-epidermal junction was found and a less signal intensity in the dermis as shown in OCT images. ET measured in untreated plaques was thicker reflecting epidermal hyperproliferation and inflammation. The changes were significantly correlated with the biopsy grading (r (2) = 0.41, p = 0.001) and ET significantly decreased with treatment (p = 0.0001). ET correlated significantly with self-reported measures of disease severity, but not with physician-assessed global PASI. The data suggest that OCT may be used to measure ET in psoriasis and the measurements correlate with several other parameters of disease severity. This implies that OCT assessment of psoriatic plaques may provide a useful method for non-invasive in vivo method to follow the evolution of psoriasis lesions.

A fluorescence assay to determine the viable biomass of microcosm dental plaque biofilms

Dental plaque bacteria form complex and robust cell aggregates which cannot be counted accurately using epifluorescence microscopy. This causes a significant problem for quantifying their viability. The aim of the investigation was to develop a fluorescence assay to quantify the viable biomass of dental plaque biofilms. Using an artificial mouth system, microcosm plaques were grown under a range of fluoride and mineralizing conditions, and were treated with the oral antiseptics chlorhexidine (CHX) and Listerine®. Plaques were harvested, made into suspension and stained in microtitre plates with a di-chromatic fluorescent stain (Live/Dead® BacLight™). The percentage of viable biomass was calculated from the regression data generated from a viability standard. The standard was constructed using different proportions of viable (green fluorescence) and non-viable (red fluorescence) plaque bacteria, and growth conditions for optimizing green fluorescence were investigated. The results from the assay showed that fluoride at 1000 and 3000 ppm promoted plaque viability by at least 15%, from ∼ 45 to 60%, and at 5000 ppm to ∼ 87% ( P < 0.05). Plaques treated with Listerine® and CHX from d 0 yielded insufficient biomass to be tested for viability, however 14 d post-treatment, viability was comparable to untreated plaques (∼ 55%, P > 0.05). Treatment with Listerine® and CHX from d 3 reduced biomass but not viability. Development of this assay enabled viability of plaque bacteria which cannot be resolved with epifluorescence microscopy to be evaluated. It offers a rapid alternative to epifluorescence microscopy and could be applied to nonoral bacteria.

The tumour necrosis factor-alpha inhibitor adalimumab rapidly reverses the decrease in epidermal Langerhans cell density in psoriatic plaques

The pathophysiology of psoriasis is poorly understood, and the mechanism of action of biological agents interfering with tumour necrosis factor (TNF)-alpha that improve psoriatic plaques is completely unknown. To begin to unravel the mechanism of action, cellular changes occurring in plaques following administration of adalimumab, a humanized monoclonal antibody against TNF-alpha, were investigated. Thirteen different patients underwent sequential biopsies as part of a clinical trial. Each biopsy was immunostained and evaluated to calculate the relative density of epidermal Langerhans cells (LCs) before and after treatment (days 2, 7, 28, 84). To explore the basis for reduced epidermal LC densities in plaques, a SCID-Hu animal model was utilized. Acute psoriatic lesions were created within 2 weeks by injection of superantigen-activated CD4+ T cells into engrafted symptomless skin. Compared with symptomless skin, untreated plaques had a significantly reduced density of epidermal LCs. There was a rapid increase in density of epidermal LCs in plaques following treatment with adalimumab beginning as early as day 7. The paucity of epidermal LCs in plaques was contrasted to the prominent density of LCs in other skin disorders with chronic inflammation and alterations in keratinization, including lichen planus and inflamed seborrhoeic keratosis. Rapid creation of plaques using the SCID-Hu model was accompanied by loss of epidermal LCs, indicating that diminished LC density occurs at an early stage of lesion formation. These data shed light on a new immunopathological perspective highlighting a rapid loss of epidermal LCs in acute psoriatic lesions, with sustained decreased density of LCs in chronic plaques. Furthermore, an unexpected insight into the mechanism of action was uncovered for adalimumab, in which rapid restoration of epidermal LC density was observed.

