Photodynamic therapy with topical delta-aminolaevulinic acid for the treatment of plantar warts

Evaluation of anti-viral photodynamic therapy effects of different concentrations of 5-ALA using light irradiation on HSV-1

BACKGROUND

Herpes simplex virus (HSV) infections are prevalent worldwide, posing challenges due to asymptomatic carriage and recurrent outbreaks. Conventional treatments, including antiviral medications, are limited by drug resistance. Photodynamic therapy (PDT) offers a promising alternative, leveraging photosensitizers to induce viral inactivation via reactive oxygen species (ROS) generation upon light activation.

METHODS

This study investigates the efficacy of 5-aminolevulinic acid (5-ALA) as a photosensitizer in antiviral PDT against HSV-1. HSV-1 was treated with varying concentrations of 5-ALA and subjected to light irradiation at a 630 nm wavelength. Virus titers were assessed using the 50 % Tissue Culture Infectious dose (TCID50) assay. Six experimental groups were used: [1] Control (no 5-ALA or light), HSV-1 with 0.05 g/ml 5-ALA and 630 nm light, [2] HSV-1 with 0.05 g/ml 5-ALA (no light), [3] HSV-1 with 0.1 g/ml 5-ALA and light, [4] HSV-1 with 0.1 g/ml 5-ALA (no light), and [5] HSV-1 with light (no 5-ALA).

RESULTS

Virus treatment with 0.1 g/ml 5-ALA combined with light irradiation significantly reduced HSV-1 titer compared to control groups (p < 0.05). Specifically, the virus titer decreased from 10 6.3 TCID50/ml in the control group to 10 4.5 TCID50/ml in the treated group. However, lower concentrations of 5-ALA or light irradiation alone did not yield significant reductions in HSV-1 titer (p > 0.05). Group 4, receiving 0.1 g/ml 5-ALA with light irradiation, exhibited a significantly greater reduction in virus titer than group 2, receiving 0.05 g/ml 5-ALA with light irradiation (p < 0.05).

CONCLUSIONS

5-ALA-mediated PDT demonstrates selective antiviral efficacy against HSV-1, particularly at higher concentrations coupled with light irradiation. These findings underscore the potential of 5-ALA-based PDT as a promising approach for HSV-1 treatment, especially in cases of drug-resistant strains and immunocompromised individuals. Optimization of dosage and treatment protocols is essential for maximizing effectiveness in clinical applications, highlighting the need for further research in this area.

Photodynamic therapy for recalcitrant plantar warts: Case reports and a literature review

Plantar wart is one of the most recalcitrant types of cutaneous warts with a high recurrence rate. Recalcitrant plantar warts are resistant to traditional treatments such as cryotherapy. Photodynamic therapy (PDT) is a modern, non-invasive method utilized to treat benign and malignant skin disorders. Several previous studies have reported the effective application of PDT treatment for plantar warts. We reported three cases of recalcitrant plantar warts successfully treated with PDT.

Effect of 5-Aminolevulinic Acid Photodynamic Therapy with Transfer Factor Capsules in the Treatment of Multiple Plantar Warts

BACKGROUND

Plantar warts are a common cutaneous disease of the sole of the foot caused by human papillomavirus. Photodynamic therapy has gained increasing attention in the treatment of plantar warts.

OBJECTIVE

To investigate the effect of photodynamic therapy combined with transfer factor capsules in the treatment of multiple plantar warts.

METHODS

Sixty-one patients with multiple plantar warts who visited our outpatient department from September 2017 to August 2019 were randomly divided into two groups. Twenty-three patients received photodynamic therapy (treatment group) and thirty-eight received cryotherapy (control group). Both groups also received immune modulator transfer factor capsules. Skin lesion score, numeric rating scale- (NRS-) 10 score, recurrence rate, adverse reactions, and Dermatology Life Quality Index (DLQI) were analyzed in both groups.

