Homology modeling and epitope prediction of Der f 33

Dermatophagoides farinae (Der f), one of the main species of house dust mites, produces more than 30 allergens. A recently identified allergen belonging to the alpha-tubulin protein family, Der f 33, has not been characterized in detail. In this study, we used bioinformatics tools to construct the secondary and tertiary structures and predict the B and T cell epitopes of Der f 33. First, protein attribution, protein patterns, and physicochemical properties were predicted. Then, a reasonable tertiary structure was constructed by homology modeling. In addition, six B cell epitopes (amino acid positions 34-45, 63-67, 103-108, 224-230, 308-316, and 365-377) and four T cell epitopes (positions 178-186, 241-249, 335-343, and 402-410) were predicted. These results established a theoretical basis for further studies and eventual epitope-based vaccine design against Der f 33.

Impacto de la inmunoterapia subcutánea con Dermatophagoides farinae y Dermatophagoides pteronyssinus sobre la calidad de vida de pacientes con rinitis y asma alérgica / The impact of subcutaneous immunotherapy with Dermatophagoides farinae and Dermatophagoides pteronyssinus on the quality of life of patients with allergic rhinitis and asthma

Introducción. Como sucede en otras partes del mundo, la prevalencia de asma y rinitis alérgica en Colombia está en aumento. Se ha establecido que la inmunoterapia subcutánea con alérgenos es eficaz a largo plazo en pacientes con rinitis alérgica y asma sensibilizados a Dermophagoides. Objetivo. Proveer evidencia sobre los cambios relacionados con la calidad de vida inducidos por la inmunoterapia subcutánea en sujetos con alergia respiratoria. Materiales y métodos. Se seleccionaron 76 sujetos con diagnóstico de alergia respiratoria con sensibilización a Dermatophagoides farinae y Dermatophagoides pteronyssinus . Para la evaluación de la calidad de vida se emplearon los instrumentos Kidscreen-27 y SF-36 ( Short form 36 ). Estos instrumentos se aplicaron en dos ocasiones: durante la primera visita, en la cual se iniciaba la inmunoterapia subcutánea, y un año después de haberse iniciado el tratamiento. Resultados. Al año de estar recibiendo la inmunoterapia, los 22 sujetos que completaron el estudio presentaron cambios positivos en términos de calidad de vida. En los niños, el principal cambio se presentó en el dominio del ´entorno escolar´ mientras que en los adultos fue en el de la ´función física´ . Discusión. Se evaluaron por primera vez en Colombia los beneficios inducidos por la inmunoterapia subcutánea para ácaros de polvo en la calidad de vida de sujetos con rinitis alérgica y asma mediante los cuestionarios Kidscreen-27 y SF-36. Los resultados proveen evidencia de que la inmunoterapia subcutánea influye positivamente en la calidad de vida en sujetos con rinitis asmática y asma sensibilizados a los ácaros de polvo.

Introduction: The prevalence of asthma and allergic rhinitis in Colombia is increasing at the same rate as it is in other parts of the world. It has been determined that allergen-specific subcutaneous immunotherapy is effective in subjects with allergic rhinitis and asthma that are sensitized to house dust mites: Dermatophagoides farinae and Dermatophagoides pteronyssinus . Objective: To provide evidence on changes in the quality of life of subjects induced by allergen-specific subcutaneous immunotherapy with Dermatophagoides farinae and Dermatophagoides pteronyssinus . Materials and methods: We selected 76 subjects with a diagnosis of respiratory allergy with sensitization to Dermatophagoides farinae and Dermatophagoides pteronyssinus . The instruments used for evaluating the quality of life were Kidscreen-27 and SF-36. These instruments were applied twice for each subject: once during the first visit, and during the twelfth visit corresponding to the one-year follow-up. Results: Twenty-two subjects completed this study. After one year of treatment with allergen-specific subcutaneous immunotherapy, we found positive changes in terms of the quality of life. In children, the main change was in the School Environment domain while in adults it was in the Physical Function domain. Conclusion: We evaluated, for the first time in Colombia, benefits induced by allergen-specific subcutaneous immunotherapy for dust mites in terms of quality of life in subjects with allergic rhinitis and asthma. These results demonstrated that allergen-specific subcutaneous immunotherapy produces a positive influence on subjects sensitized to dust mites that received allergen-specific subcutaneous immunotherapy to Dermatophagoides farinae and Dermatophagoides pteronyssinus after one year.

