Novel immunomodulators for topical skin disease therapy

Serum Levels of Eosinophil-Derived Neurotoxin, Platelet-Activating Factor and Vascular Endothelial Growth Factor in Adult Patients with Atopic Dermatitis-A Pilot Study

Atopic dermatitis (AD) is a chronic, highly pruritic, relapsing-remitting inflammatory skin disease. The etiology of AD has not been fully explained yet and complex interactions of various small molecules are still being taken into account. The aim of this research was to investigate the serum eosinophil-derived neurotoxin (EDN), platelet activating factor (PAF) and vascular endothelial growth factor (VEGF) concentrations in relation to the disease severity and pruritus intensity in adult patients with AD. This pilot study was performed on 30 participants (15 patients with AD and 15 healthy controls). Blood samples were taken to examine the serum levels of EDN, PAF and VEGF using the enzyme-linked immunosorbent assay (ELISA) test. The severity of disease was assessed by the Scoring Atopic Dermatitis (SCORAD) index. The intensity of pruritus, as a subjective symptom, was determined by the Visual Analogue Scale (VAS). Obtained results revealed that the EDN (p = 0.016) and VEGF (p = 0.032), but not PAF (p = 0.841) concentrations were significantly higher in patients with AD compared with those of the control group. There was positive correlation between the EDN level and the SCORAD index in patients with AD (r = -0.9, p = 0.037) which was not found for the PAF and VEGF levels. Circulating EDN, PAF and VEGF levels were not significantly correlated with the severity of pruritus. Our results suggest that the END and VEGF serum levels are significantly increased in patients with AD compared to control group. Moreover, EDN might be useful to reflect the severity of symptoms.

Serum Levels of Vascular Endothelial Growth Factor, Platelet Activating Factor and Eosinophil-Derived Neurotoxin in Chronic Spontaneous Urticaria—A Pilot Study in Adult Patients

Chronic spontaneous urticaria (CSU) is a skin disease characterized by the presence of wheals, angioedema, or both for at least 6 weeks. Although, CSU is often regarded as autoimmune in nature, its etiology is not fully explained and interactions between various small molecules are still taken under account. The aim of this research was to investigate the mean serum concentration of vascular endothelial growth factor (VEGF), platelet activating factor (PAF), and eosinophil-derived neurotoxin (EDN) in relation to the disease activity and pruritus intensity in adult patients with CSU. Fifteen patients with CSU and 15 healthy subjects participated in this pilot study. Blood samples were taken to examine the mean serum levels of VEGF, PAF, and EDN by the enzyme-linked immunosorbent assay test (ELISA). The Urticaria Activity Score (UAS7) and The Visual Analogue Scale (VAS) were used to assess the disease activity and the pruritus intensity, respectively. Obtained results revealed that VEGF, PAF, and EDN concentrations were higher in patients with CSU compared with those of the control group, but only for VEGF it was statistically significant (p = 0.008). However, levels of all investigated cytokines were not significantly correlated neither with the disease activity nor with the pruritus intensity. Our results showed higher serum levels of VEGF, PAF, and EDN among CSU patients which may highlight a functional role of these cytokines in the disease’s pathogenesis. In contrast, VEGF, PAF, or EDN might not be useful to reflect the severity of symptoms.

Biological drugs targeting the immune response in the therapy of psoriasis

Chronic plaque psoriasis affects more than 2% of world population, has a chronic recurrent behavior, gives a heavy burden to the patients’ quality of life, and hence remains a huge medical and social problem. The clinical results of conventional therapies of psoriasis are not satisfactory. According to the current knowledge of the molecular and cellular basis of psoriasis, it is defined as an immune-mediated chronic inflammatory and hyperproliferative skin disease. A new generation of biological drugs, targeting molecules and cells involved into perturbed pro-inflammatory immune response in the psoriatic skin and joints, has been recently designed and applied clinically. These biological agents are bioengineered proteins such as chimeric and humanized antibodies and fusion proteins. In particular, they comprise the antitumor necrosis factor-α agents etanercept, infliximab, and adalimumab, with clinical efficacy in both moderate-severe psoriasis and psoriatic arthritis, and the anti-CD11a efalizumab with selective therapeutic action exclusively in the skin. Here, we overview recent findings on the molecular pathways relevant to the inflammatory response in psoriasis and present our clinical experience with the drugs currently employed in the dermatologic manifestations, namely etanercept, infliximab, and efalizumab. The growing body of clinical data on the efficacy and safety of antipsoriasis biological drugs is reviewed as well. Particular focus is given to long-term safety concerns and feasibility of combined therapeutic protocols to ameliorate clinical results.

