Heterogeneity of allergen content in male dog urine and dander

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Allergological characterisation of the storage mite Acarus gracilis(Acari: Acaridae)

BACKGROUND: Storage mites of the genus Acarus can be responsible for allergic sensitisation in domestic environments.Acarus gracilis is a frequent species in some geographical regions of the Iberian Peninsula. Since the allergenicity of this mite has not been described before, the objectives of this study were to characterise it immunologically, and to compare it with the closely related and more extensively studied speciesAcarus siro. METHODS: Extracts from A. gracilis and A. siro cultures were characterised by Lowry, 1D and 2D-SDS and IEF. Zymogram, and determination of different enzymatic activities were performed. Skin prick solution of A. gracilis was tested in consecutive patients attending the Hospital of Mérida (Extremadura, Spain). Serum samples from eight individuals with positive skin prick test were collected. IgE determination, immunoblot and immunoblot-inhibition studies were performed. RESULTS: Extracts of both species showed a very similar protein and allergenic profile. Allergens at 14 and 17 kDa were clearly recognised in both extracts by serum samples. Immunoblot-inhibition studies demonstrated that both extracts were totally inhibited by the opposite one. Enzymatic activity was similar in both cases with the most important differences being in kallikrein, serine protease and collagenase activities. CONCLUSION: The storage mite A. gracilis has a similar protein and allergen profile to A. siro and can induce allergic sensitisation. Due to the higher prevalence of this species respect to A. siro in some regions, more studies are needed to determine the clinical significance of sensitisation to this storage mite species

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Allergological characterisation of the storage mite Acarus gracilis (Acari: Acaridae).

BACKGROUND: Storage mites of the genus Acarus can be responsible for allergic sensitisation in domestic environments. Acarus gracilis is a frequent species in some geographical regions of the Iberian Peninsula. Since the allergenicity of this mite has not been described before, the objectives of this study were to characterise it immunologically, and to compare it with the closely related and more extensively studied species Acarus siro. METHODS: Extracts from A. gracilis and A. siro cultures were characterised by Lowry, 1D and 2D-SDS and IEF. Zymogram, and determination of different enzymatic activities were performed. Skin prick solution of A. gracilis was tested in consecutive patients attending the Hospital of Mérida (Extremadura, Spain). Serum samples from eight individuals with positive skin prick test were collected. IgE determination, immunoblot and immunoblot-inhibition studies were performed. RESULTS: Extracts of both species showed a very similar protein and allergenic profile. Allergens at 14 and 17 kDa were clearly recognised in both extracts by serum samples. Immunoblot-inhibition studies demonstrated that both extracts were totally inhibited by the opposite one. Enzymatic activity was similar in both cases with the most important differences being in kallikrein, serine protease and collagenase activities. CONCLUSION: The storage mite A. gracilis has a similar protein and allergen profile to A. siro and can induce allergic sensitisation. Due to the higher prevalence of this species respect to A. siro in some regions, more studies are needed to determine the clinical significance of sensitisation to this storage mite species.

Domestic mites on the hair/scalp, pillows, and mattresses of mite-sensitized children in a subtropical area

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Tetranychus urticae allergy in a population without occupational exposure.

BACKGROUND: Tetranychus urticae is a phytophagus mite found in the leaves of numerous plants. High sensitization rates have been demonstrated, however, provocation tests have only been performed in an occupational setting. OBJECTIVE: To assess accuracy of skin prick tests and clinical relevance of T. urticae sensitization by means of conjunctival provocation tests (CPT) in a population without occupational exposure and to evaluate possible environmental risk factors for T. urticae allergy. METHODS: Patients ≥ 18 years old sensitized to T. urticae (n = 12) and a non-sensitized control group (n = 12) were invited to perform CPT with T. urticae and fulfill a questionnaire including demographic data, questions on environmental exposure to T. urticae and allergy symptoms/diagnosis. A single-blinded placebo-controlled CPT with T. urticae (Leti®) was performed with increasing concentrations (0.002, 0.02, 0.2 and 2 mg/mL) and considered positive if conjunctival hyperemia, palpebral edema or lacrimation were observed in the tested eye. RESULTS: Of T. urticae sensitized patients (mean wheal 4.4 ± 1.5 mm), 9 had a positive CPT, including 3 monosensitized. A good diagnostic accuracy was found for skin prick tests: AUC = 0.952, sensitivity = 100%, specificity = 80%, positive likelihood ratio = 5 and negative likelihood ratio = 0 for a 3 mm wheal. No differences were found between allergic and non-allergic subjects regarding atopy, allergic disease or farming activities. CONCLUSIONS: A high prevalence of allergy to Tetranychus urticae was found in the north of Portugal. Future studies with a larger number of patients are needed to evaluate its relation to clinical symptoms and the impact of environmental factors.

