Storage Mite Lepidoglyphus Destructor Research Articles

Der p 23 sensitization in patients with house dust mite respiratory allergy.

Background. The sensitization profile of patients allergic to house dust mites (HDM) and its molecular diagnosis may determine treatment and evolution of the disease. The present study investigates the prevalence of Der p 23 sensitization and its relation to asthma in a population of HDM-allergic patients. Methods. We conducted a cross-sectional study of 891 patients with HDM allergy with symptoms of rhinitis and 52.1% of them with asthma. Total and specific IgE (sIgE) was measured against Dermatophagoides pteronyssinus and its molecular components and the storage mite Lepidoglyphus destructor using ImmunoCAP. Prevalence of sensitization and levels of sIgE were analyzed according to asthma diagnosis and asthma severity. Results. Der p 23 was the predominant allergen in this population (83.7%), but IgE levels were lower than those of sIgE to Der p 1 and Der p 2. A good correlation was found between sIgE to Der p 23 and the other allergens. A total of 8.2% patients were monosensitized to Der p 23. Asthma was more frequent in patients with positive sIgE against Der p 23 than in patients without this sensitization (p = 0.027). A tendency to increase both total IgE and sIgE was observed in relation to the severity of asthma from intermittent mild asthma to persistent moderate asthma, but a substantial decrease in total IgE and sIgE was detected in more severe asthmatics. Conclusions. Der p 23 might be a prevalent allergen in regions with high rates of HDM exposure and its presence could increase the risk of asthma.

Mite and cockroach sensitisation in patients with allergic rhinitis in the Free State

Studies in patients with allergic rhinitis living in the Free State have showed grass pollens to be the predominant allergens, with house-dust mite sensitisation being less prevalent than in the coastal areas and a low rate of sensitisation to the storage mite Lepidoglyphus destructor. No studies have been conducted on sensitisation to the other storage mites, spider mites or cockroaches. We aimed to determine the prevalence of sensitisation to various house-dust mites, storage mites, spider mites and cockroaches in patients with allergic rhinitis living in the Free State. Fifty consecutive patients with allergic rhinitis attending the ear, nose and throat clinic at Universitas Hospital underwent skin-prick testing and/or ImmunoCAP RAST testing for common aero-allergens, house-dust mites, storage mites, spider mites and cockroaches. Forty-six per cent of patients were sensitised to one of the house-dust mites, with house mite sensitisation being significantly more common in patients who had previously lived at the coast. Storage mites were not common aero-allergens, while 46% of patients were sensitised to the spider mite Tetranychus urticae. Blatella germanica was the cockroach species to which patients were most commonly found to be sensitised on ImmunoCAP RAST testing, with 38% of patients being sensitised to this aero-allergen. House-dust mites, T. urticae and the cockroach B. germanica appear to be important aero-allergens in the Free State. Storage mite sensitisation is not common.

Nasal complaints and signs of disease in farmers – a methodological study

Conclusion. The methods used in this study are suitable for field studies that involve examinations of groups of workers. For individual examinations, there is no gold standard method that can discriminate work-related discomfort from other causes of rhinitis. Objectives. Studies of the effects of occupation on farmers’ health have mainly focused on lower airways; few studies have examined effects on upper airways. This study investigated nasal functions in three groups of farmers (swine, milk and grain producers) and a control group using different methods, suitable for field studies. Subjects and methods. Health-related complaints were examined and several functional tests, such as expirogram, olfactory threshold test, acoustic rhinometry, nasal lavage with biomarkers of inflammation (eosinophilic cationic proteins (ECP), myeloperoxidase (MPO), tryptase, albumin) and allergy tests were performed. The different tests were correlated to nasal complaints and to each other. Results. Nasal blockage complaints were more common among farmers; overall, nasal polyps were more frequent in grain producers. Objective parameters showed more pronounced mucosal swelling in farmers and higher concentrations of ECP in nasal lavage compared with controls. Lung function, olfactory threshold, atopy frequency and allergen-specific IgE to the storage mite Lepidoglyphus destructor did not differ between farmers and controls. Mucosal swelling measured with acoustic rhinometry was more pronounced in subjects with nasal complaints, hypersensitivity, nasal polyps and symptoms from lower airways. There was a correlation between biomarkers in nasal lavage (MPO, albumin and ECP).

