Investigations of the 'active' edge of plaque psoriasis: vascular proliferation precedes changes in epidermal keratin

Line-field confocal optical coherence tomography: New insights for psoriasis treatment monitoring

BACKGROUND

Line-field confocal optical coherence tomography (LC-OCT) is a new, valid means for a rapid and non-invasive in vivo examination of the epidermis and upper dermis, allowing digital interpretation and measurement of high-resolution images on a cellular level. Given these properties, it may represent a valid tool for monitoring psoriasis during treatment, allowing a new method to set a precise objective severity of the disease.

OBJECTIVES

We aimed to investigate the potentialities of LC-OCT in the non-invasive monitoring of microscopical changes associated with moderate-severe plaque psoriasis (PP) during the treatment with the most common biological drugs.

MATERIALS AND METHODS

We performed LC-OCT imaging of PP lesions from 17 patients before and after 8 weeks of treatment. The clinical severity of the single lesions was evaluated using a lesion score (LS), designed considering three parameters: erythema, desquamation and infiltration. LC-OCT images were segmented by artificial intelligence and evaluated based on three microscopic criteria: the thickness of the stratum corneum, the thickness of the living epidermis and the undulation of the dermo-epidermal junction.

RESULTS

Line-field confocal optical coherence tomography digital analysis allowed recognition and quantification of the three microscopic criteria, showing a reduction of all these during the follow-up. Furthermore, a high correlation between change in LS and the thickness of the stratum corneum and the thickness of the living epidermis was found.

CONCLUSION

Line-field confocal optical coherence tomography can non-invasively monitor the response of PP to different treatments. Morphometric changes occurring in the psoriatic lesion during the 8-week treatment period were identified by in vivo LC-OCT and measured by using artificial intelligence. Although future studies are required, based on these preliminary results, LC-OCT may represent a valid potential tool for precise monitoring of therapeutic response.

Nailfold capillaroscopy as diagnostic test in patients with psoriasis and psoriatic arthritis: A systematic review

Up to 30 % of patients with psoriasis (PsO) develop psoriatic arthritis (PsA), and diagnosis can be difficult. Nailfold capillaroscopy (NC) is an easily applicable, non-invasive procedure to assess skin microcirculation. This systematic review investigates NC as diagnostic tool for PsO and PsA, including correlations between NC outcome measures to clinical and laboratory outcome measures. This systematic review was built on the PICO and PRISMA guidelines. In total 22 relevant studies were found Searching in the Web of Science, PubMed and Embase, latest update June 13th, 2022. The following NC outcome measures are found to be significantly more prevalent in PsO patients than healthy controls: reduced density, reduced length and more abnormal morphology. Likewise, in PsA patients, reduced density, more abnormal morphology, more microhaemorrhages and fewer hairpin shapes are found to be significantly more prevalent. Results were non-conclusive in terms of disease activity and duration with NC findings. Random-effects meta-analysis showed a significant reduction of density in PsO patients compared to healthy controls (studies: 6, n = 249; SMD = -0.91; 95 % CI [-1.41, -0.40], p = 0.0058, heterogeneity I²=74 %, AUC = 0.740) and in PsA patients compared to healthy controls (studies: 5, n = 130; SMD = -1.22; 95 % CI [-2.38, -0.06], p = 0.0432, heterogeneity I²=89 %, AUC = 0.806). No NC outcome measures were overall conclusive in differentiating PsO from PsA. Considering the conflicting results and small sample sizes further large-scale research on the identification of capillaroscopic changes in PsO and PsA and correlations with standardised clinical and laboratory outcome measures are necessary.

Can Essential Oils/Botanical Agents Smart-Nanoformulations Be the Winning Cards against Psoriasis?

Although psoriasis remains one of the most devastating inflammatory disorders due to its huge negative impact on patients’ quality of life, new “green” treatment approaches still need to be fully explored. The purpose of this review article is to focus on the utilization of different essential oils and active constituents of herbal botanical origin for the treatment of psoriasis that proved efficacious via both in vitro and in vivo models. The applications of nanotechnology-based formulations which displayed great potential in augmenting the permeation and delivery of these agents is also addressed. Numerous studies have been found which assessed the potential activity of natural botanical agents to overcome psoriasis. Nano-architecture delivery is applied in order to maximize the benefits of their activity, improve properties, and increase patient compliance. This field of natural innovative formulations can be a promising tool to optimize remediation of psoriasis while minimizing adverse effects.

Transcriptome profiling in psoriasis: NB-UVB treatment-associated transcriptional changes and modulation of autoinflammation in perilesional skin in early-phase disease

BACKGROUND

Psoriasis is a chronic inflammatory skin condition. It is widely treated with phototherapy using narrowband ultraviolet B (NB-UVB). The therapeutic mechanisms of NB-UVB, however, remain unclear, particularly in the early phases of the disease.

OBJECTIVE

To investigate the mechanisms underlying the effects of NB-UVB on psoriasis in a model of perilesional psoriasis.

METHODS

Psoriatic patients that received NB-UVB treatment and were evaluated with the psoriasis area and severity index were included in the study. Skin biopsies obtained before and after treatment were subjected to RNA sequencing (RNA-seq) and Ingenuity Pathway Analyses for genome-wide transcriptome profiling to gain further insights into the signaling pathways underlying the improvement of psoriasis with therapeutic intervention.

RESULTS

Our findings revealed that NB-UVB treatment may exert its effects by suppressing nuclear factor kappa B, which leads to upregulation of the sirtuin signaling pathway, as well as by decreasing the function of major upstream regulators associated with proinflammatory and inflammatory cytokines, which blocks the expression of downstream toll-like receptors. Psoriasis improvement after NB-UVB treatment was associated with decreased expression of NFKBIZ, SERPINB4, ATG13, and CTSS and increased expression of SKP1 gene. Our results also highlighted the expression of proposed genes associated with the modulation of autoinflammation.

CONCLUSIONS

To the best of our knowledge, this is the first study to apply advanced molecular techniques to explore the effects of phototherapy on psoriasis in the early-phase, providing new insights into the disease pathogenesis and novel genetic information for the development of new therapeutic modalities and potential treatment targets.