Occupational Allergy to Aquarium Fish Food: Red Midge Larva, Freshwater Shrimp, and Earthworm. A Clinical and Immunological Study

Background: Chironomids seem to be the main cause of occupational allergy to aquarium fish food. Objective: The aim of this study was to investigate the pattern of occupational sensitization to 3 different arthropod species used as components of aquarium fish food. Methods: The study sample comprised 8 workers from a fish food packing department. The control group comprised 40 atopic patients (20 of whom were allergic to mites). We performed prick tests with extracts of red midge larva (Chironomus thummi), freshwater shrimp (Gammarus species), earthworm (Tubifex species), and other arthropod species and a battery of common inhalant allergens. We measured peak expiratory flow rate (PEFR) and specific immunoglobulin (Ig) E and performed a methacholine challenge test, nasal challenge test, and immunoblotting. Cross-reactivity analyses were completed using immunoblotting and CAP inhibition. Results: Prick test results were positive to red midge larvae in 7 patients (87.5%), Gammarus in 5 (62.5%), Tubifex in 3 (37.5%), and mites in 6 (75%). In the mite-allergic controls, 30% had positive prick test results to red midge larvae. PEFR decreased 􀀪20% during the packing process in all patients, and in 1 patient it indicated a dual asthmatic response. Methacholine challenge test results were positive in all participants. Nasal challenge tests were performed in 4 patients, and the results were positive. Specific IgE to red midge larvae was detected in 62.5%, Gammarus in 50%, and Tubifex in 16%. Bands of approximately 14-15 kDa and 31 kDa were observed in Gammarus and red midge larvae extracts. Cross-reactivity assays demonstrated that Gammarus totally inhibited red midge larvae, while Tubifex did so partially. Dermatophagoides pteronyssinus showed very low inhibitory capacity. Conclusions: Aquarium fish food arthropods are potent allergens with an elevated prevalence of sensitization and variable degree of cross-reactivity. This is the first report of occupational allergy to Tubifex. More data are necessary to identify and characterize the responsible allergens (AU)

Introducción: Los quironómidos parecen ser la principal causa de alergia ocupacional a la comida para peces de acuario. Objetivo: El objetivo de este estudio fue investigar el patrón de sensibilización ocupacional a tres diferentes especies de artrópodos que componen la comida para peces de acuario en 8 de 10 trabajadores expuestos con rinitis y asma en el lugar del trabajo. Métodos: Se realizaron prick-tests con extractos de Chironomus thummi, Gammarus y Tubifex, otras especies de artrópodos y batería de alérgenos inhalantes comunes. Cuarenta pacientes atópicos (20 de ellos alérgicos a ácaros) fueron utilizados como controles. Se realizaron mediciones de peak-flow, test de metacolina, pruebas de provocación nasal, determinación de IgE específica e inmunoblotting. El estudio de la reactividad cruzada se completó mediante inmunoblotting y CAP-inhibición. Resultados: 87.5% de los pacientes presentaron prick-tests positivos a larva roja (Chironomus thummi), 62.5% a Gammarus y 37.5% a Tubifex. El prick-test fue también positivo a ácaros en el 75% de los pacientes. El 30% de los pacientes controles alérgicos a ácaros tuvieron prick-tests positivos a larva roja. El peak-flow cayó ≥ 20% en todos los pacientes durante el proceso de empaquetado. En un paciente el peak-flow demostró una respuesta asmática dual. El test de metacolina fue positivo en todos. Las provocaciones nasales fueron realizadas en cuatro pacientes con resultados positivos. 62.5% de los pacientes tuvieron IgE específica positiva a larva roja, 50% a Gammarus y 16% a Tubifex. Se observaron bandas de 14-15 y 31 kDa en los extractos de Gammarus y larva roja. Las pruebas de reactividad cruzada demostraron que Gammarus inhibía totalmente a larva roja mientras que Tubifex solo lo hacía parcialmente y el extracto de D. pteronyssinus demostró muy baja capacidad de inhibición. Conclusiones: Los artrópodos componentes de la comida para peces de acuario son potentes alérgenos con una elevada prevalencia de sensibilización. Presentan un grado variable de reactividad cruzada. Es el primer caso descrito de alergia ocupacional a Tubifex. Se necesitan más datos para identificar los alérgenos responsables y su naturaleza (AU)

Occupational allergy to aquarium fish food: red midge larva, freshwater shrimp, and earthworm. A clinical and immunological study.