Sister chromatid exchange analysis in patients with psoriasis

Psoriasis is a common, chronic inflammatory skin disease with unknown aetiology. An increased reactive oxygen species (ROS) and insufficient antioxidant activity have been determined in psoriatic lesions. The analysis of sister chromatid exchange (SCE) is a cytogenetic technique used to show DNA damage caused by an exchange of DNA fragments between sister chromatids. The study aimed to determine the rates of SCE in psoriatic patients (17 female and 19 male) and healthy controls (15 female and 15 male) as well as superoxide dismutase (SOD), glutathione peroxidase (GP) and catalase (CAT) activity in both groups. We found significantly higher SCE rates in the patients (P < 0.00001). In addition, statistically significant decreased levels of erythrocyte SOD and CAT activities were noted in the patients(P < 0.001 and P < 0.05 respectively). Furthermore, a statistically significant increased erythrocyte GP activity was found in the psoriasis group (P < 0.05). Our results indicate that chromosomal instability may play an important part in the aetiology of psoriasis. In addition, the results support the hypothesis of an imbalance in the oxidant-antioxidant system in psoriasis.

Effects of a mixture of fatty acids from sugar cane (Saccharum officinarum L.) wax oil in two models of inflammation: zymosan-induced arthritis and mice tail test of psoriasis

A mixture of fatty acids obtained from sugar cane (Saccharum officinarum L.) wax oil (FAM), in which the main constituents are palmitic, oleic, linoleic, and linolenic acids, was evaluated in two models of inflammation: zymosan-induced arthritis and in the tail test for psoriasis, both on mice. In the first model, FAM significantly reduced zymozan-induced increase of beta glucuronidase (DE(50) 90+/-7 mg/kg). Histopathological studies showed inhibition in cellular infiltration and reduction of synovial hyperplasia and synovitis, whereas in the second test, histopathological and ultrastructural studies showed that topical application of FAM induced orthokeratosis with the presence of keratohyalin granules in the previously parakeratotic adult mouse tail, and without effects on epidermal thickness. The ED(50) of FAM in this model was 155+/-10 mg. The results of our studies showed that topical application of FAM exerts an important anti-inflammatory activity in both tests without evidence of irritant effects. The anti-inflamatory effects exerted by FAM may be due to its inhibitory effects on arachidonic acid metabolism. To our knowledge, this is the first report on the anti-inflammatory effect of sugar cane by-products in experimental models of arthritis and psoriasis.

Topical pimecrolimus: a review of its clinical potential in the management of atopic dermatitis

Pimecrolimus (SDZ ASM 981), an ascomycin derivative, is a nonsteroid, has anti-inflammatory activity, and has demonstrated efficacy in reducing symptoms of atopic dermatitis in adult and paediatric patients when applied topically. Compared with vehicle, topical pimecrolimus 1.0% cream was significantly more effective at reducing symptoms of atopic dermatitis, as measured by the Eczema Area and Severity Index (EASI), in infants aged 3 to 23 months, children aged 2 to 17 years and adults. The median reductions from baseline in the total EASI score in adults after treatment with pimecrolimus 1.0% or corresponding vehicle twice daily for 3 weeks were 47 and 0%, respectively. In infants and children, treatment with pimecrolimus 1.0% twice daily for 6 weeks resulted in significant decreases in mean EASI scores compared with vehicle. The severity of pruritus was significantly reduced in patients of all age groups after topical treatment with pimecrolimus 1.0% cream. Compared with vehicle, the incidence of eczematous flares was also reduced by intermittent long-term use of topical pimecrolimus 1.0% in adults, children and infants. Sixty percent of children treated with pimecrolimus for 1 year completed the first 6 months of treatment without experiencing a flare, compared with 35% of patients who received vehicle. Furthermore, the use of topical corticosteroids for the treatment of uncontrolled flares in adults, children and infants was lower in the pimecrolimus groups than in the vehicle groups. Topical pimecrolimus 1.0% cream is well tolerated in atopic dermatitis patients of all age groups. There were no clinically relevant systemic adverse events reported from any of the studies in patients with atopic dermatitis. The most frequently reported adverse events pertained to application site reactions, such as burning and a feeling of warmth. In conclusion, topical pimecrolimus 1.0% cream has shown efficacy in the treatment of mild to moderate atopic dermatitis in infants, children and adults. Although tolerability data concerning infants and children have not yet been published in full, the drug appears to be well tolerated in all age groups, and there have been no reports of clinically relevant systemic adverse events. Furthermore, pimecrolimus 1.0% cream has shown no potential for skin atrophy, a problem commonly associated with treatment with topical corticosteroids. Pimecrolimus 1.0% cream provides a promising and well tolerated treatment option in the management of infants, children and adults with mild to moderate atopic dermatitis.

