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PubMed1996

The Allergen Bank: a source of extra contact allergens for the dermatologist in practice.

The Allergen Bank was established to give dermatologists easy access to special test materials in order to make early diagnoses of special cases of allergic contact dermatitis. The Allergen Bank comprises a computer system to register several hundred contact allergens in appropriate patch test concentrations available at the allergy laboratory and the patch test results. At the request of dermatologists in practice for Allergen Bank may supply special contact allergens for aimed patch testing of contact dermatitis patients. The organization of the Allergen Bank and the procedure of its use are described. During its first 23 months 28 dermatologists asked for 2,209 allergen samples for testing of 386 patients, an average of 6 allergens per patient and 14 patients per dermatologist. A total number of 164 positive reactions have been registered, and 440 of the 540 allergens have been in use. One third of the positive reactions were caused by the 16 most frequently ordered allergens, which amounted to 340 allergen samples. The allergens included plant chemicals, acrylates, animal feed additives, fragrance chemicals and preservatives. Selected allergens were investigated for stability during handling and shipping under varying conditions relevant to the function of the Allergen Bank. The possible inhomogeneity of petrolatum based allergen preparations is discussed in relation to diagnostic patch testing.

Allergens↗
PubMed1991

[Reappraisal of inhalant allergens available for allergy practice in Japan. A need to increase allergen extracts available for immunotherapy].

In an attempt to assess whether or not the availability of inhalant allergens for diagnosis and treatment of allergic diseases in Japan is adequate, we tested 21 Japanese patients with allergic rhinitis or bronchial asthma against 75 inhalant allergens commonly used in the United States of America. These 21 patients had never lived outside of Japan and came to the United States for the purpose of diagnosis and treatment of their allergic diseases. We determined the importance of each allergen by calculating an allergenicity index. Allergenicity index for a given allergen was defined as a sum of a multiple of each of 4 grades of prick test reactions to the allergen and a number of patients reacting to the allergen with each corresponding grade. Mite had the highest allergenicity index, followed by house dust. All 14 pollen allergens occupying the 3rd through 12th ranks including many grass and weed pollens are not available for immunotherapy in Japan. Japanese cedar pollen which is considered the most important pollen allergen in Japan ranked the 13th. Of a total 25 allergens occupying from the 1st through 13th ranks 22 allergens are not available for immunotherapy including the most important allergen, mite. These results suggest that we should expand the list of allergens available for diagnosis and treatment of allergic diseases in Japan.

Administration, Inhalation↗
PubMed2000

Exposure to mite and cat allergens on a range of clothing items at home and the transfer of cat allergen in the workplace.

BACKGROUND: Clothing has been proposed as an additional source of exposure to mite and cat allergens. Dispersal of allergen into public places has also been attributed to clothing. OBJECTIVES: We sought to study the contribution of various types of clothing on mite and cat exposure in a domestic environment. Also, we studied the ability of clothing to transfer allergen in a workplace. METHODS: Personal exposure to mite and cat allergen from a range of clothing was measured by using intranasal air samplers in 11 homes. Five categories of clothing were tested. Wearing no upper clothing was the sixth category tested to distinguish the contribution of clothing over ambient background exposure. An adhesive tape was used to sample allergen from the surface of clothing, and reservoir dust samples were also collected. The above techniques were also used in the workplace to examine the amount of cat allergen transferred from cat owners to non-cat owners. RESULTS: The amount of mite and cat allergen inhaled differed among the clothing types worn and whether they had been washed recently. Wearing a woolen sweater increased personal allergen exposure to cat and mite allergen by a mean of 11 and 10 times, respectively. Clothing items that were less frequently washed carried more allergen whether assessed by vacuuming or sampled with adhesive tape. This corresponded to the amount of allergen inhaled. We also found that cat levels on non-cat owners' clothing increased significantly at the end of a working day, which lead to the increase in their personal allergen exposure to cat. CONCLUSIONS: These studies strongly support the emerging model that personal clothing is an important source of both mite and cat allergen exposure. This article also demonstrates the importance of clothing as a means of distributing cat allergen into cat-free environments.

Allergens↗
PubMed2000

Evolution in the understanding of cross-reactivities of respiratory allergens: the role of recombinant allergens.