BACKGROUND: Chironomids seem to be the main cause of occupational allergy to aquarium fish food. OBJECTIVE: The aim of this study was to investigate the pattern of occupational sensitization to 3 different arthropod species used as components of aquarium fish food. METHODS: The study sample comprised 8 workers from a fish food packing department. The control group comprised 40 atopic patients (20 of whom were allergic to mites). We performed prick tests with extracts of red midge larva (Chironomus thummi), freshwater shrimp (Gammarus species), earthworm (Tubifex species), and other arthropod species and a battery of common inhalant allergens. We measured peak expiratory flow rate (PEFR) and specific immunoglobulin (Ig) E and performed a methacholine challenge test, nasal challenge test, and immunoblotting. Cross-reactivity analyses were completed using immunoblotting and CAP inhibition. RESULTS: Prick test results were positive to red midge larvae in 7 patients (87.5%), Gammarus in 5 (62.5%), Tubifex in 3 (37.5%), and mites in 6 (75%). In the mite-allergic controls, 30% had positive prick test results to red midge larvae. PEFR decreased > or = 20% during the packing process in all patients, and in 1 patient it indicated a dual asthmatic response. Methacholine challenge test results were positive in all participants. Nasal challenge tests were performed in 4 patients, and the results were positive. Specific IgE to red midge larvae was detected in 62.5%, Gammarus in 50%, and Tubifex in 16%. Bands of approximately 14-15 kDa and 31 kDa were observed in Gammarus and red midge larvae extracts. Cross-reactivity assays demonstrated that Gammarus totally inhibited red midge larvae, while Tubifex did so partially. Dermatophagoides pteronyssinus showed very low inhibitory capacity. CONCLUSIONS: Aquarium fish food arthropods are potent allergens with an elevated prevalence of sensitization and variable degree of crossreactivity. This is the first report of occupational allergy to Tubifex. More data are necessary to identify and characterize the responsible allergens.

Mite exposure in a Spanish Mediterranean region

Background: Knowledge of the domestic mite fauna and allergen levels is important for a correct diagnosis and treatment of mite allergy. Our objectives were to describe the domestic mite fauna in the region of Murcia, Spain, to quantify mite allergens in dust samples obtained from mattresses of this area and to assess the influence of geographical, climatic and dwelling factors. Methods: Dust samples were collected in a transversal descriptive study from mattresses of 51 patients who went to the Allergology Service, and from mattress of 81 neighbours or family members of these patients. A questionnaire about home environment was filled in and obtained by all participants. Mite identification was done by light microscopy and allergen determinations (Der p 1 and Der f 1) by monoclonal antibodies. Results: Sixteen mite species were identified in the 132 dust samples collected. The most frequent species were Dermatophagoides farinae (36% of the samples), Dermatophagoides pteronyssinus (32%) and Tyrophagus putrescentiae (5.3%). There were significant differences among climatic regions. The coastal sector had greater mite abundance, being D. pteronyssinus more frequent and abundant than D. farinae. In inland areas D. farinae was the predominant mite species. Allergen levels correlated with the concentration of Dermatophagoides, with higher levels detected in coastal regions. Average annual temperature was the main outdoor factor that correlated with higher mite concentrations. Indoor main predictor of higher levels of mites was the presence of obvious signs of humidity in the home. Conclusion: This study demonstrates the existence of a mite fauna dominated by D. pteronyssinus and D. farinae with a strong influence of climatic factors and residential characteristics(AU)

Immunogenicity of Phleum pratense depigmented allergoid vaccines: experimental study in rabbits.

