Síndrome DRESS inducido por ácido valproico en una niña que respondió a la ciclosporina con análisis de HLA / Valproic acid-induced DRESS in a child responding to cyclosporine with HLA analysis

El síndrome de erupción medicamentosa con eosinofilia y síntomas sistémicos (drug reaction with eosinophilia and systemic symptoms, DRESS), también conocido como síndrome de hipersensibilidad inducida por medicamentos, es una reacción rara potencialmente mortal que causa una erupción grave y que puede provocar insuficiencia multiorgánica. Como con otras erupciones medicamentosas graves, los linfocitos T específicos para un medicamento tienen una función crucial en el síndrome DRESS. El modelo de hapteno/pro-hapteno, el modelo de interacción farmacológica y el modelo alterado de repertorio de péptidos son tres modelos diferentes desarrollados para describir la relación/interacción entre un medicamento o sus metabolitos y el sistema inmunitario. Analizamos nuestra experiencia con el tratamiento con ciclosporina en un caso de síndrome DRESS resistente a esteroides causado por ácido valproico en una niña y sus resultados clínicos, de laboratorio y de antígeno leucocitario humano (HLA).

Drug reaction with eosinophilia and systemic symptoms (DRESS), also known as drug-induced hypersensitivity syndrome, is a potentially life-threatening rare reaction that causes a severe rash and can lead to multiorgan failure. As in other severe drug eruptions, drug-specific T lymphocytes play a crucial role in DRESS. The hapten/pro-hapten model, pharmacological interaction model, and altered peptide repertoire model are three different models developed to describe the relationship/interaction between a medication or its metabolites and the immune system. We discuss our experience with cyclosporine treatment in a steroid-resistant DRESS syndrome caused by valproic acid in a girl, as well as her clinical, laboratory, and human leukocyte antigens (HLA) study results

Valproic acid-induced DRESS in a child responding to cyclosporine with HLA analysis. / Síndrome DRESS inducido por ácido valproico en una niña que respondió a la ciclosporina con análisis de HLA.

Drug reaction with eosinophilia and systemic symptoms (DRESS), also known as drug-induced hypersensitivity syndrome, is a potentially life-threatening rare reaction that causes a severe rash and can lead to multiorgan failure. As in other severe drug eruptions, drug-specific T lymphocytes play a crucial role in DRESS. The hapten/pro-hapten model, pharmacological interaction model, and altered peptide repertoire model are three different models developed to describe the relationship/interaction between a medication or its metabolites and the immune system. We discuss our experience with cyclosporine treatment in a steroid-resistant DRESS syndrome caused by valproic acid in a girl, as well as her clinical, laboratory, and human leukocyte antigens (HLA) study results.

El síndrome de erupción medicamentosa con eosinofilia y síntomas sistémicos (drug reaction with eosinophilia and systemic symptoms, DRESS), también conocido como síndrome de hipersensibilidad inducida por medicamentos, es una reacción rara potencialmente mortal que causa una erupción grave y que puede provocar insuficiencia multiorgánica. Como con otras erupciones medicamentosas graves, los linfocitos T específicos para un medicamento tienen una función crucial en el síndrome DRESS. El modelo de hapteno/pro-hapteno, el modelo de interacción farmacológica y el modelo alterado de repertorio de péptidos son tres modelos diferentes desarrollados para describir la relación/interacción entre un medicamento o sus metabolitos y el sistema inmunitario. Analizamos nuestra experiencia con el tratamiento con ciclosporina en un caso de síndrome DRESS resistente a esteroides causado por ácido valproico en una niña y sus resultados clínicos, de laboratorio y de antígeno leucocitario humano (HLA).