The aim of this review is to show the impact of the use of purified and recombinant allergens to discriminate between co- and cross-sensitization to respiratory allergens. The author describes the evolution of diagnostic tests over the last decades; the tests initially allowed the detection of simultaneously positive cutaneous tests and/or simultaneous positivity of specific IgE to different allergen extracts, but they did not differentiate cross-sensitization from co-sensitization. RAST inhibition studies with crude extracts then established cross-reactivity, but did not identify the cross-reactive allergens involved. Later, immunoblot and CRIE inhibition were able to detect multiple cross-reactive allergens and to assess their physicochemical properties. But it is only since purified and recombinant allergens have been used in the different investigations that identification of cross-reactive allergens has been made possible at a molecular level. This historical approach is illustrated by examples selected from some of the main respiratory allergen sources: tree pollen, grass pollen, weed pollen, acarids, cockroaches and mammalians. For each of these allergen sources, the author gives an updated presentation of major and minor cross-reactive allergen molecules and refers to the last decade's major publications concerning immunochemical investigations carried out in the field of cross-reactive respiratory allergens. Emphasis is placed on the clinical applications for allergic patients: improvement in the accuracy of the diagnosis of sensitization, new concepts of immunotherapy based on genetically engineered hypoallergenic variants of cross-reactive allergens used alone or in combination, evaluation of allergen load with environmental tests using monoclonal antibodies against cross-reactive allergens.

Acari↗
PubMed1999

The relationships among environmental allergen sensitization, allergen exposure, pulmonary function, and bronchial hyperresponsiveness in the Childhood Asthma Management Program.

BACKGROUND: Sensitivity and exposure to indoor allergens constitutes a risk factor for the development and persistence of asthma in children. OBJECTIVE: Our purpose was to evaluate the relationship between sensitivity and exposure to inhalant allergens and lung function and bronchial responsiveness in a group of children (n = 1041) aged 8.9 +/- 2.1 years with mild to moderate asthma enrolled in the Childhood Asthma Management Program (CAMP). METHODS: With use of the extensive CAMP baseline cross-sectional data on spirometry, bronchial responsiveness, allergen sensitivities, and household allergen levels, the relationship of sensitization and exposure to allergens to lung function and methacholine sensitivity was evaluated. Children who enrolled in CAMP stopped all antiasthma medication except rescue use of albuterol and prednisone for exacerbations during the 5- to 16-week screening period. During the last 2 of these weeks they underwent spirometry and methacholine challenge. Indoor allergen exposures were determined from questionnaires completed by the parent. Household levels of indoor allergens (mite, cat, dog, cockroach, mold) were determined on house dust samples. Allergen sensitivity was determined by percutaneous skin testing with a standard battery of allergens plus locally important pollen and fungal spores. Lung function and bronchial hyperresponsiveness were compared for children sensitive and not sensitive to both indoor and outdoor allergens on skin testing and, if sensitive, for exposed and not exposed to the allergens to which they were positive on skin testing. RESULTS: There was a strong direct correlation between increased sensitivity to inhaled methacholine and skin test sensitivity to tree, weed, Alternaria, cat, dog, and indoor molds. When the relationship was examined by stepwise regression, the skin test sensitivities showing the strongest associations with the concentration of methacholine that caused a 20% fall in FEV(1) were dog (P =.003), Alternaria (P =.01), and cat (P =.05). Children sensitive to any one of the aeroallergens tested were compared for the presence or absence of exposure to that allergen at the time that the methacholine challenge was performed. Those who were sensitive and exposed to weed and cat had greater methacholine sensitivity than those similarly sensitive but not exposed (P =.003 and P =.02, respectively). CONCLUSIONS: Sensitivity to dog or cat dander or Alternaria by skin testing was associated with increased bronchial responsiveness but not decreased lung function in children with mild to moderate asthma. These findings support the important role that sensitization to certain allergens plays in modulating bronchial responsiveness.

Adolescent↗
PubMed2001

Pyr c 1, the major allergen from pear (Pyrus communis), is a new member of the Bet v 1 allergen family.

