Is quantitative sIgE serology suitable for distinguishing between silent sensitization and allergic rhinitis to dermatophagoides pteronyssinus?

Background: An increasing number of studies have recently discussed whether provocation tests might be replaced by specific IgE serology in patients sensitized to airborne allergens. Objective: Our study aimed to analyze the concordance between a nasal provocation test with Dermatophagoides pteronyssinus and specific IgE measurements based on real-life data. Patients and Methods: We retrospectively analyzed concordance between the result of the provocation test and the IgE titer for house dust mite components and extracts in 223 patients with proven sensitization to D pteronyssinus. Results: In contrast to findings from other studies, the anti-Der p 1 level alone was not sufficient to distinguish between silent sensitization and allergy to D pteronyssinus. ROC curve analysis revealed that the sum of sIgE against Der p 1 and Der p 2 is-after adjustment for total serum IgE-the best parameter for discriminating between clinically silent and relevant sensitization. However, it does not have sufficient validity to confirm a diagnosis. Conclusions: Despite the high correlation between sIgE levels and symptoms, no serologic parameter is sufficiently accurate to distinguish between silent sensitization and clinically relevant allergy. Therefore, nasal provocation tests remain the gold standard for assessing clinical relevance in sensitization to D pteronyssinus

Introducción: Recientemente, un número cada vez mayor de estudios se han centrado en el debate sobre si las pruebas de provocación podrían ser reemplazables por medición de IgE específica en suero en pacientes sensibilizados a aeroalérgenos. Objetivo: Nuestro estudio tuvo como objetivo analizar la concordancia entre la prueba de provocación nasal con Dermatophagoides pteronyssinus y la IgE específica con datos de vida real. Pacientes y métodos: En 223 pacientes con sensibilización probada a Dermatophagoides pteronyssinus, se analizó retrospectivamente la concordancia entre el resultado de la prueba de provocación y el título de IgE frente a varios componentes y extractos de ácaros del polvo doméstico. Resultados: A diferencia de otros estudios, el nivel de anti-Der p 1 no fue adecuado para distinguir entre una sensibilización silente y la alergia a Dermatophagoides pteronyssinus. El análisis de las curvas ROC reveló que la suma de sIgE frente a Der p 1 y Der p 2, después del ajuste a la IgE sérica total, es el mejor parámetro para discriminar entre sensibilización clínicamente silente y relevante, aunque lejos de alcanzar una suficiente validez diagnóstica. Conclusiones: A pesar de la alta correlación entre los niveles de sIgE y los síntomas, ningún parámetro serológico tenía una precisión suficientemente alta para distinguir entre la sensibilización silente y una alergia clínicamente relevante. Por lo tanto, las pruebas de provocación nasal siguen siendo el patrón estándar para investigar la relevancia clínica de la sensibilización a Dermatophagoides pteronyssinus

Immunomodulation of allergic response in children and adolescents: What we can learn from lymphatic filarial infection

Background: Although it is well known that allergic diseases involve a strong Th2 immune response, with production of high levels of specific IgE allergen, knowledge on the association between filarial infection and allergies, among paediatric patients is scarce. Objective: To evaluate the allergic response patterns in cases of filarial infection by comparing peripheral eosinophils, total IgE levels, immediate hypersensitivity and cytokine levels in children and adolescents in Brazil. Methods: This was an exploratory study with three groups: (I) with filarial infection and without allergic diseases; (II) without filarial infection and with allergic diseases; and (III) without filarial infection and without allergic diseases. The prick test and specific IgE tests for aeroallergens were performed using five antigens. Peripheral eosinophils and total IgE were also evaluated. IL-4 and IL-5 were determined using whole-blood culture stimulated by three antigens. Results: Eosinophilia and elevated levels of total IgE (≥ 400IU/dl) were observed in all groups. The prick test was positive in 56.6% of the cases. Group I presented hypersensitive responses similar to the allergic disease groups. In the whole-blood culture stimulated by Dermatophagoides pteronyssinus, average IL-4 production did not differ significantly among the groups, but IL5 production resulting from stimulation was greater in the allergic disease groups (p < 0.05). Conclusions: The allergic response pattern in group with filarial infection was similar to that of the groups with and without allergic diseases, but the response to IL-5 in the culture stimulated by D. pteronyssinus was an exclusive characteristic of the allergic group (AU)