RESULTS

The mean skin lesion score improved from 13.39 ± 3.88 before treatment to 1.48 ± 2.50 after the last treatment in the treatment group and from 12.47 ± 2.99 before treatment to 4.47 ± 3.67 after the last treatment in the control group. The success rate after 3 months of treatment was 86.96% in the treatment group and 39.47% in the control group. After 3 months of follow-up, the recurrence rate was significantly lower in the treatment group (20%) than in the control group (53.33%). The mean DLQI score at three months after treatment was significantly lower in the treatment group (3.61 ± 1.16) than in the control group (6.31 ± 2.59).

CONCLUSION

Photodynamic therapy combined with immunomodulators significantly increased the cure rate and reduced the recurrence rate of multiple plantar warts compared with traditional cryotherapy combined with immunomodulators.

The cell-impermeable Ru(II) polypyridyl complex as a potent intracellular photosensitizer under visible light irradiation via ion-pairing with suitable lipophilic counter-anions

Developing the cell-impermeable Ru(II) polypyridyl cationic complexes as effective photosensitizers (PS) which have high cellular uptake and photo-toxicity, but low dark toxicity, is quite challenging. Here we found that the highly reactive singlet oxygen (¹O₂) can be generated by the irradiation of a typical Ru(II) polypyridyl complex Ru(II)tris(tetramethylphenanthroline) ([Ru(TMP)₃]²⁺) under visible light irradiation by ESR with TEMPO (2,2,6,6-tetramethyl-4-piperidone-N-oxyl) as ¹O₂ probe. Effective cellular and nuclear delivery of cationic [Ru(TMP)₃]²⁺ was achieved through our recently developed ion-pairing method, and 2,3,4,5-tetrachlorophenol (2,3,4,5-TeCP) was found to be the most effective among all chlorophenols tested. The accelerated cellular, especially nuclear uptake of [Ru(TMP)₃]²⁺ results in the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and DNA strand breaks, caspase 3/7 activation and cell apoptosis in HeLa cells upon light irradiation. More importantly, compared with other traditional photosensitizers, [Ru(TMP)₃]²⁺ showed significant photo-toxicity but low dark toxicity. Similar effects were observed when 2,3,4,5-TeCP was substituted by the currently clinically used anti-inflammatory drug flufenamic acid. This represents the first report that the cell-impermeable Ru(II) polypyridyl complex ion-paired with suitable lipophilic counter-anions functions as potent intracellular photosensitizer under visible light irradiation mainly via a ¹O₂-mediated mechanism. These findings should provide new perspectives for future investigations on other metal complexes with similar characteristics as promising photosensitizers for potential photodynamic therapy.

Topical treatment for plantar warts: A systematic review

There are a wide variety of treatments for plantar warts, but none has been shown to be effective in all patients. We aimed to perform a systematic review of the efficacy of different topical treatments on plantar warts. Systematic electronic searches (Pubmed, Cochrane Library, Embase, and Web of Science) were conducted in April 2020. Meta-analyses, systematic reviews, and retrospective or prospective clinical trials of the effects of topical and nonsurgical treatments of plantar warts were included. Two authors performed the study selection and data extraction. Any discrepancies between the two reviewers were discussed with a third reviewer. Forty-four studies were included. The average cure rates of the most frequent treatments were variable across the studies: cryotherapy (45.61%), salicylic acid (13.6%), cantharidin-podophyllin-salicylic acid formulation (97.82%), laser (79.36%), topical antivirals (72.45%), intralesional bleomycin (83.37%), and intralesional immunotherapy (68.14%). Twenty-two studies (50%) had a level of evidence 1b and grade of recommendation A, five studies (11.4%) had a level of evidence 2b and grade of recommendation B, two studies (4.5%) had a level of evidence 3b and grade of recommendation B, and 15 studies (34,1%) with a level of evidence 4 and grade of recommendation C. First-choice treatments for common warts, such as cryotherapy and salicylic acid, have low-cure rates for plantar warts. Other treatments, such as CPA formulation, immunotherapy, and intralesional bleomycin, which have compassionate use, have higher cure rates. This review should stimulate future high-quality research to evaluate these specialized treatments.