Contact haptens in emollients marketed in two European countries (Poland and Spain)

INTRODUCTION AND OBJECTIVES: Atopic dermatitis (AD) is the most common skin disease among pediatric patients, which affects up to 20% of children worldwide. Characterized by pruritus and eczema, it is also associated with improper skin barrier function and allergen sensitization. Here, we aimed to assess the presence of haptens in emollients marketed in two European countries: in Poland and Spain, as, firstly, these products are considered to be AD's basic therapy, and, secondly, frequent application of potent sensitizers on atopic skin may result in contact dermatitis. MATERIALS AND METHODS: We systematically searched for moisturizers explicitly described as "Atopic skin care" products in the most frequently visited online pharmacies in Poland and Spain. Subsequently, we created a database of all products and compared their composition with 139 contact haptens listed in the European Baseline Series (EBS), Fragrance and Cosmetic Series. RESULTS: As of December 2018, our list comprised 159 and 111 emollients available on the Polish and Spanish markets, respectively. There were no ingredients listed in 28 (17.5%) products in Poland and 24 (21.6%) in Spain. Only 23 (17.5%) and 13 (14.8%) products were hapten free. The pattern of most common haptens was similar in both countries, including phenoxyethanol, tocopherol and tocopheryl acetate, undefined parfum in Poland and tocopherol, phenoxyethanol, tocopheryl acetate and undefined parfum in Spain. CONCLUSIONS: This study shows that a vast majority of products taken into consideration contain at least one potential contact hapten. These findings indicate a need for patient education about potentially allergenic ingredients and stronger cooperation between academia and cosmetic manufacturers

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Allergic contact dermatitis: From pathophysiology to development of new preventive strategies.

As the body's first line of defense, the skin is the organ most frequently exposed to chemicals present in personal hygiene products, household products, or materials used in the work environment. In this context, skin disorders account for more than 40 % of all occupational and work-related diseases, constituting a significant public health burden. Among skin disorders, allergic contact dermatitis (ACD) is the most prevalent occupational disease and the most common form of immunotoxicity in humans. ACD is a T-cell-mediated skin inflammation resulting from the priming and expansion of allergen-specific CD4+ and CD8+ T cells. The clinical condition is characterized by local skin rash, itchiness, redness, swelling, and lesions, being mainly diagnosed by the patch test. Upon ACD diagnosis, avoiding the exposure to the triggering allergen is the mainstay of treatment to prevent future flares. In cases where avoidance is not possible, the use of a standard of care interim treatments such as steroid creams or ointments, barrier creams, and moisturizers are strongly recommended to alleviate symptoms. In this review, we sought to provide the reader with an overview of the pathophysiology of ACD as well as the currently available pharmacological treatment options. Furthermore, a comprehensive outline of several preventive strategies is also provided.

Refinement of the Peroxidase Peptide Reactivity Assay and Prediction Model for Assessing Skin Sensitization Potential.

A peptide reactivity assay with an activation component was developed for use in screening chemicals for skin sensitization potential. A horseradish peroxidase-hydrogen peroxide (HRP/P) oxidation system was incorporated into the assay for characterizing reactivity of hapten and pre-/prohapten sensitizers. The assay, named the Peroxidase Peptide Reactivity Assay (PPRA) had a predictive accuracy of 83% (relative to the local lymph node assay) with the original protocol and prediction model. However, apparent false positives attributed to cysteine depletion at relatively high chemical concentrations and, for some chemicals expected to react with the -NH2 group of lysine, little to no depletion of the lysine peptide were observed. To improve the PPRA, cysteine peptide reactions with and without HRP/P were modified by increasing the number of test concentrations and refining their range. In addition, removal of DL-dithiothreitol from the reaction without HRP/P increased cysteine depletion and improved detection of reactive aldehydes and thiazolines without compromising the assay's ability to detect prohaptens. Modification of the lysine reaction mixture by changing the buffer from 0.1 M ammonium acetate buffer (pH 10.2) to 0.1 M phosphate buffer (pH 7.4) and increasing the level of organic solvent from 1% to 25% resulted in increased lysine depletion for known lysine reactive chemicals. Refinement of the prediction model improved the sensitivity, specificity, and accuracy for hazard identification. These changes resulted in significant improvement of the PPRA making it is a reliable method for predicting the skin sensitization potential of all chemicals, including pre-/prohaptens and directly reactive haptens.

Contact haptens in emollients marketed in two European countries (Poland and Spain).