Transcriptomic Profiling of Peripheral Edge of Lesions to Elucidate the Pathogenesis of Psoriasis Vulgaris

Elucidating transcriptome in the peripheral edge of the lesional (PE) skin could provide a better understanding of the molecules or signalings that intensify inflammation in the PE skin. Full-thickness biopsies of PE skin and uninvolved (UN) skin were obtained from psoriasis patients for RNA-seq. Several potential differentially expressed genes (DEGs) in the PE skin compared to those in the UN skin were identified. These DEGs enhanced functions such as angiogenesis, growth of epithelial tissue, chemotaxis and homing of cells, growth of connective tissues, and degranulation of myeloid cells beneath the PE skin. Moreover, the canonical pathways of IL-17A, IL-6, and IL-22 signaling were enriched by the DEGs. Finally, we proposed that inflammation in the PE skin might be driven by the IL-36/TLR9 axis or IL-6/Th17 axis and potentiated by IL-36α, IL-36γ, IL-17C, IL-8, S100A7, S100A8, S100A9, S100A15, SERPINB4, and hBD-2. Along with IL-36α, IL-17C, and IκBζ, ROCK2 could be an equally important factor in the pathogenesis of psoriasis, which may involve self-sustaining circuits between innate and adaptive immune responses via regulation of IL-36α and IL-36γ expression. Our finding provides new insight into signaling pathways in PE skin, which could lead to the discovery of new psoriasis targets.

A Cross-Sectional Study of Nailfold Capillary Changes in Psoriasis

Background:

Microcirculation in the skin of psoriasis patients significantly differs from unaffected individuals. Vascular changes precede skin lesions and occur even in nonlesional skin.

Aims:

The primary aim of this work was to study the nailfold capillary changes in psoriasis patients, and to compare it with that of controls. The secondary aim of this work was to compare the nailfold capillary changes in psoriasis patients with and without nail changes.

Methods:

A comparative cross-sectional study of 40 psoriasis patients and 40 age and sex-matched controls analyzed the capillaries of the proximal nailfold of all fingers using a dermoscope. The mean capillary loop density/mm, tortuous capillaries, capillary hemorrhages, and avascular areas were assessed.

Results:

The mean nailfold capillary loop density in psoriasis (6.98 ± 0.54 per mm) was significantly less than that in controls (8.01 ± 0.61 per mm) (P < 0.001). Avascular areas in the nailfold of psoriasis patients (55%) were significantly more than the same in controls (22.5%) (P = 0.003). Of 40 psoriasis patients, 26 had nail psoriasis. Of this, 19 (73%) had avascular areas (P = 0.002). No significant association of nailfold capillary density or avascular areas with disease duration or severity was noted. An increase in tortuous capillaries and nailfold hemorrhages noted in psoriasis was not significant.

Limitations:

Small sample size, not having participants with psoriatic arthropathy, and lack of information on capillary diameter and capillary changes in hyponychium were the limitations.

Conclusion:

The reduced mean capillary loop density, and higher frequency of avascular areas noted in cases compared to controls, points to a pathogenic role for microvascular damage in psoriasis. Whether the lack of association of these changes with disease duration and severity suggests the possibility of these being early disease markers for psoriasis, needs further analysis in larger prospective studies.

Perfusion measured by laser speckle contrast imaging as a predictor for expansion of psoriasis lesions

Background

Skin microvasculature changes are crucial in psoriasis development and correlate with perfusion. The noninvasive Handheld Perfusion Imager (HAPI) examines microvascular skin perfusion in large body areas using laser speckle contrast imaging (LSCI).

Objectives

To (i) assess whether increased perilesional perfusion and perfusion inhomogeneity are predictors for expansion of psoriasis lesions and (ii) assess feasibility of the HAPI system in a mounted modality.

Methods

In this interventional pilot study in adults with unstable plaque psoriasis, HAPI measurements and color photographs were performed for lesions present on one body region at week 0, 2, 4, 6 and 8. The presence of increased perilesional perfusion and perfusion inhomogeneity was determined. Clinical outcome was categorized as increased, stable or decreased lesion surface between visits. Patient feedback was collected on a 10‐point scale.

Results

In total, 110 lesions with a median follow‐up of 6 (IQR 6.0) weeks were assessed in 6 patients with unstable plaque psoriasis. Perfusion data was matched to 281 clinical outcomes after two weeks. A mixed multinomial logistic regression model revealed a predictive value of perilesional increased perfusion (OR 9.90; p < 0.001) and perfusion inhomogeneity (OR 2.39; p = 0.027) on lesion expansion after two weeks compared to lesion stability. HAPI measurements were considered fast, patient‐friendly and important by patients.

Conclusion

Visualization of increased perilesional perfusion and perfusion inhomogeneity by noninvasive whole field LSCI holds potential for prediction of psoriatic lesion expansion. Furthermore, the HAPI is a feasible and patient‐friendly tool.

Non-Invasive Diagnosis of a Facial Tumor Using Dermoscopy and Successful Treatment with 595 nm Pulsed Dye Laser

Clear cell acanthoma (CCA) is an uncommon, benign epithelial tumor presenting as a well-defined, slow-growing solitary nodule. The diagnosis of CCA is usually based on clinical and histopathological evaluation of the tumor. However, when such type of benign tumor occurs on an exposed area, a biopsy is not always the best diagnostic option since it may leave scar. The recent advent of dermoscopy has offered an accurate and non-invasive method to diagnose CCA without resorting to skin biopsy. A 40-year-old male presented with a shiny, erythematous-to-brown, flattened nodule on the left cheek. Dermoscopic examination revealed a 'string of pearls' vascular pattern, a characteristic dermoscopic feature of CCA. Under the clinical and dermoscopic impression of CCA, a 595 nm pulsed dye laser (PDL) therapy targeting the vascular tissue in the superficial dermis of the lesion was chosen for a minimally invasive treatment. After repeated sessions of PDL, an optimal cosmetic outcome was achieved and no recurrence was recorded during the follow-up period. Herein, we report a case of presumed CCA which was successfully diagnosed and treated by utilizing non-invasive modalities.