The application of medical scale in the treatment of plantar warts: analysis and prospect

Plantar warts are common cutaneous diseases on the sole caused by the human papillomavirus, with a high annual incidence rate of 14%. It often causes pain, which impairs quality of life of patients. Numerous therapeutic options for plantar warts exist with variable success. However, all of them, including first-line treatment, have different adverse reactions or high recurrence rates. There is no one effective method for all patients. The choice of treatment method puzzles doctors. With the help of medical scales, we can analyze the patients' condition, so as to guide the choice of treatment methods, which is of great significance for the individualized treatment of patients with plantar warts. This review takes cryotherapy, intralesional injection of bleomycin and photodynamic therapy as examples to discuss the application of medical scales in the treatment of plantar warts, summarizes the scales that can be used to evaluate the status of plantar wart, adverse reactions, prognosis and patient's financial situation, and discusses their clinical and scientific value. We hope to use scales to consider the severity of plantar warts and economic level, help different patients to choose different treatment options, and make suggestions on the evaluation of the adverse reactions and treatment effect.

Mineral Trioxide Aggregate Mixed with 5-Aminolevulinic Acid for the Photodynamic Antimicrobial Strategy in Hard Tissue Regeneration

Aminolevulinic acid (ALA) based photodynamic antimicrobial strategy can provide good antimicrobial effects and be used for medical applications. The aim of this study was to apply this strategy to Mineral Trioxide Aggregate (MTA), which is commonly used as a filling material for root endings and by doing so, to increase the bactericidal capability of MTA, as well as to investigate its characterization, cytocompatibility, and odontogenic differentiation potential. MTA is known to be a derivative of calcium silicate (CS). In this study, MTA specimens with or without ALA and light treatment were prepared. Diametral tensile strength values (DTS), setting durations, X-ray diffraction (XRD) spectra, apatite-mineralization, and antimicrobial abilities of the MTA, were also analyzed. Human dental pulp cells (hDPCs) can proliferate into the newly formed matrix and differentiate into odontoblasts to reinforce and strengthen the root. Levels of hDPCs proliferation and its odontogenic capabilities when cultured on MTA with ALA and light treatment, and the percentages of cells existing in the various cell cycle stages, were further evaluated in this study. The results indicated that MTA added ALA with light treatment had greater antibacterial ability and cytocompatibility, compared to MTA alone. A higher percentage S phase of the cells cultured on MTA added ALA with light treatment was observed. Furthermore, hDPCs cultured on MTA added ALA with light treatment had the highest expression levels of the odontoblastic differentiation markers. ALA has great antimicrobial efficiency and is a potential material for future medical applications. ALA-based photodynamic antibacterial strategy applied in the MTA has great antibacterial ability, cytocompatibility, and odontoblastic differentiation potential, and can facilitate the development of root canal treatment.

Therapeutic management of cutaneous and genital warts

During their lifetime, at least 10 % of the population will be infected by human papillomaviruses (HPV), clinically characterized by the formation of cutaneous or genital warts. Although warts are ubiquitous, there are no defined treatments. Especially in the first six months, warts frequently resolve without therapeutic intervention. This complicates the interpretation of study data, given that many studies do not differentiate between newly infected patients and those with infections that have persisted for a long time. Similarly, most studies do not take location, size, and thickness of lesions into account, either. The objective of the present review article is to analyze the study data currently available, taking into consideration both subtypes and locations - factors exceedingly crucial in clinical practice. In particular, the distinction between new-onset and chronic recalcitrant warts is reflected in a therapeutic algorithm. In the case of genital warts, the algorithm is more clearly determined by the extent of the area affected rather than the longevity of lesions. In immunocompetent individuals, any therapeutic intervention must be aimed at achieving complete resolution.

Treatment of warts and molluscum: what does the evidence show?