Pear is known as an allergenic food involved in the 'oral allergy syndrome' which affects a high percentage of patients allergic to birch pollen. The aim of this study was to clone the major allergen of this fruit, to express it as bacterial recombinant protein and to study its allergenic properties in relation to homologous proteins and natural allergen extracts. The coding region of the cDNA was obtained by a PCR strategy, cloned, and the allergen was expressed as His-Tag fusion protein. The fusion peptide was removed by treatment with cyanogen bromide. Purified non-fusion protein was subjected to allergenicity testing by the enzyme allergosorbent test (EAST), Western blotting, competitive inhibition assays, and basophil histamine release. The deduced protein sequence shared a high degree of identity with other major allergens from fruits, nuts, vegetables, and pollen, and with a family of PR-10 pathogenesis related proteins. The recombinant (r) protein was recognised by specific IgE from sera of all pear-allergic patients (n = 16) investigated in this study. Hence, the allergen was classified as a major allergen and named Pyr c 1. The IgE binding characteristics of rPyr c 1 appeared to be similar to the natural pear protein, as was demonstrated by EAST-inhibition and Western blot-inhibition experiments. Moreover, the biological activity of rPyr c 1 was equal to that of pear extract, as indicated by basophil histamine release in two patients allergic to pears. The related major allergens Bet v 1 from birch pollen and Mal d 1 from apple inhibited to a high degree the binding of IgE to Pyr c 1, whereas Api g 1 from celery, also belonging to this family, had little inhibitory effects, indicating epitope differences between Bet v 1-related food allergens. Unlimited amounts of pure rPyr c 1 are now available for studies on the structure and epitopes of pollen-related food allergens. Moreover, the allergen may serve as stable and standardised diagnostic material.

Allergens↗
PubMed2003

The detection of clinically relevant contact allergens using a standard screening tray of twenty-three allergens.

BACKGROUND: The current standard tool for diagnosing allergic contact dermatitis (ACD) in the United States is the T.R.U.E. test panels, which consist of 23 allergens. Previous studies have raised concern regarding the adequacy of these panels in fully assessing patients with possible ACD. OBJECTIVE: We sought to examine the use of the T.R.U.E. test allergens as the primary diagnostic method for detecting ACD. METHODS: A retrospective analysis of all patients with possible ACD who presented to the University of Kansas' Section on Occupational and Contact Dermatitis in Kansas City, Kansas, and subsequently underwent patch testing from January 1, 1995, to December 31, 2001. Patients with positive allergic reactions were stratified into 3 groups: (1) reactions only to allergens on the T.R.U.E. test; (2) reactions only to allergens not present on the T.R.U.E. test; and (3) reactions to allergens on the T.R.U.E. test and additional allergens. These 3 groups were further analyzed to assess clinical relevance. RESULTS: Of the 898 patients who were patch tested, 616 (68.6%) had at least 1 positive allergic reaction. Among these 616 patients, 25.5% would have been fully evaluated using the T.R.U.E. test allergens only. Of the remaining patients, 22.4% would not have had any of their allergens detected and 52.1% would have only been partially evaluated had only the T.R.U.E. test allergens been used. Similar percentages were observed when only patients with clinically relevant reactions were included. CONCLUSIONS: In our study, the current T.R.U.E. test series of 23 allergens would have completely identified all allergens in only 25.5% of patients and clinically relevant allergens in 28% of patients. Expanding the number of allergens used according to a patient's environment and history will lead to improved outcome in the treatment and prevention of ACD.

Allergens↗
PubMed2005

Characterization of the T cell response to the major hazelnut allergen, Cor a 1.04: evidence for a relevant T cell epitope not cross-reactive with homologous pollen allergens.

BACKGROUND: IgE antibodies specific for the major birch-pollen allergen, Bet v 1, cross-react with homologous allergens in particular foods, e.g. apples, carrots and hazelnuts. In a high number of tree pollen-allergic individuals, this cross-reactivity causes clinical symptoms, commonly known as the 'birch-fruit-syndrome'. OBJECTIVE: To characterize the T cell response to the Bet v 1-related major allergen in hazelnuts, Cor a 1.04, and its cellular cross-reactivity with Bet v 1 and the homologous hazel pollen allergen, Cor a 1. METHODS: Using recombinant Cor a 1.04, T cell lines (TCL) and T cell clones (TCC) were established from peripheral blood mononuclear cells of tree pollen-allergic patients with associated food allergy. T cell epitopes were determined using overlapping synthetic peptides in Cor a 1.04-reactive TCL and TCC. In parallel, reactivity to Bet v 1 and Cor a 1 was tested. RESULTS: In total, 20 distinct T cell epitopes on the hazelnut allergen were identified. Several Cor a 1.04-specific TCL and TCC reacted with pollen allergens albeit less pronounced than with the hazelnut allergen. Several Cor a 1.04-specific TCC did not react with pollen allergens. Interestingly, these clones were found to react with the Bet v 1-related major allergen in carrots, Dau c 1. The cellular cross-reactivity between both food allergens could be associated with the most frequently recognized T cell epitope of Cor a 1.04, Cor a 1.04(142-153). CONCLUSIONS: The major hazelnut allergen cross-reacts with the major allergens of birch and hazel pollen but apparently contains a relevant T cell epitope not shared with pollen allergens. Our finding may have important implications for the specific immunotherapy of tree pollen-allergic patients suffering from concomitant hazelnut allergy.

