Tape Stripping Technique Research Articles

Solid Lipid Nanoparticles of Serine Designed by Evaluating Affinity of Solid Lipids to Stratum Corneum for Enhanced Skin Hydration in Combination with Reed Root Extract

The study aimed to assess the skin hydrating effect of hydrogels containing serine‐loaded solid lipid nanoparticles (SLN) prepared with lipids having high affinity to the stratum corneum (SC) and polysaccharide‐rich reed (Phragmites communis) root extract (RRE). To select a lipid with high affinity to the SC, the interaction between the SC obtained by a tape stripping technique and three different lipids such as glycerol mono‐oleate (GMO), lauric acid (LA), and capric acid (CA) was examined by ATR‐FTIR. After choosing GMO as the lipid with the highest affinity to the SC, hydrogel formulations containing serine‐loaded GMO SLN and/or RRE were prepared, and their skin hydrating effect was evaluated after applying the hydrogels to the surface of human skin. The hydrogel containing serine‐loaded GMO SLN and RRE exhibited the greatest skin moisturizing effect, followed by the hydrogels with serine‐loaded GMO SLN, RRE, and blank hydrogel. The results implied that SLN prepared with GMO having high affinity to the SC could be used as an efficacious carrier of serine for the purpose of skin hydration, and synergistic skin hydrating effect could be achieved by different skin moisturizing mechanisms of the serine‐loaded SLN and RRE.

Topical bioavailability of diclofenac from locally-acting, dermatological formulations

Assessment of the bioavailability of topically applied drugs designed to act within or beneath the skin is a challenging objective. A number of different, but potentially complementary, techniques are under evaluation. The objective of this work was to evaluate in vitro skin penetration and stratum corneum tape-stripping in vivo as tools with which to measure topical diclofenac bioavailability from three approved and commercialized products (two gels and one solution). Drug uptake into, and its subsequent clearance from, the stratum corneum of human volunteers was used to estimate the input rate of diclofenac into the viable skin layers. This flux was compared to that measured across excised porcine skin in conventional diffusion cells. Both techniques clearly demonstrated (a) the superiority in terms of drug delivery from the solution, and (b) that the two gels performed similarly. There was qualitative and, importantly, quantitative agreement between the in vitro and in vivo measurements of drug flux into and beyond the viable skin. Evidence is therefore presented to support an in vivo − in vitro correlation between methods to assess topical drug bioavailability. The potential value of the stratum corneum tape-stripping technique to quantify drug delivery into (epi)dermal and subcutaneous tissue beneath the barrier is demonstrated.

Models of wound healing: an emphasis on clinical studies.

The healing of wounds has always provided challenges for the medical community whether chronic or acute. Understanding the processes which enable wounds to heal is primarily carried out by the use of models, in vitro, animal and human. It is generally accepted that the use of human models offers the best opportunity to understand the factors that influence wound healing as well as to evaluate efficacy of treatments applied to wounds. The objective of this article is to provide an overview of the different methodologies that are currently used to experimentally induce wounds of various depths in human volunteers and examines the information that may be gained from them. There is a number of human volunteer healing models available varying in their invasiveness to reflect the different possible depth levels of wounds. Currently available wound healing models include sequential tape stripping, suction blister, abrasion, laser, dermatome, and biopsy techniques. The various techniques can be utilized to induce wounds of variable depth, from removing solely the stratum corneum barrier, the epidermis to even split-thickness or full thickness wounds. Depending on the study objective, a number of models exist to study wound healing in humans. These models provide efficient and reliable results to evaluate treatment modalities.

