The role of interleukins 1, 6 and 8 as lymphocyte attractants in the photodermatoses polymorphic light eruption and chronic actinic dermatitis

Association of polymorphous light eruption with NOD-2 and TLR-5 gene polymorphisms

BACKGROUND

Polymorphous light eruption (PLE) is a common, immunologically mediated, photosensitive skin disease. After ultraviolet-B (UV-B) irradiation, patients with PLE show reduced Langerhans cell (LC) depletion in the epidermis, which results in a non-suppressive microenvironment in the skin. Interestingly, severe acute graft-versus-host-disease (aGvHD) occurred in stem cell transplanted patients that showed no or incomplete depletion of LCs after UVB-irradiation. Genetic variation in nucleotide-binding oligomerization domain 2 (NOD-2) and toll-like receptor 5 (TLR-5) genes also confers susceptibility to aGvHD.

OBJECTIVES

We hypothesized that PLE is associated with genetic variation in the NOD-2 and TLR-5 genes.

METHODS

We investigated single nucleotid polymorphisms (SNPs) of NOD-2 (R702W, G908R, 3020Cins) and TLR-5 (A592S, P616L, N392STOP) in skin biopsies of PLE-patients (n=143) and in healthy controls (n=104) using restriction fragment-length polymorphism analysis.

RESULTS

The frequency of NOD-2 alleles with the SNP R702W was significantly higher in PLE than in controls (31.8% vs 6.3%; p<0.0001), and homozygous carriers of this mutation were more common in PLE (27.9% vs 0%; p<0.0001). For SNP 3020Cins, the allele frequency (7.3% vs 0.7%; p=0.0025) and the number of heterozygotes (14.7% vs 1.3%; p=0.0019) were higher in PLE. The frequency of alleles with the N392STOP SNP of the TLR5 gene, which is associated with a truncated, non-functional receptor, was significantly higher in PLE (21% vs 5%; 7% vs 1% homozygotes, 28% vs 8% heterozygotes; p<0.0001). The other SNPs did not differ significantly.

CONCLUSIONS

This study yielded a high frequency of functional SNPs in the NOD-2 and TLR-5 genes in PLE. The same SNPs are associated with aGvHD and there are similarities in the reaction of LCs after UVB-irradiation between aGvHD and PLE. This leads to the hypothesis that PLE-patients may be more susceptible to developing GvHD after stem-cell transplantation, an assumption that needs to be investigated further.

Ultraviolet a Radiation and The Need for Protection

Erythema is a readily visible, often painful, natural phenomenon indicative of prolonged cutaneous exposure to ultraviolet (UV) radiation in the UVB range. As a result, early sunscreens were designed to provide adequate protection from UVB radiation. However, the continuous rise in the melanoma incidence rate alludes to the existence of an established photocarcinogen from which we are not well protected. Recently, scientists have been evaluating the photodamaging effects caused by wavelengths other than UVB. They have presented evidence that suggests that UVA exposure poses a greater hazard than previously acknowledged. For this reason, more emphasis must be placed on the development of broad-spectrum sunscreens providing adequate UVA and UVB protection. Additionally, regular sunscreen application must be advocated, proactive sun-protective practices must be implemented, and greater public awareness of the harmful effects of UVA and UVB radiation must be improved on, with the hope of decreasing the rate of cutaneous malignant melanoma.

Purification, characterization and potent lung lesion activity of an L-amino acid oxidase from Agkistrodon blomhoffii ussurensis snake venom

L-amino acid oxidases (LAOs) are one of the major components of snake venoms, which possess numerous biological functions. However, little is known of the influence of LAOs on organ lesions. In the present study, a unique LAO from Agkistrodon blomhoffii ussurensis snake venom named ABU-LAO was purified by Heparin-Sepharose FF chromatography followed by an ion-exchange chromatography procedure. The purified ABU-LAO appears a dimer with a molecular mass of approximately 108.8kDa. Kinetics studies showed that ABU-LAO is very active towards its substrates L-Asn, L-Phe, L-Tyr, L-Leu, L-Ile and L-Trp. The most striking observation in the present study is that ABU-LAO causes severe pneumorrhagia, pulmonary interstitial edema, fusion of pulmonary alveoli, cardiac interstitial edema and bleeding when being intravenously injected into BALB/c mice. ABU-LAO also induces liver cell necrosis and release of cytokines including IL-6, IL-12 and IL-2 from highly purified human peripheral blood monocytes and T cells, respectively. In conclusion, ABU-LAO potently induces lesions in lungs and livers. The ability of ABU-LAO will contribute to the understanding of the pathogenesis of snakebite wound.

