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

T-cell-mediated drug hypersensitivity: immune mechanisms and their clinical relevance

T-cell-mediated drug hypersensitivity represents a significant proportion of immune mediated drug hypersensitivity reactions. In the recent years, there has been an increase in understanding the immune mechanisms behind T-cell-mediated drug hypersensitivity. According to hapten mechanism, drug specific T-cell response is stimulated by drug-protein conjugate presented on major histocompatibility complex (MHC) as it is presented as a new antigenic determinant. On the other hand, p-i concept suggests that a drug can stimulate T cells via noncovalent direct interaction with T-cell receptor and/or peptide-MHC. The drug binding site is quite variable and this leads to several different mechanisms within p-i concept. Altered peptide repertoire can be regarded as an 'atypical' subset of p-i concept since the mode of the drug binding and the binding site are essentially identical to p-i concept. However, the intracellular binding of abacavir to HLA-B*57:01 additionally results in alteration in peptide repertoire. Furthermore the T-cell response to altered peptide repertoire model is only shown for abacavir and HLA-B*57:01 and therefore it may not be generalised to other drug hypersensitivity. Danger hypothesis has been postulated to play an important role in drug hypersensitivity by providing signal 2 but its experimental data is lacking at this point in time. Furthermore, the recently described allo-immune response suggests that danger signal may be unnecessary. Finally, in view of these new understanding, the classification and the definition of type B adverse drug reaction should be revised.

La problemática del endosulfán: aspectos químicos, analíticos y ambientales / The roblem of enndosulfan: chemical, analytical and environmental issues

Introducción. Dado el carácter residual y el alto nivel de toxicidad del endosulfán, se ha incrementado la preocupación a nivel mundial por su impacto ambiental. Por eso la búsqueda de metodologías analíticas que permitan su detección y cuantificación es un tema de investigación vigente. Las propiedades del endosulfán y su patrón de degradación le confieren características que hacen muy compleja la problemática, al tiempo que el pesticida y sus metabolitos se expanden extensivamente por la atmósfera y contaminan tanto matrices lipofílicas como hidrofílicas. Objetivo. Llevar a cabo una revisión sobre las investigaciones más recientes acerca de la problemática del endosulfán, que incluye aspectos químicos, su problemática ambiental y técnicas inmunoquímicas para su análisis, tema en el que ha estado interesado nuestro grupo de investigación en la Universidad de Caldas. Método. El presente artículo de revisión analiza, cualitativamente, la literatura científica disponible en las bases de datos Science Direct, PubMed, Scielo y páginas Web oficiales, empleando como palabras de búsqueda: endosulfán, haptenos, análisis inmunoquímico del endosulfán, problemática ambiental del endosulfán, regulaciones internacionales sobre el endosulfán, normatividad vigente sobre el endosulfán, y métodos instrumentales de análisis. Resultados. Se obtuvo información pertinente relacionada con el objetivo propuesto, la cual se presenta en 3 secciones: aspectos químicos del endosulfán, problemática ambiental y técnicas inmoquímicas para su análisis. Conclusión. El endosulfán ha sido prohibido por los organismos internacionales. Sin embargo, el pesticida se continúa usando en algunos países y éste se difunde fácilmente hacia otras regiones, de tal manera que se ha convertido en un problema global. Hay investigaciones recientes sobre métodos de remediación química o biológica, pero los esfuerzos son modestos frente a la enorme problemática de este pesticida. En lo pertinente a análisis químicos de endosulfán, en los últimos 15 años se han investigado técnicas inmunoquímicas de análisis (basadas en haptenos), como alternativa a los métodos cromatográficos instrumentales.

Introduction. Due to the residual character and high level of toxicity of endosulfan, worldwide concern for its environmental impact has increased. Therefore, the search for analytical methodologies that allow its detection and quantification continues to be a topic of current research. Endosulfan properties and its degradation pattern confer it characteristics that make very complex the problematic while the pesticide and its metabolites are extensively spread throughout the atmosphere and contaminate both lipophilic and hydrophilic matrixes. Objective. To conduct a review on some recent research about the endosulfan problematic including chemical aspects, environmental issues and immunochemical techniques for its analysis, which is an area of current interest in this research group at Universidad de Caldas. Method. This review article analyzes qualitatively scientific literature from Science Direct, PubMed, Scielo databases and official Web pages using key words such as endosulfan, endosulfan immunochemical analysis, endosulfan environmental problematic, endosulfan international regulations, endosulfan current normativity and instrumental methods for the analysis. Results. Relevant information related to the proposed objective was found which is presented in 3 sections: chemical aspects of endosulfan, environmental issues, and immunochemical techniques for its analysis. Conclusions. Endosulfan has been banned by international organizations. However, the pesticide is still being used in some countries and is easily spread to other regions, so that the problem became a global concern. There is some recent research on biological or chemical remediation techniques, but efforts seem insufficient in comparison to the enormous impact of the pesticide. In regard to Endosulfan chemical analyses, during the past 15 years immunochemical hapten-based analysis techniques have been investigated as alternatives to the instrumental chromatographic methods.