The Effect of an Emollient Containing Urea, Ceramide NP, and Lactate on Skin Barrier Structure and Function in Older People with Dry Skin

Xerosis affects up to 75% of older people and develops as a result of a skin barrier defect. Emollients are widely used to treat xerosis; however, there is limited understanding of the differences between them and their effects on the skin barrier in older people. This study aimed to compare the effect of a commercially available emollient containing 5% urea, ceramide NP and lactate (test emollient) to an alternative emollient without these additives (control emollient) on the properties of the skin barrier in older people. Two cohorts of 21 volunteers aged >60 years with dry skin were recruited. The first applied the test emollient to one forearm and no treatment to the other for 28 days. The second compared the test emollient to the control emollient observing the same parameters. Effects on the skin barrier were determined by measuring skin barrier function, hydration, skin surface pH and by analysing Fourier transform infrared spectra before and after treatment. A third cohort of 6 young adults was recruited to investigate the effect of a single treatment with the test emollient on the molecular structure of the skin barrier at greater depths by employing the tape-stripping technique. The test emollient hydrated the skin to a significantly greater extent and for a longer period of time compared to the control emollient, an effect associated with a significant elevation of carboxylate groups (a marker of natural moisturizing factor content) within the stratum corneum. Furthermore, the test emollient imparted additional benefits to the structure and function of the skin barrier not exhibited by the control emollient. In conclusion, the test emollient addressed the pathological features of xerotic aged skin, supporting its use as first-line therapy for xerotic skin conditions in this population.

Clinical features, cytology and bacterial culture results in dogs with and without cheilitis and comparison of three sampling techniques.

Cheilitis is a common presentation in dogs associated with a variety of skin diseases and often complicated by microbial infections. To describe and compare clinical and cytological features and bacterial culture results from the lower lips of dogs with cheilitis (as compared to healthy controls), and to evaluate three cytology sampling techniques for their abilities to differentiate between the groups. Fifty six dogs with cheilitis and 54 controls. Anatomy and clinical signs of the lower lip were recorded. Cytology samples taken by tape strip, direct impression and swabs rolled over skin were scored semiquantitatively for microorganisms, inflammatory cells and keratinocytes. Cytology scores were correlated with semiquantitative bacterial culture scores. Pure breeds, frequency of lip folds and all cytology scores except keratinocytes were higher in dogs with cheilitis than in controls, but a substantial overlap was seen in all microorganisms between the groups. Hypersensitivity disorders were diagnosed in 40 of 56 dogs with cheilitis. The tape strip technique yielded the greatest differences between groups. Bacterial growth was reported in 100% of dogs with cheilitis and in 93% of the controls. Pathogens such as Staphylococcus pseudintermedius, Escherichia coli and Pseudomonas spp were found more frequently in dogs with cheilitis. Cytology and bacterial culture were poorly correlated. Cheilitis was associated with primary hypersensitivity disorders and the presence of a lip fold was a predisposing factor. Results of aerobic culture were similar to prior studies on pyoderma of other body sites, except for higher rates of Pseudomonas spp. isolation.

Colloidal nanocarriers for the enhanced cutaneous delivery of naftifine: characterization studies and in vitro and in vivo evaluations.

In topical administration of antifungals, the drugs should pass the stratum corneum to reach lower layers of the skin in effective concentrations. Thus, the formulation of antifungal agents into a suitable delivery system is important for the topical treatment of fungal infections. Nanosized colloidal carriers have gained great interest during the recent years to serve as efficient promoters of drug penetration into the skin. Microemulsions are soft colloidal nanosized drug carriers, which are thermodynamically stable and isotropic systems. They have been extensively explored for the enhancement of skin delivery of drugs. This study was carried out to exploit the feasibility of colloidal carriers as to improve skin transport of naftifine, which is an allylamine antifungal drug. The microemulsions were formulated by construction of pseudoternary phase diagrams and composed of oleic acid (oil phase), Kolliphor® EL or Kolliphor® RH40 (surfactant), Transcutol® (cosurfactant), and water (aqueous phase). The plain and drug-loaded microemulsions were characterized in terms of isotropy, particle size and size distribution, pH value, refractive index, viscosity, and conductivity. The in vitro skin uptake of naftifine from microemulsions was studied using tape stripping technique in pig skin. The drug penetrated significantly into stratum corneum from microemulsions compared to its marketed cream (P<0.05). Moreover, the microemulsion formulations led to highly significant amount of naftifine deposition in deeper layers of skin than that of commercial formulation (P<0.001). Microemulsion–skin interaction was confirmed by attenuated total reflectance – Fourier transformed infrared spectroscopy data, in vitro. The results of the in vivo tape stripping experiment showed similar trends as the in vitro skin penetration study. Topical application of the microemulsion on human forearms in vivo enhanced significantly the distribution and the amount of naftifine penetrated into the stratum corneum as compared to the marketed formulation (P<0.05). The relative safety of the microemulsion formulations was demonstrated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability test. This study indicated that the nanosized colloidal carriers developed could be considered as an effective and safe topical delivery system for naftifine.