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The safety profile of subcutaneous allergen immunotherapy in children with asthma in Hangzhou, East China

Background: The aim of the current study is to evaluate the prevalence, severity and possible risk factors of systemic reactions (SRs) to subcutaneous allergen immunotherapy (SCIT) in children and adolescents with asthma in Hangzhou, east China's Zhejiang province. Methods: From January 2011 to December 2016, this survey analysed the SCIT-related SRs involving 429 patients (265 children and 134 adolescents) affected by allergic asthma. Recorded data included demographics, diagnosis, patient statuses, pulmonary function testing results before and after each injection, allergen dosage, and details of SRs. Results: All patients finished the initial phase and six patients withdrew during the maintenance phase. There were 2.59% (328/12,655) SRs in all injections (3.28% in children and 1.47% in adolescents); 15.62% (67/429) patients experienced SRs (18.49% children and 10.98% adolescents). There were 54.57% SRs of grade 1; 42.37% SRs of grade 2; 3.05% SRs of grade 3; and no grades 4 or grade 5 SRs occurred in patients. Most reactions were mild, and were readily controlled by immediate emergency treatment. There was no need for hospitalisation. The occurrence of SRs was significantly higher in children than that in adolescents (p < 0.01). A higher ratio of SRs was found among patients with moderate asthma. Conclusion: This retrospective survey showed that properly-conducted SCIT was a safe treatment for children and adolescents with asthma in Hangzhou, East China. Children and patients with moderate asthma may be prone to develop SRs (AU)

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Construction and expression of Dermatophagoides pteronyssinus group 1 major allergen T cell fusion epitope peptide vaccine vector based on the MHC II pathway / Construcción y expresión de vector de vacuna de péptido epítopo de fusión de células t de alérgeno principal del grupo 1 dermatophagoides pteronyssinus basado en la vía MHC II

Backgound and aims: Dermatophagoides peteronyssinus is one of the important house dust mites responsible for allergic asthma that can be tentatively managed by specific immunotherapy. The present study was to construct a vector encoding T-cell epitopes of major allergen group 1 of Dermatophagoides pteronyssinus as a vaccine delivered by MHC class II pathway. Methods: the nucleotide sequences of the 3 target genes were synthesized, including TAT, IhC and the recombinant fragment of Der p 1 encoding 3 T-cell epitopes. After amplification of the 3 target fragments by PCR and digestion with corresponding restriction endonucleases, the recombinant gene TAT-IhC-Der p 1-3T was ligated using T4 DNA ligase and inserted into the prokaryotic expression vector pET28a(+) to construct the recombinant plasmid pET- 28a(+)-TAT-IhC-Der p 1-3T, which was confirmed by digestion with restriction endonucleases and sequencing. The recombinant vector was transformed into E. coli strain BL21 (DE3) and induced with IPTG, and the induced protein TAT-IhC-Der p1-3T was detected by SDS-PAGE. After purification, the recombinant protein was confirmed by Western blotting and its allergenicity tested using IgE-binding assay. Results: the recombinant plasmid pET-28a-TAT-IhCDer p1-3T was successfully constructed as confirmed by restriction endonuclease digestion and sequencing, and the expression of the recombinant protein TAT-IhC-Der p1-3T was induced in E. coli. Western blotting verified successfull purification of the target protein, which showed a stronger IgE-binding ability than Der p1. Conclusion: we successfully constructed the recombinant expression vector pET-28a-TAT-IhC-Der p1-3T expressing a T-cell epitope vaccine delivered by MHC II pathway with strong IgE-binding ability, which provides a basis for further study on specific immunotherapy via MHC class II pathway (AU)

