N-terminal aminoacid sequence of principal allergen of storage mite Lepidoglyphus destructor.
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Allergens↗
Biomedical subjects
M van Hage-Hamsten
Publications and source records attributed to M van Hage-Hamsten.
Storage mites.
The interest in allergy to storage mites has increased over the past few years. Storage mites feed on a variety of substances and they can be found in many different products such as grain, flour, hay and straw, but also in house dust samples. The more common genera are Lepidoglyphus, Tyrophagus, Glycyphagus, Acarus and Blomia. Several species of storage mites have been shown to cause IgE-mediated sensitization among rural workers, who to a varying extent develop asthma, rhinitis or conjunctivitis when exposed to barn dust. However, a number of studies have reported on sensitization to storage mites also among urban people, indicating that sensitization is not restricted to individuals with occupational exposure. Regarding the allergenic relationship between storage mites and house dust mites, there appears to be a limited allergenic cross-reactivity between the two species. However, both species also possess their own unique allergens. Further research on identification and characterization of storage mite allergens and their cross-reactivity is required to understand the complexity of epitopes and allergens.
Agricultural Workers' Diseases↗
Monoclonal antibodies to Lepidoglyphus destructor: delineation of crossreactivity between storage mites and house dust mites.
We have developed monoclonal antibodies (MoAbs) to the storage mite Lepidoglyphus destructor (Ld). Employing these anti-Ld MoAbs Ld-MoAbs) in ELISA and ELISA inhibition techniques we have analysed the reaction pattern of Ld-MoAbs to both non-pyroglyphid and pyroglyphid mites. The storage mite Glycyphagus domesticus (Gd) exhibited most efficient inhibition, followed by Acarus siro (As), Tyrophagus putrescentiae (Tp), Dermatophagoides pteronyssinus (Dpt) and Euroglyphus maynei (Em). Of the two pyroglyphid species, Dpt showed at least 1000 times less inhibition than Gd. Two of the MoAbs immunoprecipitated a band of 39 kD whereas the third reacted weakly, with a high-molecular band of approximately 110 kD. The Ld extract was also subjected to various reagents and conditions and the antigen was heat stable, it was not affected by low pH, or sensitive to dimethyl sulphoxide (DMSO) or paraformaldehyde. After exposure of the extract to various reagents, such as protease trypsin and periodate, we conclude that the epitopes recognized by Ld-MoAbs were of carbohydrate rather than of protein nature. It would thus seem that MoAbs recognize the carbohydrate part of a glycoprotein.
Animals↗
Comparison of allergic responses to dust mites in U.K. bakery workers and Swedish farmers.
The IgE RAST response to Dermatophagoides pteronyssinus and four storage mites (Lepidoglyphus destructor, Tyrophagus putrescentiae, Glycyphaghus domesticus, and Acarus siro) was examined in 251 U.K. bakery workers and compared with that previously found in 440 Swedish farmers. Storage mites are found commonly in stored hay and grain so both these groups potentially encounter them in their work. In neither group of workers was a positive RAST (greater than or equal to 0.35 PRU) to D. pteronyssinus correlated with a positive RAST to a single storage mite. As in the Swedish farmers, significant though not strong correlations were found in the U.K. bakers between positive RAST responses to G. domesticus and L. destructor and to T. putrescentiae and L. destructor (P less than 0.05). Homologous and heterologous RAST inhibition studies showed there was low cross-reactivity between storage mites and D. pteronyssinus. L. destructor showed the least inhibition by the other antigens, suggesting it possessed the fewest common allergens. The most important difference in the IgE responses between the two groups was the much higher response to D. pteronyssinus in the U.K. bakers, which was not found in the Swedish farmers whose highest IgE response was to L. destructor.
Agriculture↗
Localization of allergens in the domestic mite Lepidoglyphus destructor.