Tape Stripping Technique for Stratum Corneum Protein Analysis.

The aim of this study was to investigate the amount of protein in stratum corneum in atopic dermatitis (AD) patients and healthy controls, using tape stripping technique. Furthermore, to compare two different methods for protein assessment. Tape stripping was performed in AD patients and healthy controls to collect stratum corneum samples and subsequently analysed with two different methods: Squame Scan, which gives an estimate of total protein (soluble and insoluble) and Micro BCA protein determination kit which measures soluble protein. Significant differences in cumulative protein content between AD lesional, AD non-lesional and healthy control skin was found using the Squame Scan as well as the Micro BCA protein determination kit. AD patients had significantly lower amount of protein, both total protein and soluble protein compared to healthy controls. Furthermore, soluble protein formed 82% of total protein in AD lesional skin, compared to 17–24% for AD non-lesional skin and healthy control. A decreasing amount of total protein with increasing stratum corneum depth was found for all skin types. Significant differences in stratum corneum protein content between AD lesional, AD non-lesional and healthy control skin were revealed, independent of method used.

Mast cell chymase in experimentally induced psoriasis.

Mast cell chymase can have a pro-inflammatory or an immunosuppressive function in psoriasis, but the outcome may depend on the level of chymase activity. Therefore, mast cells showing chymase activity (Chyact ) and immunoreactivity (Chyprot ) were studied during the Köbner reaction (0 days, 2 h, 1 day, 3 days and 7 days) of psoriasis induced by the tape-stripping technique. Also, the effect of recombinant human chymase (rh-chymase) or human LAD2 mast cells (LAD2) on the (3) H-thymidine uptake of psoriatic peripheral blood mononuclear cells (PBMC) or total T cells was studied. The Chyact /Chyprot ratio tended to be higher in all time-point biopsies in the Köbner-negative (n = 10) than -positive (n = 8) group (P = 0.073), although chymase activity decreased significantly at 2 h to 1 day only in the Köbner-negative group. rh-chymase (0.05-0.5 μg/mL) stimulated to a varying extent PBMC in eight out of nine cultures, but in all cultures 5 μg/mL rh-chymase turned the stimulation towards inhibition. The effect of rh-chymase on T cells varied from stimulation to inhibition, but in 11 of 15 cultures rh-chymase, at least at 5 μg/mL, produced a change to inhibition. In co-cultures, LAD2 inhibited PBMC in the absence of soybean trypsin inhibitor (SBTI). In the presence of SBTI, LAD2 stimulated PBMC in the majority of seven cultures. In summary, the psoriatic immunopathogenesis may be promoted at low, but controlled at high, activity status of chymase.