INTRODUCTION AND OBJECTIVES: Atopic dermatitis (AD) is the most common skin disease among pediatric patients, which affects up to 20% of children worldwide. Characterized by pruritus and eczema, it is also associated with improper skin barrier function and allergen sensitization. Here, we aimed to assess the presence of haptens in emollients marketed in two European countries: in Poland and Spain, as, firstly, these products are considered to be AD's basic therapy, and, secondly, frequent application of potent sensitizers on atopic skin may result in contact dermatitis. MATERIALS AND METHODS: We systematically searched for moisturizers explicitly described as "Atopic skin care" products in the most frequently visited online pharmacies in Poland and Spain. Subsequently, we created a database of all products and compared their composition with 139 contact haptens listed in the European Baseline Series (EBS), Fragrance and Cosmetic Series. RESULTS: As of December 2018, our list comprised 159 and 111 emollients available on the Polish and Spanish markets, respectively. There were no ingredients listed in 28 (17.5%) products in Poland and 24 (21.6%) in Spain. Only 23 (17.5%) and 13 (14.8%) products were hapten free. The pattern of most common haptens was similar in both countries, including phenoxyethanol, tocopherol and tocopheryl acetate, undefined parfum in Poland and tocopherol, phenoxyethanol, tocopheryl acetate and undefined parfum in Spain. CONCLUSIONS: This study shows that a vast majority of products taken into consideration contain at least one potential contact hapten. These findings indicate a need for patient education about potentially allergenic ingredients and stronger cooperation between academia and cosmetic manufacturers.

Endomorphin-2- and Neurotensin- Based Chimeric Peptide Attenuates Airway Inflammation in Mouse Model of Nonallergic Asthma.

We examined anti-inflammatory potency of hybrid peptide-PK20, composed of neurotensin (NT) and endomorphin-2 (EM-2) pharmacophores in a murine model of non-atopic asthma induced by skin sensitization with 2,4-dinitrofluorobenzene and intratracheal challenge of cognate hapten. Mice received intraperitoneally PK20, equimolar mixture of its structural elements (MIX), dexamethasone (DEX), or NaCl. Twenty-four hours following hapten challenge, the measurements of airway responsiveness to methacholine were taken. Bronchoalveolar lavage (BALF) and lungs were collected for further analyses. Treatment with PK20, similarly to dexamethasone, reduced infiltration of inflammatory cells, concentration of mouse mast cell protease, IL-1ß, IL-12p40, IL-17A, CXCL1, RANTES in lungs and IL-1α, IL-2, IL-13, and TNF-α in BALF. Simple mixture of NT and EM-2 moieties was less potent. PK20, DEX, and MIX significantly decreased malondialdehyde level and secretory phospholipase 2 activity in lungs. Intensity of NF-κB immunoreactivity was diminished only after PK20 and DEX treatments. Neither PK20 nor mixture of its pharmacophores were as effective as DEX in alleviating airway hyperresponsiveness. PK20 effectively inhibited hapten-induced inflammation and mediator and signaling pathways in a manner seen with dexamethasone. Improved anti-inflammatory potency of the hybrid over the mixture of its moieties shows its preponderance and might pose a promising tool in modulating inflammation in asthma.

Beneficial Effects of Neurotensin in Murine Model of Hapten-Induced Asthma.