The non-pyroglyphid domestic mite Lepidoglyphus destructor is a major source of allergen causing respiratory symptoms in farming environments. This study is the first to focus on the localization of the allergens in the non-pyroglyphid domestic mite Lepidoglyphus destructor. Cryostat-cut sections of L. destructor mite bodies and faecal pellets were probed with one of three mouse monoclonal antibodies (MoAbs) raised against L. destructor or with patient sera, and stained with immunoperoxidase. Eight sera were RAST-positive to L. destructor and L. destructor faecal pellets. These eight RAST-positive patient sera labelled the wall of the L. destructor gut and two of them also the faecal pellets. The MoAbs additionally labelled parts of the exoskeleton and reacted with a majority of the faecal pellets. Cryostat-cut sections of Dermatophagoides pteronyssinus mite bodies and faecal pellets were probed with L. destructor MoAbs, which resulted in only slight staining of a few faecal pellets. The results suggest that at least one L. destructor allergen is associated with digestion.
Adult↗
Identification of a new major allergen of 39 kilodaltons of the storage mite Lepidoglyphus destructor.
The allergen composition of a non-denatured extract of the storage mite Lepidoglyphus destructor was studied by a combination of hybridoma technology, sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) and a sandwich radio-allergosorbent test (four-step RAST). Using hybridoma technology, monoclonal antibodies (mAbs) were generated against the non denatured extract of the L. destructor. After screening by ELISA, mAb 42B6 was selected for further studies. This mAb specifically recognized an antigen of L. destructor of 39 kDa in SDS-PAGE. By a sandwich RAST, sera from 8 patients with known allergy to L. destructor were compared with control sera from 8 allergic patients. The results showed the presence of specific IgE against the 39-kDa protein in the sera of the test group, but not in the control group. There was also a good correlation observed between these data and the results obtained with the classical RAST. These results indicate that the newly identified antigen of 39 kDa is a major allergen of the storage mite Lepidoglyphus destructor.
Allergens↗
Storage mites dominate the fauna in Swedish barn dust.
The mite fauna in hay dust of 16 farms located on the island of Gotland was analysed to establish whether there is a clear relationship between environmental exposure to storage mites and development of allergic symptoms. Eight of these farms belonged to farmers with respiratory symptoms related to barn dust (RS) and eight to healthy farmers (H). All farmers had previously participated in an epidemiological survey of hypersensitivity to respiratory allergens. The symptomatic farmers had not only a positive RAST to storage mites but they developed more than a 20% fall in FEV1 when challenged with Lepidoglyphus destructor (L. destructor) extract. The asymptomatic farmers were all negative in RAST to storage mites. Mites were found on all farms and the degree of infestation varied enormously, mite counts ranging from 75-150,000 mites/g dust. Five genera were detected but the different mite species were not represented on all farms. L. destructor was the dominating species on 13 of 16 farms. Samples from RS farms contained a significantly higher number of mites than H farms. The results of this study are in good agreement with our earlier studies showing that L. destructor is the most important allergen causing symptoms from both upper and lower airways among farmers.
Agricultural Workers' Diseases↗
Comparison of clinical significance and allergenic cross-reactivity of storage mites Blomia kulagini and Lepidoglyphus destructor in Sweden and Brazil.
Comparison of the clinical significance and allergenic cross-reactivity of Blomia kulagini (B. kulagini) and Lepidoglyphus destructor (L. destructor) was made on sera from Sweden and Brazil using the radio-allergo-sorbent test (RAST) and the RAST inhibition technique. RAST-positive sera were obtained from 53 allergic Swedish farmers and 31 allergic subjects from Brazil who were positive to B. kulagini and/or L. destructor. B. kulagini was shown to be a common cause of sensitization especially in Brazil. There was a fairly high correlation between positive RAST results to L. destructor and B. kulagini based on sera from both Sweden and Brazil. The highest RAST scores were found against L. destructor in Swedish sera and against B. kulagini in Brazilian sera. The RAST inhibition studies showed that the L. destructor extract was able to inhibit the B. kulagini system (a positive RAST to B. kulagini allergen disc) in Swedish but not in Brazilian sera. In contrast, the B. kulagini extract was only able to inhibit the L. destructor system in sera from Brazil and not in sera from Sweden. This study shows that results obtained with RAST inhibition are not entirely dependent on the overall specificity of the IgE antibodies in the patient's sera, since the more subtle specificity of the primarily sensitizing allergen will dominate. Thus, conclusions drawn regarding allergenic cross-reactivity are dependent on the populations tested, and conclusions on the existence or absence of cross-reactivity, e.g. between two species of mites may be contradictory.
