Increased urinary leukotriene E4 excretion in patients with atopic dermatitis

BACKGROUND: Synthesis of cysteinyl leukotrienes (LTs) is known to play a part in the pathogenesis of inflammatory diseases. OBJECTIVES: To define the involvement of cysteinyl LTs in atopic dermatitis (AD). METHODS: Synthesis of cysteinyl LTs was assessed in patients with AD and healthy volunteers by measuring urinary LTE4, a useful index of systemic cysteinyl LT synthesis, using liquid chromatography/tandem mass spectrometry. RESULTS: Mean +/- SD urinary LTE4 levels in patients with AD (125 +/- 69 pg mg(-1) creatinine, n = 20) were significantly higher (P < 0.01) than in healthy volunteers (60 +/- 19 pg mg(-1) creatinine, n = 17). A significant correlation between urinary LTE4 and total serum IgE levels in patients with AD was observed (r = 0.643, P < 0.05). CONCLUSIONS: Our findings demonstrate an enhanced synthesis of cysteinyl LTs in patients with AD and suggest that cysteinyl LTs are involved in the pathophysiology of AD.     

Enhanced synthesis of cysteinyl leukotrienes in psoriasis.

Cysteinyl leukotriene synthesis was investigated in patients with psoriasis. A non-invasive test requiring no stimulation was employed by measuring the major index metabolite of LTC4, which appears in urine. The presence of this metabolite, LTE4, was shown unequivocally by gas chromatography-mass spectrometry. Routinely LTE4 was quantitated by specific radio immunoassay after its isolation by reversed-phase high-performance liquid chromatography. Furthermore, in representative samples amounts of LTE4 obtained by radioimmunoassay were validated by gas chromatography-mass spectrometry. We demonstrate a significant (p less than 0.01) more than fourfold increase of urinary LTE4 in psoriasis compared to healthy volunteers. Urinary LTE4 was log normally distributed with geometric mean values (95% confidence intervals) of 11 (9-14) nmol LTE4/mol creatinine in healthy volunteers (n = 11) and 51 (28-95) nmol LTE4/mol creatinine in psoriasis (n = 9). The present study shows that cysteinyl leukotriene synthesis is enhanced in patients with psoriasis and that measurement of urinary LTE4 is a useful parameter to monitor its rate of synthesis.     

Sodium tetrachloropalladate (Na2[PdCl4]) as an improved test salt for palladium allergy patch testing

Background:  In the last decades, palladium is widely used in dentistry. Allergic reactions to palladium are rarely diagnosed with patch testing, even when positive results would be expected. Palladium tends to cross-react with nickel, which should give rise to more positive reactions to palladium dichloride (standard test salt).
Objective:  The aim of the study was to test whether or not mono-nuclear sodium tetrachloropalladate (Na₂[PdCl₄]) in petrolatum is a better test salt for diagnosing palladium allergy. Positive reactions to the investigated test salt are compared not only with PdCl_2(aq.), but also to NiSO_4(aq.) and NiSO_4(pet.).
Patients/Methods:  Concentration series of Na₂[PdCl₄] were carried out. 164 consecutive patients were patch tested.
Results:  3% of Na₂[PdCl₄]_(pet.) was found to be the highest non-irritative concentration. The results show ( n  = 164) that Na₂[PdCl₄] covers all reactions to PdCl₂ (1.8%) and provokes more positive reactions (14%). From the 164 patients, 18.3% reacted positively to at least 1 of the nickel salts.
Conclusion:  The sensitivity of patch testing with Na₂[PdCl₄] is increased compared with the PdCl₂ salt. Therefore, it can be concluded that Na₂[PdCl₄] is to be a better test salt for diagnosing palladium allergy with patch testing.     

Detection of leukotrienes in the serum of asthmatic and psoriatic patients

Purified serum samples from asthmatic and psoriatic patients and healthy controls were analysed by high-pressure liquid chromatography (HPLC) and the amounts of leukotrienes were measured from the corresponding HPLC fractions by specific radioimmunoassays. In the serum of healthy controls the amounts of leukotrienes B4, C4 and D4 were very small or negligible. Rather great amount of leukotriene B4 was, however, detected in the serum of many asthmatic and psoriatic patients. The amount of leukotriene B4 was in the serum of asthmatic patients 120 +/- 20 pmol/ml (n = 11, mean +/- SEM) and in that of psoriatic patients 100 +/- 10 pmol/ml (n = 10). The amounts of leukotrienes C4 and D4 were rather small in the serum of most patients. The amount of leukotriene C4 was, however, very high (250 pmol/ml) in the serum of a psoriatic patient. Significant amount of leukotriene D4 was also detected in the serum of this patient. The present study indicated that leukotrienes are formed during blood clotting in the leukocytes of asthmatic and psoriatic patients and that the rate of formation is so high that leukotrienes may have a role in these diseases.     