007 308 nm excimer laser for the treatment of scalp psoriasis

Our intent was to determine the effectiveness of the 308 rim excimer laser for the treatment of scalp psoriasis through a non‐blinded, randomized, controlled study. Institutional approval for this study was achieved. Twenty consecutive volunteers with stable large plaques of scalp psoriasis were enrolled. Mineral oil was applied before each treatment. A modified psoriasis area severity index (PASI) score was determined before each treatment. Excimer laser generated 308‐rim (Photomedex, San Diego, CA, Model #AL 7000) UV‐13 radiation was administered evenly to each large plaque of scalp psoriasis twice weekly for up to 30 treatments. Untreated areas of adjacent scalp psoriasis served as controls. Each plaque received a set dose of radiation based on a predetermined minimal erythema dose. The dose of radiation was increased incrementally at each visit, as tolerated. There was a clear improvement as assessed by the mean PASI scores for treated vs. untreated plaques of scalp psoriasis. Adverse effects were minimal. The 308 nm excimer laser is a safe, novel and effective method of treating scalp psoriasis.

UVB therapy decreases the adhesive interaction between peripheral blood mononuclear cells and dermal microvascular endothelium, and regulates the differential expression of CD54, VCAM-1, and E-selectin in psoriatic plaques

A dermal lymphocytic infiltrate is a characteristic feature of psoriasis, and may be involved in the pathogenesis of the disease. We have previously shown that specialized dermal microvascular endothelial cells (DMEC) in psoriatic lesions promote the selective adherence of the CD4 CD45Ro helper T-cell subset. In this study, we examined the adhesive interaction between peripheral blood mononuclear cells and psoriatic DMEC in patients treated with ultraviolet B light (UVB), and correlated the results with the expression and function of endothelial adhesion molecules on DMEC. Seven psoriatic patients were exposed to one MED of UVB daily for 14 days, and the binding properties of their peripheral blood mononuclear cells (PBMC), and tissue specimens taken from their lesions on days 0, 2, 3, 6, 8, 11 and 14 of UVB treatment, were studied. The ability of psoriatic PBMC to adhere to non-irradiated control or UVB-treated psoriatic plaques was reduced by 70% after treatment with 2-3 MED, and complete inhibition was obtained after 8-11 MED. In contrast, exposure of psoriatic plaques to 2-3 MED had no effect on the capacity of DMEC to support normal PBMC binding, which was only reduced after 8-11 MED. In addition, psoriatic plaques which were shielded from direct UVB exposure also showed decreased PBMC binding, suggesting a systemic effect of UVB treatment. Immunoperoxidase staining revealed that CD54 (ICAM-1) and E-selectin were strongly expressed on dermal vessels in untreated psoriatic plaques. Treatment of patients with 6-8 MED significantly decreased CD54 and E-selectin expression. In contrast, VCAM-1 expression on untreated plaques was weaker than that of CD54 and E-selectin, but was markedly induced following UVB treatment. In functional blocking studies, preincubation of tissue from untreated psoriatic plaques with anti-E-selectin antibody, but not antibodies against CD54 and VCAM-1, significantly inhibited the ability to bind normal PBMC. These observations suggest that UVB treatment interferes with the adhesive properties of both psoriatic PBMC and endothelial cells, and differentially regulates the expression of endothelial adhesion molecules. The study also provided direct evidence for the involvement of E-selectin in the adhesion of circulating lymphocytes to psoriatic endothelial cells.

Prolonged occlusion in the treatment of psoriasis: A clinical and immunohistologic study

Background: An occlusive dressing that is both cosmetically acceptable and long term is needed for psoriasis treatment. The mechanisms that underlie the efficacy of occlusion in psoriasis are unknown. Objective: We performed a clinical and immunohistologic study in patients with psoriasis of the effects of occlusion, topical corticosteroid alone, and occlusion plus corticosteroid, with a new prolonged dressing as the occlusive therapy. Methods: Nineteen patients completed a 3-week study of efficacy of prolonged occlusion dressing, fluocinonide ointment, or a combination of the two. An immunohistologic study was performed in 10 patients with psoriasis treated for 1 week with prolonged occlusion. Results: The combination of fluocinonide ointment and occlusion produced significantly more improvement than either treatment alone ( p < 0.01). There was no significant difference between the efficacy of prolonged occlusion or fluocinonide ointment. On 4-week follow-up plaques treated with occlusion alone or combined fluocinonide and occlusion were still significantly improved ( p = 0.05 and p < 0.001, respectively). None of the immunohistologic and proliferation markers assessed in psoriatic plaques was significantly affected by occlusion as compared with untreated plaques. Conclusion: Prolonged occlusion is an effective therapy for psoriasis either as monotherapy or in combination with a high-potency topical corticosteroid. However, the mechanism of action of prolonged occlusion alone in the improvement of psoriasis is unknown.

Eosinophilic cellulitis (Wells' syndrome) associated with ascariasis.