PURPOSE OF REVIEW

Warts and molluscum contagiosum are very common viral skin infections, usually presenting in childhood. Despite the large number of people affected by them, high-quality trials of treatment are few and treatment is often chosen on the basis of cost, convenience and tradition.

RECENT FINDINGS

Over recent years, two further trials of the most commonly used treatments for warts, salicylic acid and cryotherapy, have been performed and for molluscum contagiosum, there is growing evidence for the use of irritants. For both infections, there are new evaluations of immunological approaches to therapy.

SUMMARY

Strong, high-quality evidence for treatments used very frequently for warts or molluscum is still lacking, but recent publications have helped to strengthen or weaken belief in commonly used therapies and to add weight to the immunological approach to management.

Photodynamic therapy for onychomycosis: A systematic review

Other than a cosmetic concern, Onychomycosis is also a prevalent nail disease, which is extremely difficult to treat, and sometimes is refractory to conventional therapy. Moreover, many patients are not eligible to take oral antifungals owing to polypharmacy and comorbidities. Systemic side effects seen with oral antifungals have lead to patient nonadherence and adverse events. Therefore, newer therapies are being investigated for onychomycosis that would be free of systemic complications posed by oral therapy. Photodynamic therapy (PDT) is one of those being currently studied, which involves the use of photosensitizer and a light source to excite the photosensitizer to generate reactive oxygen species. The present review will put some light on PDT as an upcoming treatment modality for onychomycosis. We performed a systematic review of the literature to find the articles relevant to the use of PDT for onychomycosis. From the primary search of 43 articles, 17 papers are included in this review.

Off-label photodynamic therapy for recalcitrant facial flat warts using topical 5-aminolevulinic acid

The facial flat wart (verruca plana) is one of the most common reasons for dermatology and primary care visits. Although there are many therapeutic modalities, no single therapy has been proven to be completely curative. Case reports and uncontrolled studies suggested that photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) can effectively treat recalcitrant facial flat warts. A total of 12 patients with recalcitrant facial flat warts were enrolled in the study. ALA gel (10 %) was applied topically to lesions and incubated for 3 h. The lesions were irradiated by an LED light of 630 ± 10 nm at dose levels of 60-100 mW/cm. Clinical assessment was conducted before and after every treatment for up to 24 weeks. Among the ten patients completing three sessions of ALA-PDT, five had complete lesions clearance, and the other five patients were significantly improved. At the 24-week follow-up, the average effective rate was 88.8 %, with no recurrences. No significant side effects were reported. A low-dose topical ALA-PDT regimen using 10 % ALA, 3 h incubation, and a red light source for three treatment sessions are suggested as the optimal scheme for the treatment of recalcitrant flat warts on the face in Chinese patients. Superior efficacy is found in elevated or active period lesions with mild side effects.

[Photodynamic therapy in dermatology, other indications and perspectives]

PDT licensed indications in dermatology are actinic keratosis, Bowen's disease and superficial basal cell carcinomas. Skin tumors are sensitized by methyl aminomevulinate then illuminated with red light. Beyond these indication PDT is now widely used for the treatment of various others skin tumors and infectious or inflammatory skin disorders. PDT treatment of large areas can induce intense pain. Optimising PDT treatment needs to optimize pain control. Freezing or cooling procedure is the best way to decrease pain. The most interesting aspects of PDT is the absence of severe delayed adverse events and an optimal healing.

Topical treatments for cutaneous warts

BACKGROUND

Viral warts are a common skin condition, which can range in severity from a minor nuisance that resolve spontaneously to a troublesome, chronic condition. Many different topical treatments are available.

OBJECTIVES

To evaluate the efficacy of local treatments for cutaneous non-genital warts in healthy, immunocompetent adults and children.

SEARCH METHODS

We updated our searches of the following databases to May 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), AMED (from 1985), LILACS (from 1982), and CINAHL (from 1981). We searched reference lists of articles and online trials registries for ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of topical treatments for cutaneous non-genital warts.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and extracted data; a third author resolved any disagreements.