Fiber-based SORS-SERDS system and chemometrics for the diagnostics and therapy monitoring of psoriasis inflammatory disease in vivo

Psoriasis is considered a widespread dermatological disease that can strongly affect the quality of life. Currently, the treatment is continued until the skin surface appears clinically healed. However, lesions appearing normal may contain modifications in deeper layers. To terminate the treatment too early can highly increase the risk of relapses. Therefore, techniques are needed for a better knowledge of the treatment process, especially to detect the lesion modifications in deeper layers. In this study, we developed a fiber-based SORS-SERDS system in combination with machine learning algorithms to non-invasively determine the treatment efficiency of psoriasis. The system was designed to acquire Raman spectra from three different depths into the skin, which provide rich information about the skin modifications in deeper layers. This way, it is expected to prevent the occurrence of relapses in case of a too short treatment. The method was verified with a study of 24 patients upon their two visits: the data is acquired at the beginning of a standard treatment (visit 1) and four months afterwards (visit 2). A mean sensitivity of ≥85% was achieved to distinguish psoriasis from normal skin at visit 1. At visit 2, where the patients were healed according to the clinical appearance, the mean sensitivity was ≈65%.

Nailfold capillaroscopy in psoriasis

Background

Psoriasis a chronic inflammatory skin disease manifests with microcirculatory changes within skin which may precede skin manifestations, correlate with their severity, joint involvement and resolve with treatment. Nailfold capillaroscopy (NFC) is used in rheumatology for connective tissue disorder assessment and is assuming significance in psoriasis. The aim was to study the nailfold capillaroscopic findings in patients with psoriasis.

Methods

A cross-sectional observational study was carried out at a skin center of a tertiary care hospital from January 2016 to June 2017. Selected cases underwent NFC using a portable color capillaroscope with an attached computer with software to analyze the nailfold capillaries for morphological parameters and abnormalities. Independent-samples t test and chi-square test was used to analyze the relationships between variables.

Results

Mean capillary loop density in 96% of study population was subnormal (<9 capillaries/mm), mean arterial limb diameter 11.37 ± 2.434μ; mean venous limb diameter 15.89 ± 3.131μ, top of the loop diameter 14.41 ± 4.373μ and length of the loop was 152.51 ± 57.21μ. Only 3 had length of loop >300μ. Bizarre morphology was seen in 15.5% of capillaries (p value < 0.001). Crossed loops/tortuous capillaries were seen in 17.3% of patients (p value < 0.001). Ramified capillaries were seen in 9.1% of patients with psoriasis (p value < 0.001). Other abnormalities observed were hemorrhage, avascular areas and subpapillary plexus. Widespread disease and psoriatic arthritis (18.2%) had irregular and haphazard distribution of capillaries (p value < 0.001). Analysis of Psoriasis Area Severity Index score, age of the patient and NFC did not reveal any statistically significant relationship.

Conclusions

Nailfold capillaroscopy (NFC), a non invasive imaging technique for microcirculation evaluation can serve to prognosticate and follow up patirents with psoriasis as a simple and highly reproducible tool. Nailfold capillaroscopy is a simple and an easy method to study the microvascular abnormalities in psoriasis. Findings correlate with disease severity. It can be used for follow-up as a predictor of disease worsening or response to treatment.

A study of dermoscopic features of nail psoriasis

Introduction

Dermoscopy is a non-invasive imaging method that enables the evaluation of pigmented and non-pigmented skin lesions. More recently, dermoscopy has been recognized as an effective tool in the diagnosis of nail diseases.

Aim

To evaluate the dermoscopic features of nail psoriasis and to assess the relationship between these features and disease severity.

Material and methods

A total of 67 patients with clinically evident nail psoriasis (14 women, 53 men) were prospectively enrolled. Following a thorough clinical examination, patients were graded according to the Nail Psoriasis Severity Index and physician’s global assessment score. A dermoscopic examination of all fingernails and toenails was performed using a videodermatoscope. Mann-Whitney U and χ² tests were used for statistical analysis, with a significance threshold of p < 0.05.

Results

The most frequently observed dermoscopic features were splinter haemorrhage (73.1%), pitting (58.2%), distal onycholysis (55.2%), dilated hyponychial capillaries (35.8%) and the pseudo-fiber sign (34.3%). The pseudo-fiber sign, dilated hyponychial capillaries, nail plate thickening and crumbling, subungual hyperkeratosis, transverse grooves, trachyonychia, pitting and salmon patches were positively associated with disease severity.

Conclusions

The pseudo-fiber sign described in this study appears to be a novel dermoscopic feature of nail psoriasis. We have demonstrated positive associations between a number of dermoscopic manifestations and disease severity. Further studies are required to support the present findings.

Relationship between Histological and Clinical Course of Psoriasis: A Pilot Investigation by Reflectance Confocal Microscopy during Goeckerman Treatment

Alterations of the skin microvasculature are known to play an important role in the development and maintenance of psoriatic skin lesions. In this study, we investigated lesional skin in 11 psoriatic patients during a modified Goeckerman treatment using reflectance confocal microscopy (RCM) to study the relationship between clinical clearance and histological normalization of psoriatic skin and the significance of histological abnormalities on the course of disease. The treatment regimen resulted in a significant reduction of the Psoriasis Area and Severity Index (PASI) as well as capillary and papillary diameters (p < 0.0001). The capillary and papillary diameters were still enlarged when compared to those in normal skin (p < 0.001). Capillary and papillary diameters correlated with each other prior to and after treatment (correlation coefficient = 0.63 and 0.64, p = 0.01 and 0.002, respectively) but not with the PASI. Capillary and papillary diameters after treatment and percentage reduction of the PASI during treatment seemed to be better predictors for the clinical course of relapse than the PASI after treatment. These findings make the subclinical changes of psoriatic skin vessels and dermal papillae a legitimate target for treatment. Further investigations of a large group of patients are needed to evaluate the potential of RCM findings as successor of the PASI in the monitoring of psoriasis.

