Phototherapy with narrowband vs broadband UVB

Efficacy and safety of narrowband ultraviolet B versus combined ultraviolet A/narrowband ultraviolet B phototherapy in the treatment of chronic atopic dermatitis: A randomised double-blind study

Phototherapy is a useful treatment modality for atopic dermatitis (AD). This is a prospective randomised double-blind study comparing the clinical efficacy of combined ultraviolet-A (UVA)/narrowband ultraviolet-B (NBUVB) versus NBUVB phototherapy in the treatment of chronic AD. Patients with moderate-to-severe AD were randomised to receive either UVA/NBUVB or NBUVB phototherapy twice weekly over 12 weeks. At baseline, weeks 6 and 12, Eczema Area And Severity Index (EASI), itch score and adverse effects were assessed. At baseline and week 12, disease-related quality of life was evaluated using the Dermatology Life Quality Index (DLQI). Nine patients were randomised to receive UVA/NBUVB and 10 received NBUVB. At week 12, both groups showed significant improvement in EASI and itch scores (p < 0.05). Significant improvement in DLQI was seen in the UVA/NBUVB arm (p = 0.009) with a trend towards improvement in the NBUVB arm (p = 0.11). The efficacy of both modalities were comparable, as were reported adverse effects aside from skin dryness which was higher in the NBUVB arm (40% vs. 0%, p = 0.033). Combined UVA/NBUVB and NBUVB phototherapy have comparable clinical efficacy and safety in the treatment of chronic AD. NBUVB may induce greater skin dryness.

UVA1 radiation attenuates pro-inflammatory functions in human monocytes

UVA1 therapy is effective in the treatment of inflammatory and autoimmune skin diseases. The mode of action of UVA1 therapy is not completely understood and especially data on cells of the innate immune system like monocytes, which are critically involved in many inflammatory processes, are sparse. We wanted to answer the question whether UVA1 irradiation alters functional properties of human monocytes. We treated human peripheral blood monocytes in vitro with 2 J/cm² UVA1 light, incubated the cells for 48 h and examined both functional properties and alterations in the gene and protein expression profile. While UVA1 did not alter cell viability or susceptibility to apoptosis inducing agents, it decreased the capacity of monocytes for phagocytosis and to eliminate infectious agents like Leishmania major. Moreover, we measured a significantly reduced production of interleukin (IL)-1β mRNA in lipopolysaccharide activated monocytes after UVA1 treatment. Importantly, UVA1-treated monocytes not only produce less IL-1β, but also upregulate expression of the anti-inflammatory IL-1β decoy receptor. Our data provide evidence that UVA1 radiation not only interferes with fundamental monocyte properties like phagocytosis, pathogen killing and activation, but could also specifically attenuate pro-inflammatory IL-1 effects. This might constitute a hitherto unknown anti-inflammatory mechanism of UVA1 in human monocytes.

Energy Transfer from Pr3+ to Gd3+ and Upconversion Photoluminescence Properties of Y7O6F9:Pr3+, Gd3

Upconversion materials have numerous potential applications in light energy utilization due to their unique optical properties. The use of visible light excitation to obtain ultraviolet emission is a promising technology with broad application prospects, while relevant research is absent. A series of Pr³⁺, Gd³⁺ doped Y₇O₆F₉ phosphors were synthesized by traditional solid-state reaction. X-ray diffraction, scanning electronic microscopy, steady-state photoluminescence spectra, a decay dynamic, and upconversion emission spectra of the samples were studied. Under the excitation of 238 nm, the energy transfer from Pr³⁺ to Gd³⁺ was realized and a strong ultraviolet B emission due to the ⁶P_7/2→⁸S_7/2 transition of the Gd³⁺ ions was achieved. Under the excitation of a 450 nm blue laser, Pr³⁺ absorbed two blue photons to realize the upconversion process and then transferred the energy to Gd³⁺ to obtain the ultraviolet B emission.

The Effect of Narrow-Band Ultraviolet B Irradiation on the Vascularized Composite Allotransplantation Rat Model

INTRODUCTION

Vascularized composite allotransplantation (VCA) allows functional and esthetic reconstruction for patients with complex anatomical defects. However, acute and chronic graft rejections are significant obstacles to VCA. Ultraviolet light is an oncogenic environmental hazard. However, ultraviolet B (UVB) has an immunomodulation effect. Therefore, this study aims to elucidate the impact of UVB irradiation on the VCA rat model.