Antecedentes y objetivo: el Dermatophagoides peteronyssinus es uno de los principales ácaros del polvo doméstico responsables del asma alérgica que se pueden administrar provisionalmente para una inmunoterapia específica. El presente estudio busca construir un vector que codifique epítopos de células T del grupo de alérgenos principal, el Grupo 1 de Dermatophagoides pteronyssinus como una vacuna suministrada mediante la vía MHC de clase II. Métodos: se sintetizaron las secuencias de nucleótidos de los 3 genes objetivo, incluyendo TAT, IhC y el fragmento recombinante de Der p 1 encargado de codificar 3 epítopos de célula T. Después de la amplificación de los 3 fragmentos objetivo por PCR y digestión con endonucleasas de restricción correspondientes, el gen recombinante TAT-IhC-Der p 1-3T se ligó usando T4 DNA ligasa y se insertó en el vector de expresión procariota pET28a (+) para construir el plásmido recombinante pET 28a (+)-TAT-IHC-Der p 1-3T, que se confirmó por digestión con endonucleasas de restricción y secuenciación. El vector recombinante se transformó en E. coli cepa BL21 (DE3) y se indujo con IPTG, y la proteína inducida TATIHC-Der p1-3T se detectó mediante SDS-PAGE. Después de la purificación, la proteina recombinante se confirmó por análisis de inmunotransferencia (Western blot) y se probó su alergenicidad usando el ensayo de unión a IgE. Resultados: el plásmido recombinante pET-28a-TATIHCDer p1-3T se construyó con éxito, se confirmó por digestión con endonucleasas de restricción y la secuenciación y la expresión de la proteína recombinante TAT-IHCDer p1-3T fue inducida en E. coli. Purificación con éxito verificada mediante Western blot de la proteína objetivo, que mostró una capacidad de unión a IgE más fuerte que Der p1. Conclusión: hemos construido con éxito el vector de expresión recombinante pET-28a-TAT-IHC-Der p1-3T que expresa una vacuna de epítopo de células T administrada por vía MHC II con fuerte capacidad de unión a IgE. Este trabajo proporciona una base para seguir estudiando la inmunoterapia específica mediante la vía MHC de clase II (AU)

Dual oxidase 2 is essential for house dust mite-induced pro-inflammatory cytokine production in human keratinocytes.

House dust mites (HDMs) are known to trigger chronic inflammation through Toll-like receptors (TLRs) and their signalling cascades. In this study, we found that TLR2 ligation by HDMs induced the activation of dual oxidase 2 (Duox2) and nuclear factor-κB (NF-κB), leading to the production of pro-inflammatory cytokines in human keratinocytes. Stimulation of human keratinocytes with HDMs resulted in increases in interleukin-8 (IL-8) and chemokine (C-C motif) ligand 20 (CCL20) levels. However, pro-inflammatory cytokine production was abolished in keratinocytes transfected with TLR2 siRNA, indicating that HDM-induced cytokine production was mediated via TLR2 signalling. We also examined the function of Duox1/2 isozymes, which are primarily expressed in keratinocytes, in HDM-mediated pro-inflammatory cytokine production. Human keratinocytes transfected with control siRNA or Duox1 siRNA showed no inhibition of IL-8 or CCL20 production in response to HDMs, whereas the silencing of Duox2 expression resulted in a failure to induce cytokine production. Moreover, the phosphorylation and nuclear localization of RelA/p65, a component of NF-κB, were induced by HDMs in human keratinocytes. Transfection of human keratinocytes with TLR2 siRNA or Duox2 siRNA resulted in the complete abolishment of RelA/p65 nuclear localization in response to HDMs. Taken together, these results indicate that the HDM-dependent TLR2-Duox2 signalling axis indeed promotes NF-κB activation, which induces IL-8 and CCL20 production and mediates epidermal keratinocyte inflammation.

Mite hypersensitivity in patients with rhinitis and rhinosinusitis living in a tropical environment

PURPOSE: Rhinitis and rhinosinusitis are major concerns in public health. Mites are important aetiological agents in the tropics. The present study investigated the in vivo response to mite allergens in patients with rhinitis and rhinosinusitis. METHODS: All patients with presumptive nasal allergy were included. Skin tests were done with inhalants and mite extracts. Patients were classified as allergic or non-allergic according to skin tests and history. RESULTS: Out of 229 patients, 175 (76.4%) showed positive skin tests. Allergic patients showed positivity to mites in 97.1% of cases, 51.4% to dog dander; 40.5% to cat dander; 36.5% to German cockroach; 22.8% to moulds; and 21.1% to grass pollens. Dermatophagoides farinae induced responses in 90.8% of patients, D. pteronyssinus in 90.1%, Blomia tropicalis in 74.8%, Glycyphagus domesticus in 62.2%, Chortoglyphus arcuatus in 58.2%, Acarus siro in 46.2%, Lepidoglyphus destructor in 35.4%, and Tyrophagus putrescentiae in 35.0%. Higher correlations were found between skin test diameters induced by mites from the same family. CONCLUSIONS: Sensitisation to inhalant allergens is present in 76% of allergy clinics' patients with rhinitis or rhinosinusitis. Our results confirm previous observations showing that mites constitute the most important cause of respiratory allergy in tropical settings and suggest that mite allergen cross-reactivity is responsible for the positivity of skin tests to mites not present in the patient's environment since the species Glycyphagus, Chortoglyphus, Acarus, Lepidoglyphus and Tyrophagus have not been found in Caracas house dust

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Absence of c-Jun NH2-terminal kinase 1 protects against house dust mite-induced pulmonary remodeling but not airway hyperresponsiveness and inflammation.