BACKGROUND: Immunogenicity studies are based on accurate preclinical and clinical assessment of pharmaceutical products. The immunogenicity of modified allergen vaccines has not been fully elucidated, and the mechanisms involved are not well understood. Animal and human models have recently shown that depigmented allergoids induce specific immunoglobulin (Ig) G against individual allergens, thus supporting the clinical efficacy of these vaccines. OBJECTIVE: The aim of this study was to investigate the production of specific IgG against individual antigens and their isoforms in rabbits injected with depigmented allergoid extracts of Phleum pratense pollen. METHODS: Two New Zealand rabbits were immunized with depigmented-polymerized extracts adsorbed onto aluminum hydroxide (Depigoid) of P pratense. Rabbits were injected 3 times (35 microg Phl p 5). Specific IgG titers against native, depigmented, and depigmented-polymerized extracts and individual allergens (rPhl p 1 and rPhl p 5a) were analyzed by direct enzyme-linked immunosorbent assay. The capacity of these synthesized antibodies to recognize individual native and depigmented allergens and different isoforms was evaluated by immunoblot and 2-D analysis. RESULTS: All rabbits produced high titers of specific IgG against the 3 extracts. Rabbits injected with depigmented allergoids produced similar specific antibody titers against native, depigmented, and depigmented-polymerized extracts. Serum samples recognized individual allergens and their isoforms in the nonmodified extracts. CONCLUSION: Vaccines containing depigmented allergoid extracts of P pratense induce immunogenicity in vivo. The antibodies produced after injection of these extracts clearly recognized allergens and different isoforms in their native configuration.

Mite exposure in a Spanish Mediterranean region.

BACKGROUND: Knowledge of the domestic mite fauna and allergen levels is important for a correct diagnosis and treatment of mite allergy. Our objectives were to describe the domestic mite fauna in the region of Murcia, Spain, to quantify mite allergens in dust samples obtained from mattresses of this area and to assess the influence of geographical, climatic and dwelling factors. METHODS: Dust samples were collected in a transversal descriptive study from mattresses of 51 patients who went to the Allergology Service, and from mattress of 81 neighbours or family members of these patients. A questionnaire about home environment was filled in and obtained by all participants. Mite identification was done by light microscopy and allergen determinations (Der p 1 and Der f 1) by monoclonal antibodies. RESULTS: Sixteen mite species were identified in the 132 dust samples collected. The most frequent species were Dermatophagoides farinae (36% of the samples), Dermatophagoides pteronyssinus (32%) and Tyrophagus putrescentiae (5.3%). There were significant differences among climatic regions. The coastal sector had greater mite abundance, being D. pteronyssinus more frequent and abundant than D. farinae. In inland areas D. farinae was the predominant mite species. Allergen levels correlated with the concentration of Dermatophagoides, with higher levels detected in coastal regions. Average annual temperature was the main outdoor factor that correlated with higher mite concentrations. Indoor main predictor of higher levels of mites was the presence of obvious signs of humidity in the home. CONCLUSION: This study demonstrates the existence of a mite fauna dominated by D. pteronyssinus and D. farinae with a strong influence of climatic factors and residential characteristics.

Depigmented and polymerised house dust mite allergoid: allergen content, induction of IgG4 and clinical response.

BACKGROUND: Polymerised allergenic extracts (allergoids) are commonly used in allergen immunotherapy. Clinical efficacy and safety of these extracts have been demonstrated. Recently, allergen sequences have been identified by mass spectrometry in depigmented and polymerised (Dpg-Pol) extracts. The objectives of this study were to investigate the presence of allergens in Dpg-Pol extracts of house dust mite and to analyze the immunological changes induced by these extracts in asthmatic patients enrolled in a double-blind, placebo-controlled study. METHODS: Dpg-Pol extracts were manufactured and vaccines with a composition of 50% Dermatophagoides pteronyssinus and 50% D. farinae (100 HEPL/ml) were prepared. Allergen composition was analyzed by mass spectrometry. Patients with asthma and rhinoconjunctivitis were treated in a 1-year, double-blind, placebo-controlled, parallel-group study with 6 up-dosing and monthly maintenance injections. Specific IgE and IgG4 titres to D. pteronyssinus, Der p 1 and Der p 2 were measured in patients' sera using the CAP system and direct ELISA experiments. RESULTS: Sequences from the major allergens Der p 1 and Der p 2 and from other allergens were identified in native and Dpg-Pol extracts. There was a statistically significant increase in specific IgG4, a decrease in the ratio of IgE/IgG4 to D. pteronyssinus and a significant increase in specific IgG4 to Der p 1 and Der p 2 in the patients allotted to active treatment. CONCLUSIONS: The detection of allergen sequences suggests preservation of major and minor allergens in Dpg-Pol allergoids from house dust mites. Efficacy in asthma treatment and the increase in specific IgG4 seem to be associated with the presence of major allergens in Dpg-Pol allergen extracts.

Bronchial asthma, sensitisation and exposure to Der p1 and Der f1 in an Andean Ecuadorian school

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