Elaboration of sponge-like particles for textile functionalization and skin penetration

The preparation and characterization of active-loaded microparticles for cosmetic textile applications were studied in this work. The double emulsion diffusion/evaporation technique was served and the Eudragit® RS100 (ethyl acrylate and methyl methacrylate copolymers) was used as biodegradable polymer. Two actives molecules, vitamin E and Lauryl isoquinolinium bromide (LIB) were successfully loaded during the formulation. Obtained particles were spherical in shape with a little variable diameter about 1 μm and zeta potential of 55 mV. The cutaneous penetration of the particles was evaluated by dermal microdialysis, tape stripping, and punch-biopsy techniques from ex vivo human skin. LIB or vitamin E concentrations in the different layers of the skin were analyzed by high-performance liquid chromatography method. Finally, these particles were adsorbed onto a textile in optimized conditions. The scanning electron microscopy is used to confirm the total threads coverage by particles.

Enhancement of in vivo human skin penetration of resveratrol by chitosan-coated lipid microparticles

In this study, lipid microparticles (LMs) uncoated or coated with chitosan, and containing the antioxidant polyphenol, resveratrol were developed in order to enhance its in vivo skin permeation. The LMs loaded with resveratrol were prepared by melt emulsification and sonication, using tristearin as lipidic material and hydrogenated phosphatidylcholine as the surfactant. Two different methods were examined for the coating of the LMs: chitosan addition during LM preparation or treatment of already formed LMs with a chitosan solution. The latter method achieved a better modulation of the in vitro release of resveratrol and hence was used for subsequent studies.The resveratrol loading and mean diameter of the LMs were 4.1±0.3% (w/w) and 5.7μm and 3.8±0.2 % (w/w) and 6.1μm for the uncoated and the chitosan-coated LMs, respectively. Chitosan coating changed the LM surface charge, from a negative zeta potential value (−17.8±4.8mV) for the uncoated particles, to a higher positive values (+64.2±4.4mV) for the chitosan-coated ones.Creams containing resveratrol free, encapsulated in the uncoated or chitosan-coated LMs were applied to the forearm of human volunteers and the penetration of the polyphenol in the stratum corneum was investigated in vivo by the tape stripping technique. Uncoated LMs did not produce any significant increase in the fraction of the applied resveratrol dose diffused in the stratum corneum (32.8±8.9 %) compared to the control cream containing the non-encapsulated polyphenol (26.2±5.6 % of the applied dose). On the other hand, application of the cream containing the chitosan-coated LMs produced a significant enhancement in the in vivo permeation of resveratrol to 49.3±5.9% of the applied dose, the effect being more marked in the upper region of the horny layer. The observed improvement in the human stratum corneum penetration of resveratrol achieved by the LMs coated with chitosan should favour the efficiency of its topical application.

Probing the effects of fish oil on the delivery and inflammation-inducing potential of imiquimod

Imiquimod is a chemotherapeutic agent for many skin-associated diseases, but it has also been associated with inflammatory side effects. The aim of this study was to prevent the inflammatory effect of commercial imiquimod (Aldara®) by controlled release of imiquimod through a hydrogel/oleogel colloidal mixture (CA bigel) containing fish oil as an anti-inflammatory agent. Imiquimod permeability from Aldara® cream and bigel through mice skin was evaluated, and the drug content residing in the skin via the tape stripping technique was quantified. The fish oil fatty acid content in skin along with its lipophilic environment was also determined. An inflammation study was conducted using animal models, and Aldara® cream was found to potentially cause psoriasis-like inflammation, which could be owing to prolonged application and excessive drug permeation. Controlled release of imiquimod along with fish oil through CA bigel may have caused reduced imiquimod inflammation. NMR studies and computerized molecular modeling were also conducted to observe whether the fish oil and imiquimod formed a complex that was responsible for improving imiquimod transport and reducing its side effects. NMR spectra showed dose-dependent chemical shifts and molecular modeling revealed π–σ interaction between EPA and imiquimod, which could help reduce imiquimod inflammation.