MAIN RESULTS

We included 85 trials involving a total of 8815 randomised participants (26 new studies were included in this update). There was a wide range of different treatments and a variety of trial designs. Many of the studies were judged to be at high risk of bias in one or more areas of trial design.Trials of salicylic acid (SA) versus placebo showed that the former significantly increased the chance of clearance of warts at all sites (RR (risk ratio) 1.56, 95% CI (confidence interval) 1.20 to 2.03). Subgroup analysis for different sites, hands (RR 2.67, 95% CI 1.43 to 5.01) and feet (RR 1.29, 95% CI 1.07 to 1.55), suggested it might be more effective for hands than feet.A meta-analysis of cryotherapy versus placebo for warts at all sites favoured neither intervention nor control (RR 1.45, 95% CI 0.65 to 3.23). Subgroup analysis for different sites, hands (RR 2.63, 95% CI 0.43 to 15.94) and feet (RR 0.90, 95% CI 0.26 to 3.07), again suggested better outcomes for hands than feet. One trial showed cryotherapy to be better than both placebo and SA, but only for hand warts.There was no significant difference in cure rates between cryotherapy at 2-, 3-, and 4-weekly intervals.Aggressive cryotherapy appeared more effective than gentle cryotherapy (RR 1.90, 95% CI 1.15 to 3.15), but with increased adverse effects.Meta-analysis did not demonstrate a significant difference in effectiveness between cryotherapy and SA at all sites (RR 1.23, 95% CI 0.88 to 1.71) or in subgroup analyses for hands and feet.Two trials with 328 participants showed that SA and cryotherapy combined appeared more effective than SA alone (RR 1.24, 95% CI 1.07 to 1.43).The benefit of intralesional bleomycin remains uncertain as the evidence was inconsistent. The most informative trial with 31 participants showed no significant difference in cure rate between bleomycin and saline injections (RR 1.28, 95% CI 0.92 to 1.78).Dinitrochlorobenzene was more than twice as effective as placebo in 2 trials with 80 participants (RR 2.12, 95% CI 1.38 to 3.26).Two trials of clear duct tape with 193 participants demonstrated no advantage over placebo (RR 1.43, 95% CI 0.51 to 4.05).We could not combine data from trials of the following treatments: intralesional 5-fluorouracil, topical zinc, silver nitrate (which demonstrated possible beneficial effects), topical 5-fluorouracil, pulsed dye laser, photodynamic therapy, 80% phenol, 5% imiquimod cream, intralesional antigen, and topical alpha-lactalbumin-oleic acid (which showed no advantage over placebo).We did not identify any RCTs that evaluated surgery (curettage, excision), formaldehyde, podophyllotoxin, cantharidin, diphencyprone, or squaric acid dibutylester.

AUTHORS' CONCLUSIONS

Data from two new trials comparing SA and cryotherapy have allowed a better appraisal of their effectiveness. The evidence remains more consistent for SA, but only shows a modest therapeutic effect. Overall, trials comparing cryotherapy with placebo showed no significant difference in effectiveness, but the same was also true for trials comparing cryotherapy with SA. Only one trial showed cryotherapy to be better than both SA and placebo, and this was only for hand warts. Adverse effects, such as pain, blistering, and scarring, were not consistently reported but are probably more common with cryotherapy.None of the other reviewed treatments appeared safer or more effective than SA and cryotherapy. Two trials of clear duct tape demonstrated no advantage over placebo. Dinitrochlorobenzene (and possibly other similar contact sensitisers) may be useful for the treatment of refractory warts.

Liposomes in topical photodynamic therapy

INTRODUCTION

Topical photodynamic therapy (PDT) refers to topical application of a photosensitizer onto the site of skin disease which is followed by illumination and results in death of selected cells. The main problem in topical PDT is insufficient penetration of the photosensitizer into the skin, which limits its use to superficial skin lesions. In order to overcome this problem, recent studies tested liposomes as delivery systems for photosensitizers.