Histology of psoriatic erythroderma in infants: analytical study of eight cases

BACKGROUND

Erythroderma in infants is a rare condition of varied etiology. Psoriasis is now emerging as the most common cause of erythroderma in infants. Early diagnosis of the etiological cause much depends upon the histological confirmation, which is essential for an early and appropriate treatment.

AIM

It was aimed to study the histological findings in psoriatic erythroderma in infants.

MATERIALS AND METHODS

A total of 8 infants up to 1 year of age presenting with erythroderma, clinically suspected to be of psoriatic etiology attending private clinic were included. After detailed history taking and astute clinical exam, all of them were biopsied. In case 6, with a positive family history of psoriasis and asthma in parents, biopsy was taken from two sites. The histological findings of all nine biopsies were studied and analyzed.

RESULTS

Histology of all eight children showed psoriasi form pattern with acanthosis (AC) and dilated papillary capillaries (PC). Spongiform (SF) pattern was seen in the second biopsy (6b) of child with features of both psoriasis and atopy. SF pustule of Kogoj or Munro's abscess was not seen in any of them.

CONCLUSION

Regular AC and PC dilatation were the consistent histological findings observed in infants with erythrodermic psoriasis. These were the early findings observed in younger infants. Co-existence of psoriasis with atopic dermatitis may indicate a common pathogenic mechanism or an immunogenetic spin-off.

Study of in vitro capillary-like structures in psoriatic skin substitutes

Angiogenesis is one of the important hallmarks of psoriasis. The extension of the superficial microvascular structure and activated pro-angiogenic mediators in psoriasis seem to be important factors involved in the pathology. According to the changes of superficial microvasculature in psoriatic lesions, anti-angiogenic treatment could be a promising therapeutic strategy for psoriasis. The aim of this study was to construct an in vitro vascularized psoriatic skin substitute for fundamental research. Psoriatic fibroblasts and keratinocytes were isolated from psoriatic plaque biopsies, while healthy fibroblasts and keratinocytes, as well as microvascular endothelial cells, were isolated from healthy skin biopsies of cosmetic breast surgery. Psoriatic and healthy skin substitutes with and without endothelial cells were produced using the self-assembly approach. Afterward the substitutes were examined by histology, immunofluorescence studies, and three-dimensional (3D) confocal microscopy. Histological analysis and immunofluorescence staining of specific markers for endothelial cells (von Willebrand, PECAM-1 [CD31], and VE-cadherin [CD144]) and basement membrane component (collagen IV) demonstrated that endothelial cells have the ability to form capillary-like tubes. Moreover, the 3D branched structure of the capillary-like structures and an eagle eye view of them were observed by confocal microscopy. Also the semiquantification of capillary-like tubes (CLTs) was carried out with a 3D eagle eye view of substitutes, and more CLTs were observed in psoriatic substitutes. These results suggest that it is possible to observe 3D capillary-like structures in the self-assembled psoriatic skin substitutes, which could become a good in vitro testing model for anti-angiogenic drug research, and facilitate the study of this complex pathology, which links angiogenesis to its development.

Combined Clinical, Capillaroscopic and Ultrasound Evaluation during Treatment of Plaque Psoriasis with Oral Cyclosporine

Imaging techniques have only recently been utilized in combination with clinical observation to objectively quantify psoriasis severity and evaluate therapeutic response. This study evaluated the sensitivity of videodermatoscopy (VD) and ultrasound (US) imaging to assess the therapeutic effect of cyclosporine (Cs) in patients with moderate-to-severe psoriasis. Twenty patients with moderate-to-severe psoriasis were divided into two groups (A and B) based on PASI score. Group A (PASI >16) was treated with 5 mg/Kg/day Cs for 4 weeks and another 4 weeks with 3 mg/Kg/day Cs. Group B (PASI 1016) received 3 mg/Kg/day Cs for 8 weeks. A “target” plaque was selected for each subject and evaluated using a Target Lesion Score (TLS) for erythema, scaling and degree of infiltration, in addition to VD and US at baseline, 2, 4 and 8 weeks. At the end of the study, improvement rate was quicker in group A vs group B after 8 weeks of Cs therapy. All three parameters (TLS, VD and US) strongly correlated with one another. Skin thickness was the first parameter that improved, followed by TLS. In contrast, improvement in VD was delayed. Normalization rate of vascular pattern (assessed by VD) was low in both groups but higher in group A vs group B (46% vs 22%), despite virtually complete normalization by clinical and US assessment. In conclusion, while both TLS and US can be utilized in the evaluation of therapeutic efficacy in patients with plaque psoriasis, VD can provide information on vascular response to treatment, which may likely affect the duration of therapy and the relapse rates.

Videocapillaroscopic findings in the microcirculation of the psoriatic plaque during etanercept therapy

BACKGROUND

Vascular endothelial growth factor (VEGF) is a pivotal cytokine in the pathogenesis of psoriasis, and upregulation of VEGF by tumour necrosis factor (TNF)-α and inflammatory factors causes marked alterations in the cutaneous microcirculation. Etanercept is a fully soluble TNF receptor fusion protein that primarily binds soluble TNF-α, thus blocking its pro-angiogenic function.

AIM

To assess the modifications in the superficial capillary bed in psoriatic plaques during treatment with etanercept.

METHODS

The study enrolled 22 patients (13 men, 9 women; age range 31-74 years) with plaque psoriasis resistant to conventional therapy. The patients were stated on etanercept 50 mg/week, which was continued for 24 weeks. At the beginning of the study (baseline), and at weeks 6, 12, 18 and 24, in vivo videocapillaroscopy analysis of a selected plaque was performed. Levels of erythema, scaling and infiltration were assessed using a four-point plaque severity score, with an overall score obtained by the sum of these three scores. The Psoriasis Activity and Severity Index (PASI) was also determined.

RESULTS

Etanercept produced a significant reduction in PASI, plaque severity score and diameter of the basket-weave area at every time point. Four patients had complete remission, although none of the patients regained a normal capillaroscopic pattern.

CONCLUSIONS

Similar to other conventional therapies, etanercept is able to improve PASI, plaque severity score and basket-weave area diameter, but it is unable to induce normalization of the microcirculation in psoriatic plaques.