Advance of studies on application of hapten antibodies / 中国中药杂志

Hapten antibodies are active components of traditional Chinese medicines, have been widely applied in all of study fields of traditional Chinese medicine. First, hapten monoclonal antibodies could be designed into ELISA kits for quantitative analysis on the content of effective components in plant crude extracts or biological samples, which be applied for quality control and studies on pharmacokenetics of traditional Chinese medicines. Second, hapten monoclonal antibodies could be coupled with solid-phase carriers to generate immunoaffinity chromatography column, which could be used for knock-out extract preparation or pre-treatment of complicated sampless. Finally, a single-chain variable fragment antibody (scFV) gene segment of effective components of hapten monoclonal antibodies could be transformed into relative plant cells to gain new varieties with high-enrichment effective components, and thus achieve the molecular breeding of medicinal plants.

Application of bispecific antibody against antigen and hapten for immunodetection and immunopurification

We present a bispecific antibody that recognizes an antigen and a hapten and can be applied to various biological assays, including immunoblotting and immunoprecipitation. In immunoblot analysis of serum, an anti-C5 x anti-cotinine bispecific tandem single-chain variable fragment (scFv)-Fc fusion protein and cotinine-conjugated horseradish peroxidase (HRP) generated a clean signal without the high background that was observed in a parallel experiment using HRP-conjugated goat anti-rabbit immunoglobulin G (Fc-specific) antibody. In immunoprecipitation analysis of serum, use of the bispecific tandem scFv-Fc fusion protein and cotinine-crosslinked magnetic beads significantly reduced the amount of protein contaminants compared with a parallel experiment done with protein A agarose beads. In subsequent immunoblot analysis, use of cotinine-HRP as the secondary probe instead of HRP-conjugated goat anti-rabbit IgG (Fc-specific) antibody successfully eliminated the band corresponding to the bispecific tandem scFv-Fc fusion protein.

Imunopatologia da dermatite de contato alérgica / Immunopathology of allergic contact dermatitis

A dermatite de contato alérgica é consequência de uma reação imune mediada por células T contra químicos de baixo peso molecular, denominados haptenos. É uma condição frequente que ocorre em todas as raças e faixas etárias e afeta a qualidade de vida de seus portadores. O mecanismo imunológico desta doença vem sendo revisto nas últimas décadas com significativo avanço no seu entendimento. A metabolização e o caminho dos haptenos, bem como a formação e o mecanismo de ação das células responsáveis tanto pela reação quanto pelo seu término, são discutidos neste artigo.

Allergic contact dermatitis is the consequence of an immune reaction mediated by T cells against low molecular weight chemicals known as haptens. It is a common condition that occurs in all races and age groups and affects the quality of life of those who present it. The immunological mechanism of this disease has been reviewed in recent decades with significant advance in its understanding. The metabolism and pathway of the haptens as well as the activation and mechanism of action of the cells responsible for both the immune reaction and its completion are discussed in this article.

Food Additives and Allergic Diseases in Childhood / 한양의대학술지

Many different additives include preservatives, stabilizers, conditioners, thickeners, colorings, flavorings, sweeteners, and antioxidants. Despite the multitude of additives known, only a small number has been associated with hypersensitivity reactions. A number of investigators have suggested that a significant population of patients with allergic diseases has symptoms related to the ingestion of food additives. However, the incidence and mechanism of reactions to additives in patients with chronic urticaria, angioedema, and atopic dermatitis remain unknown. A few studies of monosodium glutamate is reported to be associated with atopic dermatitis, but their relationship remains unknown. The best known dye is tartrazine. The group of azo dyes includes ponceau and sunset yellow. Amaranth (FD&C red no. 5) was banned from use in the US in 1975 because of claims related to carcinogenicity. Most of them are reported to be associated with aggravation of atopic dermatitis. Parabens are aliphatic esters of parahydroxybenzoic acid. Sodium benzoate is a closely related substance usually reported to cross-react with these compounds. These agents, which are widely used as preservatives in both food and drugs, are well recognized as causes of severe contact dermatitis. Additives would have to act as haptens to create a response mediated by IgE. The majority of these reactions are not of the immediate hypersensitivity type. Many cases of additive-provoked urticaria or dermatitis occur as late as 24 hours after challenge, arguing against an IgE-mediated mechanism. In conclusion, the exact relationship between food additives and the allergic diseases still remains to be solved.