METHODS

The rat vascularized bone marrow allotransplantation model was used. A vascularized bone marrow from a Brown Norway rat (RT1Ac) was transplanted into a Lewis rat (RT1Ab). The allograft and surrounding abdominal skin were exposed to narrow-band ultraviolet B (NB-UVB) (311 nm) radiation with an energy of 1350 mJ/cm2 3 times a week until the end of the study period. There were 5 study groups: syngeneic transplantation (group 1), allogeneic transplantation (group 2), allogenic transplantation-NB-UVB (group 3), allogenic transplantation-antilymphocyte serum (ALS)-tacrolimus (group 4), and allogenic transplantation-antilymphocyte serum-tacrolimus-NB-UVB (group 5).

RESULTS

Group 5 had decreased graft survival compared with group 4. In the donor cell chimerism analysis, donor cell chimerism decreased significantly after UVB irradiation and was unresponsive to the administered immunosuppressants. After UVB irradiation, the CD8 T-cell ratio was increased, and the regulatory T-cell ratio was decreased.

CONCLUSIONS

The preliminary data showed that NB-UVB irradiation of the VCA rat model may decrease graft survival. However, further studies are needed to elucidate the possible mechanisms of this phenomenon.

Clinical Patterns and Treatment Response of Patients With Mycosis Fungoides a Retrospective Study

Background

Mycosis fungoides (MF) is one of the primary cutaneous T-cell lymphomas and is considered to be the most common extranodal non-Hodgkin lymphomas. MF is characterized by different subtypes based on clinical presentation and immunophenotyping studies. We aimed to study the clinical patterns and treatment response in cases of MF among the patients attending a tertiary referral hospital in Saudi Arabia.

Methodology

A retrospective study, case record-based study was done to review all the patients diagnosed with MF from January 2011 to May 2016. All cases with histopathological confirmation and immunophenotyping were included in the study. Treatment follow-up was reviewed for 9 months in all cases. Treatment response was graded based on a global physician assessment-complete response, good response, moderate response, and minimal or no response.

Results

Out of 34 cases of MF included in the study, 11 were hyperpigmented MF, 21 were hypopigmented MF, and there was one case each of poikilodermatous MF and pagetoid reticulosis. Of the total, fourteen (66.7%) of hypopigmented MF patients showed a complete response to phototherapy Narrowband UVB (NB-UVB) in combination with topical corticosteroids. Nine (81.8%) of hyperpigmented MF patients showed partial to the phototherapy NB-UVB in combination with the topical corticosteroid. Among the other types; one case of poikilodermatous MF (2.9%) showed a moderate response to phototherapy NB-UVB with topical corticosteroid and systemic acitretin.

Conclusions

The most common type of MF seen in our study was the hypopigmented type, affecting a younger age group, and the same showed a good response to phototherapy NB-UVB combined with topical corticosteroids.

Die Kunst der UV-Phototherapie und Photodiagnostik nicht verlernen!

Die UV-Phototherapie ist trotz der Entwicklung der hochwirksamen Biologicals nach wie vor Bestandteil diverser Leitlinienempfehlungen. Die Durchführung der verschiedenen Formen der Phototherapie bedarf einer profunden Ausbildung, um Schaden an Patienten zu vermeiden. Dies spiegelt sich in einer zunehmenden Anzahl von Behandlungsfehlervorwürfen, bspw. bei der Kommission für ärztliche Behandlungsfehler der Ärztekammer Nordrhein, wider. Im Folgenden werden anhand von vier Beispielen typische Fehler bei der UV-Phototherapie und Photodiagnostik aufgezeigt, die zu Schäden bei den Patienten geführt haben. Zusammenfassend ist festzustellen, dass in allen geschilderten Fällen Behandlungsfehler aufgetreten sind, die bei fundierter Ausbildung und Kenntnis der einschlägigen Literatur zu vermeiden gewesen wären. Dieses Manuskript soll auch als Appell an die Ausbilder verstanden werden, die Kunst der Phototherapie und Photodiagnostik den ihnen anvertrauten Auszubildenden fundiert weiterzugeben.

Narrow-band ultraviolet B therapy attenuates cutaneous T-cell responses in hapten-induced, experimental contact dermatitis in beagles

BACKGROUND

In human medicine, narrow-band ultraviolet B (NB-UVB) phototherapy has been used to treat various T-cell-mediated skin diseases. However, the effect of NB-UVB on inflamed canine skin remains uncertain.

OBJECTIVES

To investigate the effect of NB-UVB phototherapy on the skin of dogs with hapten-induced contact dermatitis.

ANIMALS

Seven healthy beagles without skin problems.

METHODS AND MATERIALS

Dogs were irradiated with varying doses of NB-UVB to determine the minimal erythema dose (MED). After determining the MEDs of six dogs (excluding one of the seven whose skin did not show a visible reaction), we investigated the effect of NB-UVB on their inflamed skin by topically applying 2,4-dinitrochlorobenzene (DNCB), which causes type 1 helper T cell (Th1)- and cytotoxic T-cell (Tc)1-induced skin inflammation. We then irradiated the skin with NB-UVB. We analysed the treated skin samples via histopathological and immunohistochemical methods, and TdT-mediated dUTP nick-end labelling (TUNEL) to demonstrate apoptotic cells. We also analysed the cytokine gene transcription via real-time quantitative reverse transcription PCR.