Adolescent↗
Immune response to Blomia kulagini and Dermatophagoides pteronyssinus in Sweden and Brazil.
The immune responses to the non-pyroglyphid mite Blomia kulagini and the pyroglyphid mite Dermatophagoides pteronyssinus were compared in 440 Swedish farmers and 34 allergic subjects from Brazil using the radioallergosorbent test (RAST). Both B. kulagini and D. pteronyssinus were shown to be a common cause of sensitization, particularly in Brazil. The highest RAST scores were found against D. pteronyssinus in sera from both countries. Allergenic cross-reactivity between the two mites was studied by the RAST inhibition technique. Both B. kulagini and D. pteronyssinus possess their own unique allergens as well as allergens in common. Thus, besides mites belonging to the Dermatophagoides genus, other pyroglyphid and non-pyroglyphid mites in different countries should be taken into consideration before starting hyposensitization treatments.
Adolescent↗
Clinical significance and allergenic cross-reactivity of Euroglyphus maynei and other nonpyroglyphid and pyroglyphid mites.
The clinical significance and allergenic cross-reactivity of the storage mites Lepidoglyphus destructor and Acarus siro and the house dust mites Dermatophagoides pteronyssinus and Euroglyphus maynei were investigated with specific IgE antibodies by use of the RAST and the RAST-inhibition technique. RAST-positive sera were obtained from 64 Swedish farmers whose test results were positive to at least one of the four mite species. E. maynei was shown to be a common cause of sensitization among the whole farming population with a prevalence of 4.5% of positive RAST reactions. Farmers with asthma alone or in combination with rhinitis were more often sensitized to storage mites and house dust mites than farmers with rhinitis only. No significant correlation was found between positive RAST resuts to L. destructor and E. maynei on the one hand and L. destructor and D. pteronyssinus on the other. Statistical significance was reached only between RAST results to E. maynei and D. pteryonssinus. However, by RAST-inhibition studies E. maynei was shown to possess its own unique allergen(s).
Adolescent↗
Bronchial provocation studies in farmers with positive RAST to the storage mite Lepidoglyphus destructor.
Bronchial provocation studies with L. destructor (L. des.) extract were made on 12 farmers with asthma who were exposed daily to stored hay and grain and had positive radio-allergo-sorbent test (RAST) to L. des. All 12 farmers developed more than a 20% fall in FEV1 to the extract. None of the symptomatic farmers who were also RAST positive to the L. des. culture medium developed an asthmatic reaction to the medium extract. Neither four healthy farmers nor two patients with asthma caused by D. pteronyssinus (D. pt.) responded to L. des. or the L. des. culture medium. Challenges with D. pt. extract were negative in two symptomatic farmers who were RAST positive to L. des. and negative to D. pt. The present study further supports our previous hypothesis that there is an IgE-mediated immunological mechanism behind L. des.-induced asthma in farmers and that atopic farmers are liable to develop occupational asthma caused by allergy to L. des..
Adult↗
Demonstration of allergen components in the storage mite Lepidoglyphus destructor by an immunoblotting technique.
The allergen composition of crude extracts of the storage mite Lepidoglyphus destructor were investigated by sodium dodecylsulphate polyacrylamide gel electrophoresis and immunoblotting. The allergen components were detected by sera from allergic farmers with a positive radioallergosorbent test to L. destructor. The allergen-antibody complexes were visualized by rabbit anti-IgE and beta-galactosidase-labelled sheep antirabbit IgG in a chromogenic substrate. Six out of the forty-three sera also had IgE antibodies to the culture medium, which were neutralized by addition of medium antigens before the demonstration of mite allergen components. A total of 11 allergen components were identified. Two of them were found to be major allergen components, identified by more than 50% of the 43 sera used in the study. These 2 IgE-binding components had molecular weights of approximately 18,000 and 16,000 daltons, respectively.