Fucosyltransferase VII-positive, skin-homing T cells in the blood and skin lesions of atopic dermatitis patients

Abstract: Patients with atopic dermatitis (AD) have an abnormally increased frequency of cutaneous lymphocyte antigen (CLA)⁺ Th2 cells responsible for local inflammation; however, this is paradoxical, given the well-recognized defective capacity of Th2 cells to migrate to the skin sites of inflammation. These discrepant observations would stem from the ambiguity of CLA⁺ T cells, because CLA does not represent the epitope required for binding to E-selectin but the epitope generated by fucosyltransferase VII (Fuc-TVII) and because skin-homing T cells are composed of three distinct subpopulations; Fuc-TVII⁺ E-selectin ligand (ESL)⁺ CLA⁻, Fuc-TVII⁺ ESL⁺ CLA⁺ and Fuc-TVII⁻ ESL⁻ CLA⁺ cells. We therefore asked which subpopulations of skin-homing Th2 cells could be increased in the blood and skin lesions of AD. We analysed the frequencies of the three subpopulations in purified CD4⁺ peripheral blood T cells from AD patients and healthy controls by immunohistochemistry and flow cytometry. The Fuc-TVII⁺ CLA⁺ or CLA⁺ ESL⁺ CCR4⁺ cells were dramatically increased in frequency not only in the blood but also in the skin lesions of AD patients and this increase was related to the severity of the clinical symptoms. Our data indicate the clinical importance of identifying skin-homing T cells with the potent capacity to migrate into the skin by analysing their Fuc-TVII expression and E-selectin binding ability in patients with AD.     

Allergy to phosphorus sesquisulfide: 0.5% pet. is a more appropriate concentration for patch testing

Patch testing was performed with phosphorus sesquisulfide P₄S₃ in 2 groups containing equal numbers of patients using different concentrations (0.5% P₄S₃ in pet. and 1% P₄S₃ in pet., the usual suggested test concentration as recommended by the International Contact Dermatitis Research Group). We found that there was a statistically significant increase in the number of clinically irrelevant irritant reactions in the group tested with the concentration (χ²= 16, P < 0.0004). We recommend that patch testing with phosphorous sesquisulfide should he at a reduced concentration of 0.5% pet.     

Allergenicity of rosin (colophony) esters

In the esterification of rosin with glycerol, the main compound formed, glyceryl triabietate, shows low allergenic activity. In this study, compounds formed in smaller amounts, when abietic acid (main component in rosin) was esterified with glycerol, were identified as glyceryl-1-monoabietate (GMA), glyceryl-1,2-diabietate (GDA_1,2) and glyceryl-1,3-diabietate (GDA_1,3), using nuclear magnetic resonance (NMR), infra-red (IR) and mass spectrometry (MS) analyses. According to animal experiments, GMA was a contact allergen. No cross-reactivity was seen to allergens in unmodified rosin. Some patients allergic to unmodified rosin reacted when tested with GMA. No reactions were seen to the 2 diabietates. Some patients also reacted to commercial glycerol-modified rosins. GMA together with unmodified abietic acid were identified in these rosin samples. The reactions seen in rosin-sensitive patients to commercial glycerol-esterified rosins probably derive from the unmodified material still present in the product, but could also be the result of GMA obtained from the glycerol derivatization.     

Erythema-multiforme-like, urticarial papular and plaque eruptions from bufexamac: report of 4 cases

8 nickel-sensitive subjects were given a gradually increasing daily oral intake of NiSO₄ in water. The exposure lasted from between 91 and 178 days and the total intake ranged from between 113 and 278 mg of Ni⁺⁺. While 6 subjects were continuously exposed over the entire period, the other 2 were exposed for 2 shorter periods with an interval between the 2 exposures of 84 and 63 days, respectively. Nickel exposure was well tolerated by all subjects, and there was no worsening of the cutaneous manifestations. Ni⁺⁺ serum and urine concentrations were repeatedly assayed. A reduction of intestinal adsorption and an activation of the renal excretion were shown through an evaluation of the ratios of Ni⁺⁺ serum concentration/Nr + cumulative oral intake, Ni⁺⁺ urinary amount/nickel cumulative oral intake and Ni⁺⁺ serum amount/Ni⁺⁺ urine amount, The course of Ni⁺⁺ faecal amounts, calculated indirectly, increased rapidly in time and was consistent with the other courses. In many subjects, the decrease in serum concentrations was followed by a slight increase. It is likely that this phenomenon is due to the release of epidermally stored nickel. These data seem to indicate that in some sensitive subjects, prolonged oral exposure to NiSO₄ in water reduces the intestinal adsorption of nickel and activates its renal excretion, also promoting the mobilization of accumulated element.     