Chronic allergic asthma leads to airway remodeling and subepithelial fibrosis via mechanisms not fully understood. Airway remodeling is amplified by profibrotic mediators, such as transforming growth factor-ß1 (TGF-ß1), which plays a cardinal role in various models of fibrosis. We recently have identified a critical role for c-Jun-NH2-terminal-kinase (JNK) 1 in augmenting the profibrotic effects of TGF-ß1, linked to epithelial-to-mesenchymal transition of airway epithelial cells. To examine the role of JNK1 in house dust mite (HDM)-induced airway remodeling, we induced allergic airway inflammation in wild-type (WT) and JNK1-/- mice by intranasal administration of HDM extract. WT and JNK1-/- mice were sensitized with intranasal aspirations of HDM extract for 15 days over 3 wk. HDM caused similar increases in airway hyperresponsiveness, mucus metaplasia, and airway inflammation in WT and JNK1-/- mice. In addition, the profibrotic cytokine TGF-ß1 and phosphorylation of Smad3 were equally increased in WT and JNK1-/- mice. In contrast, increases in collagen content in lung tissue induced by HDM were significantly attenuated in JNK1-/- mice compared with WT controls. Furthermore HDM-induced increases of α-smooth muscle actin (α-SMA) protein and mRNA expression as well as the mesenchymal markers high-mobility group AT-hook 2 and collagen1A1 in WT mice were attenuated in JNK1-/- mice. The let-7 family of microRNAs has previously been linked to fibrosis. HDM exposure in WT mice and primary lung epithelial cells resulted in striking decreases in let-7g miRNA that were not observed in mice or primary lung epithelial cells lacking JNK1-/- mice. Overexpression of let-7g in lung epithelial cells reversed the HDM-induced increases in α-SMA. Collectively, these findings demonstrate an important requirement for JNK1 in promoting HDM-induced fibrotic airway remodeling.

House dust mite subcutaneous immunotherapy does not induce new sensitization to tropomyosin: does it do the opposite?

Background: It is still uncertain whether house dust mite (HDM) tropomyosin present in allergen extracts can cross-sensitize patients receiving subcutaneous immunotherapy (SCIT) and thus induce food allergy. Objectives: Our aim was to assess whether new sensitization to tropomyosin occurred during HDM-SCIT, and, if so, whether it was clinically relevant. Patients and Methods: The study sample comprised 56 HDM-allergic patients treated with SCIT using HDM extract. All patients were screened for specific IgE (sIgE) to mite tropomyosin (rDer p 10) before and after SCIT. In patients with a positive result, we also monitored the dynamics of sIgE to rDer p 10 and shrimp tropomyosin (rPen a 1) at several time points. The levels of sIgE were measured using the CAP System fluorescent-enzyme immunoassay. Results: sIgE to tropomyosin was found in only 5 patients, 3 of whom expressed low and clinically irrelevant levels of sIgE to Der p 10, while sIgE to Pen a 1 was not found. The remaining 2 patients expressed sIgE to both tropomyosins. In the first, the initial increase and subsequent decrease resembled the dynamics of the IgE antibodies usually seen in SCIT patients and were never accompanied by seafood-induced symptoms. In the other, a decrease in levels of sIgE to both tropomyosins resulted in the complete loss of his reactivity toward seafood. Conclusions: Immunotherapy using HDM extracts does not induce clinically relevant sensitization to tropomyosin. In certain cases of combined mite and seafood allergy, treatment may even lead to the improvement of food allergy symptoms. The levels of sIgE to Der p 10 and Pen a 1 may be useful monitoring markers (AU)