Effect of Prolactin-Induced Protein on Human Skin: New Insight into the Digestive Action of This Aspartic Peptidase on the Stratum Corneum and Its Induction of Keratinocyte Proliferation

Human prolactin-induced protein (PIP) is a major protein found in exocrine fluids such as saliva and sweat. Intriguingly, PIP possesses residues (human PIP (hPIP): PIP (29-63)) that display similarity to the aspartic peptidase candidapepsin. Here, we aimed to determine the effect of PIP as a protease on normal skin structure. Using an adhesive tape-stripping technique, we applied hPIP peptide on the corneocytes of normal-appearing facial skin from infants with eczema and healthy infants and then analyzed the morphological structure of corneocytes with Nile Red fluorescence. We also repeatedly applied the hPIP peptide onto the surface of a three-dimensional (3-D) human skin model and then analyzed any changes to the stratum corneum and epidermis using light microscopy and scanning electron microscopy. In both infant groups, a decrease in hydrophobic lipids from the cornified envelope was observed after treatment with hPIP. The peptide hPIP appeared to digest the fine structure of the stratum corneum and induce a proliferation of epidermal keratinocytes within the 3-D human skin model. Our results suggest that aspartic peptidase of PIP found in sweat or saliva deteriorates the skin barrier in a de novo manner, which potentially leads directly to the proliferation of epidermal keratinocytes without any external antigenic factors.

Serum microRNA Expression in Maternal Blood or in Cord Blood As Biomarkers of Atopic Dermatitis at One Year of Age

T U E S D A Y 852 Activity of Natural Moisturizing Factor Forming Enzyme Bleomycin Hydrolase in Atopic Dermatitis Affected By Disease Control Status and Seasonal Change Takeshi Chiba, MD; Division of Allergy, National Center for Child Health and Development, Tokyo, Japan. RATIONALE: Bleomycin hydrolase (BH) is thought to have an important physiological role by localizing at the stratum corneum (SC) in mammalian skin, and generating free amino acids from citrullinated peptides in the last step of filaggrin degradation pathway. In this study, we investigated whether disease activity and seasonal change affected BH activity. METHODS: We recruited 11 poorly controlled AD children (SCORAD>25), 51 well-controlled AD children (SCORAD<10) and 27 healthy volunteer children aged 15 or younger. SC samples were collected from the forearms in summer and winter using the tape-stripping technique. BH activity was measured using a fluorescent substrate, citrullinated aminomethylcoumarine as a substrate. RESULTS: BH activity was low in summer across all three groups. In winter, the activity elevated significantly in both the well-controlled AD and healthy groups, but not in the poorly controlledAD group. (summer vs. winter: well-controlled, 29620.3 pmol/mg/min vs. 174.26156.8 pmol/ mg/min, p<0.0001; poorly controlled, 24.0265.24 pmol/mg/min vs. 28.41610.4 pmol/mg/min, p50.252). In winter, BH activity of poorly controlled AD was significantly lower than that of well-controlled AD and healthy controls. (healthy vs. poorly controlled in winter: mean (SD), 76675.0 pmol/mg/min vs. 28610.9 pmol/mg/min, p50.013). CONCLUSIONS: BH activity is affected by seasonal change and disease control status. Regardless of the baseline severity of AD, the skin barrier can be recovered with improved BH activity as a result of appropriated treatment of AD.

Role of dermal exposure in systemic intake of methylenediphenyl diisocyanate (MDI) among construction and boat building workers

The causal relationship between inhalation exposure to methylenediphenyl diisocyanate (MDI) and the risk of occupational asthma is well known, but the role of dermal exposure and dermal uptake of MDI in this process is still unclear. The aims of this study were to measure dermal exposure to and the dermal uptake of MDI among workers (n=24) who regularly handle MDI-urethanes. Dermal exposure was measured by the tape-strip technique from four sites on the dominant hand and arm. The workers with the highest exposure (n=5) were biomonitored immediately after their work shift, in the evening and the next morning, using urinary 4,4´methylenedianiline (MDA) as a marker. Dermal uptake was evaluated by comparing workers' MDA excretions both when they were equipped with respiratory protective devices (RPDs) and when they did not use them. The measured amounts of MDI on their hands varied from below 0.1 to 17μg/10cm2 during the test. MDI concentrations were in the range of 0.08 to 27μgm-3 in the breathing zone outside the RPDs. MDA concentrations varied from 0.1 to 0.2μmolmol-1 creatinine during the test period. The decreasing effect of RPDs on inhalation exposure was absent in the next morning urine samples; this excretion pattern might be an indication of dermal uptake of MDI.

