Tyrophagus putrescentiae group 4 allergen allergenicity and epitope prediction

INTRODUCTION AND OBJECTIVES

Allergen-specific immunotherapy (ASIT) is the only allergic disease-modifying therapy available for children and adults, and recombinant allergens are an interesting approach to improve allergy diagnosis and ASIT. Tyrophagus putrescentiae is a common storage mite that produces potent allergens. The aim of this study was to express and characterize recombinant group 4 allergen protein of T. putrescentiae (Tyr p 4), and to further investigate allergenicity and potential epitopes of Tyr p 4.

MATERIALS AND METHODS

The cDNA encoding Tyr p 4 was generated by RT-PCR and subcloned into pET-28a(+) plasmid. The plasmid was then transformed into E. coli cells for expression. After purification by nickel affinity chromatography and identification by SDS-PAGE, recombinant Tyr p 4 protein was used for a skin prick test and an ELISA to determine the allergic response.

RESULTS

Study participants' allergic response rate to Tyr p 4 protein was 13.3% (16/120). Eight B-cell epitopes and three T-cell epitopes of Tyr p 4 were predicted.

CONCLUSIONS

Similar to group 4 allergens of other species of mite, allergenicity of Tyr p 4 is weak. The expression, characterization and epitope prediction of recombinant Tyr p 4 protein provide a foundation for further study of this allergen in the diagnosis and ASIT of storage mite allergy.

Evaluation of Sensitivity Toward Storage Mites and House Dust Mites Among Nasobronchial Allergic Patients of Kolkata, India

House dust mites (HDMs) are the major constituents of house dust (HD). HD and HDM sensitization is well documented worldwide. Storage mite (SM) sensitization is presently lacking from India. The present study evaluated the sensitization of both HDM and SM among 372 allergic rhinitis patients reported to the Allergy and Asthma Research Center of Kolkata metropolitan, India. HD samples were collected from the patients' home and analyzed for the major constituent mites. HD and six constituent mites Dermatophagoides pteronyssinus (DP), Dermatophagoides farina Hughes (Acari: Pyroglyphidae) (DF), Blomia tropicalis (BT), Acarus siro Linnaeus (Acari: Acaridae) (AS), Lepidoglyphus destructor (LD), and Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) (TP) are tested for the allergenic potential through Skin Prick Test (SPT). Three SMs, namely AS, LD, and TP, were newly included in the mite SPT extract for the first time in Kolkata. In total, 330 patients showed significant positive SPT toward any one allergen tested. HD was the major elicitor exhibiting 92.42% response. Individuals of age group 15-40 were the worst sufferers. DF showed the highest sensitization (87.87%) among the dust mites. The SMs also contributed significantly to prove their sensitizing potential. SPT rates for AS, LD, and TP were 33, 25, and 18%, respectively. SPT grades and total Immunoglobulin E (IgE) were positively correlated for each of the allergens. Most of the patients were multi-sensitized (95%) and represented markedly high total IgE levels (>500 IU/ml). Three SMs proved to be significant allergens for the studied population. The sensitization toward these SMs is first time reported from India and can be recommended for inclusion of routine SPT for better outcome in the future.

Equine intradermal test threshold concentrations for house dust mite and storage mite allergens and identification of stable acari fauna

BACKGROUND

House dust mite (HDM) and storage mite (SM) stable fauna and their associated equine intradermal test (IDT) threshold concentrations (TCs) for the midwestern region of the USA are unknown.

HYPOTHESIS/OBJECTIVES

To determine IDT TCs and serum IgE concentrations for two HDM and three SM species in clinically normal horses over two seasons, and to identify the mite taxa and habitats in a stable.

ANIMALS

Thirty-eight clinically normal horses.

METHODS

Threshold concentrations for HDMs and SMs were determined using IDT subjective measurements and a statistical model. An enzyme-linked immunosorbent assay was used to quantify serum IgE concentrations for the same mite species. A modified flotation method was used to identify morphologically HDMs and SMs.