Antecedentes: Es un hecho incierto que la tropomiosina presente en los extractos alergénicos puede sensibilizar a los pacientes que reciben inmunoterapia Ag-específica e inducir alergia alimentaria. Objetivo: El objetivo de este estudio fue evaluar si una inmunoterapia subcutánea con extractos de ácaros del polvo de casa puede inducir a una sensibilización a tropomiosina y si esta podría ser clínicamente relevante. Métodos: Se incluyeron en el estudio 56 pacientes alérgicos al ácaro del polvo de casa, tratados con un extracto de ácaros. En todos los pacientes se analizó la IgE esp frente a tropomiosina del ácaro (rDer p 10) antes y después de la IT. En los pacientes con resultado positivo tambien se monitorizó la IgE esp frente a las tropomiosinas del ácaro y de la gamba (rPen a 1) en varios tiempos, mediante CAP-System FEIA. Resultados: En cuanto a los resultados obtenidos, la IgE esp frente a tropomiosina fue positiva únicamente en 5 pacientes, tres de los cuales mostraban valores bajos y clínicamente irrelevantes de IgE esp frente a Der p 10 y no se encontró en ningún caso IgE esp positiva frente a Pen a 1. Los otros dos pacientes mostraron IgE esp positiva a ambas tropomiosinas. En el primero de ellos se observó un incremento inicial y una posterior disminución tras la IT, dinámica similar a la observada habitualmente con los anticuerpos IgE en los pacientes sometidos a inmunoterapia subcutánea y que nunca se acompañaba de síntomas con la ingesta de marisco. En el otro caso, la disminución de la IgE esp frente a ambas tropomiosinas resultó en la completa pérdida de reactividad frente a marisco. Conclusiones: En conclusión, la inmunoterapia frente a ácaros del polvo de casa no induce a una sensibilización a tropomiosina clínicamente relevante. En algunos casos, la alergia frente a ácaros y marisco tratada con IT puede mejorar los síntomas de la alergia alimentaria. Los niveles de IgE específica frente a Der p 10 y Pen a 1 pueden ser marcadores útiles para monitorizar a estos pacientes (AU)

Effects of diisononyl phthalate on atopic dermatitis in vivo and immunologic responses in vitro.

BACKGROUND: Diisononyl phthalate (DINP), a principal plasticizer in many polyvinyl chloride products, has been shown to have an adjuvant effect on immunoglobulin (Ig) production in mice. However, the effects of DINP on allergic diseases have not been fully elucidated. OBJECTIVES: In the present study we investigated the effects of DINP on atopic dermatitis (AD)-like skin lesions induced by Dermatophagoides pteronyssinus (Dp) in atopic-prone NC/Nga mice. METHODS: Mice were injected intradermally with Dp on their ears and were exposed to DINP (0, 0.15, 1.5, 15, or 150 mg/kg/day) intraperitoneally. We evaluated clinical scores, ear thickening, histologic findings, protein expression of cytokines/chemokines in the ear, and serum levels of Ig and histamine. Furthermore, we investigated the effects of DINP on bone-marrow-derived dendritic cells (BMDCs) or splenocytes in vitro. After exposure to DINP (0-100 microM), cells were evaluated for phenotype and function. RESULTS: DINP aggravated AD-like skin lesions related to Dp. The aggravation was consistent with eosinophilic inflammation, mast cell degranulation, and thymic stromal lymphopoietin (TSLP) expression in the ear. DINP enhanced the expression of cell surface activation markers on BMDCs and their production of TARC/CCL17 (thymus- and activation-regulated chemokine) and MDC/CCL22 (macrophage-derived chemokine), as well as their capacity to stimulate Dp-specific T-cell proliferation. DINP also enhanced interleukin-4 production and Dp-stimulated proliferation of splenocytes. CONCLUSIONS: DINP can aggravate AD-like skin lesions related to Dp. The mechanisms of the aggravation might be mediated, at least partly, through the TSLP-related activation of dendritic cells and by direct or indirect activation of the immune cells.

Early allergen exposure and atopic eczema.