A comparison of erythema efficacy of ultraviolet B irradiation from Philips TL12 and TL01 lamps

The erythema efficacy of UVB irradiation from Philips TL12 and TL01 lamps has been evaluated and compared. Thirty-seven healthy Thai volunteers were irradiated on the previously unexposed lower back with TL12 and TL01 lamps in doses ranging 100 to 550 mJ/cm² and 360 to 2020 mJ/cm², respectively. Erythema was evaluated clinically and measured by a narrow-band spectrophotometer before exposure and 24 h after exposure. The threshold doses of UVB that induced barely perceptible erythema (MED_b) with well-defined border erythema (MED_w) and the steepness of the dose-response curves for erythema (DRAE) were compared. We found that MED_b and MED_w of the TL01 lamps were 4.19 and 4.52 times those of TL12 lamps, which were similar to those calculated from the CIE erythema action spectrum (4.2). However, the DRAE of the two lamps were quite similar. Because the initial dosage of UVB phototherapy is usually given as a percentage of a patient's MED, the initial exposure of TL01-UVB phototherapy should be about 4.2 times that of TL12-UVB.     

Interaction of metals in nickel-sensitive patients

Nickel (Ni) dermatitis is, thought to involve the formation of complexes between Ni ions and suitable proteins. 4 groups of 30 subjects who gave positive patch test responses to NiSO₄ 2.9% aq. were each retested to 1 of 4 different solutions containing equimolar (0.1 M) amounts of NiSO₄ plus MgSO₄. NiSO₄ plus CuSO₄, NiSO₄plus ZnSO₄. and NiSO₄ plus Li₂SO₄, respectively. The results, evaluated at 2 days by visual scoring only, demonstrated that the 4 metals exerted a different influence on the nickel reactions, perhaps interfering with one or more factors affecting the formation of Ni++ complexes.     

Transcutaneous pO2 imaging during tourniquet-induced forearm ischemia using planar optical oxygen sensors

Background: Oxygen-dependent quenching of luminescence using transparent planar sensor foils was shown to overcome the limitations of the polarographic electrode technique in an animal model. This method was then transferred to a clinical setting to measure the transcutaneous pO₂ (p_tcO₂).
Methods: In six healthy subjects, a cuff on the upper arm was occluded up to 20 mmHg above systolic pressure and released after 8 min. P_tcO₂ was measured at the lower arm every 30 s before, during, and up to 20 min after cuff occlusion (40 °C applied skin temperature) using luminescence lifetime imaging (LLI) of platinum(II)-octaethyl-porphyrin immobilized in a polystyrene matrix. For validation, the polarographic Clark electrode technique was applied in close proximity, and measurements were conducted simultaneously.
Results: P_tcO₂ measurements before (70.8±19.1 vs. 66.2±7.7 mmHg) and at the end of ischemic (2.7±1.2 vs. 3.6±1.7 mmHg) and reperfusion phases (72.2±3.6 vs. 68.4±8.9 mmHg) did not differ significantly using the Clark electrode vs. LLI. At both the initial ischemic and the reperfusion phases, the Clark electrode measured a faster decrease or increase, respectively, in p_tcO₂ because of the oxygen consumption occurring in this method.
Conclusion: The presented method provides accurate and reproducible p_tcO₂ values under changing microcirculatory conditions. The lack of oxygen consumption during measurement allows both a more realistic estimation of p_tcO₂ than compared with the gold standard and permanent use in regions with critical oxygen supply.     