AREAS COVERED

This paper reviews the use of different types of liposomes for encapsulating photosensitizers for topical PDT. Liposomes should enhance the photosensitizers' penetration into the skin, while decreasing its absorption into systemic circulation. Only few photosensitizers have currently been encapsulated in liposomes for topical PDT: 5-aminolevulinic acid (5-ALA), temoporfin (mTHPC) and methylene blue.

EXPERT OPINION

Investigated liposomes enhanced the skin penetration of 5-ALA and mTHPC, reduced their systemic absorption and reduced their cytotoxicity compared with free drugs. Their high tissue penetration should enable the treatment of deep and hyperkeratotic skin lesions, which is the main goal of using liposomes. However, liposomes still do not attract enough attention as drug carriers in topical PDT. In vivo studies of their therapeutic effectiveness are needed in order to obtain enough evidence for their potential clinical use as carriers for photosensitizers in topical PDT.

Treatment of cutaneous warts: an evidence-based review

Cutaneous warts are common skin lesions caused by human papillomavirus infection. Treatment is aimed at relieving the patient's physical and psychological discomfort and at preventing the spread of infection by autoinoculation. Among the available medical and destructive therapeutic options for cutaneous warts, none is uniformly effective or virucidal. Moreover, in most cases their safety and efficacy has not been assessed in double-blind, controlled clinical trials, so that the reproducibility of many of the listed treatments is difficult to evaluate and a possible placebo effect cannot be ruled out. The aim of this article is to describe the outcome of current therapies for each clinical wart type according to evidence-based medicine studies published in the literature. For each clinical form, the existing treatments are classified as first-, second-, and third-line therapy. First-line therapy includes medical treatments (salicylic acid, silver nitrate, glutaraldehyde) that are useful to treat a single wart or a few and/or small common warts of short duration (less than 1 year). If these treatments have failed or are contraindicated, cryotherapy may be considered as second-line therapy. For recurrent or difficult-to-treat lesions, third-line therapy includes a variety of alternative therapeutic options (topical, intralesional, systemic, and physical destruction) that are generally off-label (not US FDA approved), and whose use is limited by drawbacks or adverse effects. From pooled evidence-based medicine data, it is possible to conclude that significantly higher remission rates may be expected only with cryotherapy and salicylic acid used in combination.

Photodynamic therapy can improve warts' discomfort in renal transplant patients prospective multicenter study

Many studies have been conducted showing that aminolevulinic acid (ALA)-photodynamic therapy (PDT) can be an alternative treatment for recalcitrant warts. Recently, we performed a study evaluating methyl-aminolevulinic acid (MAL)-PDT for the treatment of hand warts in a population of renal transplant patients. Two symmetrical targets were selected on each hand and randomly assigned to chemical keratolytic treatment followed by three cycles of ALA-PDT (75 J cm(-2) red light). Patients were evaluated after 3 months and a second run of PDT was performed if the total area and number of warts decreased less than 50%, with evaluation every 3 months for 1 year. Twenty patients were included and 16 were evaluable (9 M, 7 F). After 6 months the reduction of warts' area was 48.4% on the treated side versus 18.4% in the control area (P = 0.021). The decrease in the total number of warts was 41%versus 19.4% (P = NS). The global tolerance of the treatment was good with acceptable pain during irradiation. These results suggest that ALA-PDT is a safe and efficient treatment for transplanted patient warts. The improvement between treated and control zone is 20% due to the decrease in untreated warts' area and number.