The Indoor Level of House Dust Mite Allergen Is Associated with Severity of Atopic Dermatitis in Children

We attempted to investigate the correlation between the severity of atopic dermatitis (AD) in children and the indoor level of house dust mite (HDM) allergens. Ninety-five patients (31.1 +/- 19.5 months of age) with AD were enrolled in this study, and serum specific IgE against Dermatophagoides pteronyssinus and D. farinae was measured. The severity of AD was assessed using the visual analogue scale on the same day of house dust collection. Living rooms and mattresses where the child usually slept were vacuumed for 2 minutes and concentrations of Der f 1 were measured by enzyme-linked immunosorbent assay. The skin symptoms were more severe in patients with Der f 1 concentrations in living room > 2 microg/g dust than < or = 2 microg/g dust (P = 0.018). This difference was noted in AD patients without sensitization to HDM (P = 0.004), but not in patients with sensitization. There was no difference in symptom severity according to Der f 1 concentrations in mattresses (P = 0.062). The severity of skin symptoms is associated with indoor concentrations of HDM in children with AD, and it is likely to act as nonspecific irritants as well as allergens in AD skin lesions.

Cloning, bioinformatics analysis, and expression of the dust mite allergen Der f 5 of Dermatophagoides farinae

Crude extracts of house dust mites are used clinically for diagnosis and immunotherapy of allergic diseases, including bronchial asthma, perennial rhinitis, and atopic dermatitis. However, crude extracts are complexes with non-allergenic antigens and lack effective concentrations of important allergens, resulting in several side effects. Dermatophagoides farinae (Hughes; Acari: Pyroglyphidae) is one of the predominant sources of dust mite allergens, which has more than 30 groups of allergen. The cDNA coding for the group 5 allergen of D. farinae from China was cloned, sequenced and expressed. According to alignment using the VECTOR NTI 9.0 software, there were eight mismatched nucleotides in five cDNA clones resulting in seven incompatible amino acid residues, suggesting that the Der f 5 allergen might have sequence polymorphism. Bioinformatics analysis revealed that the matured Der f 5 allergen has a molecular mass of 13604.03 Da, a theoretical pI of 5.43 and is probably hydrophobic and cytoplasmic. Similarities in amino acid sequences between Der f 5 and allergens of other domestic mite species, viz. Der p 5, Blo t 5, Sui m 5, and Lep d 5, were 79, 48, 53, and 37%, respectively. Phylogenetic analysis indicated that Der f 5 and Der p 5 clustered together. Blo t 5 and Ale o 5 also clustered together, although Blomia tropicalis and Aleuroglyphus ovatus belong to different mite families, viz. Echimyopodidae and Acaridae, respectively.

Usefulness of Total IgE in Predicting Positive Allergen Specific IgE Tests in Korean Subjects / 대한진단검사의학회지

BACKGROUND: Total IgE levels in allergic patients tend to be higher than those in healthy individuals. We evaluated the usefulness of total IgE levels in predicting positive results of allergen specific IgEs in multiple allergen simultaneous tests. METHODS: A total of 133 patients with allergic symptoms were evaluated. Allergen specific IgEs were detected using 3 different kits: Allergy screen (R-biopharm, Germany), AdvanSure Allergy Screen (LG Life Science, Korea) and Polycheck allergy (Biocheck Co., Germany). Total IgE was measured by turbidoimmunometric assay (LX-2200, Eiken Chemical Co., Japan). The patients were divided into high (> or =170 IU/mL) and low ( or =50%. Allergen specific IgEs to these two allergens showed good correlation with total IgE (correlation coefficients >0.5). CONCLUSIONS: Total IgE appears to be useful in predicting positive results in allergen specific IgE tests to common allergens. The specific IgEs to D. farinae and D. pteronyssinus showed good correlation with total IgE. However, for other allergens, significant differences were observed among different test kits, and the standardization of allergens in multiple allergen simultaneous tests is needed.

Changes in serum specific IgG4 and IgG4/ IgE ratio in mite-sensitized Taiwanese children with allergic rhinitis receiving short-term sublingual-swallow immunotherapy: a multicenter, randomized, placebo-controlled trial.

The aim of this study was to evaluate the clinical and immunologic effects of sublingual-swallow immunotherapy (SLIT). A six-month, multicenter, double-blind, placebo-controlled trial was carried out in 59 patients aged 6 to 18 years with allergic rhinitis who were sensitized to mites only. Patients were randomly assigned to placebo or SLIT with a standardized Dermatophagoides pteronyssinus (D.p.)/D. farinae (D.f) 50/50 extract. Nasal symptom scores and use of medications were recorded. Skin sensitivity, mite-specific IgE, IgG4, and IgG4/IgE were evaluated before and after treatment. The skin sensitivity, total nasal symptom scores and medication consumption did not differ significantly after treatment. Specific IgG4 (both p <0.001) and IgG4/IgE to D.p. and D.f (p = 0.010, p = 0.001, respectively) increased significantly in the treatment group. Specific IgE increased significantly in both placebo and SLIT groups after treatment but did not differ between the two groups. The medication was well tolerated. SLIT did not significantly improve clinical manifestations of allergic rhinitis when used for 6 months. We demonstrated SLIT did significantly increase specific IgG4 and IgG4/IgE compared to treatment with placebo.