RESULTS

Subjective IDT TCs were as follows: 1:80,000 w/v for Dermatophagoides farinae in both seasons; 1:80,000 w/v in spring and 1:160,000 w/v in late summer for Dermatophagoides pteronyssinus; 1:40,000 w/v in spring and 1:20,000 w/v in late summer for Acarus siro; 1:20,000 w/v for Lepidoglyphus destructor in both seasons; and 1:20,000 w/v in spring and 1:10,000 w/v in late summer for Tyrophagus putrescentiae. Statistically significant associations for increased serum IgE and a positive IDT reaction were evident for D. farinae in the spring and D. pteronyssinus in both seasons. One mite from all four genera specific to this study was identified; however,two HDM and A. siro species were not detected.Conclusions and clinical importance – This study established HDM and SM IDT dilution concentrations for the horses in this region. Exposure to diverse acaridae fauna may contribute to the pathogenesis of equine allergic disease.

Effect of different diets on Tyrophagus putrescentiae population and amelioration of their immunological disorder by garlic

BACKGROUND

The storage mite, Tyrophagus putrescentiae, detected in the samples collected from stored products and house dust, is one of the major causes of allergic disorders.

OBJECTIVE

The purpose of this study was to ameliorate the T. putrescentiae faeces allergic immunological disorder by garlic.

METHODS

Albino experimental rats were classified into control, inhaled and treated groups. Mass rearing of T. putrescentiae on different diets, and ELISA of some cytokines and IgE techniques were used.

RESULTS

The results obtained showed the highest population of T. putrescentiae reared in four from thirteen tested diets. In addition, significantly higher serum levels of INF-γ and IgE were found in rats treated with faeces than the other groups; especially the garlic-treated group. In contrast, IL-4 was lower in faeces-treated rats than the others; however, the control group had the highest level of IL-4. Statistical analysis of data showed a significant difference between the garlic-treated group and either control or faeces-treated groups (P<0.05).

CONCLUSIONS

The population of T. putrescentiae mites peaked in four from thirteen tested diets. The immunological disorder caused by repeated exposure to T. putrescentiae faeces might be modulated by garlic.

Immune responses to tyrophagus putrescentiae-induced airway inflammation in mice

BACKGROUND

Storage mites are a source of aeroallergens that affect patients with allergic rhinitis and asthma. Tyrophagus putrescentiae is a causative factor of airway hypersensitivity, but the mechanisms and pathogenesis of Tputrescentiae-induced allergy are not well understood.

OBJECTIVE

This study aimed to develop a murine model of T putrescentiae-induced allergic asthma.

METHODS

Immune responses and physiologic variations in immunoglobulins (Ig), leukocyte subpopulations, cytokines, gene expression, pulmonary function, and lung pathology were evaluated after intraperitoneal sensitization and intratracheal challenge with crude extract of T putrescentiae.

RESULTS

After sensitization with aluminum hydroxide and challenge with T putrescentiae in mice, levels of T putrescentiae-specific IgE and IgG1 in sera increased significantly compared to the normal saline group (P < .01): Values for inflammatory leukocytes (neutrophils and eosinophils) and cytokines (interleukin [IL] 4, IL-5, and IL-13) increased significantly after sensitization. In terms of pulmonary function, pause values were significantly enhanced in T putrescentiae-sensitized mice after intratracheal challenge with T putrescentiae (P < .05). Expression of type 2 helper T cell (T(H)2)-related genes (IL4, IL5, IL13, and RANTES), T(H)2-specific transcription factor (GATA-3), and proinflammatory genes (IL6), and T(H)(H)17-related genes (IL17F) increased significantly after airway challenge. Sensitization with T putrescentiae crude extract led to inflammation of lung tissue, thickening of the tracheal wall, and tracheal rupture.

CONCLUSIONS

Intraperitoneal sensitization followed by intratracheal challenge with crude extract of T putrescentiae can induce airway inflammation in BALB/c mice. The symptoms observed in a mouse model of allergic asthma, in terms of immune and clinical parameters, are reminiscent of the symptoms of allergic asthma in humans. A mouse model can be used to evaluate the therapeutic effectiveness of drugs on T putrescentiae-induced airway inflammation in humans.