Preparation of anti-salbutamol antibody based on a new designed immunogen and development of a heterologous indirect ELISA for detection of salbutamol residue / 药学学报

To synthesize salbutamol immunogen and develop an enzyme immunoassay (ELISA), a new salbutamol immunogen was synthesized using 4-aminobenzoic acid as a linker to connect hapten with carrier protein. An enzyme immunoassay based on the antibody prepared was developed and applied to detect salbutamol residue spiked in swine liver. An unusual coating antigen, clenbuterol-ovalbumin (OVA) conjugate instead of salbutamol-OVA conjugate, was used in the immunoassay and the results were discussed based on the structures of related compounds. The antibodies showed high sensitivity in the heterologous assay when using clenbuterol-OVA as a coating antigen, with an IC50 value of 8.97 ng mL(-1) toward salbutamol. The antibodies prepared showed high cross-reactivity with clenbuterol (107%) and were promising for the simultaneous determination of salbutamol and clenbuterol residues in food and food products. Recovery rates from the salbutamol-spiked swine liver samples were in the range of 70%-99%, while the intra-assay and inter-assay coefficients of variation were <13.3% and <14.3%, respectively. In summary, the antibodies of salbutamol have been successfully prepared. Sensitive and stable analysis for the detection of salbutamol residues in swine liver was obtained based on the competitive ELISA methods developed in this study.

Migration inhibitory factor is involved in experimental colitis induced by intrathecal injection of haptten to rat / 生理学报

In recent years, there has emerged academic tendency towards the neurogenic mechanism of ulcerative colitis (UC). As one of the supports to the hypothesis of UC being a neurogenic inflammation, we have built a colitis model by intrathecal (ith) injection of a haptten 2,4-dinitrochlorobenzene (DNCB) to DNCB-sensitized rats. In order to explore further the neuroimmunal mechanism of this colitis model, we here focused on a pro-inflammatory cytokine, migration inhibitory factor (MIF), to observe its expression in rat colon nervous tissue and spinal cord in the colitis induced by ith injection of DNCB. At the same time we also observed the effect of MIF antibody pretreatment on the disease active index (DAI) score and the colon pathology by HE staining in the colitis rats. The results obtained showed that the immunofluorescence intensity of double staining of MIF protein in colon nervous tissue and spinal cord was increased in 0.8% and 1.6% DNCB-induced colitis groups than that in the control (60% ethanol) group. Both the colon pathology and the DAI score were significantly reduced by MIF antibody ith pretreatment. Ith injection of 0.8% DNCB after MIF antibody (1:10, 1:5) pretreatment could only induce lower DAI score (P<0.01 as compared, respectively, to the IgG pretreatment group). The colon pathological changes in ith 0.8% DNCB rats were mild, even little after MIF antibody (1:10, 1:5) pretreatment. These results suggest that MIF in spinal cord and enteric nervous system is possibly involved in the rat colitis induced by ith injection of DNCB, which reflects a neuroimmunal mechanism underlying this kind of colitis. MIF is possibly one of the important neurochemical factors in this experimental colitis, even in the UC.

The Production and Functions of Reactive Oxygen Species in Mouse Bone Marrow-derived Dendritic Cells by Various Haptens and Irritants / 대한피부과학회지

BACKGROUND: Various allergens and irritants induced the production of reactive oxygen species (ROS) in the well-established mouse dendritic cell (DC) line XS106 and this production of ROS was inhibited by antioxidants. OBJECTIVE: To investigate the production and functions of ROS in mouse bone marrow-derived DCs (BM-DCs) by various haptens and irritants, we examined the production of ROS, the expression of surface molecules, and the production of interleukin-12 (IL-12) in mouse BM-DCs. METHODS: Six to eight-week-old female C57/BL6 mice were used in this study. Mouse BM-DCs were co-cultured with DNFB, DNCB, TNBS, hydroquinone, NiSO4, CoCl2, MnCl2, thimerosal, SDS, and BKC. The production of ROS and the expression of surface molecules (CD40, CD80, CD86, and MHC-II) were measured by flow cytometry in chemical-treated mouse BM-DCs. In addition, the cells were pretreated with antioxidants to determine whether the production of ROS can be inhibited. The production of IL-12 was also measured in DNCB and SDS-treated mouse BM-DCs using ELISA. Results: The production of ROS in mouse BM-DCs was induced by various allergens, including DNFB, DNCB, TNBS, hydroquinone, MnCl2 and irritants like SDS, BKC. The expression of surface molecules was induced by various chemicals and NiSO4 was the most potent inducer of surface molecules in mouse BM-DCs. The production of ROS in DNCB and SDS-treated mouse BM-DCs was partially inhibited by diphenylene iodonium, but not by rotenone, vitamin E, allopurinol, glutathione. The production of IL-12 was not detected in DNCB and SDS-treated mouse BM-DCs. CONCLUSION: The production of ROS was induced in mouse BM-DCs by various allergens and irritants. The expression of surface molecules was also induced by various chemicals. The production of ROS was partially inhibited by DPI. The production of IL-12 was not detected.