RESULTS

The NB-UVB MEDs caused mild inflammatory changes yet no severe epidermal exfoliations in the irradiated skin. In DNCB-treated skin irradiated by the NB-UVB MEDs, TUNEL-positive dermal apoptotic cells were increased significantly compared with those of DNCB-treated, nonirradiated skin. INF-γ and TNF-α transcription levels in DNCB-treated, irradiated skin were significantly lower than those in the DNCB-treated, nonirradiated skin.

CONCLUSION AND CLINICAL RELEVANCE

Phototherapy using NB-UVB MEDs attenuated cutaneous Th1 and Tc1 cytokine responses with minimal skin damage in a canine model of hapten-induced contact dermatitis.

Differences in phototherapy among skin diseases and genders in real-life conditions-A retrospective analysis of the cumulative doses, numbers of sessions, side effects and costs in 561 patients

BACKGROUND

Phototherapy has been a mainstay therapy for dermatological diseases since more than a century. Although phototherapy is still extensively used and some recommendations exist, only scarce data are available addressing disease-specific differences in cumulative doses, treatment durations and costs. Knowledge of such differences could help to avoid over-/undertreatment, predict treatment duration and costs. Therefore, we sought to determine differences in cumulative doses, numbers of sessions, side effects and costs among different skin diseases and genders in real-life conditions.

METHODS

In this single-centre, retrospective study, patients treated with phototherapy between March 2014 and April 2019 were classified into seven diagnostic groups and analysed according to the study goals.

RESULTS

Out of 561 patients (age 53.9 ± 20.3 yrs; 52.9% females), 83.7% percent were treated with cabin NB-UVB (mean cumulative dose 17.79 ± 17.11 J/cm² ). Patients with vitiligo and psoriasis were treated with significantly higher cumulative NB-UVB doses (cabin, local) in comparison with the five other diagnostic groups as were males in comparison with females. Consequently, significantly higher UV-related costs resulted in patients with vitiligo, psoriasis and males. Patients with atopic dermatitis and pruritus were treated with significantly higher cumulative UVA1 doses compared to patients with non-atopic eczema. The complication rate (pooled from all UV modalities) in our population was 3.8% (erythema 3.4%, aggravated itch 0.4% and worsening of symptoms 0.2%).

CONCLUSIONS

Our results demonstrate that cumulative doses and phototherapy-related costs vary strongly among skin diseases-a fact not adequately considered in recommendations. A more disease-specific stratification of phototherapy could not only help to optimize outcomes, but also to facilitate comparability of clinical trials using phototherapy.

[UV phototherapy : UV phototherapy and photodiagnostics-a practical overview]

UV phototherapy is an essential and efficient therapeutic option in the treatment of dermatological diseases. It is an integral part of multiple guidelines and maintains its high clinical significance despite the development of new therapeutic options for systemic treatment. Due to the difficult revenue situation, the market for ready-to-use products of psoralen and UV therapy devices is constantly changing.

A deep dive into UV-based phototherapy: Mechanisms of action and emerging molecular targets in inflammation and cancer

UV-based phototherapy (including psoralen plus UVA (PUVA), UVB and UVA1) has a long, successful history in the management of numerous cutaneous disorders. Photoresponsive diseases are etiologically diverse, but most involve disturbances in local (and occasionally systemic) inflammatory cells and/or abnormalities in keratinocytes that trigger inflammation. UV-based phototherapy works by regulating the inflammatory component and inducing apoptosis of pathogenic cells. This results in a fascinating and complex network of simultaneous events-immediate transcriptional changes in keratinocytes, immune cells, and pigment cells; the emergence of apoptotic bodies; and the trafficking of antigen-presenting cells in skin-that quickly transform the microenvironment of UV-exposed skin. Molecular elements in this system of UV recognition and response include chromophores, metabolic byproducts, innate immune receptors, neurotransmitters and mediators such as chemokines and cytokines, antimicrobial peptides, and platelet activating factor (PAF) and PAF-like molecules that simultaneously shape the immunomodulatory effects of UV and their interplay with the microbiota of the skin and beyond. Phototherapy's key effects-proapoptotic, immunomodulatory, antipruritic, antifibrotic, propigmentary, and pro-prebiotic-promote clinical improvement in various skin diseases such as psoriasis, atopic dermatitis (AD), graft-versus-host disease (GvHD), vitiligo, scleroderma, and cutaneous T-cell lymphoma (CTCL) as well as prevention of polymorphic light eruption (PLE). As understanding of phototherapy improves, new therapies (UV- and non-UV-based) are being developed that will modify regulatory T-cells (Treg), interact with (resident) memory T-cells and /or utilize agonists and antagonists as well as antibodies targeting soluble molecules such as cytokines and chemokines, transcription factors, and a variety of membrane-associated receptors.