Enzymatic activity of allergenic house dust and storage mite extracts

Proteases are involved in the pathogenicity of allergy, increasing epithelial permeability and acting as adjuvants. Enzymatic activity is therefore important for the allergenicity of an extract and also affects its stability and safety. However, the enzymatic activity of extracts is not usually evaluated. The objective of this study was to evaluate the enzymatic activity of the most allergenic mite extracts and to investigate their allergenic properties. Extracts from nine allergenic mite species (Dermatophagoides pteronyssinus, Dermatophagoides farinae Hughes, Euroglyphus maynei, Lepidoglyphus destructor, Tyrophagus putrescentiae (Schrank), Glycyphagus domesticus (DeGeer), Acarus siro L., Chortoglyphus arcuatus, and Blomia tropicalis) were characterized. Protein and allergen profiles were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and western-blot, respectively. Gelatinolytic activity was evaluated with a zymogram and the activity of other enzymes (cysteine, serine proteases, and esterases) was evaluated individually or with the API-ZYM system. The main differences in protease activity were found between house dust mites and storage mites. House dust mites presented higher cysteine protease activity while storage mites presented higher serine protease activity. These differences are in line with their trophic specialization. A wide range of different activities was found in all the extracts analyzed, reflecting the fact that the extracts preserve the activity of many enzymes, this being necessary for a correct diagnosis. However, enzymes may act as adjuvants and, therefore, could lead to undesirable effects in immunotherapies, making this activity not suitable for treatment products. Modified extracts with lower enzymatic activity could be more appropriate for immunotherapy.

Effect of stored product mite extracts on human dermal microvascular endothelial cells

Stored product mites commonly occur in agricultural work environments and sometimes in homes in significant numbers. They are a source of allergens that sensitize and induce allergic reactions. This may include atopic dermatitis. The purpose of this investigation was to determine if the common species of storage mites are the sources of molecules that influence the function of human dermal microvascular endothelial cells that regulate the trafficking of inflammatory and immune cells into the dermis during allergic reactions and other skin diseases. Human dermal microvascular endothelial cells were challenged with varying doses of extracts of the storage mites Acarus siro L., Chortoglyphus arcuatus (Troupeau), Lepidoglyphus destructor (Schrank), or Tyrophagus putrescentiae (Schrank) and the secretion of cytokines and expression of adhesion molecules were measured. The role of endotoxin and protein in inducing these responses was evaluated. These stored product mite extracts induced secretion of interleukin-6, interleukin-8, monocyte chemotactic protein-1, and granulocyte/monocyte colony stimulating factor. Some of these effects were induced by protein present in the extracts, some were induced by endotoxin, and some were induced by other substances. C. arcuatus and T. putrescentiae extracts also down-regulated tumor necrosis factor a-induced vascular cell adhesion molecule-1 expression. Stored product mite extracts contain an assortment of molecules, including endotoxins and proteins, which modulate the expression of cell adhesion molecules and the secretion of cytokines by microvascular endothelial cells. These modulating properties varied among mite species indicating that each mite species has a unique set of molecules that is responsible for its activity.

Rapid method for the detection of storage mites in cereals: feasibility of an ELISA based approach