Lucite estivale bénigne : prévention par un topique associant des filtres anti-UVA et des antioxydants

BACKGROUND

In a recent randomized, double-blind, placebo-controlled clinical study, the efficacy of a combination consisting of 0.25% alpha-glucosyl-rutin, 1% vitamin E and a broad-spectrum, highly UVA-protective sunscreen (sun protector factor 15 - persistent pigmentation darkening 6) regarding prevention of polymorphous light eruption was well demonstrated. We evaluated this combination under real solar exposure conditions.

PATIENTS AND METHODS

Patients with three previous typical polymorphous light eruptions (including one in the last year) were included in an open prospective multicenter study. The preparation was applied every two hours after the first summer exposure. No topical or systemic treatments presumed to be effective against polymorphous light eruption were given concomitantly. Evaluation was performed after the summer by a dermatologist.

RESULTS

Two of the 54 patients dropped out of the study, one for an adverse effect (contact dermatitis). At the end of the study following application of the test preparation, no eruption was seen for 35 patients (67%), with minor eruption for 10 patients (19%) and an marked eruption for 7 patients (13%). Pruritus (present in all patients the year before) was not seen in 36 patients (69%), was considered bearable for 36 patients and unbearable for only 3 patients compared to 27 before inclusion. For the dermatologists, efficacy was excellent for 35 patients and good for 7 patients, giving global efficacy of around 80%, with inadequate results in 10% of cases (5 patients). Concerning protection against erythema, the test product reduced sunburn by 60% compared with the previous year.

DISCUSSION

Because of the high clinical efficacy of the product noted after UVA challenge tests and verified by this clinical study under actual conditions of exposure, it may be proposed as a new prophylactic treatment for polymorphous light eruption.

Polymorphous light eruption (PLE) and a new potent antioxidant and UVA-protective formulation as prophylaxis

BACKGROUND

Polymorphous light eruption (PLE) is the most common photodermatosis. While its etiology still remains elusive, pathogenesis seems to involve UVA-induced oxidative stress and subsequent deregulation of antioxidative immune responses. Only few and often ineffective prophylactic and therapeutic measures exist to date.

METHODS

In our randomized, double-blind, placebo-controlled clinical study, we compared the efficacy of a new topical formulation, consisting of 0.25%alpha-glucosylrutin (AGR) (a natural, modified flavonoid), 1% tocopheryl acetate (vitamin E) and a broad-spectrum, highly UVA-protective sunscreen (SPF 15) in a hydrodispersion gel vehicle, to a sunscreen-only gel and vehicle. Thirty patients with a history of PLE were pretreated with either the above formulation, a similar preparation (with the same concentration for vitamin E and AGR, but a different UV filter system), placebo or a SPF 15 sunscreen-only gel, 30 min prior to daily photoprovocation with UVA irradiations of 60-100 J/cm(2) to 5 x 5 cm(2) areas on the upper arms.

RESULTS

After 4 days, results revealed a statistically highly significant difference (P<0.001) between the antioxidant containing formulations and placebo, and sunscreen-only formulation, respectively, in experimentally eliciting PLE. While only one patient developed clinical signs of PLE with accompanying itch in the area treated with the new antioxidant UV-protective gel formulation, 62.1% of the placebo-treated areas and 41.3% of the sunscreen-only treated areas showed mild to moderate signs of PLE.

CONCLUSION

Combining a potent antioxidant with a broad-spectrum, highly UVA-protective sunscreen is far more effective in preventing PLE than sunscreen alone or placebo and should thus be employed as the prophylaxis of choice for PLE.

Benign summer light eruption and polymorphic light eruption: genetic and functional studies suggest that a revised nomenclature is required

New research indicates that polymorphic light eruption (PLE) is an autoimmune disease against an ultraviolet radiation-induced cutaneous antigen. PLE may even confer some protection against skin cancer later in life. This new information demands a reassessment of the precise nature and nomenclature of PLE. Benign summer light eruption (BSLE) (lucite estivale bénigne) is the name used in continental Europe, and particularly France, to describe a clinically short-lived, itchy, papular eruption particularly affecting young women after several hours of sunbathing at the beginning of summer or on sunny vacations. Clinically more prolonged forms of solar eruption, starting early in spring and persisting for long periods, have been known in France as polymorphic light eruption (PLE) (lucite polymorphe) ('European PLE'). Investigative studies, however, now suggest that BSLE and some cases of 'European PLE' are part of the same spectrum. In the Anglo-Saxon literature, they are lumped together as PLE ('Anglo-Saxon PLE'). The other cases of 'European PLE', which do not fall within the compass of 'Anglo-Saxon PLE', are, in the Anglo-Saxon literature, classified as either actinic prurigo (AP) (a genetically determined, prolonged, excoriated form of Anglo-Saxon PLE), or chronic actinic dermatitis (CAD) (a sunlight-induced eczema precisely resembling allergic contact dermatitis, apparently to an ultraviolet radiation-induced antigen). It is therefore proposed that: i. the European term BSLE be dropped and that these patients be reclassified within the spectrum of (Anglo-Saxon) PLE, ii. the European use of the term PLE ('European PLE') be discontinued, iii. those previously diagnosed as having 'European PLE' be reclassified as (Anglo-Saxon) PLE, AP or CAD, as appropriate. The benefits of such a change in nomenclature would be twofold, firstly a uniformity of terminology and secondly, and more importantly, terminology would then correlate better with our recently improved understanding of the pathogenesis of these disorders.