Proteome analysis of stratum corneum from atopic dermatitis patients by hybrid quadrupole-orbitrap mass spectrometer

Proteome analysis of stratum corneum from atopic dermatitis patients by hybrid quadrupole-orbitrap mass spectrometer

Skin permeation enhancement effects of the gel and whole-leaf materials of Aloe vera, Aloe marlothii and Aloe ferox.

The aim of this study was to investigate the in-vitro permeation enhancement effects of the gel and whole-leaf materials of Aloe vera, Aloe marlothii and Aloe ferox using ketoprofen as a marker compound. The permeation studies were conducted across excised female abdominal skin in Franz diffusion cells, and the delivery of ketoprofen into the stratum corneum-epidermis and epidermis-dermis layers of the skin was investigated using a tape-stripping technique. A. vera gel showed the highest permeation-enhancing effect on ketoprofen (enhancement ratio or ER = 2.551) when compared with the control group, followed by A. marlothii gel (ER = 1.590) and A. ferox whole-leaf material (ER = 1.520). Non-linear curve fitting calculations indicated that the drug permeation-enhancing effect of A. vera gel can be attributed to an increased partitioning of the drug into the skin, while A. ferox whole leaf modified the diffusion characteristics of the skin for ketoprofen. The tape stripping results indicated that A. marlothii whole leaf delivered the highest concentration of the ketoprofen into the different skin layers. Of the selected aloe species investigated, A. vera gel material showed the highest potential as transdermal drug penetration enhancer across human skin.

Anthocyanin-dependent anoxygenic photosynthesis in coloured flower petals?

Chlorophylless flower petals are known to be composed of non-photosynthetic tissues. Here, we show that the light energy storage that can be photoacoustically measured in flower petals of Petunia hybrida is approximately 10-12%. We found that the supposed chlorophylless photosynthesis is an anoxygenic, anthocyanin-dependent process occurring in blue flower petals (ADAPFP), accompanied by non-respiratory light-dependent oxygen uptake and a 1.5-fold photoinduced increase in ATP levels. Using a simple, adhesive tape stripping technique, we have obtained a backside image of an intact flower petal epidermis, revealing sword-shaped ingrowths connecting the cell wall and vacuole, which is of interest for the further study of possible vacuole-related photosynthesis. Approaches to the interpretations of ADAPFP are discussed, and we conclude that these results are not impossible in terms of the known photochemistry of anthocyanins.

Development of a prospective isopropyl alcohol-loaded pharmaceutical base using simultaneous in vitro/in vivo characterization methods of skin performance

Context: Approaching of pharmaceutical and cosmetic industries in some aspects inevitably influence formulation of topical pharmaceuticals, urging researchers to introduce novel excipients with proven benefits over traditional ones. In that context, alkyl polyglucosides (APG) emerge as prominent natural-origin emulsifiers with numerous favorable features (biodegradability, dermatological acceptability, desirable sensory properties).Objective: To evaluate APG-stabilized bases (alone and upon addition of isopropyl alcohol) and their impact on skin performance. A simultaneous in vitro/in vivo skin absorption study was conducted to evaluate whether the tape stripping technique could be recommended as an in vivo tool for skin penetration assessment during formulation optimization process.Materials and methods: After a comprehensive physicochemical characterization, biopharmaceutical properties of APG-bases versus reference ones were assessed through a combined in vitro (release/permeation) and in vivo approach.Results and discussion: Physicochemical characterization revealed substantial difference in structural ordering due to the formation of various mesomorphic phases. The enhancer-loaded APG base resulted in significantly higher drug levels at all depths into the stratum corneum, indicating that the selected enhancer along with specific colloidal structure has increased the extent of drug delivery.Conclusion: Results recommend the investigated emulsifier for stabilization of topical drug delivery systems, not only for their ability to sustain the addition of isopropyl alcohol which proved to be a valuable enhancer, but also satisfactory skin absorption and tolerability when compared to samples stabilized by conventional emulsifier. Tape stripping proved to be a useful and yet inexpensive tool for in vivo trials, able to discriminate subtle differences in dermal availability.