White-light flashlight activated up-conversion luminescence for ultraviolet-B tagging

Optical tagging technology with emission in the ultraviolet region upon visible-light excitation is promising for objects identified in visually bright environments, while the relevant research is absent. Here we put forward a covert tagging concept, which is based on up-converting phosphors (e.g., Lu₃Al₅O₁₂:Pr³⁺) with emission peaking in the ultraviolet-B region (UV-B, 290-320 nm). A white-light flashlight serves as excitation source to make the up-converter emit, and an ultraviolet camera is applied to see such an emission wavelength range. This Letter expands the excitation source for an up-conversion process to a convenient flashlight for the first time, to the best of our knowledge. Moreover, such a flashlight-pumped UV-B tagging technology is generally applicable for many other phosphors, which can be utilized to mark and differentiate objects in commercial, civilian, or military applications.

The Effect of UVB Irradiation and Oxidative Stress on the Skin Barrier-A New Method to Evaluate Sun Protection Factor Based on Electrical Impedance Spectroscopy

Sunlight is vital for several biochemical processes of the skin organ. However, acute or chronic exposure to ultraviolet radiation (UVR) has several harmful effects on the skin structure and function, especially in the case of the failing function of antioxidative enzymes, which may lead to substantial tissue damage due to the increased presence of reactive oxygen species (ROS). The aim of this work was to investigate the combined effect of ultraviolet B (UVB) irradiation and oxidative stress on the skin barrier integrity. For this, we employed electrical impedance spectroscopy (EIS) to characterize changes of the electrical properties of excised pig skin membranes after various exposure conditions of UVB irradiation, oxidative stress, and the inhibition of antioxidative enzymatic processes. The oxidative stress was regulated by adding hydrogen peroxide (H₂O₂) as a source of ROS, while sodium azide (NaN₃) was used as an inhibitor of the antioxidative enzyme catalase, which is naturally present throughout the epidermis. By screening for the combined effect of UVB and oxidative stress on the skin membrane electrical properties, we developed a new protocol for evaluating these parameters in a simple in vitro setup. Strikingly, the results show that exposure to extreme UVB irradiation does not affect the skin membrane resistance, implying that the skin barrier remains macroscopically intact. Likewise, exposure to only oxidative stress conditions, without UVB irradiation, does not affect the skin membrane resistance. In contrast to these observations, the combination of UVB irradiation and oxidative stress conditions results in a drastic decrease of the skin membrane resistance, indicating that the integrity of the skin barrier is compromised. Further, the skin membrane effective capacitance remained more or less unaffected by UVB exposure, irrespective of simultaneous exposure of oxidative stress. The EIS results were concluded to be associated with clear signs of macroscopic tissue damage of the epidermis as visualized with microscopy after exposure to UVB irradiation under oxidative stress conditions. Finally, the novel methodology was tested by performing an assessment of cosmetic sunscreen formulations with varying sun protection factor (SPF), with an overall successful outcome, showing good correlation between SPF value and protection capacity in terms of skin resistance change. The results from this study allow for the development of new skin sensors based on EIS for the detection of skin tissue damage from exposure to UVB irradiation and oxidative stress and provide a new, more comprehensive methodology, taking into account both the influence of UVB irradiation and oxidative stress, for in vitro determination of SPF in cosmetic formulations.

Tuscan consensus on the use of UVBnb phototherapy in the treatment of psoriasis

Psoriasis (PSO) is traditionally defined as an immune-mediated, inflammatory dermatological disease characterized by a chronic-relapsing course and associated with multifactorial inheritance (genetic predisposition and influence of various environmental factors). Considered until recently a dermatological disease only, today PSO is correctly known as a systemic one because of the involvement of multiple organs with important impact on social life and relationships. PSO is found in the 0.3-4.6% of the world's population, while its prevalence in the Italian population is estimated at 2.8%. Therefore, if we consider that in Tuscany more than 100,000 people out of 3,672,202 suffer of psoriasis, it is of paramount importance to focus on a shared clinical and therapeutic protocol to manage the disease. With the aim of ensuring diagnostic-therapeutic suitability, high levels of care and standardization of treatment, a unique clinical-therapeutic management model has been developed and validated in Tuscany, involving all accredited regional dermatological centers. Among the possible alternatives to be implemented in the treatment of patients with mild, moderate-severe psoriasis, UVBnb phototherapy is widely used alone or in association with other systemic and non-systemic devices. Despite this, there is still no universally shared therapeutic protocol. In this context the CO.FO.TO working group (Consensus Fototerapia Toscana) is born with the aim of defining and validating the main guidelines in the use of phototherapy with UVBnb in psoriasis; the guidelines are based both on the real-life experience of the different centers of reference in the region and on the revision of the recent literature.