BACKGROUND: The relationship between exposure to indoor aeroallergens in early life and subsequent eczema is unclear. We have previously failed to show any significant associations between early life exposure to house dust mite and cat fur allergens and either sensitization to these allergens or wheeze. We have also previously reported a lower prevalence of parent-reported, doctor-diagnosed eczema by age 2 years for children exposed to higher concentrations of house dust mite, but no other associations with other definitions of eczema or for exposure to cat allergen. OBJECTIVES: To extend the exposure-response analysis of allergen exposure and eczema outcomes measured up to age 8 years, and to investigate the role of other genetic and environmental determinants. METHODS: A total of 593 children (92 x 4% of those eligible) born to all newly pregnant women attending one of three general practitioner surgeries in Ashford, Kent, were followed from birth to age 8 years. Concentrations of house dust mite and cat allergen were measured in dust samples collected from the home at 8 weeks after birth. The risk of subsequent eczema as defined by the U.K. diagnostic criteria was determined according to different levels (quintiles) of allergen exposure at birth. RESULTS: By age 8 years, 150 (25 x 3%) children had met the diagnostic criteria for eczema at least once. Visible flexural dermatitis was recorded at least once for 129 (28 x 0%). As in other studies, parental allergic history was positively associated with most eczema outcomes, as were higher maternal education and less crowded homes. No clear linear associations between early exposure to house dust mite or cat allergen were found, regardless of the definition of eczema used. The risk of eczema appeared to increase for the three lowest quintiles of house dust mite allergen exposure (odds ratio, OR 1 x 37 for third quintile compared with first), and then to fall for the two highest quintiles (OR 0 x 66 and 0 x 71) even after controlling for confounding factors. CONCLUSIONS: The lack of any clear exposure-disease relationship between allergens in early life and subsequent eczema argues against allergen exposure being a major factor causing eczema. If the lower levels of eczema at higher levels of house dust mite are confirmed, then interventions aimed at reducing house dust mite in early infancy could paradoxically increase the risk of subsequent eczema.

Exposición y sensibilización a Tyrophagus putrescentiae en una población de alérgicos a Dermatophagoides pteronyssinus en Huelva / Exposition and sensitization to Tyrophagus putrescentiae in a allergic population to Dermatophagoides pteronyssinus in Huelva, Spain

Objetivos: En este trabajo se analiza la importancia alergológica del Tyrophagus putrescentiae (Tp) en la provincia de Huelva, determinando, tanto el nivel de exposición como el grado de sensibilización a dicho ácaro en una población de alérgicos a Dermatophagoides pteronyssinus (Dpt). Además también se estudió la reactividad cruzada existente entre Dpt y Tp mediante RAST inhibición. Métodos y resultados: Se analizaron muestras de polvo de las viviendas de alérgicos a Dpt y en aquellos pacientes donde se identificó Tp se realizaron pruebas cutáneas (PC), prueba de provocación conjuntival (PCC) y/o determinación de IgE específica (RAST) a dicho ácaro. Se analizaron 136 muestras de polvo en las que Dpt fue el ácaro más frecuente (94,8 %) y Tp apareció en tercer lugar (41,1 %) tras Glycyphagus domesticus (54,4 %). De los 45 pacientes estudiados, en 23 (51,1 %), al menos dos pruebas fueron positivas, 18 (40 %) no mostraron sensibilización a Tp y en 4 (8,8 %) los datos no fueron concluyentes. Con respecto al hábitat domiciliario, 26 pacientes (57,7 %) vivían en ambiente urbano y 19 (42,2 %) en vivienda rural. Se realizó la determinación de IgE específica a Tp en 25 pacientes, siendo positiva en 12, de los cuales 7 presentaron valores superiores a 2 kU/L. No se encontró correlación significativa entre los títulos de IgE a Dpt y Tp. El experimento de RAST inhibición confirmó la baja reactividad cruzada entre ambos ácaros en los sueros analizados y sólo en un caso Dpt logró inhibir parcialmente la unión de IgE al extracto de Tp. Conclusiones: Tp es el segundo ácaro de almacén más identificado en las viviendas de los pacientes alérgicos a Dpt en la provincia de Huelva. Sin embargo, sólo la mitad de los pacientes expuestos son sensibles a dicho ácaro y viven en su mayoría en un ambiente urbano. No se ha encontrado una correlación significativa entre los títulos de IgE específica a Dpt y Tp y mediante RAST inhibición se confirma la baja reactividad cruzada entre ambos ácaros