Antiglaucoma eye drop pulses--increased interleukin-6 secretion by Tenon's capsule fibroblast cultures

PURPOSE

Long-term antiglaucoma eye drop therapy prior to trabeculectomy is a risk factor for surgical failure resulting from Tenon's capsule fibrosis at the fistula site. The study tested the hypothesis that secretion of the proinflammatory cytokine interleukin (IL)-6 by wounded Tenon's capsule-fibroblasts is elevated by prior long-term antiglaucoma eye drop treatment.

METHODS

Fibroblast cultures were established from Tenon's capsule biopsies during trabeculectomy. Twice daily and for four and a half days, confluent secondary (2-4 passages) cultures were treated (30 minutes at 37 degrees C) with the following drugs (diluted at 1:400-1:100): 0.2% brimonidine-tartrate (Alphagan), 2.0% dorzolamide-HCl (Trusopt), 0.5% timolol-maleate (Timoptic), 2.0% dorzolamide-HCl/0.5% timolol-maleate (Cosopt), 2 and 4% pilocarpine-HCl (Akarpine and Pilocar), 0.005% latanoprost (Xalatan), placebos for Trusopt and Timoptic, and 0.01% benzalkonium chloride. Subsequently, cultures were wounded by removing cells grown on half of each culture dishes along with the medium and conditioned for 20 hours in serum-free growth medium, which was then collected for ELISA for IL-6 (and TNF-alpha and IL-1 beta). Cultures were grown for four additional days to show the maintenance of culture sterility.

RESULTS

Latanoprost, pilocarpine-HCl, and timolol-maleate increased IL-6 levels in the conditioned medium in a dilution factor-dependent manner (P < 0.05, ANOVA). IL-6 concentrations were increased most significantly by latanoprost and were (pg/ml; mean +/- SEM; N = 3 cultures) 186 +/- 37, 187 +/- 33, 295 +/- 46 and 336 +/- 76 in cultures treated at 1:400, 1:250, 1:150, and 1:100 dilutions, respectively, whereas those of six control cultures averaged 80 +/- 9. Benzalkonium chloride, brimonidine-tartrate, dorzolamide-HCl, Cosopt placebo, Timoptic placebo, and dorzolamide-HCl/timolol-maleate did not significantly elevate IL-6 concentrations. IL-1 beta and TNF-alpha were not detected in the medium of control cultures and those treated with pilocarpine (1:200).

CONCLUSIONS

The present study demonstrated for the first time that the level of IL-6 secretion by wounded Tenon's capsule fibroblast cell cultures was increased by repeat pulsing of these cultures with some, but not all, antiglaucoma eye drops prior to wounding.

Polymorphous light eruption

Polymorphous light eruption (PLE) is a common idiopathic photosensitivity disorder with an estimated prevalence of 10-20%. It is characterized by an intermittent skin reaction to ultraviolet (UV) radiation exposure, consisting of non-scarring pruritic erythematous papules, vesicles or plaques that develop on light-exposed skin. Despite the different morphology in different individuals, the eruption tends to have a monomorphous presentation in any single subject. The histopathological features of PLE are distinct and comprise a perivascular lymphocytic infiltrate in the dermis, subepidermal oedema and variable epidermal changes. The pathogenesis of PLE is not well known, but findings suggest that it is a delayed-type hypersensitivity reaction to one or more UV-modified cutaneous antigens. The principal action of PLE is mainly in the UVA region, although some subjects exhibit sensitivity to UVB alone or to both UVA and UVB radiation at the same time. Preventive measures in PLE include the regular use of photoprotective methods combined with graduated exposures to natural sunlight. The induction of immune tolerance by phototherapy and photochemotherapy are useful prophylactic methods in moderate to severe cases. The role of systemic agents in the management of PLE is under investigation. This article reviews the epidemiological, pathogenetic and clinical aspects of PLE and discusses recent advances in the diagnostic approach and management of this condition.

Antimalarials

Antimalarial medications have become the parenteral drugs of choice for treating the cutaneous manifestations of lupus erythematosus. The immune-modulating activity of these agents makes them useful in a variety of other dermatoses. With prudent dosage and monitoring, these agents can be used safely and effectively in the treatment and management of dermatologic disease.