This paper describes the development of rapid immunodiagnostic tests for the detection of storage mite infestations in cereals and cereal products. The study's first phase (proof of concept) involved the production of a species-specific enzyme-linked immunoassay (ELISA) for the flour mite, Acarus siro (L.), a major pest of stored commodities. The specificity of this new assay was assessed against key stored product contaminants (13 species of mites of which three were predatory, five species of insects and five species of fungi) in the presence and absence of grain. The assay was species-specific (no cross-reactivity to other storage contaminants) and was unaffected by the presence of cereal antigens in the extract. In the study's second phase, species- and genera-specific ELISAs were developed for a range of key storage mite pests: the cosmopolitan food mite (Lepidoglyphus destructor), the grocers' itch mite (Glycyphagus domesticus), the grainstack mite (Tyrophagus longior), mites of the Tyrophagus and Glycyphagus generas, and all storage mites. All tests were demonstrably specific to target species or genera, with no cross-reactions observed to other storage pest contaminants or cereals. The final, validation phase, involved a comparative assessment of the species-specific A. siro and the genus-specific Tyrophagus ELISAs with the flotation technique using laboratory and field samples. Both ELISAs were quantitative (0-30 mites per 10 g wheat) and produced good comparative data with the flotation technique (A. siro r(2)=0.91, Tyrophagus spp. r(2)=0.99).

[Identification and purification of Tyrophagus putrescentiae allergens]

OBJECTIVE

To identify and purify the allergens of Tyrophagus putrescentiae.

METHODS

Tyrophagus putrescentiae extract was analyzed by SDS-PAGE and Western blotting, and was partially purified by DE52 anion-exchange chromatography and HiLoad 16, 60 Superdex 200 prep grade Size-exclusion chromatography.

RESULTS

23 bands were found after SDS-PAGE with comparative molecular weight (Mr) of 177,000, 118,000, 107,000, 70,000, 67,000, 60,000, 52,000, 45,000, 41,000, 40,000, 38,000, 37,000, 35,000, 27,000, 23,000, 22,000, 18,000, 17,000, 16,000, 15,000, 14,000, 13,000 and 12,000. Five allergens were detected by Western blotting with Mr 128,000, 67,000-70,000, 36,000-37,000, 18,000 and 16,000, respectively. The positive reaction rate of 3 allergens, with Mr 128,000, 67,000-70,000 and 36,000-37,000, were 100%, while that of other 2 allergens with Mr 18,000 and 16,000 was 77.8% and 44.4% respectively. The allergen with Mr 18,000 was purified by anion-exchange chromatography and Size-exclusion chromatography.

CONCLUSION

Four major allergens and one minor allergen from Tyrophagus putrescentiae have been identified.

Use of nasal provocation test in the diagnostics of occupational rhinitis

OBJECTIVES

The purpose of the study was to evaluate the usefulness and clinical value of the nasal provocation test (NPT) with various allergens and non-IgE-mediated irritants in the diagnostics assessing occupational rhinitis.

METHODS

A large number nasal provocation data from patients with suspected occupational rhinitis was evaluated retrospectively. The results of nasal provocation tests with different agents, as well as the correlation of nasal scoring to weighed mucus secretion, were analyzed.

RESULTS

Altogether 507 NPTs were done in three years in 165 persons. In total, 39% of the allergen provocations (125/318) were positive. The most common positive reactions were against flours, animal epithelia, storage mites and various plants. Wood dusts, mainly through non-IgE-mediated reactions, gave 50% positive results. Positive NPTs to moulds were observed mainly in sensitized patients. Altogether, 10% of the control provocations were positive. The weighting of mucus secretion added sensitivity of NPT.

CONCLUSIONS

The NPT is an essential standard tool in the diagnostics of allergic occupational rhinitis; however it needs to be evaluated in the context of the medical and work history and knowledge of sensitization. Although expensive and laborious, NPT is safe and easy for the patient. We still need reliable diagnostic tools for non-allergic work-related rhinitis.

Allergic sensitization to common airborne allergens among adults in Estonia

BACKGROUND

Allergies and asthma exhibit a growing health problem in the world. Sparse data are available about the prevalence of allergic sensitization in Estonia and Eastern Europe as well. We studied the prevalence of allergic sensitization, the associations between respiratory symptoms and allergic sensitization, and the influence of age, gender, area of residence, number of siblings and other demographic attributes on allergic sensitization in the population aged 17-69 years.

METHODS

We conducted a cross-sectional study with 1,346 randomly selected participants distributed in 3 geographically and culturally distinct areas of Estonia. Sensitization to 15 aeroallergens was assessed by skin prick tests. The study also included a structured interview.