Photodynamic therapy based on 5-aminolevulinic acid and its use as an antimicrobial agent

Exogenous 5-aminolevulinic acid (ALA) is taken up directly by bacteria, yeasts, fungi, and some parasites, which then induces the accumulation of protoporphyrin IX (PPIX). Subsequent light irradiation of PPIX leads to the inactivation of these organisms via photodamage to their cellular structures. ALA uptake and light irradiation of PPIX produced by host cells leads to the inactivation of other parasites, along with some viruses, via the induction of an immune response. ALA-mediated PPIX production by host cells and light irradiation result in the inactivation of other viruses via either the induction of a host cell response or direct photodynamic attack on viral particles. This ALA-mediated production of light-activated PPIX has been extensively used as a form of photodynamic therapy (PDT) and has shown varying levels of efficacy in treating conditions that are associated with microbial infection, ranging from acne and verrucae to leishmaniasis and onychomycosis. However, for the treatment of some of these conditions by ALA-based PDT, the role of an antimicrobial effect has been disputed and in general, the mechanisms by which the technique inactivates microbes are not well understood. In this study, we review current understanding of the antimicrobial mechanisms used by ALA-based PDT and its role in the treatment of microbial infections along with its potential medical and nonmedical applications.

Update: treatment of cutaneous viral warts in children

Warts remain one of the most common reasons for dermatology and primary care visits, yet no definitive therapy is available. Treatment of pediatric patients adds additional challenges, as the adept provider must effectively manage parents' expectations and patients' fears. This article provides an update on research in the field of viral cutaneous wart therapies with a focus on pediatric patients. Safety issues and potential complications of therapy are also addressed.

Efficiency of photodynamic therapy in the treatment of diffuse facial viral warts in an immunosuppressed patient: towards a gold standard?

A 64-year-old man with a pulmonary transplant developed diffuse verrucae vulgares of the neck. After the failure of multiple cryotherapy treatments, 3 sessions of photodynamic therapy resulted in rapid therapeutic clinical success. This moderately painful and well-tolerated treatment is reproducible and can be very useful in treating papillomavirus infections in the immunosuppressed patient.

Detection and photodynamic therapy of inflamed atherosclerotic plaques in the carotid artery of rabbits

Photodynamic therapy (PDT) has been applied in the treatment of artery restenosis following balloon injury. This study aimed to detect the accumulation of 5-aminolevulinic acid (ALA)-derived protoporphyrin IX (PpIX) in inflamed atherosclerotic plaque in rabbit model and evaluate the efficacy of PDT. The inflamed atherosclerotic plaque in the common carotid artery was produced by combination of balloon denudation injury and high cholesterol diet. After intravenous administration of ALA, the fluorescence of PpIX in plaque was detected. At the peak time, the correlation between the fluorescence intensity of PpIX and the macrophage infiltration extent in plaque was analyzed. Subsequently, PDT (635nm at 50J/cm(2)) on the atherosclerotic plaques (n=48) was performed and its effect was evaluated by histopathology and immunohistochemistry. The fluorescence intensity of PpIX in the plaque reached the peak 2h after injection and was 12 times stronger than that of adjacent normal vessel segment, and has a positive correlation with the macrophage content (r=0.794, P<0.001). Compared with the control group, the plaque area was reduced by 59% (P<0.001) at 4week after PDT, the plaque macrophage content decreased by 56% at 1week and 64% at 4week respectively, the smooth muscle cells (SMCs) was depleted by 24% at 1week (P<0.05) and collagen content increased by 44% at 4week (P<0.05). It should be pointed out that the SMC content increased by 18% after PDT at 4week compared with that at 1week (P<0.05). Our study demonstrated that the ALA-derived PpIX can be detected to reflect the macrophage content in the plaque. ALA mediated PDT could reduce macrophage content and inhibit plaque progression, indicating a promising approach to treat inflamed atherosclerotic plaques.