Dynamic observation of repigmentation in vitiligo lesions after narrow-band ultraviolet B phototherapy by using an adhesive tape stripping technique

Objective To observe the changes of melanin granules in superficial corneocytes in vitiligo lesions after irradiation with narrow-band ultraviolet B (NB-UVB) by using an adhesive tape stripping technique.Methods Vitiligo lesions were selected from 6 patients and irradiated with NB-UVB every other day for 31 sessions.Superficial corneocytes were obtained by an adhesive tape stripping technique from the vitiligo lesions and perilesional normal skin before every treatment.The morphology,distribution and color of melanin granules were observed after Masson-Fontana silver staining.The percentage of area occupied by melanin granules in superficial corneocytes were calculated by using the Image-Pro Plus 6.0 software.Statistical analysis was conducted by the SPSS11.5 software.Results There were still a few superficial corneocytes containing melanin granules remaining in the vitiligo lesions before treatment.The percentage of area occupied by melanin granules was (5.31 ± 4.12)％ before treatment,(6.24 ± 2.65)％ after 10 treatment sessions,(10.14 ± 5.73)％ after 20 sessions,and (13.05 ± 6.17)％ after 30 sessions,with significant differences between these time points (F =4.334,P ＜ 0.05).Multiple comparisons revealed a significant increase in the percentage of area occupied by melanin granules after 30 treatment sessions compared with those before treatment and after 10 treatment sessions (both P ＜ 0.01 ).The morphology and color of melanin granules in repigmented lesions after treatment differed from those in perilesional normal skin before treatment.Conclusion The adhesive tape stripping technique may serve as a useful tool for the evaluation of repigmentation in vitiligo lesions after phototherapy. Key words: Vitiligo; Ultraviolet therapy; Adhesive tape stripping technique; Melanocytes

Interleukin-8 Content in the Stratum Corneum as an Indicator of the Severity of Inflammation in the Lesions of Atopic Dermatitis

Background: Atopic dermatitis (AD) is an inflammatory skin disease characterized by both acute and chronic eczema. Various markers are used to clinically evaluate the severity of AD. In order to identify a marker of local severity of AD, we measured IL-8, IL-18, vascular endothelial growth factor (VEGF), and transforming growth factor-α (TGF-α) levels in the stratum corneum (scIL-8, scIL-18, scVEGF and scTGF-α) and evaluated the correlation between the levels of these cytokines and the clinical severity scores of localized skin lesions. Methods: Stratum corneum samples were collected from the skin lesions of 50 patients with AD using the tape-stripping technique, and the scIL-8, scIL-18, scVEGF and scTGF-α levels were evaluated using the ELISA method. The trans-epidermal water loss and skin water content of the lesions were also measured prior to tape stripping. Results: The levels of scIL-8, scIL-18, scVEGF and scTGF-α were significantly higher in patients with AD than in healthy controls. Additionally, the levels of scIL-8, scIL-18 and scVEGF significantly correlated with the severity of AD. Conclusions: Among these cytokines, scIL-8 showed the highest correlation with the severity scores of lesions in AD as well as other parameters. Our results also suggest that measuring cytokines in the stratum corneum by using ELISA combined with tape stripping is a convenient method to evaluate the severity of skin lesions in AD.