Aging reduces the primary humoral response and the in vitro cytokine production in mice

Aging is accompanied by a decrease in several physiological functions that make older individuals less responsive to environmental challenges. In the present study, we analyzed the immune response of female BALB/c mice (N = 6) of different ages (from 2 to 96 weeks) and identified significant age-related alterations. Immunization with hapten-protein (trinitrophenyl-bovine serum albumin) conjugates resulted in lower antibody levels in the primary and secondary responses of old mice (72 weeks old). Moreover, young mice (2, 16, and 32 weeks old) maintained specific antibodies in their sera for longer periods after primary immunization than did old mice. However, a secondary challenge efficiently induced memory in old mice, as shown by the increased antibody levels in their sera. The number of CD4+ and CD8+ T cells in the spleen increased until 8 weeks of age but there was no change in the CD4+/CD8+ ratio with aging. Splenic T cells from old mice that had or had not been immunized were less responsive to concanavalin-A and showed reduced cytokine production compared to young mice (IL-2: 57-127 vs 367-1104 pg/mL, IFN-g: 2344-12,836 vs 752-23,106 pg/mL and IL-10: 393-2172 vs 105-2869 pg/mL in old and young mice, respectively). These data suggest that there are significant changes in the organization of the immune system throughout life. However, the relevance of these alterations for the functioning of the immune system is unknown.

Atopic Dermatitis and Food Additives in Childhood

Many different additives are added to the food that we consume, and the number of additives is estimated to range from 2,000 to 20,000. These substances include preservatives, stabilizers, conditioners, thickeners, colorings, flavorings, sweeteners, and antioxidants. Despite the multitude of additives known, only a surprisingly small proportion of them has been associated with hypersensitivity reactions. A number of investigators have suggested that a significant proportion of patients with chronic urticaria, angioedema, atopic dermatitis, and asthma have symptoms related to the ingestion of food additives. However, the incidence and mechanisms of reactions to additives in patients with chronic urticaria, angioedema, and atopic dermatitis remain unknown. Monosodium glutamate(MSG) produces the flavor-enhancing properties of seaweed, the traditional component of Japanese and Chinese cooking. A few studies on MSG have reported an association between MSG and atopic dermatitis, but the exact nature of the relationship remains unknown. Dyes approved under the Food Dye and Coloring Act are coal tar derivatives, the best known of which is tartrazine(FD&C yellow no. 5). The group of azo dyes includes ponceau(FD&C red no. 4) and sunset yellow (FD&C yellow no. 6). Amaranth(FD&C red no. 5) was banned from use in US in 1975 due to the claims related to carcinogenicity. Most of them were reported to be associated with an aggravation of atopic dermatitis. Parabens are aliphatic esters of parahydroxybenzoic acid. Sodium benzoate is a closely related substance usually reported to cross-react with these compounds. These agents, which are widely used as preservatives in both foods and drugs, are well recognized as the cause of severe contact dermatitis. Additives can serve as haptens to create a response mediated by IgE. Only a few reports have suggested IgE-mediated reactions, notably to sulfites and parabens. Instead, the overwhelming majority of these reactions are not of the immediate hypersensitivity type. Many cases of additive-provoked urticaria or dermatitis occur as late as 24 hours after the challenge,arguing against an IgE-mediated mechanism.