Allergens↗
PubMed2005

The links between allergen skin test sensitivity, airway responsiveness and airway response to allergen.

BACKGROUND: The allergen-induced early asthmatic response [provocation concentration (PC)20, the concentration causing a 20% forced expiratory volume in 1 s (FEV)1 fall] depends on the level of IgE sensitivity and the degree of nonallergic airway hyperresponsiveness (AHR) and can be predicted from histamine PC20 and allergen skin test endpoint. OBJECTIVES: We examined the relationships between allergen PC20, methacholine PC20, and allergen skin test endpoint and assessed the accuracy of both the histamine PC20-based prediction of allergen PC20 (using methacholine) and a new methacholine PC20-based prediction equation. METHODS: From 158 allergen challenges, the allergen PC20, the methacholine PC20, and the skin test endpoint were recorded and relationships between these three were sought. We compared the measured allergen PC20 to that predicted from the previous histamine PC20-based and the new methacholine-based formulae. RESULTS: In single regressions, allergen PC20 correlated with both methacholine PC20 (r=0.25, P=0.0015) and skin test endpoint (r=0.52, P <0.00005). The relationship was improved by multiple regression of log-allergen PC20vs. log-methacholine PC20 and log-endpoint (r=0.61, P <0.00005). The histamine-based formula predicted allergen PC20 to within 2 doubling concentrations in 80% and within 3 in 92%. The new methacholine-based formula to within 2 and 3 concentrations in 81% and 94%, respectively; only nine of 158 subjects were outside the 3 concentrations. CONCLUSIONS: We have confirmed the dependence of the allergen-induced early asthmatic response upon the level of allergic sensitivity and the degree of AHR, the latter as assessed by methacholine challenge. The allergen PC20 can be predicted to within 3 doubling concentrations in 94% of cases.

Adult↗
PubMed2004

Exposure to indoor allergens in homes of patients with asthma and/or rhinitis in southeast Brazil: effect of mattress and pillow covers on mite allergen levels.

BACKGROUND: Exposure and sensitization to indoor allergens have been associated with the development of asthma and other allergic diseases in many parts of the world. It is important to establish the degree of exposure, and to evaluate whether allergen control measures are effective in a particular area. METHODS: Concentrations of major allergens of mites, cockroach, cat and dog were measured in dust samples from homes of 24 mite-allergic patients living in Ribeirão Preto, Brazil. Allergen concentrations were quantitated by monoclonal antibody-based ELISA. Mite-impermeable mattress and pillow covers were applied to beds in the homes of 19 of the 24 patients, and group 1 mite allergen levels were measured 1 and 6 months following intervention. RESULTS: Patients were exposed to high concentrations of mite allergens in their homes. 87.5% of the homes presented concentrations of group 1 allergens >10 microg/g of dust in at least one site. Cockroach allergen concentrations were low in most samples. Dog allergen concentrations were significantly higher in homes with dogs as compared to those without dogs. Mean concentrations of cat allergen were 0.1 microg/g. Mite allergen concentrations in bedding samples dropped from 24 microg/g at baseline to 0.9 and 1.0 microg/g, respectively, 1 and 6 months following encasement of mattresses and pillows. CONCLUSIONS: Significant mite allergen reduction can be achieved in an area of high degree of exposure to mite allergens. Further studies evaluating the effect of this reduction on symptoms and airway inflammation will be necessary to establish the effectiveness of mite avoidance measures in our area.

Adolescent↗
PubMed1997

[New aero-allergens. Interaction between allergens and the environment].