Whole field laser Doppler imaging of the microcirculation in psoriasis and clinically unaffected skin

BACKGROUND

Angiogenesis represents a key phenomenon in psoriasis. Insights in the microcirculation within psoriatic lesions in a whole field are lacking. Recently, the Twente Optical Perfusion Camera (TOPCam) was developed, which provides the possibility of evaluating the superficial cutaneous microcirculation in a whole field.

OBJECTIVES

This pilot study aims to examine whether the TOPCam can be used to visualize the microcirculation within and around psoriatic lesions, and whether it is capable of revealing vascular changes during topical treatment.

METHODS

Five patients with chronic plaque psoriasis were included. The superficial microcirculation and clinical local scores (SUM score) were analyzed in two comparable lesions within one patient. At baseline and after 2, 4, 6, and 8 weeks the disease's natural course was evaluated in one plaque versus topical treatment in the other.

RESULTS

The TOPCam was able to visualize an increased microcirculation within psoriatic lesions and perfusion variability due to the heartbeat. Whole field images demonstrated heterogeneity in perfusion intensity (hot and cold spots) within clinically homogeneous-looking plaques. Topical therapy induced a decrease in overall perfusion and a significant decrease in SUM score.

CONCLUSION

The TOPCam is the first noninvasive technique to visualize the microcirculation of psoriatic lesions in a whole field, to correct images for the heartbeat, and to reveal heterogeneity in perfusion intensity.

Periungual capillaroscopy in psoriasis

BACKGROUND

Nailfold capillaroscopy is a useful technique for evaluating changes in microcirculation.

OBJECTIVE

To investigate changes at nailfold capillaroscopy in psoriatic patients compared with controls.

METHODS

Nailfold capillaroscopy was performed in 46 psoriatic patients and 50 controls to assess microscopic morphological changes, capillary density and the presence of areas with devascularization.

RESULTS

Patients with psoriasis had lower capillary density (p=0.0005), increased avascular areas (p=0.0035) and an increased number of morphologically abnormal capillaries (coiled, p<0.0001) compared to controls. No association was found between capillary density and the duration of the disease (p = 0.92) or the extent of skin involvement, as measured by the psoriasis area and severity index (PASI) score (p = 0.59). The presence of avascular areas was more common in psoriatic individuals whose nails were affected by the condition (p = 0.047).

CONCLUSION

Patients with psoriasis have decreased capillary density and a greater presence of morphologically abnormal capillaries when compared to controls.

Dermal vasculature in psoriasis and psoriasiform dermatitis: a morphometric study

Background:

Vascular proliferation in the papillary dermis is considered to be an important and probably an early feature of psoriasis. Few morphometric studies have attempted to analyze the vascular changes. However, no study was found in the available literature comparing vascular changes between psoriasis and psoriasiform dermatitis.

Materials and Methods:

Skin biopsies from 25 cases each of psoriasis and psoriasiform lesions were immunohistochemically stained for CD34 (endothelial marker). Microvessel density (MVD), microvessel length density and ratio of microvessel area to papillary dermal area were calculated using image analysis software.

Results:

Skin biopsies from psoriasis showed higher staining for CD34 on light microscopy. Using morphometric techniques, microvessel length density was significantly higher in psoriasis compared to psoriasiform lesions (P value <0.05). MVD was also higher in psoriasis, though the difference was not significant. The ratio of microvessel area to dermal area was almost similar in both the groups.

Conclusion:

Our results indicate that vascular tortuousity and dilatation is significant only in psoriatic lesions. These results may assist in automated diagnosis of skin biopsies.

Differential expression of the angiogenesis growth factors in psoriasis vulgaris

Background

Angiogenesis has been reported to be one of the contributory factors to the pathogenesis of psoriasis vulgaris. This study aims to compare the expression of different angiogenesis growth factors namely (1) the vascular endothelial growth factor (VEGF) subfamily: A, B, C, D and placenta growth factor (PlGF); (2) nerve growth factor (NGF) and (3) von Willebrand factor (vWFr) in the skins of patients with psoriasis vulgaris and non-psoriatic volunteers.

Results

Comparative immunohistochemistry study was performed on the paraffin-sectioned psoriatic and healthy skins with the abovementioned markers. VEGF-C (p = 0.016) and NGF (p = 0.027) were expressed intensely in the cases when compared with the controls. The NGF was the only marker that was solely expressed in the cases and absent in all the controls.

Conclusion

The NGF (angiogenesis) and VEGF-C (lymphangiogenesis) might play a crucial role in the pathogenesis of psoriasis vulgaris and could be researched further as potential new targeted therapies for psoriasis vulgaris.

Vascular endothelial growth factor (VEGF) in the pathogenesis of psoriasis--a possible target for novel therapies?

Angiogenesis is defined as the formation of new capillaries from pre-existing blood vessels. The process of angiogenesis is tightly regulated by a balance between pro- and anti-angiogenic factors. Vascular endothelial growth factor (VEGF) is a pro-angiogenic factor and several anti-VEGF therapies are used in the treatment of diseases that are characterized by abnormal formation of blood vessels such as certain cancers and age-related macular degeneration. In addition, dysregulated angiogenesis has been observed in inflammatory diseases and might underly chronic cutaneous inflammation in psoriasis. Several experimental studies and clinical reports suggest that VEGF is involved in psoriasis pathogenesis. Among those, transgenic over-expression of VEGF in keratinocytes in mice resulted in skin inflammation and a phenotype resembling human psoriasis. In different psoriasis models, anti-VEGF antibody treatment of mice, already displaying disease symptoms, resulted in an overall improvement of the cutaneous lesions. On the molecular level human keratinocytes produce VEGF after stimulation with cytokines involved in psoriasis pathogenesis. Finally, patients with psoriasis receiving anti-VEGF treatment for cancer showed complete remission of their cutaneous symptoms. Therefore, VEGF might be an underappreciated pro-inflammatory factor in the pathogenesis of psoriasis. In this review, current knowledge on the significance of VEGF in psoriasis pathogenesis is summarized. Furthermore, current reports on treatments directed against VEGF or its receptors and their potential as future therapy for psoriasis are discussed.