Tacrolimus ointment. A review of its therapeutic potential as a topical therapy in atopic dermatitis

Tacrolimus, a macrolide immunomodulator, is believed to control atopic dermatitis by inhibiting T lymphocyte activation, altering cell surface expression on antigen-presenting dendritic cells and modulating the release of inflammatory mediators from skin mast cells and basophils. Tacrolimus ointment penetrates human skin with no systemic accumulation after repeated applications; systemic absorption is generally low, with most patients in clinical trials having blood concentrations of the drug below the limit of quantification. Moderate to severe atopic dermatitis significantly improved (measured using multiple end-points, including > or = 90% improvement in Physician's Global Evaluation of Clinical Response) with tacrolimus 0.03 and 0.1% ointment compared with vehicle in both adult (n = 304 and 328) and pediatric (n = 351) patients in three 12-week, double-blind, randomized, phase III trials. In adults, tacrolimus ointment was effective therapy for the treatment of atopic dermatitis on all skin regions, including the head and neck. The 0.1% concentration was more effective than the 0.03% concentration. Clinical improvement in moderate to severe atopic dermatitis in adult (n = 316) or pediatric (n = 255) patients was seen as early as week 1, and improvement continued and/or was maintained for up to 6 and/or 12 months in long-term studies. The 0.1% formulation was also effective and well tolerated for up to 2 years. Tacrolimus 0.03 and 0.1% ointment was associated with significant quality-of-life benefit in adults, children (aged 5 to 15 years) and toddlers (aged 2 to 4 years) with atopic dermatitis in 12-week phase III trials (n = 985). Skin burning and pruritus were the most common application site adverse events in adult and pediatric patients in short-term and long-term trials. These events were generally of short duration and mild or moderate severity. Cutaneous infections occurred with a similar incidence after treatment with tacrolimus ointment to that seen after vehicle in short-term trials.

CONCLUSION

Both short- and long-term monotherapy with tacrolimus 0.03 and 0.1% ointment improves moderate to severe atopic dermatitis in adult and pediatric patients. Topical tacrolimus ointment is well tolerated, with the majority of adverse events being localized, transient in nature and of mild or moderate severity. Tacrolimus ointment provides a promising addition to the currently available treatments for atopic dermatitis; it can be used as a short- or long-term intermittent therapy for moderate to severe disease, including disease on the head or neck, in adult (0.1 and 0.03% formulations) and pediatric (0.03% formulation) patients who are not adequately responsive to or are intolerant of conventional treatments.

New approaches to topical therapy

Despite the rapid and proven efficacy of topical corticosteroids, side-effects can limit their clinical usefulness. Topically active macrolide immunosuppressants such as ascomycin and tacrolimus appear to provide comparable therapeutic potency without significant local or adverse effects. Data from ongoing studies will be crucial in determining the safety of these agents in the long term, and also their place within the current therapeutic armamentarium available for patients with atopic dermatitis. Enzyme inhibitors of PLA(2) and PDE 4 currently in the very early stages of clinical development also show potential promise as additional alternative strategies to topical treatment and may perhaps act as steroid sparing agents. Having been in the therapeutic doldrums for years, topical management of atopic dermatitis is likely to show great changes in the very near future.