Terapia fotodinâmica em dermatologia: princípios básicos e aplicações

A terapia fotodinâmica envolve a administração de uma droga fotossensibilizante e sua ativação subsequente pela luz de comprimento de onda correspondente ao espectro de absorção do fotossensibilizador. Atualmente, a terapia fotodinâmica tópica é aprovada para o tratamento de condições oncológicas cutâneas como queratoses actínicas, doença de Bowen e carcinoma basocelular superficial em diversos países do mundo. Estudos multicêntricos controlados e randomizados demonstram a alta eficácia e resultado cosmético final superior dessa modalidade terapêutica em relação aos tratamentos convencionais. Para condições cutâneas não oncológicas, como acne vulgar, verrugas virais e esclerodermia localizada, há também relatos e série de casos confirmando o potencial terapêutico da terapia fotodinâmica. O desenvolvimento de fotossensibilizantes tópicos, ácido 5-aminolevulínico (ALA) ou seu metiléster (MAL), frente aos derivados da hematoporfirina de aplicação sistêmica, permitiu um grande avanço na popularidade da TFD na dermatologia, uma vez que tanto ALA quanto MAL tópicos não induzem mais fotossensibilidade generalizada prolongada. A produção de intermediários reativos de oxigênio, como oxigênio singlet, depende da concentração, da localização do fotossensibilizante no tecido alvo, assim como da dose de luz utilizada. Tanto as lâmpadas de amplo espectro quanto os LEDs (do inglês light emitting diodes) constituem fontes de luz adequadas para que os efeitos citotóxicos da terapia fotodinâmica resultem na destruição do tumor ou seus efeitos imunomodulatórios atuem melhorando as condições inflamatórias cutâneas.

Guidelines for topical photodynamic therapy: update

Multicentre randomized controlled studies now demonstrate high efficacy of topical photodynamic therapy (PDT) for actinic keratoses, Bowen's disease (BD) and superficial basal cell carcinoma (BCC), and efficacy in thin nodular BCC, while confirming the superiority of cosmetic outcome over standard therapies. Long-term follow-up studies are also now available, indicating that PDT has recurrence rates equivalent to other standard therapies in BD and superficial BCC, but with lower sustained efficacy than surgery in nodular BCC. In contrast, current evidence does not support the use of topical PDT for squamous cell carcinoma. PDT can reduce the number of new lesions developing in patients at high risk of skin cancer and may have a role as a preventive therapy. Case reports and small series attest to the potential of PDT in a wide range of inflammatory/infective dermatoses, although recent studies indicate insufficient evidence to support its use in psoriasis. There is an accumulating evidence base for the use of PDT in acne, while detailed study of an optimized protocol is still required. In addition to high-quality treatment site cosmesis, several studies observe improvements in aspects of photoageing. Management of treatment-related pain/discomfort is a challenge in a minority of patients, and the modality is otherwise well tolerated. Long-term studies provide reassurance over the safety of repeated use of PDT.

Successful treatment of periungual warts using photodynamic therapy: a pilot study

AIM

The aim of this pilot study was an investigation on photodynamic therapy (PDT) whether it is a good alternative for treating periungual and subungual warts of the hands.

STUDY DESIGN

Twenty patients (mean age: 30.5 years) with a total of 40 periungual and subungual warts were treated with PDT. A photosensitizer, 20%delta-aminolevulinic acid was applied on the warts. After a mean incubation time of 4.6 h (SD: 1.2), the warts were irradiated with the VersaLight for 5-30 min (15.2 +/- 4.3 min).

RESULTS

After a mean of 4.5 treatments a mean clearance of 100% was achieved in 90% of the patients. One patient (5%) showed a clearance of 50% and another showed no improvement. The subungual or periungual location of the wart had no influence on the number of treatments or end result (P > 0.05). There were two recurrences during the mean follow-up period of 5.9 months (SD: 7.6). Besides mainly pain and hyperpigmentation, most treatments had no side-effects.

CONCLUSION

PDT can offer a good alternative for treating periungual warts of the hands. Larger studies are indicated.

[Photodynamic therapy: non-oncologic indications]

While efficacy of topical photodynamic therapy (PDT) for the treatment of superficial non-melanoma skin cancer is already well-proven by several controlled clinical trials, there are only a few controlled studies showing efficacy of PDT for non-oncologic skin disorders. This report provides information on the use of PDT for inflammatory skin disorders, disorders of the pilosebaceous unit, infections of the skin, sclerotic skin diseases and cosmetic indications.