Exposure to Ultraviolet Radiation in the Modulation of Human Diseases

This review focuses primarily on the beneficial effects for human health of exposure to ultraviolet radiation (UVR). UVR stimulates anti-inflammatory and immunosuppressive pathways in skin that modulate psoriasis, atopic dermatitis, and vitiligo; suppresses cutaneous lesions of graft-versus-host disease; and regulates some infection and vaccination outcomes. While polymorphic light eruption and the cutaneous photosensitivity of systemic lupus erythematosus are triggered by UVR, polymorphic light eruption also frequently benefits from UVR-induced immunomodulation. For systemic diseases such as multiple sclerosis, type 1 diabetes, asthma, schizophrenia, autism, and cardiovascular disease, any positive consequences of UVR exposure are more speculative, but could occur through the actions of UVR-induced regulatory cells and mediators, including 1,25-dihydroxy vitamin D₃, interleukin-10, and nitric oxide. Reduced UVR exposure is a risk factor for the development of several inflammatory, allergic, and autoimmune conditions, including diseases initiated in early life. This suggests that UVR-induced molecules can regulate cell maturation in developing organs.

Skin Burn Associated With Photochemotherapy

OBJECTIVE

psoralen and ultraviolet A (PUVA) phototherapy (PT) has become a standard treatment for several severe skin diseases. Photosensitization is done by oral psoralen intake. In minor cases, PUVA can lead to skin changes like erythema and hyperpigmentation. However, it can also lead to severe burn injuries when exposed to extensive UV light. This makes the treatment in a burn center inevitable.

METHODS

We report the clinical observation of a 38-year-old man presenting with an extensive burn injury caused by sun tanning after PUVA PT.

CONCLUSIONS

There are just few cases of extensive burns induced by PUVA PT. Prevention becomes manifest in patient information, correct calculation of dosage, evaluation of photosensitivity, and close observation. In cases of severe burn injuries, patients should be referred to a burn center for optimal conservative treatment. Surgical intervention is usually not necessary.

A Dynamic Model for Prediction of Psoriasis Management by Blue Light Irradiation

Clinical investigations prove that blue light irradiation reduces the severity of psoriasis vulgaris. Nevertheless, the mechanisms involved in the management of this condition remain poorly defined. Despite the encouraging results of the clinical studies, no clear guidelines are specified in the literature for the irradiation scheme regime of blue light-based therapy for psoriasis. We investigated the underlying mechanism of blue light irradiation of psoriatic skin, and tested the hypothesis that regulation of proliferation is a key process. We implemented a mechanistic model of cellular epidermal dynamics to analyze whether a temporary decrease of keratinocytes hyper-proliferation can explain the outcome of phototherapy with blue light. Our results suggest that the main effect of blue light on keratinocytes impacts the proliferative cells. They show that the decrease in the keratinocytes proliferative capacity is sufficient to induce a transient decrease in the severity of psoriasis. To study the impact of the therapeutic regime on the efficacy of psoriasis treatment, we performed simulations for different combinations of the treatment parameters, i.e., length of treatment, fluence (also referred to as dose), and intensity. These simulations indicate that high efficacy is achieved by regimes with long duration and high fluence levels, regardless of the chosen intensity. Our modeling approach constitutes a framework for testing diverse hypotheses on the underlying mechanism of blue light-based phototherapy, and for designing effective strategies for the treatment of psoriasis.

Irradiation with narrowband-ultraviolet B suppresses phorbol ester-induced up-regulation of H1 receptor mRNA in HeLa cells

Conclusion These findings suggest that low dose irradiation with 310 nm NB-UVB specifically suppressed the up-regulation of H1R gene expression without inducing apoptosis and that UVB of shorter or longer wavelength than 310 nm NB-UVB had no such effects. Objective To develop a narrowband-ultraviolet B(NB-UVB) phototherapy for allergic rhinitis, this study investigated the effects of irradiation with NB-UVB at wavelength of 310 nm on phorbol-12-myristate-13-acetate (PMA)-induced up-regulation of histamine H1 receptor (H1R) mRNA in HeLa cells. Methods The mRNA levels of H1R in HeLa cells were measured using real-time RT-PCR. Apoptosis were evaluated with DNA fragmentation assay. Results PMA induced a significant increase in H1R mRNA expression in HeLa cells. Irradiation with 305 nm UVB and 310 nm NB-UVB, but not with 315 nm UVB at doses of 200 and 300 mJ/cm(2) significantly suppressed PMA-induced up-regulation of H1R mRNA. At a dose of 200 mJ/cm(2), irradiation with 305 nm UVB, but not with 310 nm NB-UVB, induced apoptosis, although exposure of the cells to both 305 and 310 nm UVB induced apoptosis at a dose of 300 mJ/cm(2) after PMA treatment in HeLa cells. Conversely, irradiation with 315 nm UVB at doses of 200 and 300 mJ/cm(2) did not induce apoptosis.