Determinación de sensibilización alérgica a dermatofagoides en niños de 5 años y menores por fluoroinmuno ensayo-UniCAP / Dust mite allergic sensitization in children aged 1 month to 5 years-old using specific IgE determination by unicap fluoroimmunoassay

Dust mite sensitization is considered a major risk factor for pediatric asthma; however, there are few data about early sensitization in Chilean children available. This study aimed to investigate allergic sensitization to mites in infancy and early childhood. The patient population, 224 children aged 0 to 5 years with suspected respiratory allergy, was divided into 3 groups of age: 1 to 12 months-old, 13 to 35 months-old, and 3 to 5 years-old. Sensitization status was ascertained by assessing the specific IgE to mite by UniCAP fluoroimmunoassay (Pharmacia). Sixty eight (30.6 percent) patients were sensitized to mites. The frequency and level of sensitization increased with the age of the children. Our data support that avoidance measures in the domestic environment aimed at the primary prevention of mite-driven sensitization should be introduced at the earliest possible stage.

La sensibilización a dermatofagoides es un factor de riesgo para el desarrollo de asma. Hay escasa información sobre la sensibilización temprana en niños chilenos. Objetivo: Investigar la sensibilización a dermatofagoides en niños de 5 años y menores. Método: Revisión de resultados de IgE específica por ensayo UniCAP (Pharmacia) contra dermatofagoides de niños de hasta 5 años con sospecha de alergia respiratoria, divididos en 3 grupos de edad: 1-12 meses, 13-35 meses y 3-5 años. Resultados: Se estudió un total de 224 niños, entre 1 mes y 5 años de edad (x 2,65 años +/- 1,48 DS), 57,1 por ciento de sexo masculino. Su distribución según grupo etario fue: 66 en el grupo 1; 45 en el grupo 2 y 113 en el grupo 3. El 30,6 por ciento presentó sensibilización a dermatofagoides (18,2 por ciento grupo 1; 33,3 por ciento grupo 2 y 36,3 por ciento grupo 3). El grupo 3 presentó concentraciones de IgE específica significativamente más elevadas que los otros grupos. Conclusiones: La sensibilización a dermatofagoides es detectable en menores de un año, con frecuencia y nivel que aumentan en forma paralela a la edad.

Perfil de sensibilização a alérgenos domiciliares em pacientes ambulatoriais / Indoor allergen sensitization profile in allergic patients of the allergy clinic in the University Hospital in Uberlândia, Brazil

OBJETIVO: Conhecer o perfil de sensibilização dos pacientes com diagnóstico de doenças alérgicas atendidos no Ambulatório de Alergia do Hospital de Clínicas da Universidade Federal de Uberlândia. MÉTODOS: Foi realizado um estudo retrospectivo por meio da análise de prontuários de pacientes atendidos no serviço, que foram submetidos ao teste cutâneo de puntura (TCP) para os alérgenos de Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) e Alternaria alternata, e respondido corretamente ao questionário ISAAC. RESULTADOS: Foram analisados 212 prontuários de pacientes que preenchiam os critérios de inclusão. A rinite alérgica isoladamente foi a maior causa de atendimento (32 por cento), seguida das associações asma e rinite (29,7 por cento) e asma, rinite e eczema (9,4 por cento). Pacientes com asma isoladamente perfizeram apenas 1,9 por cento dos atendimentos. A sensibilização dos pacientes observada foi de 73,5 por cento, sendo de 61,7 por cento para Der p, 59,9 por cento para Der f, 54,7 por cento para Blo t, 45,7 por cento para Bla g, 38,2 por cento para Can f, 33,3 por cento para Fel d e 9,9 por cento para Alternaria. Não houve diferenças significantes entre as patologias encontradas e os perfis de sensibilização. CONCLUSÃO: Os principais alérgenos sensibilizantes determinados pelo TCP foram os ácaros, com predomínio de Der p e Der f, chamando a atenção a elevada prevalência de sensibilização ao último. Ainda foi observada elevada sensibilização aos alérgenos de B. germanica, superior aos estudos anteriores realizados no País.

OBJECTIVE: To evaluate allergens among patients with allergic respiratory disease attended at the Allergy Clinic of the University Hospital - Federal University of Uberlândia. METHODS: A retrospective study was performed using medical records. Patients were included if their ISAAC questionnaires were correctly filled out and their skin prick tests were positive to at least one of the allergens from Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) and Alternaria alternata. RESULTS: Two-hundred and twelve medical records fulfilled the inclusion criteria. Allergic rhinitis was the main clinical diagnosis (32 percent), followed by concomitant manifestation of asthma and rhinitis (29.7 percent), and asthma, rhinitis and atopic dermatitis (9.4 percent). Asthma alone was found only in 1.9 percent of patients. The total sensitization observed was 73.5 percent, of which 61.7 percent, 59.9 percent, 54.7 percent, 45.7 percent, 38.2 percent, 33.3 percent, 9.9 percent were sensitized to Der p, Der f, Blo t, Bla g, Can f, Fel d and Alternaria, respectively. No significant difference was found between allergic disease types and source of allergen sensitization. CONCLUSION: The highest sensitization in allergic patients under study was to dust mites, especially Der p and Der f. It is noteworthy that the number of patients sensitized to cockroach extract was uncommonly high when compared to previous studies.