A case of contact dermatitis due to impurities of cetyl alcohol

A 29-year-old man being treated for itchy lesions on the amputation stump of the thigh became allergic to betamethasone valerate and gentamicin sulfate cream (Rinderon VG®. Closed patch tests with all the ingredients of the cream revealed positive reactions to cetyl alcohol 30% to 5% pet. Gas chromatographic analysis of the cetyl alcohol in the cream base detected stearyl alcohol (C₁₈), myristyl alcohol (C₁₄) and lauryl alcohol (C₁₂) in addition to the main component of cetyl alcohol (C₁₆). Patch testing with 99% pure analytical reagent grade saturated alcohols. (C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀) showed negative reactions. Thus, it is concluded that some minor impurities in cetyl alcohol not detected by gas chromatography might be the cause of this dermatitis.     

Leukotrienes orchestrating allergic skin inflammation

Leukotrienes constitute a group of lipid mediators, which may be subdivided into two groups, with leukotriene B₄ on the one hand and cysteinyl leukotrienes on the other. Although leukotrienes are abundantly expressed in skin affected by diverse chronic inflammatory diseases, including atopic dermatitis, psoriasis, pemphigus vulgaris and bullous pemphigoid, their pathological roles in these diseases have remained elusive. Recent data now reveal that both leukotriene B₄ and cysteinyl leukotrienes are indispensable in the pathogenesis of atopic dermatitis, with leukotriene B₄ initiating the recruitment of inflammatory cells, particularly neutrophils and T_H2 cells into the skin, and cysteinyl leukotrienes later inducing characteristic structural alterations of chronically affected skin, specifically skin fibrosis and keratinocyte proliferation. Thus, these results reveal a sequential cooperation of LTB₄ and cysteinyl leukotrienes to initiate and perpetuate allergic skin inflammation. These new insights highlight leukotrienes as promising therapeutic targets in allergic skin inflammation and should encourage more research into the role of leukotrienes in other inflammatory skin diseases.     

The role of psychological factors and serum zinc, folate and vitamin B12 levels in the aetiology of trichodynia: a case–control study

Background.  Cutaneous dysaesthesia syndromes are characterized by chronic cutaneous symptoms without objective findings, and their aetiologies are obscure. Trichodynia describes pain and a stinging sensation of the scalp related to diffuse alopecia.
Aims.  To determine the prevalence rate of trichodynia in patients with diffuse alopecia; to assess the serum zinc, folate and vitamin B₁₂ levels; and to investigate the significance of psychological disorders in these patients.
Methods.  The study comprised 91 patients with a diagnosis of diffuse hair loss and 74 healthy controls. Patients were questioned about the presence of trichodynia, and their serum zinc, folate and vitamin B₁₂ levels were assessed. They were also evaluated using the Beck Depression Inventory (BDI), the Beck Anxiety Inventory, and the Somatoform Dissociation Questionnaire (SDQ).
Results.  The rates of androgenetic alopecia and telogen effluvium were 26.4% and 73.6%, respectively, Trichodynia was found in 30 patients (33%), and was more common in the telogen effluvium group than in the androgenetic alopecia group ( P  = 0.5). There was no significant difference between the patients with alopecia and controls for zinc, folate and vitamin B₁₂ levels, or for psychological test scores. However, the BDI and SDQ scores were significantly higher ( P  = 0.03 and P  = 0.01, respectively) in patients with than those in without trichodynia.
Conclusions.  Trichodynia is a commonly encountered symptom in patients with diffuse alopecia, and depression and somatoform dissociation disorders may play an important role in its aetiology. Our data provide no evidence that serum levels of zinc, folate or vitamin B₁₂ are involved in the pathogenesis of trichodynia.     

Development of occupational skin diseases during vocational training in baker and confectioner apprentices: a follow-up study

Baker and confectioner apprentices have been included in a prospective follow-up study in the region of East Thuringia, to evaluate risk factors for the development of hand dermatitis. Starting in August 1996, the apprentices have been interviewed and examined in a standardized way right at the beginning ( n =91) of their vocational training, 6 ( n =79) and 12 months ( n =63) later. To gain objective data, TEWL score was also assessed at 3 standardized sites on the hands. In their case histories, 3.3% ( n =3) of the apprentices reported hand dermatitis. The 1st assessment after 2 to 4 weeks vocational training revealed hand eczema in 17.5% ( n =16) of the individuals. At the follow-up after 6 months of training 29.1% ( n =23), and after 12 month of training 27.0% ( n =17), of the apprentices had hand dermatitis of mild to moderate severity. Within 6 months, the TEWL score rose significantly ( p <0.001) from 11.9 g m⁻² h⁻¹ (± 5.4) to 16.8 g m⁻² h⁻¹ (± 9.5). After 12 months, the TEWL score was 14.9 g m⁻² h⁻¹ (± 4.6). For the atopic skin diathesis (> 10 points of Diepgen's atopy score), there was a significant tendency to be a predictive factor for the development of occupational hand dermatitis. TEWL score failed to correlate with the development of skin damage in our study. The same was true for respiratory atopy and metal sensitization.     