RESULTS

The total prevalence of allergic sensitization was 33.0%. When estimated in patients aged 20-44 years, the prevalence was 38.5%. The most common sensitizer was cockroach followed by storage mites, while sensitization to cat, dog or pollen (common sensitizers in Scandinavian countries) was low. Allergic sensitization was significantly more common in urban and suburban compared with rural areas. Storage mites were the most common sensitizers in rural areas. Living in urban or suburban areas before the age of 5 significantly increased the risk for positive skin prick tests to several allergens.

CONCLUSIONS

A higher prevalence of allergic sensitization than previously believed was found. Cockroach and storage mite allergens are suggested to be included in the routine investigation panel in Estonia.

Immunoglobulin E binding reactivity of a recombinant allergen homologous to alpha-Tubulin from Tyrophagus putrescentiae

Storage mites may cause allergic respiratory diseases in urban areas as well as pose an occupational hazard in rural areas. Characterization of storage mite allergens is important for the development of diagnostic and therapeutic agents against mite-associated allergic disorders. Here we report on the cloning and expression of alpha-tubulin from the storage mite (Tyrophagus putrescentiae). The deduced amino acid sequence of the alpha-tubulin from the storage mite showed as much as 97.3% identity to the alpha-tubulin sequences from other organisms. The highly conserved amino acid sequences of alpha-tubulins across different species of mites may indicate that cross-reactivity for this potential allergen exists. The frequency of immunoglobulin E reactivity of this recombinant protein is 29.3% in sera from storage mite-allergic subjects.

Prevalence of serum IgE to storage mites in a southwestern Ohio population

BACKGROUND

Storage mites of the families Chortoglyphidae, Glycyphagidae, Echimyopodidae, and Acaridae are commonly found in agricultural and nonagricultural environments. The prevalence of sensitization to these storage mites in the general population in the United States is unknown.

OBJECTIVE

To determine the prevalence of serum IgE to the storage mites Lepidoglyphus destructor and Acarus siro and to evaluate the degree of co-sensitization to various other astigmatid mites in a population in southwestern Ohio.

METHODS

Serum samples from 600 people randomly selected from a 1-day submission of approximately 3,000 samples to a clinical diagnostic laboratory were screened for IgE to allergens of L destructor and A siro. Proteins in the extracts of each mite were electrophoretically separated, transferred to membranes, and incubated in the serum samples, and the slot blots were probed for IgE binding using radiolabeled anti-human IgE and autoradiography.

RESULTS

Thirty-two (5.3%) of the 600 serum samples screened had IgE to allergens from at least 1 of the 2 mite species; 14 (2.3%) and 20 (3.3%) had serum IgE to proteins of the mites A siro and L destructor, respectively. Additional analysis revealed that most serum samples also had IgE that bound to proteins in extracts prepared from a variety of other astigmatid mite species, but IgE binding profiles suggested little cross-reactivity.

CONCLUSIONS

Sensitization to the mites L destructor and A siro is significant in this region of southwestern Ohio. Further studies are needed to determine the importance of these and other storage mites in occupationally exposed and urban populations of the United States.

Occupational rhinitis: diagnostic criteria, relation to lower airway symptoms and IgE sensitization in bakery workers

CONCLUSIONS

The use of different diagnostic criteria has considerable consequences for the prevalence estimates of occupational rhinitis. There is a strong relationship between occupational rhinitis and lower airway symptoms. Storage mites appear to be important occupational allergens in Norwegian bakeries.

OBJECTIVES

To study the consequences of various diagnostic criteria on the prevalence of occupational rhinitis, assess the prevalence of IgE sensitization and explore the relationships between upper and lower airway symptoms and between symptoms and IgE sensitization.

MATERIAL AND METHODS

A total of 197 employees in 6 bakeries were interviewed and completed a questionnaire. A skin prick test was performed, total and specific IgE were determined and a histamine release test was performed for relevant allergens. The criteria for the diagnosis of occupational rhinitis were based on the 1994 International Consensus Report on Rhinitis.