Angiogenesis drives psoriasis pathogenesis

Psoriasis pathogenesis is closely associated with disease-inducing Th1 and Th17 cells. Yet, several studies suggest that aberrant keratinocyte or endothelial cell signalling significantly contributes to disease manifestation. Histological hallmarks of psoriatic skin include the infiltration of multiple immune cells, keratinocyte proliferation and increased dermal vascularity. Formation of new blood vessels starts with early psoriatic changes and disappears with disease clearance. Several angiogenic mediators like vascular endothelial growth factor, hypoxia-inducible factors, angiopoietins and pro-angiogenic cytokines, such as tumour necrosis factor (TNF), interleukin (IL)-8 and IL-17, are up-regulated in psoriasis development. Contact- and mediator-dependent factors derived from keratinocytes, mast cells and immune cells may contribute to the strong blood vessel formation of psoriasis. New technologies and experimental models provide new insights into the role of angiogenesis in psoriasis pathogenesis. Interestingly, many therapies target not only immune cells, but also protein structures of endothelial cells. Here we summarize the role of pro-angiogenic factors in psoriasis development and discuss angiogenesis as a potential target of novel therapies.

In vivo quantification of microvessels in clinically uninvolved psoriatic skin and in normal skin

BACKGROUND

Microvascular abnormalities (capillary elongation, widening and tortuosity) are a characteristic feature of psoriasis and form one of the pathological diagnostic criteria. However, it is still not entirely clear when these microcirculatory changes appear in the skin of psoriatic subjects. Some studies suggest that capillary dilatation and elongation are present in the clinically uninvolved skin of psoriatic patients even at sites at which psoriatic plaques rarely occur.

OBJECTIVES

To determine, using noninvasive techniques in vivo, the nature of any microvascular changes in the clinically uninvolved skin of psoriatic subjects and to quantify the dermal microvasculature in the clinically uninvolved skin of psoriatic subjects, in vivo.

METHODS

Dermal microvessels in both the clinically uninvolved skin of psoriatic subjects and in the skin of normal volunteers (i.e. individuals without any clinical evidence of psoriasis or other inflammatory dermatoses) were directly visualized by native video-capillaroscopy, in vivo. Images were analysed using a combination of nonstereological and stereological measurements. The findings in each group were then compared to determine if there were any differences in microvascular parameters.

RESULTS

Quantitative analysis of capillaroscopic images showed that there were no significant differences in microvessel density (P = 0.9), image area fraction (P = 0.6), microvessel length density (P = 0.7) and vessel image width (P = 1.0) in the clinically uninvolved skin of psoriatic subjects and the normal skin of healthy volunteers, when extensor forearm skin was examined.

CONCLUSIONS

These findings indicate that prior to the development of clinical lesions there are no significant morphological differences between the dermal microvessels in the clinically uninvolved skin of psoriatic subjects and the dermal microvessels in the normal skin of healthy volunteers. However, during plaque formation, the superficial papillary microvessels in plaque skin undergo a striking, characteristic change, i.e. elongation, widening and tortuosity. These blood vessels must therefore, at least in part, play an important, necessary, but probably secondary role in the pathogenesis of clinical lesions in psoriasis.

Pulsed dye laser versus treatment with calcipotriol/betamethasone dipropionate for localized refractory plaque psoriasis: effects on T-cell infiltration, epidermal proliferation and keratinization

BACKGROUND

Selective photothermolysis of diseased capillaries by pulsed dye laser (PDL) treatment has been described as a mechanism for long-lasting clearance of psoriatic plaques.

AIM

To evaluate PDL and a two-compound formulation of calcipotriol/betamethasone dipropionate ointment for the treatment of localized, recalcitrant plaque psoriasis.

METHODS

Eight psoriatic patients were treated for 4 weeks with both PDL and topical calcipotriol/betamethasone dipropionate in an open, intra-patient, left-right comparison. Biopsies were analyzed for T-cell subsets, cells expressing NK-receptors, epidermal proliferation, differentiation and epidermal thickness.

RESULTS

After active treatment, both treatments showed statistically significant but comparable improvements of T-cell subsets, epidermal proliferation, differentiation and epidermal thickness. In line with the clinical results, after an 8-week follow-up period statistically significant further reductions were observed for dermal CD3(+), CD4(+), CD45RO(+), CD2(+) T cells, epidermal CD3(+), CD8(+), CD45RO(+), CD2(+), CD25(+) T cells and the epidermal parameters for the PDL-treated plaques, in contrast to the topically treated plaques.

CONCLUSION

After 8 weeks of follow-up, PDL treatment for localized and recalcitrant plaque psoriasis resulted in persistent reductions of activated and memory effector T-helper cells in the dermis, cytotoxic T cells in the epidermis, and normalization of epidermal proliferation and keratinization, in contrast to treatment with calcipotriol/betamethasone dipropionate ointment.

A classification of psoriasis vulgaris according to phenotype

For nearly 200 years it has been appreciated that plaque psoriasis consists of a number of distinct clinical phenotypes. However, a reliable and simple stratification of clinical presentation of psoriasis is lacking. In the era of immunogenetic association studies and an advanced understanding of the pathomechanisms of psoriasis it is important that a classification of the disease according to phenotype is readily available. Such a classification would facilitate clinically relevant interpretation of investigational data. A meeting of the International Psoriasis Council produced a consensus on clinical phenotypes of psoriasis equally relevant to clinical practitioners and psoriasis researchers.

Anti-CXCR3 staining is useful for detecting human cutaneous and mucosal mast cells

Human synovial mast cells (MC) can be immunolabelled with antihuman CXCR3 antibody (Ab) (clone 49801). We have investigated whether cutaneous and mucosal MC are stained with anti-CXCR3 Ab in paraffin-embedded sections. Immunohistochemical staining and immunofluorescence double staining assays were performed with anti-CXCR3, anti-tryptase, and anti-chymase Ab using normal skin, psoriatic skin lesions, and normal colon. When compared with tryptase and chymase staining, 100% of the cutaneous and 98% of the mucosal MC were positive for CXCR3. Anti-CXCR3 staining is a useful marker for human cutaneous and mucosal MC in paraffin-embedded sections.