Allergen-sensitive atopic dermatitis is improved by injections of allergen combined with F(ab')2 fragments of specific antibodies

Summary Symptoms of atopic dermatitis (AD) can be provoked by exposure to airborne allergens. We have previously shown that patients hypersensitive to D. pteronyssinus (Dpt) allergens were improved by administration of complexes composed of specific antibodies and allergen, which reduce the allergen-specific immune response. We now report that similar results can be achieved by using F(ab')₂ fragments of specific antibodies instead of whole antibody molecules. Eight adult patients with severe AD were included in a single-blind study. During the first 11 months patients were maintained on injections of carrier buffer alone, in an effort to evaluate the extent of spontaneous improvement. They were then treated with intradermal injections of allergen-F(ab')₂ complexes made from autologous specific antibodies and Dpt allergens. The majority of the patients improved spontaneously during the summer months, with an average 30% reduction of symptoms. However, a much more pronounced improvement was observed after 3 months on active therapy, corresponding to a cumulative amount of 60 μg F(ab')₂ and 15 μg allergens. The patients continued to improve over the next 5 months, showing an average 83% reduction of severity scores. The use of F(ab')₂ antibody fragments reduces the risk of inducing an anti-allotypic immune response, and raises the possibility of adding adjuvants to allergen-antibody complexes and/or using specific antibodies isolated from pooled gammaglobulins.     

Induction of apoptosis by synthetic ceramide analogues in the human keratinocyte cell line HaCaT

Abstract: In contrast to extracellular, long chain ceramides which comprise a structural component of the epidermal water barrier, intracellular ceramides originating from sphingomyelin hydrolysis have been shown to inhibit proliferation and to induce apoptosis in different cell populations. To further elucidate the possible role of intracellular ceramides in human epidermis, two new cell-permeable ceramide analogues, N -thioacetylsphingosine (C₂-Cer=S) and 4-dodecanoylamino-decan-5-ol (FS-5), were synthesized and tested for their ability to suppress cell growth and to induce apoptosis in immortalized human keratinocytes. It was shown that the well-investigated ceramide analogue N -acetylsphingosine (C₂-Cer=O), as well as the new compound C₂-Cer=S inhibited proliferation of HaCaT cells with half-inhibitory concentrations (IC₅₀) of 20 μg/ml and 10 μg/ml, respectively, whereas FS-5 has been potent with an IC₅₀>40 μg/ml. Overall, all three ceramide analogues induced apoptosis in HaCaT cells as assessed by DNA-fragmentation using ELISA technique and in situ nick end labelling, thereby confirming the importance of ceramide signalling in keratinocytes.     

Skin barrier function in healthy volunteers as assessed by transepidermal water loss and vascular response to hexyl nicotinate: intra- and inter-individual variability

This study assesses the variability of two non-invasive methods of measuring stratum corneum barrier function in vivo . Transepidermal water loss (TEWL), and the vascular response to hexyl nicotinate (HN) penetration as determined by laser-Doppler flowmetry, were measured in a group of 21 healthy volunteers. Each time profile of the vascular response to HN penetration was analysed using the following parameters: the baseline cutaneous blood flow, the lag-time between application and initial response (to), the time between application and maximum response (t_max.), the maximum response, and the slope of the curve. TEWL measured on the left volar forearm showed a normal range of 3.9–7.6 g/m²h and a small inter-individual variability [coefficient of variation (CV) 19–4%]. TEWL values at three other forearm sites did not show differences of clinical importance compared with the left volar forearm. The parameters of the vascular response to HN penetration spanned a wider normal range than the TEWL values (CV between 33 and 52%). Repeat measurements after a 1–2 month interval showed highly reproducible individual TEWL values. The mean difference between first and second measurements was only 0.03 g/m²h: the relative difference 0.6%. The intra-individual reproducibility of t_o and t_max for HN penetration was also high (relative differences of 2.8 and 3.1%, respectively). The other vascular response parameters were less reproducible (relative differences of 6.9–18.6%). We conclude that TEWL and selected parameters of HN penetration, as non-invasive tests of the stratum corneum barrier function, yield reproducible results and are hence useful for investigations assessing the skin barrier function in various disorders.