Relationship between serum specific IgE and allergen skin test in allergic patients of Wuhan area / 华中科技大学学报（医学）（英德文版）

In order to study the relationship between serum specific IgE (sIgE) and allergen skin test, allergen skin tests and detections of sIgE in 220 allergic patients of Wuhan area were analyzed. The coherent rate of the two methods was beyond 70% (P < 0.01). It was concluded that the in vitro and in vivo detection methods of allergens have a high coherence and can be used as the effective ways to diagnose the allergic diseases in clinical practice.

Somatropin promotes dermatophagoides farinae-specific IgE generation independently of IL-4 and IL-10.

Interleukin (IL)-10 accelerates the IgE production of anti-CD40- and IL-4-stimulated PBMC by enhancing the IL-6 production of T lymphocytes or antigen-primed spleen cells, in addition to its role as a regulator of the inflammatory responses. To further investigate the mechanisms enhancing IgE synthesis, we determined the effect of somatropin as well as IL-10 on the secretion of Dermatophagoides farinae (Df)-specific IgE by K7 cells, which originate from an EBV-immortalized cell line. Df-pulsed autologous T cells, as well as the supernatants of these cultures, increased the synthesis of Df-specific IgE. Antigen-specific IgE was also enhanced when K7 cells were treated with anti-CD40 antibody and with both IL-4 and IL-10, or with IL-4 and IL-10 without anti-CD40 antibody. The treatment of K7 cells with anti-CD40 antibody and IL-4, or anti-CD40 antibody and IL-10 did not increase IgE production. The Df-specific IgE activity of the supernatants of K7 cells treated with somatropin alone was increased significantly although somatropin did not show any additive effect on the IgE production of anti-CD40 antibody-treated cells. The results indicate that IL-10, a Th2-type cytokine, directly affects the mature B cells that produce IgE, and that the secretion of IgE is increased by treatment with IL-10 in cells that are stimulated with anti-CD40 and IL-4 at the level of the EBV-immortalized cell line, which has already switched to IgE production. Somatropin similarly stimulates activated mature B cells to enhance their production of antigen-specific IgE without class switching, independently of IL-4 and IL-10.

Der f 2 activates phospholipase D in human T lymphocytes from Dermatophagoides farinae specific allergic individuals: Involvement of protein kinase C-alpha

The major house-dust mite allergen, Der f 2, stimulates the phospholipase D (PLD) in T lymphocytes from Dermatophagoides farinae specific allergic individuals. PLD activity increased more than two-fold in T cells from allergic patients compared with those cells from normal controls with maximal responses within 30 min after exposure of Der f 2. A well-known PLD activator PKC-alpha was found to be translocated to membrane from cytosol in Der f 2-treated T cells from Dermatophagoides farinae specific allergic individuals. Down-regulation of PKC-alpha with phorbol myristate acetate pretreatment for 24 h abolished Der f 2-induced PLD activation. Ro 320432, PKC inhibitor also reduced the effects of Der f 2-induced PLD activation suggesting that PKC-alpha acts as upstream activator of PLD in Der f 2-treated T cells. Taken together, the present data suggest that Der f 2 can stimulate PLD activity through the PKC-alpha activation in T cells from Dermatophagoides farinae allergic individuals

Endotoxin and House Dust Mite Allergen Levels on Synthetic and Buckwheat Pillows

Pillows are known to contain significant levels of indoor allergens and endotoxin, that are of importance to house dust mite sensitized asthmatics. Buckwheat pillows are commonly used in Korea. We studied the levels of the house dust mite allergen, Der f 1, and endotoxin on new synthetic and buckwheat pillows and their accumulation over three months. Endotoxin levels were significantly higher on new buckwheat pillows compared to synthetic pillows; geometric mean levels (95% CI) were 60,950 EU/g (30,270-122,700) and 4,887 EU/g (2,570-9,311) respectively (p<0.001). No Der f 1 was detected on the new pillows. After three months Der f 1 levels were similar on buckwheat and synthetic pillows, geometric mean levels (95% CI) were 1.16 microgram/g (0.02-8.13) and 1.08 microgram/g (0.19-1.68) respectively. These results indicate that buckwheat pillows are a source of very high endotoxin levels that may be of relevance to asthma severity of atopic asthmatics.