Background: In this work we analyzed the allergological importance of Tyrophagus putrescentiae (Tp) in Huelva (SE Spain). We studied the level of exposition and the grade of sensitization to Tp in a group of patients sensitized to Dermatophagoides pteronyssinus (Dpt). The allergenic cross-reactivity between Dpt and Tp was determined by RAST inhibition. Methods and results: We analyzed house dust samples from the dwellings of allergic patients with documented Dpt sensitization. Skin test (ST), conjunctival provocation (CP) and/or specific IgE (RAST) to Tp were performed when Tp was identificated in the house dust sample of the patient. Among the 136 dust samples studied, Dpt was the most frequently identified mite species (94,8 %) and Tp was found in third position (41,1 %) after Glycyphagus domesticus (54,4 %). Among the 45 patients studied, 23 (51,1 %) presented, at least, two positive tests, 18 (40 %) were not sensitized to Tp and 4 (8,8 %) showed contradictory results. 26 patients (57,7 %) inhabited in urban areas and 19 (42,2 %) in rural regions. We determined specific IgE (RAST) to Tp in 25 patients, and the results were positive in 12, with only 7 with values greater than 2 kU/L. No significant correlation were found between IgE-antibody levels to Dpt and Tp. The RAST inhibition studies confirmed the low cross-reactivity between these mites and only in one patient Dpt partially inhibited the IgE-binding to Dpt extract. Conclusions: Tp was the second more frequent storage mite in the house dust samples from patients allergic to Dpt in Huelva. However, only half of the exposed patients were sensitized to Tp and the majority inhabited in urban areas. No significant correlation were found between IgE-antibody levels to Dpt and Tp. The RAST inhibition studies confirmed the low cross-reactivity between these mites

Identification of immunoglobulin E binding components of the two-spotted spider mite Tetranychus urticae: allergenic relationships with the citrus red mite and house-dust mite.

The two-spotted mite (TSM) is commonly found on fruit trees, herbaceous plants, and greenhouse flowers. However, a recent investigation indicated that the sensitization rate to TSM was as high as that of house-dust mites (HDMs) in nonfarmers as well as in farmers working in orchards in this country. The aim of this study was to identify immunoglobulin E (IgE)-binding components within TSM and to evaluate the allergenic relationship with the citrus red mite (CRM) and HDM. Sera were collected from eight patients who were not farmers and who had asthma with high serum-specific IgE to the TSM and from unexposed controls showing negative responses to the TSM on skin-prick test. Twelve percent sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis were applied. To evaluate allergenic relationships with HDMs and CRMs, two kinds of sera pools were used: one (A) showing positive responses to both TSMs and HDMs and the other (B) showing an isolated positive response to TSMs. ELISA inhibition tests using A and B pooled sera were conducted. The TSM-ELISA inhibition test using sera A showed significant inhibition with addition of TSMs and CRMs, partial inhibition with HDMs, and minimal inhibition with other inhalant allergens. The ELISA inhibition test using sera B showed significant inhibition with TSMs and CRMs and minimal inhibition was noted with HDMs as well as other inhalant allergens. Immunoblot analysis using individual sera showed seven IgE-binding components (75, 56, 47, 41, 37, 28, and 14 kDa) and two (75 and 14 kDa) of them were bound to IgE in > 50% of the sera tested. Seven IgE-binding components were identified within the TSM extract and two (75 and 14 kDa) could be considered major allergens. It is suggested that the TSM contains species-specific allergen in addition to shared allergens with CRMs and HDMs.

Inmunoterapia específica en área básica: II. Estudio de su eficacia / Specific immunotherapy in basic area: II. Study of its efficiency

Introducción: la inmunoterapia específica es considerada por algunos especialistas como una técnica controvertida. El estudio se ha diseñado para conocer la eficacia de la IT en la práctica clínica. Material y métodos: veinticinco niños (edad media 10,09+/- 3 años, asmáticos, fueron tratados con IT durante 20 meses (18,96 +/- 3,7 meses) y un grupo control de niños con asma, tratados con corticoide inhalados o con Beta-2 (edad 10,87 +/ 2,1 años, tiempo 19,7 +/- 2,1 meses). Se controló el ahorro de medicación, la tolerancia al esfuerzo, las variaciones del FEM y los despertares nocturnos, así como una valoración global. Resultados: en todos los parámetros estudiados, los enfermos tratados con IT obtienen mejores resultados. Además las OR son significativas (p< 0,05) en todos y cada uno de los parámetros. El FEM se incrementó en los tratados con IT en un 28,46 por ciento. Conclusiones: la IT es un tratamiento esencial en el asma infantil (AU)