Controlled study of excimer and pulsed dye lasers in the treatment of psoriasis

BACKGROUND AND OBJECTIVES

The excimer laser delivers high energy monochromatic ultraviolet (UV) B at 308 nm. Advantages over conventional UV sources include targeting of lesional skin, reducing cumulative dose and inducing faster clearance. Studies of the pulsed dye laser (PDL) in psoriasis report between 57% and 82% response rates; remission may extend to 15 months. To our knowledge, this is the first study assessing both excimer and PDL in psoriasis.

METHODS

We conducted a within-patient controlled prospective trial of treatment of localized plaque psoriasis. Twenty-two adult patients, mean Psoriasis Area and Severity Index 7.1, were recruited. Fifteen patients completed the full treatment, of which 13 were followed up to 1 year. Two selected plaques were treated with excimer twice weekly and V Beam PDL, pretreated with salicylic acid (SA), every 4 weeks, respectively. Two additional plaques, treated with SA alone or untreated, served as controls. The primary outcome measures were: (i) changes in plaque-modified Psoriasis Activity and Severity Index (PSI) scores from baseline to end of treatment; (ii) clinical response to treatment (CR(T)), assessed by serial photographs; (iii) percentage of plaques clear at the end of treatment; and (iv) percentage of plaques clear at 1-year follow-up. The secondary outcome measures were: (i) number of laser treatments to clearance; (ii) time to relapse; (iii) frequency of side-effects; and (iv) qualitative observations with SIAscope.

RESULTS

The mean improvement in PSI was 4.7 (SD 2.1) with excimer and 2.7 (SD 2.4) with PDL. PSI improvement was significantly greater in excimer than PDL (P = 0.003) or both control plaques (P < 0.001). CR(T) indicated 13 patients responded best with excimer, two patients best with PDL, and in seven patients there was no difference between the two lasers. CR(T) was significantly greater for excimer than PDL (P = 0.003) or both controls (P < 0.001). CR(T) was also significantly greater for PDL than SA alone (P = 0.004) or untreated control (P =0.002). Nine (41%) patients cleared with excimer, after mean 8.7, median 10 weeks treatment. Seven of these nine patients were followed up to 1 year; four remained clear, two relapsed at 1 month, and one at 6 months. Six (27%) patients cleared with PDL, after mean 3.3, median four treatments. All six patients were followed up to 1 year; four remained clear, one relapsed at 4 months and one at 9 months. Despite common side-effects including blistering and hyperpigmentation, patient satisfaction was high. Serial images obtained with the SIAscope during treatment indicated different mechanisms of action of the two lasers.

CONCLUSIONS

Excimer and V Beam PDL are useful treatments for plaque psoriasis. Although the excimer appears to be on average more efficacious, a subset of patients may respond better to PDL. Long-term remission is achievable with both lasers.

Vascularity and Fractal Dimension of the Dermo-Epidermal Interface in Guttate and Plaque-Type Psoriasis

BACKGROUND

Histological structures of the skin are often irregular in size and shape. Euclidean geometry and fractal analysis are complementary for assessing distinct aspects of their dimensions.

OBJECTIVE

To determine and compare the variations in shape of the dermo-epidermal junction and the size of the superficial vessels in psoriatic lesions.

METHOD

The relative microvasculature area and the fractal dimension D of the dermo-epidermal interface were measured inside and outside growth-stunted guttate lesions (n = 22) and expanding plaques (n = 37) in psoriasis of the trunk.

RESULTS

The median D values of the dermo-epidermal interface were significantly larger (p < 0.01) in psoriatic plaques (D = 1.15) than in guttate lesions (D = 1.08), and these D values on lesional skin were significantly larger (p < 0.01) than in the uninvolved skin (D = 1.03). The microvasculature was significantly (p < 0.01) more developed in lesional (plaque: 13%, guttate: 8.20%) than in uninvolved skin (3.60 and 3.85%). No correlations were found between the relative microvasculature areas and the D values of the dermo-epidermal interface, both in the uninvolved and lesional skins of each psoriatic type.

CONCLUSION

The absence of a relationship between modulations of the dermo-epidermal junction and vascular hyperplasia, both in expanding and stable psoriasis lesions, suggests that these events are regulated by different mechanisms and do not depend on each other.

In vivo quantification of the structural abnormalities in psoriatic microvessels before and after pulsed dye laser treatment

BACKGROUND

Microvascular abnormalities (capillary elongation, widening and tortuosity) are a characteristic feature of psoriasis and form one of the pathological diagnostic criteria. These changes occur early in the progression of a psoriatic plaque, before there is clinical or histological evidence of epidermal hyperplasia. Treatment of psoriatic microvessels with a pulsed dye laser (PDL) has been associated with both clinical improvement and clearance of lesions.

OBJECTIVES

To quantify the structural vascular abnormalities in plaque skin using noninvasive techniques in vivo. Investigations were carried out before and after PDL treatment to determine the nature of laser-induced microvascular changes and the relationship between these changes and clinical improvement.

METHODS

Plaque microvessels were visualized using native capillaroscopy. Plaques were then treated three times with the PDL at 14-day intervals. Native capillaroscopy was repeated at 2 and 6 weeks after the final laser treatment. Images were analysed using a combination of nonstereological and stereological measurements.

RESULTS

Whole body disease was stable. Treated plaques showed a 48% reduction in plaque severity score (P < 0.01). Native studies showed that the PDL significantly reduced plaque microvessel density (P < 0.05), image area fraction (P < 0.01), microvessel length density (P < 0.01) and vessel image width (P < 0.01). The reduction in plaque severity score (which denoted clinical improvement) was related quantitatively to the reduction in microvessel area per unit area of plaque skin, i.e. the image area fraction (correlation coefficient = 0.772, P < 0.01). The greatest response of plaque microvessels was within 2 weeks after the final laser treatment, while the greatest reduction in plaque severity score occurred between 2 and 6 weeks after the final laser treatment, i.e. clinical improvement was preceded by microvascular improvement.