We have investigated the systemic effect of local treatment with dithranol for one week in psoriasis by a combination of subjective assessment of the severity of individual plaques and more objective assessment of blood flow (measured by laser-Doppler flowmetry) of the centre of the plaque, and at the active edge of the plaque. There is both subjective and objective evidence of an improvement in untreated plaques of psoriasis when dithranol is used on plaques elsewhere on the body. Blood flow falls at the active edge and at the centre of the plaques that are untreated. These findings indicate a systemic effect of local treatment that is more likely to be due to circulating factors, possibly T cells, rather than a direct effect of circulating dithranol. They also suggest that within patient comparisons of topical treatment in psoriasis may be inaccurate.

GRO-α mRNA Is Selectively Overexpressed in Psoriatic Epidermis and Is Reduced by Cyclosporin A In Vivo, But Not in Cultured Keratinocytes

Interleukin (IL)-8 and gro peptides are members of the intercrine-alpha family of chemotaxins known to be present in biologically active form in psoriasis lesions. However, the relative contribution of the three different gro genes to the expression of this material is unknown, as is the stimulus for gro overexpression in psoriatic lesions. To address these questions, Northern blot and semiquantitative polymerase chain reaction analysis were performed on RNA extracted from keratome biopsies of normal skin, untreated plaques of psoriasis, or plaques treated for 1 week with low-dose cyclosporin A (CsA). Northern blot analysis revealed a significant correlation between gro and IL-8 mRNA levels in psoriasis lesions from 26 different individuals (r = 0.61, p = 0.0009), and overexpression of gro was markedly reduced by CsA prior to detectable clinical improvement (79.3%, p = 0.01, n = 22). To determine which form(s) of gro were overexpressed in psoriatic lesions, total keratome RNA (1 microgram) was analyzed by semiquantitative reverse transcription-polymerase chain reaction (SQRT-PCR). In five patients known to markedly overexpress gro and IL-8 mRNAs by Northern blotting, gro-alpha was approximately six times more abundant than gro-beta, and 25 times more abundant than gro-gamma. In cultured human keratinocytes, all three forms of gro mRNA were increased by IL-1 alpha or by interferon (IFN)-gamma plus tumor necrosis factor (TNF)-alpha. However, in contrast to the situation in vivo, CsA had no inhibitory effect on cytokine-stimulated gro expression in cultured keratinocytes. Taken together, these results demonstrate that the gro-alpha gene is selectively overexpressed in psoriatic lesions and strongly suggest that overexpression of gro is a keratinocyte response to activated T cells in psoriasis.

Active and Inactive Edges of Psoriatic Plaques: Identification by Tracing and Investigation by Laser-Doppler Flowmetry and Immunocytochemical Techniques

In plaque psoriasis it is likely that biochemical and ultrastructural changes precede the appearance of the typical plaque that is recognizable clinically. Currently, no technique exists by which the very early changes in psoriasis can be investigated. We report a method in which plaques of psoriasis are serially traced to identify their advancing edge. Eight-two untreated plaques from 15 patients and 38 treated plaques from 6 patients were traced over a three-week period; 65% of untreated and 57% of treated plaques showed consistent asymmetrical movement, allowing identification of an active and an inactive edge of each plaque. Using this technique, the active edge of two or more plaques was identified in each of ten patients. Blood flow measured by laser Doppler flowmetry indicated a 2.5-to-4.5-fold increase in cutaneous blood flow at the active edge compared with the inactive edge of each plaque. Punch biopsies from the sites investigated by laser Doppler flowmetry were examined by routine histology and monoclonal antibody immunohistology, but revealed no epidermal change and no T lymphocytic excess when the two areas were compared. We infer from these findings that the earliest change in a developing plaque is an increased blood flow, probably associated with a diffusable, and possibly humoral, initiating factor that accumulates at the active edge, stimulating transformation of normal skin to psoriatic plaque.

Topical treatment of psoriatic skin with methotrexate cream: a clinical, pharmacokinetic, and histological study

Five patients were treated with either 0.25% methotrexate cream or placebo in a double blind trial. The evaluation showed no clinical or histological effect although the drug was absorbed from the skin. Methotrexate (MTX) accumulated in locally treated psoriasis plaques as well as in untreated plaques. The psoriatic skin concentrations were increased by a factor of 119 and 4, respectively. This observation is discussed in relation to the possible role of action of methotrexate in psoriasis. We suggest that methotrexate inhibits the chemotaxis of neutrophil leukocytes systemically and not primarily in the skin, thereby preventing development of the early stages in the psoriatic lesions.