Allergens↗
Predominance of mite allergy over allergy to pollens and animal danders in a farming population.
The prevalence of IgE-mediated hypersensitivity to respiratory allergens, including Lepidoglyphus destructor (a storage mite) and Dermatophagoides pteronyssinus, was studied in a rural population of Gotland, a Swedish island in the Baltic Sea. A sample of 440 farmers underwent examination, comprising skin-prick tests (animal danders, pollens, moulds, house dust mite and wheat) and blood sampling for radio-allergosorbent tests (RAST) (birch, Timothy grass, dog, D. pteronyssinus, Cladosporium and L. destructor). The highest prevalence of positive skin-prick tests was noted for D. pteronyssinus (6.0%). Low prevalences of positive skin-prick tests, 0.7-2.7%, were found for pollens, animal danders and moulds. Among the tested allergens, D. pteronyssinus and L. destructor yielded the highest prevalences of positive RAST results, namely 5.2 and 6.8%, respectively. Most farmers with allergy to pollens and animal danders had symptoms both from the upper and lower airways and from the eyes. Among farmers with both asthma and rhinoconjunctivitis, the prevalence of positive RAST results for L. destructor and D. pteronyssinus were simiar. The present study clearly demonstrates that mites are by far the most important allergens in the farming population on Gotland, whereas otherwise common allergens such as pollen and animal danders are clearly less significant.
Adolescent↗
Lack of allergenic cross-reactivity between storage mites and Dermatophagoides pteronyssinus.
The allergenic cross-reactivity between storage mites (Lepidoglyphus destructor, Glycyphagus domesticus, Tyrophagus putrescentiae and Acarus siro) and the house dust mite Dermatophagoides pteronyssinus was studied with the radio-allergo-sorbent test (RAST) and the RAST inhibition technique. RAST-positive sera were obtained from fifty-three farmers who were positive to at least one of the four storage mites. Sera from twelve of these farmers, eight of whom were also positive to D. pteronyssinus, were investigated with the RAST inhibition technique. No significant correlations were found between IgE-antibody levels to any single storage mite and D. pteronyssinus. There was no correlation between the RAST results to A. siro and G. domesticus, whereas a significant correlation was found between L. destructor, G. domesticus and T. putrescentiae. The RAST inhibition studies confirmed the greater allergenic similarity between L. destructor, G. domesticus and T. putrescentiae than between A. siro and the other three storage mites. The results of our studies support the hypothesis that each of the storage mites and D. pteronyssinus possess their own unique allergen or allergens. Furthermore, L. destructor, G. domesticus and T. putrescentiae seem to be allergenically more closely related to each other than to A. siro.
Agriculture↗
Occurrence of allergy to storage mites and IgE antibodies to pollens in a Swedish farming population.
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Adolescent↗
Storage mite allergy is common in a farming population.
The prevalence of storage mite allergy was investigated in an epidemiological study of respiratory symptoms in farmers on Gotland, an island in the Baltic Sea. A questionnaire concerning work-related and chronic symptoms from the airways and eyes was completed by 2578 farmers. A sample of 440 farmers subsequently underwent examination comprising skin-prick tests (animal danders, pollens, moulds and house dust mite), blood sampling for RAST against four storage mites (Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae and Glycyphagus domesticus) and total IgE analyses. Immediate onset hypersensitivity reactions in the airways and eyes were very common among active farmers on Gotland, the prevalence being as high as 40.0%. The prevalence of atopic allergy was 15.6%. Allergy to storage mites was diagnosed, from the case history and a positive RAST to at least one of the four storage mites, in fifty-two of 440 studied farmers (12%), corresponding to a calculated prevalence of storage mite allergy in the whole farming population of Gotland of 6.2%. The corresponding prevalence among farmers with hypersensitivity symptoms was 15.4% and among those with possibly IgE-mediated symptoms it was as high as 37.8%. The present study clearly demonstrates a high prevalence of allergy to storage mites among farmers with respiratory symptoms.
Adolescent↗