CONCLUSIONS

These findings indicate that there is a close correlation between the state of the superficial vasculature and the clinical status of psoriasis. The expanded superficial microvascular bed in plaque skin is a necessary component for maintaining clinical lesions and these blood vessels are thus a legitimate target for treatment.

K16 expression in uninvolved psoriatic skin: a possible marker of pre-clinical psoriasis

BACKGROUND

K16, a type I keratin, is upregulated in hyperproliferative states including psoriasis. It has been used as a marker of psoriasis and its expression is upregulated in relapsing psoriasis and downregulating in resolving. We evaluated non-lesional psoriatic skin for K16 expression.

METHODS

Sixty-seven non-lesional and lesional skin samples from patients with psoriasis and normal skin from 19 non-psoriatic patients were studied by immunohistochemistry on frozen sections with K16.

RESULTS

Seventeen of 19 normal skin samples showed staining of basal cells in the deeper part of the rete ridges. Sixty-two non-lesional psoriatic skin samples showed intense basal staining of K16. Of the remaining five non-lesional samples, diffuse intense suprabasal staining in one, pan-epidermal staining in two, and no staining was seen in two samples. Suprabasal (37), diffuse (14), sandwich (12), and basal (3) pattern staining were seen in psoriatic skin. One psoriatic skin sample did not show any expression.

CONCLUSION

Our results demonstrate that K16 expression is also observed in non-lesional psoriatic skin and may serve as a marker of preclinical psoriasis.

Immunohistochemical evaluation of psoriatic plaques following selective photothermolysis of the superficial capillaries

BACKGROUND

Elongated and tortuous capillary loops are distinctive features of psoriasis. The significance of these microvascular changes in the pathogenesis of plaques, however, remains unclear.

OBJECTIVES

To determine what part the expanded superficial capillary bed plays in the pathogenesis of clinical lesions by selectively thermolysing psoriatic capillaries with a pulsed dye laser (PDL).

METHODS

Cutaneous lesions were biopsied before and after treatment and sections assessed by standard immunohistochemical techniques for changes in known indicators of angiogenesis, including endothelial surface area, endothelial cell proliferation and endothelial cell expression of adhesion molecules. We also measured lymphocytic infiltration and epidermal thickness, and quantified the presence of a marker of keratinocyte proliferation before and after treatment.

RESULTS

The effect of the PDL was limited to the superficial capillary bed, with no changes in the microvessels (including venules and arterioles) of the upper reticular dermis. Although there was significant clinical improvement in plaques after treatment (P = 0.02), complete clearance of lesions was not achieved. Thermolysis of psoriatic capillaries caused a reduction in both endothelial surface area (P < 0.01) and endothelial cell proliferation in the superficial dermis (P = 0.04). Endothelial expression of surface adhesion molecules (integrins and E-selectin) important in angiogenesis was not, however, altered by treatment. The CD4+ and CD8+ T-cell infiltrate was significantly reduced in the superficial papillary dermis (P = 0.02 and P = 0.04, respectively), but not in the epidermis or upper reticular dermis. Laser treatment significantly reduced epidermal thickness (P = 0.001), but did not alter epidermal keratinocyte proliferation (P = 0.2).

CONCLUSIONS

The results demonstrate that dermal capillary changes alone are unlikely to be causal in psoriasis. They indicate that the expanded psoriatic capillaries may be important in facilitating the access of activated T cells to the skin and in maintaining the psoriatic plaque. These results do not refute the consensus view that plaque formation may be mediated by the release of growth factors/cytokines from activated epidermal T cells/keratinocytes.

The cutaneous microcirculation

The cutaneous microcirculation is organized as two horizontal plexuses. One is situated 1-1.5 mm below the skin surface and the other is at the dermal-subcutaneous junction. Ascending arterioles and descending venules are paired as they connect the two plexuses. From the upper layer, arterial capillaries rise to form the dermal papillary loops that represent the nutritive component of the skin circulation. There are sphincter-like smooth muscle cells at the point where the ascending arterioles divide to form the arteriolar component of the upper horizontal plexus. At the dermal-subcutaneous junction, there are collecting veins with two cusped valves that are oriented to prevent the retrograde flow of blood. Laser Doppler flowmetry has demonstrated vasomotion of red cell flux localized to the sites of ascending arterioles. The simultaneous recording by laser Doppler flowmetry of red cell flux and the concentration of moving red blood cells from individual sites allows one to construct topographic maps of these two values. These two maps, based on initial studies using correlative skin biopsies, can define 1 mm3 volumes of skin that are predominantly arteriolar in composition, venular in composition, or essentially devoid of all microvascular elements. The electron and light microscopic features that define the microvascular segments, when coupled with that ability of laser Doppler flowmetry to define the predominant microvascular segments under the probe, allow one to study both the mechanisms of normal physiologic states and the pathogenetic mechanisms underlying pathologic skin disorders in which the microvasculature plays a predominant role.

Increased expression of inducible nitric oxide synthase in psoriatic skin and cytokine-stimulated cultured keratinocytes

Since nitric oxide (NO) has been implicated in the pathogenesis of various hyperproliferative and inflammatory diseases, the mRNA expression of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) were investigated in psoriatic skin by reverse transcriptase coupled to the polymerase chain reaction (PCR). The study showed that the mRNA expression of brain nitric oxide synthase (bNOS), one of two isoforms of cNOS, was weak in both psoriatic plaques lesions and uninvolved skin, while mRNA transcripts for the second isoform, endothelial nitric oxide synthase (eNOS), were not detectable using the present method. In contrast, the mRNA expression of iNOS was markedly increased in lesional skin as compared to uninvolved skin. Cultured human keratinocytes exposed to a combination of interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) for 4 h, showed strong gene expression of iNOS, while in 24 h, the expression had returned to baseline expression. In summary, the study demonstrates that mRNA for the inducible form of NOS is over-expressed in psoriatic lesions. The cause of this may be the local presence of inflammatory cytokines. These findings imply that iNOS may play an important part in local regulation of NO synthesis in psoriasis and other inflammatory dermatoses.