Neurotensin (NT) demonstrates ambiguous activity on inflammatory processes. The present study was undertaken to test the potential anti-inflammatory activity of NT in a murine model of non-atopic asthma and to establish the contribution of NTR1 receptors. Asthma was induced in BALB/c mice by skin sensitization with dinitrofluorobenzene followed by intratracheal hapten provocation. The mice were treated intraperitoneally with NT, SR 142948 (NTR1 receptor antagonist) + NT or NaCl. Twenty-four hours after the challenge, airway responsiveness to nebulized methacholine was measured. Bronchoalveolar lavage fluid (BALF) and lungs were collected for biochemical and immunohistological analysis. NT alleviated airway hyperreactivity and reduced the number of inflammatory cells in BALF. These beneficial effects were inhibited by pretreatment with the NTR1 antagonist. Additionally, NT reduced levels of IL-13 and TNF-α in BALF and IL-17A, IL12p40, RANTES, mouse mast cell protease and malondialdehyde in lung homogenates. SR 142948 reverted only a post-NT TNF-α decrease. NT exhibited anti-inflammatory activity in the hapten-induced asthma. Reduced leukocyte accumulation and airway hyperresponsiveness indicate that this beneficial NT action is mediated through NTR1 receptors. A lack of effect by the NTR1 blockade on mast cell activation, oxidative stress marker and pro-inflammatory cytokine production suggests that other pathways can be involved, which requires further research.

A murine model of atopic dermatitis can be generated by painting the dorsal skin with hapten twice 14 days apart.

Drug development involves pharmacometric experiments in animals. Such experiments should limit animal pain and stress. Conventional murine models of atopic dermatitis (AD) used in drug development are generated by weekly painting of hapten on dorsal skin for 5 weeks. The present study aimed to develop a protocol that involves less animal distress. The experiments focused on serum total IgE levels, which are a marker of AD. The conventional protocol induced ever rising IgE levels. Experiments with extended intervals between sensitizations showed that IgE peaked ~5 days after the second sensitization, after which it returned to the control level within 12-19 days. An additional third sensitization on day 28 further increased the serum IgE level. In the 4-5 days after the second sensitization, the dorsal skin exhibited typical AD-like lesions with edema, scabs, epithelial-cell hypertrophy, marked mast-cell and lymphocyte infiltration of dermis, and increased IL-4, IL-6, IL-10, IL-1ß, IL-17A, IFN-γ and TNF-α expression. Thus, two 2,4-dinitrofluorobenzene sensitizations yield a murine AD model in less than 20 days. This study shows that animal model protocols used in drug development can be fine-tuned so that they remain effective yet cause animals less stress and pain.

A proposal to create an extension to the European baseline series.

BACKGROUND: The current European baseline series consists of 30 allergens, and was last updated in 2015. OBJECTIVES: To use data from the European Surveillance System on Contact Allergies (ESSCA) to propose an extension to the European baseline series in response to changes in environmental exposures. METHODS: Data from departmental and national extensions to the baseline series, together with some temporary additions from departments contributing to the ESSCA, were collated during 2013-2014. RESULTS: In total, 31689 patients were patch tested in 46 European departments. Many departments and national groups already consider the current European baseline series to be a suboptimal screen, and use their own extensions to it. The haptens tested are heterogeneous, although there are some consistent themes. Potential haptens to include in an extension to the European baseline series comprise sodium metabisulfite, formaldehyde-releasing preservatives, additional markers of fragrance allergy, propolis, Compositae mix, and 2-hydroxyethyl methacrylate. CONCLUSION: In combination with other published work from the ESSCA, changes to the current European baseline series are proposed for discussion. As well as addition of the allergens listed above, it is suggested that primin and clioquinol should be deleted from the series, owing to reduced environmental exposure.

Isothiocyanates are important as haptens in contact allergy to chloroprene rubber.