Synthesis and identification of antigenic conjugates of podophyllotoxin / 药学学报

<p><b>AIM</b>To synthesize and identify artificial antigen of podophyllotoxin for the production of podophyllotoxin polyclonal antibody.</p><p><b>METHODS</b>The hapten was synthesized by two different chemical approaches and characterized by TLC, IR, NMR, and MS. Mixed anhydride reaction (MAR) and active ester method (AEM) were used to couple the podophyllotoxin to carrier proteins (BSA and OVA). Characterization of artificial antigens was done by using spectroscopy and electrophoresis. The anti-podophyllotoxin polyclonal antibodies were obtained through immunizing rabbits.</p><p><b>RESULTS</b>The results from IR, NMR and MS showed that 4-O-succinoyl podophyllotoxin (hapten) was successfully synthesized. The coupling molar ratios of the hapten and carrier proteins were 88.6 for Hapten-BSA1, 40.3 for Hapten-BSA2, 17.8 for Hapten-OVA1, and 54.2 for Hapten-OVA2. Hapten conjugates coupled with BSA yielded two sets of the specific and affinitive polyclonal antibodies. One set of antibodies showed an IC50 value of 2.21 microg.mL(-1) with a detection limit of 0.12 microg.mL(-1).</p><p><b>CONCLUSION</b>Antigenic conjugates were artificially synthesized, and based on these artificial antigens, polyclonal antibodies against podophyllotoxin were raised from rabbits immunized with two different immunogens and characterized with an indirect ELISA format.</p>

Antígenos / Antigens

Los antígenos son compuestos de diversa naturaleza química provenientes del medio o generados por el propio organismo que son capaces de inducir una respuesta inmunológica en los vertebrados, propiedad denominada inmunogenicidad. La interacción del antígeno con los productos de la respuesta inmune, y especialmente con los anticuerpos, propiedad denominada antigenicidad, ha permitido conocer la estructura y función de numerosos antígenos, demostrándose que los productos de la respuesta inmune interactúan con regiones específicas del antígeno, denominadas epítopos, los cuales pueden corresponder a una secuencia aminoacídica determinada (epítopos lineales) o a un arreglo espacial de la cadena polipeptídica (epítopos conformacionales). Aunque la capacidad inmunogénica de un antígeno depende de su naturaleza química intrínseca (tamaño, forma, movilidad atómica, presencia de grupos químicos activos y residuos aromáticos) también está relacionada con la capacidad de respuesta del organismo y, en este sentido, son determinantes sus características genéticas y su historial inmunológico

Choque anafiláctico por ingestión de alcohol etílico / Anaphylactic shock after drinking an alcoholic beverage

Se comunica un caso raro de una paciente de 34 años de edad que sufrió un choque anafiláctico casi mortal 15 minutos después de ingerir una bebida alcohólica. La paciente refiere que seis años antes, con diferentes clases de bebidas alcohólicas manifestaba siempre urticaria generalizada, que desaparecía espontáneamente sin medicamantos. Aunque no se pudo demostrar el mecanismo de la reacción de nuesta paciente, la amplia variedad de bebidas alcoholicas que lo provocan sugiere que el etanol o sus metabolitos son el antígeno ofensor que actúa como hepteno

Binding characteristics of bovine serum albumin-aflatoxin B1 to polystyrene microtiter plates: importance of hapten to carrier protein molar ratio.

Binding characteristics of bovine serum albumin-aflatoxin B1 conjugates with high (1:54), medium (2:25) and low (1:9) hapten to carrier molar ratios, to the polystyrene microtiter plates are influenced by the stoichiometry of the hapten (Aflatoxin B1) to the carrier protein (bovine serum albumin). Conjugates with optimal hapten to carrier molar ratios (1:25) showed a better binding capacity to the polystyrene microtiter plate as compared to the conjugates with the high molar ratios in a non-competitive ELISA for aflatoxin B1. Denaturation of the conjugate with molar ratio of 1:54 in order to enhance its binding capacity, however, did not result in any significant improvement.

Unusual discrimination against carrier protein antibodies during partial purification of hapten-protein polyclonal antibodies to plant stress hormones.

Polyclonal antibodies (PcAb) were raised against t-zeatin riboside (t-ZR) and abscisic acid (ABA). t-ZR-BSA and ABA-BSA antibodies had high titre and specificity to haptens but also contained BSA specific antibodies as observed in double immuno diffusion and quantitative precipitation tests. Partial purification of antiserum by precipitation, desalting, and ion-exchange chromatography almost completely eliminated interference from BSA specific antibodies. Consequently, very little or no reaction was observed in dot-immunoblot assays even when high concentrations of BSA were probed with partially purified t-ZR-BSA IgG. Further studies with ABA antiserum showed that discrimination against BSA occurred during chromatography and not during salt fractionation. Because antibodies to both hapten and carrier protein were predominantly of IgG class, this unusual discrimination against carrier protein Ab was possibly influenced by two approaches followed for DEAE chromatography, viz. (i) adsorption of IgG at pH 8 followed by elution; or (ii) adsorption of contaminating proteins at neutral pH while specific IgG comes off as unbound fraction.