Histopathological effects of intranasal phototherapy and nasal corticosteroids in allergic rhinitis in a rabbit model

Allergic rhinitis is one of the most common health problems and has a major effect on quality of life. Although new-generation antihistamines and nasal steroids are the main treatment options, complete resolution cannot be obtained in some patients. Besides common side effects such as nasal irritation and epistaxis, the use of these drugs is controversial in some patients, such as pregnant or breastfeeding women. These findings highlight the need for new treatment options. Although phototherapy has been successfully used in the treatment of atopic dermatitis, which is an IgE-mediated disease and shares several common pathogenic features with allergic rhinitis, there are limited studies about its role in the treatment of allergic rhinitis. In this study, we aimed to evaluate and compare the histopathological effects of intranasal phototherapy (Rhinolight) and nasal corticosteroid treatment on the nasal mucosa in allergic rhinitis in a rabbit model and we found that both treatment options significantly reduced inflammation in the nasal mucosa without increasing apoptosis of mucosal cells.

Phototoxicity of narrowband ultraviolet (UV) B (311 nm) compared with broadband UVB in the photo hen's egg test

BACKGROUND

Broadband ultraviolet B (BB-UVB) is a well-established treatment option in dermatology. However, during the last decade BB-UVB has increasingly been replaced by narrowband UVB 311 nm (NB-UVB), especially in the therapy of psoriasis, atopic eczema and vitiligo. Several studies have indicated a better therapeutic response for almost all indications compared with BB-UVB.

OBJECTIVES

The aim of our study was to investigate the phototoxic effects of NB-UVB in comparison with BB-UVB in vivo.

METHODS

Therefore, we employed the photo hen's egg test (PHET), an established phototoxic model, based on the yolk sac blood vessel system of incubated hen's eggs. NB-UVB and BB-UVB dosages increasing from 30 up to 1200 mJ cm(-2) were applied on 17 test groups (each n = 12 eggs) and two unirradiated test groups served as controls. Twenty-four hours after irradiation we observed the following test parameters: lethality, membrane discoloration and haemorrhages.

RESULTS

Following our results, the lethal half dose (LD50) was 60 and 720 mJ cm(-2) for BB-UVB and NB-UVB, respectively. These LD50 dosages provoked severe membrane discoloration and haemorrhaging. Summarizing our results, the LD50 of NB-UVB was 12-fold higher than BB-UVB.

CONCLUSIONS

Interestingly, these findings are in good accordance with the literature, where the minimal erythema dose (MED) of NB-UVB in human skin is up to 14 times higher than the MED of BB-UVB. These results show that the PHET is a valid test model to evaluate the phototoxic effects of various UVB wavelengths. Moreover, our results indicate that regarding the investigation of phototoxic effects the PHET might serve as a model representative for human skin, which might reduce the extent of photoprovocation in humans in the future.

UV-based therapy

UV phototherapy has a long history of use for the treatment of select diseases in dermatology. Its use has evolved into more effective and targeted modalities, including psoralen + UV-A photochemotherapy, narrowband UV-B, excimer laser, and UV-A1 phototherapy. With its proven record of efficacy and safety, UV phototherapy is an excellent option in the treatment of an ever-growing number of skin conditions.

UVB induces HIF-1α-dependent TSLP expression via the JNK and ERK pathways

Thymic stromal lymphopoietin (TSLP) may have a key role in the initiation and maintenance of allergic inflammatory diseases, including atopic dermatitis. The present study revealed that UVB radiation exposure could induce TSLP expression in human keratinocytes and a human skin equivalent model. In addition, we investigated the regulatory mechanism of UVB-induced TSLP expression in keratinocytes. TSLP expression was upregulated by transfection with pcDNA3-hypoxia-inducible factor (HIF)-1α (P402A and P564A), which stably expresses HIF-1α protein. UVB-induced TSLP induction in keratinocytes was suppressed in the treatment of mitogen-activated protein kinase inhibitors or small interfering RNAs against HIF-1α. The results of chromatin immunoprecipitation assays indicate the direct involvement of HIF-1α in UVB-mediated TSLP induction. Taken together, these findings indicate that UVB exposure may increase TSLP expression through a HIF-1α-dependent mechanism via the c-JUN N-terminal kinase and extracellular signal-regulated kinase pathways in human keratinocytes. Our data showed that UVB-induced TSLP might increase secretion of the T-helper type 2-attracting chemokine (c-c motif) ligand 17 by human dendritic cells. The present study suggests an important role of HIF-1α in UVB-mediated immune response in keratinocytes.