BACKGROUND: Contact allergy to chloroprene rubber products is well known. Thiourea compounds are considered the cause of allergy. Diethylthiourea commonly occurs in this type of product and can decompose to the sensitizer ethyl isothiocyanate. OBJECTIVES: To investigate the clinical importance of degradation products and metabolites from organic thioureas in contact allergy to chloroprene rubber with a focus on isothiocyanates and isocyanates. METHODS: Patients with contact allergy to diphenylthiourea were patch tested with phenyl isothiocyanate and phenyl isocyanate. Patients with known contact allergy to diethylthiourea were retested with diethylthiourea, while chemical analyses of their chloroprene rubber products were performed. The stability of diethylthiourea, diphenylthiourea and dibutylthiourea in patch-test preparations was investigated. Liquid chromatography/mass spectrometry and solid-phase microextraction/gas chromatography were used for determination of organic thioureas and isothiocyanates. RESULTS: All patients allergic to diphenylthiourea reacted to phenyl isothiocyanate, two of eight reacted to phenyl isocyanate and six of eight reacted to diphenylthiourea. Four patients allergic to diethylthiourea reacted at retest; diethylthiourea was detected in all chloroprene rubber samples, with levels of 2-1200 nmol cm-2 . At 35 °C, ethyl isothiocyanate was emitted from all samples. Patch-test preparations of diethylthiourea, diphenylthiourea and dibutylthiourea all emitted the corresponding isothiocyanate, with diethylthiourea showing the highest rate of isothiocyanate emission. CONCLUSIONS: Thiourea compounds are degraded to isothiocyanates, which are generally strong or extreme sensitizers, thus acting as prehaptens. This process occurs in both chloroprene rubber products and patch-test preparations. Positive reactions to phenyl isocyanate indicate cutaneous metabolism, as the only known source of exposure to phenyl isocyanate is through bioactivation of diphenylthiourea.

The influence of the carrier molecule on amoxicillin recognition by specific IgE in patients with immediate hypersensitivity reactions to betalactams.

The optimal recognition of penicillin determinants, including amoxicillin (AX), by specific IgE antibodies is widely believed to require covalent binding to a carrier molecule. The nature of the carrier and its contribution to the antigenic determinant is not well known. Here we aimed to evaluate the specific-IgE recognition of different AX-derived structures. We studied patients with immediate hypersensitivity reactions to AX, classified as selective or cross-reactors to penicillins. Competitive immunoassays were performed using AX itself, amoxicilloic acid, AX bound to butylamine (AXO-BA) or to human serum albumin (AXO-HSA) in the fluid phase, as inhibitors, and amoxicilloyl-poli-L-lysine (AXO-PLL) in the solid-phase. Two distinct patterns of AX recognition by IgE were found: Group A showed a higher recognition of AX itself and AX-modified components of low molecular weights, whilst Group B showed similar recognition of both unconjugated and conjugated AX. Amoxicilloic acid was poorly recognized in both groups, which reinforces the need for AX conjugation to a carrier for optimal recognition. Remarkably, IgE recognition in Group A (selective responders to AX) is influenced by the mode of binding and/or the nature of the carrier; whereas IgE in Group B (cross-responders to penicillins) recognizes AX independently of the nature of the carrier.

[Anaphylactic reactions to low-molecular weight chemicals]. / Reakcje anafilaktyczne na substancje chemiczne o malej masie czasteczkowej

Low-molecular weight chemicals (haptens) include a large group of chemical compounds occurring in work environment, items of everyday use (cleaning products, clothing, footwear, gloves, furniture), jewelry (earrings, bracelets), drugs, especially in cosmetics. They cause type IV hypersensitive reactions. During the induction phase of delayed-type hypersensitivity, haptens form complexes with skin proteins. After internalization through antigen presenting cells, they are bound to MHC class II molecules. Next, they are exposed against specific T-lymphocytes, what triggers activation of Th1 cells mainly. After repeating exposition to that hapten, during effector phase, Th1 induce production of cytokines affecting non-specific inflammatory cells. Usually, it causes contact dermatitis. However, occasionally incidence of immediate generalized reactions after contact with some kinds of haptens is noticed. A question arises, how the hapten does induce symptoms which are typical for anaphylaxis, and what contributes to amplification of this mechanism. It seems that this phenomenon arises from pathomechanism occurring in contact urticaria syndrome in which an anaphylactic reaction may be caused either by contact of sensitized skin with protein antigens, high-molecular weight allergens, or haptens. One of the hypotheses indicates the leading role of basophiles in this process. Their contact with haptens, may cause to release mediators of immediate allergic reaction (histamine, eicosanoids) and to produce cytokines corresponding to Th2 cells profile. Furthermore, Th17 lymphocytes secreting pro-inflammatory interleukin-17 might be engaged into amplifying hypersensitivity into immediate reactions and regulatory T-cells may play role in the process, due to insufficient control of the activity of effector cells.