RESULTS

The prevalence of occupational rhinitis varied between 23% and 50%, depending on the criteria used. The occurrence of nasal symptoms was found to precede the development of lower airway symptoms. Occupational rhinitis, both IgE- and non-IgE-mediated, was associated with asthma symptoms. The most frequent causes of sensitization (20%) were different species of storage mites. Storage mite sensitization was related to occupational rhinitis and work exposure.

Immunoglobulin E reactivity of recombinant allergen Tyr p 13 from Tyrophagus putrescentiae homologous to fatty acid binding protein

The storage mite, Tyrophagus putrescentiae, is one of the important causes of allergic disorders. Fifteen allergenic components were demonstrated in storage mite by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, but only the group 2 allergen Tyr p 2 has been cloned and characterized. In this study, we attempted to identify and characterize new allergens from T. putrescentiae, which is a dominant species of storage mite in Korea. Expressed sequence tags were analyzed to identify possible storage mite allergens, and the cDNA sequence encoding a protein homologous to fatty acid binding protein, a mite group 13 allergen, was identified and named Tyr p 13. Its deduced amino acid sequence showed 61.1 to 85.3% identity with other mite group 13 allergens. The recombinant protein was expressed in Escherichia coli using a pET 28b vector system, and its allergenicity was investigated by enzyme-linked immunosorbent assay (ELISA). The recombinant allergen was detected in 5 of 78 (6.4%) T. putrescentiae-positive sera tested, and it inhibited 61.9% of immunoglobulin E binding to crude extract at an inhibitor concentration of 10 mug/ml by inhibition ELISA using serum from the patient who showed the strongest reaction by ELISA. In this study, a novel allergen was identified in T. putrescentiae. This allergen could be helpful for more-detailed characterizations of storage mite allergy.

Direct activation of gelatinase B (MMP-9) by hay dust suspension and different components of organic dust

Matrix metalloproteinases (MMPs) are involved in tissue destruction in allergic airway diseases. We studied the ability of various allergenic substances to directly activate recombinant 92kDa proMMP-9. The substances included hay dust suspension (HDS) and its components (supernatant, particulate matter and wash fluid of particulate matter), storage mite extract and two Aspergillus fumigatus extracts. The allergen suspensions were incubated in vitro with proMMP-9. After incubation the conversion of proMMP-9 to 10kDa lower active forms were studied using gelatin zymography and Western immunoblot quantified by computerized densitometry. All studied allergens except HDS significantly and efficiently activated proMMP-9 as compared to a negative control. At the concentrations employed, the most potent activators were A. fumigatus extracts and mite suspension. The greater potency of mite and fungi as proMMP-9 activators suggests that these allergens may be more damaging to airways even at low concentrations.

Intradermal testing with the storage mite Tyrophagus putrescentiae in normal dogs and dogs with atopic dermatitis in Colorado

The purpose of this study was to evaluate reactions to intradermal injections of Tyrophagus putrescentiae extract in healthy dogs and dogs with atopic dermatitis and to compare the prevalence of positive reactions in the two groups. Twenty-one healthy dogs and 26 atopic dogs were tested intradermally with T. putrescentiae extract at 1000, 500, 250, 125, 63, 32 and 16 PNU/mL. Reactions were evaluated objectively and subjectively. A Mann-Whitney test was used to determine differences in grade of reaction to storage mites between healthy dogs and dogs with atopic dermatitis. Positive reactions to storage mite extract were most common at 1000 PNU/mL with approximately one third of normal and atopic dogs showing a positive reaction to T. putrescentiae. There was no significant difference in the incidence of positive reactions between normal and atopic dogs for any of the Tyrophagus extract concentrations.

[Exposition and sensitization to Tyrophagus putrescentiae in a allergic population to Dermatophagoides pteronyssinus in Huelva, Spain]

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.