Effects of narrow band UVB (311 nm) irradiation on epidermal cells

Ultraviolet radiation (UVR) is known to be one of the most important environmental hazards acting on the skin. It was revealed that chronic exposure to UVR accelerates skin aging, induces immunosuppression and may lead to the development of skin cancers. On the other hand, UVR has been shown to be effective in the treatment of numerous skin diseases and thus, various phototherapy modalities have been developed to date. Narrow-band ultraviolet B (NB-UVB) emitting a light with a peak around 311 nm has been demonstrated to be effective in the treatment of various skin disorders; currently it is one of the most commonly used phototherapy devices. Despite NB-UVB has been developed more than 30 years ago, the exact mechanism of its therapeutic action remains poorly understood. To date, most of NB-UVB effects were attributed to its influence on immune cells; however, nearly 90% of NB-UVB irradiation is absorbed by epidermis and keratinocytes seem to be important players in mediating NB-UVB biological activity. Here, we have reviewed the current data about the influence of NB-UVB on epidermal cells, with a special emphasis on cell proliferation and death.

Clastogenic plasma factors in psoriasis--comparison of phototherapy and anti-TNF-α treatments

As previously described, Psoralen plus UVA (PUVA) therapy induces chromosome damage in psoriatic patients. This study evaluates whether these effects are transitory or persistent. In addition, we studied these effects after narrowband UVB (nUVB) and anti-tumor necrosis factor (TNF)-α treatments. Among 40 responder patients, 10 received PUVA, 10 nUVB, 10 Infliximab and 10 Etanercept. Disease activity was determined with Psoriasis Area and Severity Index. Chromosomal breakage was evaluated by the clastogenic factor (CF) test. Potential clastogenic agents, malondialdehyde (MDA) and TNF-α were measured. Before treatment, the plasma-adjusted clastogenic scores (ACS) of patients were increased. During treatment, a further increase in ACS was observed in both phototherapy groups. Chromosome damage persisted for PUVA patients at week 32, while it diminished after nUVB to ACS values lower than before treatment. MDA and TNF-α values were also increased at baseline. MDA decreased during treatment in all groups, but without reaching normal levels. Plasma TNF-α remained unchanged in PUVA and nUVB but decreased in both anti-TNF-α treatment groups. Psoriasis is accompanied by CF-induced chromosomal breakage that increases during PUVA and nUVB treatments. Plasma clastogenic activity persisted in the follow-up after PUVA, while after nUVB ACS returned to values even lower than baseline. Clastogenic activity during the induction phase with anti-TNF-α remained unchanged.

Currentaspects of psoriasis phototherapy

The review covers current aspects of ultraviolet therapy for patients suffering from psoriasis. It describes mechanisms of action as well as early and remote side effects of the current phototherapy methods. The review also presents data from literature about the risk of their cancerogenicity. It also discusses approaches to the optimization of phototherapy in view of risks and benefits for the patient.

Measuring colour and photostability of small fleece wool samples

A convenient method for measuring the clean colour (Y and Y-Z) and photostability Δ(Y-Z) of small samples of fleece wool (0.5 g) is described. Scoured wool samples are compressed to a constant density in disposable polymethyl methacrylate spectrophotometer cells and the wool colour is measured using a standard textile laboratory reflectance spectrophotometer. Packing scoured wool into cells ensures that the irradiated fibre surface is robust and individual fibres are unable to move relative to one another during irradiation and measurement. A UVB (280–320 nm) source was used to ensure all samples regardless of initial yellowness were yellowed following exposure and photobleaching was avoided. An apparatus capable of irradiating up to 48 scoured wool samples in one batch is described. The precision of photostability measurements was assessed and the relative error in Δ(Y-Z) was 5.7%. An initial study on 75 fleece wool samples with a high range of initial yellowness showed a moderate linear correlation (R2 = 0.68) between initial yellowness and Δ(Y-Z).

Comparison between 308-nm monochromatic excimer light and narrowband UVB phototherapy (311-313 nm) in the treatment of vitiligo--a multicentre controlled study

BACKGROUND

Vitiligo is an acquired pigmentary disorder characterized by areas of depigmented skin resulting from loss of epidermal melanocytes. Recently, it has been shown that narrowband ultraviolet B (NB-UVB) phototherapy may be more effective than psoralen and ultraviolet A (PUVA) photochemotherapy in treating vitiligo, and that 308-nm monochromatic excimer light (MEL) may present some advantages as compared to NB-UVB for the treatment of vitiligo. AIM The aim of this study was to compare the effectiveness of NB-UVB phototherapy and 308-nm MEL in vitiligo patients.