Primary Structure of Lep D I, the Main Lepidoglyphus Destructor Allergen

The most relevant allergen of the storage mite Lepidoglyphus destructor (Lep d I) has been characterized. Lep d I is a monomer protein of 13273 Da. The primary structure of Lep d I was determined by N-terminal Edman degradation and partially confirmed by cDNA sequencing. Sequence polymorphism was observed at six positions, with non-conservative substitutions in three of them. No potential N-glycosylation site was revealed by peptide sequencing. The 125-residue sequence of Lep d I shows approximately 40% identity (including the six cysteines) with the overlapping regions of group II allergens from the genus Dermatophagoides, which, however, do not share common allergenic epitopes with Lep d I.

Detection of at least one high-molecular-mass, IgE-binding component of the dust mite Lepidoglyphus destructor.

We studied the allergen composition in an extract of the storage mite Lepidoglyphus destructor. Monoclonal antibodies (mAbs) were raised against L. destructor by a standard hybridoma technique. In the subsequent screening, we concentrated on mAbs fulfilling three criteria. First, in ELISA, mAbs were assessed against a panel of various mite species, and only those reacting exclusively with L. destructor extract were selected for further analyses. Secondly, mAbs were selected in immunoblotting according to whether or not a novel pattern of reactivity emerged in comparison with earlier results. Thirdly, by radioimmunoassay (RIA), we selected mAbs that recognized components which were also recognized by human IgE from sera RAST positive to L. destructor. This yielded an L. destructor-specific mAb (117F9) reacting with two previously unknown components of approximately 79 and 93 kDa, respectively. We also analyzed 80 sera for the presence of IgE binding to these components. These sera were divided into three groups according to their RAST specificity. Eighteen of the 30 sera (60%) that were RAST positive to L. destructor were also positive in RIA. Correlation was moderate between kU/l for L. destructor and the counts per minute values for the two components in RIA. The group of control sera lacking IgE antibodies against L. destructor displayed no positive results in RIA. However, 4/20 sera RAST positive to Dermatophagoides pteronyssinus but negative to L. destructor were scored as positive in RIA. We conclude that at least one of the high-mol.-mass components of L. destructor causes IgE-mediated sensitization.

Dust mite allergy: An important cause of respiratory disease in farmers

In 2,578 Swedish farmers, 6.2% were found to have an allergy to storage mites. The storage mite Lepidoglyphus destructor has been identified by both RAST and bronchial challenges as a significant cause of occupational asthma in rural environments. Immunohistochemical studies of L. destructor disclosed that at least one L. destructor allergen is associated with digestion.

Occurrence of IgE antibodies against the 39‐kDa allergen component of the mite Lepidoglyphus destructor in urban and rural subjects

Several species of storage mite have been shown to cause IgE-mediated sensitization. Monoclonal antibodies (mabs) have been raised against the storage mite Lepidoglyphus destructor, and one mab (42B6) immunoprecipitated a band of 39 kDa of L. destructor. To search for the frequency of IgE antibodies in patient sera against this allergen component, we modified a radioimmunoassay (RIA), 42B6 being used as capturing antibody. Twenty of 43 sera from farmers who were RAST positive to L. destructor (46.5%) were scored as positive in this assay. There was a moderate degree of correlation between positive RAST results to L. destructor and the 39-kDa allergen. Among 14 sera from Stockholm residents positive in RAST to both Dermatophagoides pteronyssinus and L. destructor, six detected the 39-kDa allergen component. However, three sera from urban subjects lacking IgE antibodies against both mite species also had IgE antibodies against the 39-kDa allergen. The present study demonstrates that the 39-kDa allergen of L. destructor is an important allergen, and that rural as well as urban subjects can become sensitized.

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.

Purification and characterization of Lep d I, a major allergen from the mite Lepidoglyphus destructor

A major allergen of the storage mite Lepidoglyphus destructor (Lep d I) has been purified by affinity chromatography using an anti-Lep d I monoclonal antibody. The purity of the protein obtained by this procedure was assessed by reverse-phase HPLC. Lep d I displayed a molecular weight of 14 kD on SDS-PAGE under non-reducing conditions, and 16 kD in the presence of a reducing agent. Analytical IEF revealed a little charge microheterogeneity, showing three bands with pIs 7.6-7.8. Purified Lep d I retained IgE-binding ability, as proved by immunoblotting experiments after SDS-PAGE and RAST with individual sera from L. destructor-sensitive patients. Results from the latter technique demonstrated that 87% of L. destructor-allergic patients had specific IgE to Lep d I, and a good correlation between IgE reactivity with L. destructor extract and Lep d I was found. In addition, RAST inhibition experiments showed that IgE-binding sites on Lep d I are major L. destructor-allergenic determinants, since Lep d I could inhibit up to 75% the binding of specific IgE to L. destructor extract; on the other hand, Lep d I did not cross-react with D. pteronyssinus allergens.

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.

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 results 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).

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.