Sensitization to the storage mite Tyrophagus putrescentiae in urban population of Upper Silesia (Poland)

Exposure to indoor allergens, especially dust mites has been recognized as a risk factor for sensitization and allergy symptoms that in extreme conditions could develop into asthma. To determine specific antigens responsible for allergy in patients positive for mite allergy skin tests whole protein extracts from the cultured mite species Tyrophagus putrescentiae [TP], and from their excrements were obtained. The proteins were fractionated by SDS PAGE and identified by Western blot. The patient antibodies against particular antigens were identified in serum IgE fraction using anti-human anti-IgE monoclonal antibody. Western blot analysis revealed differences in reactivity of sera from patients positive for standard mite allergy skin tests with fractionated mite antigens. A total of 17 of 30 sera (56.7%) from patients positive to skin tests showed specific cross reactivity with antigens isolated from extracts of TP. The results revealed that 12 out of 30 tested sera (40.0%) reacted specifically with new antigens identified as protein fractions of extracts from excrements of TP. When assessing mite allergen reaction using mixture of mite proteins the results of the test are not satisfactory for determining the antigen causing patient allergy. The results obtained from studies reported here indicate significant discrepancy between the so called standard allergy skin test and what the patient is actually sensitive to. Also, a new class of immunizing protein of about 25 kDa has been identified in excrements from TP reacting with IgE from patients showing allergy to other mite extracts. A total of 4 of 30 sera (approx. 13.3%) from patients positive to skin tests showed specific cross reactivity with antigens isolated from mite excrements rather than from mite whole extracts.

The influence of temperature and relative humidity on the development of Lepidoglyphus destructor (Acari: Glycyphagidae) and its production of allergens: a laboratory experiment

Laboratory experiments with Lepidoglyphus destructor on a diet of mainly whole wheat were conducted to study the mite's development and production of a specific allergen, Lep d 2, at four different temperatures (5, 10, 15 and 20 degrees C) and three levels of relative humidity (ca. 70-88%). Statistical models were used to analyse the role played by temperature, relative humidity and time in explaining the observed number of L. destructor and the amount of allergen produced. Moreover, the life stage distributions of the mites were determined and related to the population growth. Based on a statistical model the intrinsic rate of natural increase, rm, was computed for a range of different temperatures and relative humidities. High relative humidity in combination with temperatures at about 25 degrees C will lead to the highest rm (ca. 0.15 day-1). The highest concentration of Lep d 2 was 3 micrograms g-1 grain, found at 20 degrees C and high relative humidity at a mite density of 254 mites g-1 grain. The concentration of allergens in the grain was best explained by a model that incorporated both the current and the cumulative numbers of mites.

Serum immunoglobulin E against storage mite allergens in dogs with atopic dermatitis

OBJECTIVE

To determine the prevalence of serum IgE against the storage mites Acarus siro, Blomia tropicalis, and Tyrophagus putrescentiae in a population of dogs with atopic dermatitis.

SAMPLE POPULATION

Sera from 84 dogs with atopic dermatitis residing in various regions of the United States and Europe.

PROCEDURE

Immunoblotting of sera from atopic dogs was used to identify proteins in mite extracts that bound IgE.

RESULTS

94% of the dogs had serum IgE against proteins in extracts of 1 or more of the storage mite species. Ninety-five, 92, and 89% of the storage mite-sensitive dogs had serum IgE against proteins in extracts of A siro, B tropicalis, and T putrescentiae, respectively. Eighty-two percent had serum IgE against at least 1 protein in all 3 species. Most of the major allergens had molecular weights > 80 kd. A greater percentage of the dog sera had IgE against storage mite proteins, compared with proteins of the house dust mites Dermatophagoides farinae and D pteronyssinus.

CONCLUSION AND CLINICAL RELEVANCE

Many dogs with atopic dermatitis have serum IgE against many allergens of storage mites. Most of these allergens, like allergens of dust mites, had molecular weights > 80 kd. Storage mite sensitivity in dogs may be as important, if not more important, than dust mite sensitivity.