METHODS

The study was done in a randomized, investigator-blinded and half-side comparison design. Twenty-one subjects with symmetrical vitiligo lesions were enrolled in this study. Vitiligo lesions on one body side were treated twice weekly for 6 months with 308-nm MEL, while NB-UVB phototherapy was used to treat lesions on the opposite side.

RESULTS

At the end of the study six lesions (37.5%) treated with 308-nm MEL and only one lesion (6%) treated with NB-UVB achieved an excellent repigmentation (score 4) while four lesions (25%) treated with 308-nm MEL and five lesions (31%) treated with NB-UVB showed a good repigmentation (score 3).

CONCLUSIONS

It appears that 308-nm MEL is more effective than NB-UVB in treating vitiligo lesions and it induces repigmentation more rapidly.

Current state of vitiligo therapy ? evidence-based analysis of the literature

Vitiligo is a skin disease with a worldwide prevalence ranging from 0.5% to 4%. Conservative therapies include photochemotherapy, phototherapy with UVB radiation (broadband UVB 290-320 nm, narrow band UVB 311 nm), systemic steroids and pseudocatalase. Modern therapeutic options include treatment with topical immunomodulators (tacrolimus, pimecrolimus), analogues of vitamin D3, excimer laser and surgery/transplantation. Our analysis compares these therapies for vitiligo and the evidence levels supporting their effectiveness.

CONCLUSIONS

The face and neck respond best to all therapeutic approaches, while the acral areas are least responsive. For generalized vitiligo, phototherapy with UVB radiation is most effective with the fewest side effects; PUVA is the second best choice.Topical corticosteroids are the preferred drugs for localized vitiligo. They may be replaced by topical immunomodulators which display comparable effectiveness and fewer side effects. The effectiveness of vitamin D analogues is controversial with limited data. Surgical therapy can be very successful, but requires an experienced surgeon and is very demanding of time and facilities, thus limiting its widespread use. L-phenylalanine therapy appears effective on the face but enjoys neither widespread use nor extensive data support. No single therapy for vitiligo can be regarded as the most effective as the success of each treatment modality depends on the type and location of vitiligo.

Fototerapia: aplicações clínicas

Fototerapia é a modalidade terapêutica que aplica exposições repetidas e controladas de radiação ultravioleta para alterar a fisiologia cutânea de modo a induzir a regressão ou controlar a evolução de diversas dermatoses. Este texto apresenta uma visão geral das práticas correntes que utilizam a radiação ultravioleta isolada ou em combinação com fotossensibilizantes ou outras medicações. Serão ainda discutidos os mecanismos de ação de cada modalidade, as indicações mais aceitas, seus esquemas de prescrição, efeitos adversos e cuidados especiais.

Ultraviolet light phototherapy for allergic rhinitis

Phototherapy has a profound immunosuppressive effect and is widely used for the treatment of immune mediated skin diseases. Phototherapy is able to inhibit immediate type hypersensitivity reaction in the skin. Intranasal phototherapy is a new approach for treatment of allergic rhinitis. In two open studies, 308 nm excimer laser and topical PUVA therapy efficiently inhibited clinical symptoms of allergic rhinitis. In a randomized, double-blind study combined low dose UVB, low dose UVA and visible light proved to be effective in reducing symptom scores for sneezing, rhinorrhea, nasal itching and the total nasal score in ragweed allergic patients. Mechanism of action of phototherapy is complex, it reduces the antigen presenting capacity of dendritic cells, induces apoptosis of immune cells and inhibits synthesis and release of pro-inflammatory mediator from several cell types. Therefore, intranasal phototherapy may represent an alternative treatment of allergic rhinitis and other inflammatory and immune mediated mucosal diseases.

Documento de consenso sobre fototerapia: terapias PUVA y UVB de banda estrecha

It is essential to develop a consensus document on phototherapy in order to adapt this procedure to the specific characteristics, needs and reality of our milieu. Using a review of existing literature on the subject and the experience of its own members as a reference, the Spanish Photobiology Group (GEF) of the Spanish Academy of Dermatology and Venereology (AEDV) has developed some therapeutic guidelines for the most widely used modes of phototherapy: PUVA therapy and narrow-band UVB (NBUVB) therapy. These guidelines deal with generalities about the equipment, calibration and regulation in phototherapy booths, and the concept and indications for these forms of treatment are reviewed. Recommendations are also proposed regarding patient selection, therapeutic procedures, associated pharmacological agents of interest and the prevention and management of adverse effects. The consensus document is designed as a flexible and practical instrument intended for use in daily clinical practice, aimed at optimizing the possibilities of phototherapy while reducing risks for patients and therapists.