There is a qualitative as well as a quantitative change in allergen exposure. From a qualitative viewpoint, the relevance of some allergens (domestic allergens i.e. cockroaches, outdoor allergens i.e. plane tree, chestnut and ash tree pollens) has been established. The role of some other allergens has been, strictly speaking, discovered: latex from Hevea and ficus, trichophyton mold, some occupational allergens and very recently transgenic allergens. From a quantitative viewpoint, the concentration and/or distribution of some allergens has increased. Plantation of numerous trees or fortuitous introduction of weeds has led to an increased specific sensitization. In like manner, introduction of new foods or food processing procedures has created new food allergens and allergy. Besides, the distribution of some well-known aero-allergens is better known since discovery of ELISA--technology allowing measurements of minute amounts of these allergens. A burning issue today is to know whether irritant factors could modify allergens. Few data, sometimes contradictory, are available in the field of interaction between air pollutants and allergens.

Air Pollutants↗
PubMed1997

Allergen source materials and quality control of allergenic extracts.

Allergen extracts are prepared from a wide variety of source materials including pollens, fungi, arthropods, animal danders, foods, and dusts. The composition of allergen extracts can vary depending on the allergen source, manufacturing process, and storage conditions. Allergen-specific immunoglobulin E (IgE) assays and skin tests employ a variety of allergen-containing reagents that confer specificity on the test. Given that the allergen source materials are heterogenous mixtures of proteins, glycoproteins, carbohydrates, and other substances that are not allergenic, it is not unexpected that variability exists between test results obtained with different allergen-containing reagents. Variability within a single manufacturer's allergen product can be controlled by using reproducible extraction and processing procedures, single large lots of allergen source materials, and solid-phase supports. These controls do not, however, ensure the consistency of products between manufacturers or laboratories because allergen source materials, manufacturing procedures, and acceptance criteria for allergen reagents may vary.

Allergens↗
PubMed1993

Frequency of allergen-specific T lymphocytes in blood and bronchial response to allergen in asthma.

BACKGROUND: This study was designed to investigate whether the bronchial response to the sensitizing allergen in asthma is correlated with the frequency of allergen-specific T lymphocytes. METHODS: Twenty-three asthmatic patients sensitized to Dermatophagoides pteryonyssinus who had never received hyposensitizing therapy and 11 healthy control subjects were studied. Allergen-specific T lymphocytes were enumerated in peripheral blood with limiting dilution cultures. Bronchial challenge with methacholine was performed in all subjects; patients with asthma also underwent an allergen bronchial challenge. Correlations between allergen-specific T cell frequencies and nonspecific bronchial hyperresponsiveness to methacholine as independent variables and early and late bronchial responsiveness to allergen challenge as dependent variables were investigated by means of stepwise-multiple regression analysis. RESULTS: We found that the frequency of allergen-specific T lymphocytes was higher than in control subjects in both patients with asthma with (p < 0.001) and those without (p < 0.05) late-phase asthmatic response to allergen. Moreover, the provocative does of allergen necessary to produce an early 15% fall of forced expiratory volume in 1 second could be predicted in part (59%) by an equation that incorporates methacholine sensitivity and allergen-specific T cell frequency. CONCLUSIONS: We conclude that allergen-specific T lymphocytes, which have an established influence on immunoglobulin E production, play an additional role in the induction of the bronchospastic response to inhaled allergen.

Adolescent↗
PubMed2006

Spatial clustering of the IgE epitopes on the major timothy grass pollen allergen Phl p 1: importance for allergenic activity.

BACKGROUND: The major timothy grass pollen allergen Phl p 1 is one of the most potent and frequently recognized environmental allergens. OBJECTIVE: We sought to study at a molecular and structural level the IgE recognition of Phl p 1 and its relation to allergenic activity. METHODS: Monoclonal human IgE antibody fragments specific for Phl p 1 and group 1 allergens from various grasses were isolated from a combinatorial library made of lymphocytes from patients with grass pollen allergy. Recombinant Phl p 1 fragments and the 3-dimensional structure of Phl p 1 were used to localize the major binding site for the IgE antibodies. A rPhl p 1 fragment containing this binding site was expressed in Escherichia coli, purified, and tested for IgE reactivity and allergenic activity with sera and basophils from patients with grass pollen allergy. RESULTS: Monoclonal antibodies, as well as polyclonal serum IgE, from patients with grass pollen allergy defined a C-terminal fragment of Phl p 1 that represents a sterically oriented portion on the Phl p 1 structure. This Phl p 1 portion bound most of the allergen-specific IgE antibodies and contained the majority of the allergenic activity of Phl p 1. CONCLUSION: IgE recognition of spatially clustered epitopes on allergens might be a general factor determining their allergenic activity. CLINICAL IMPLICATIONS: Geographic distribution of IgE epitopes on an allergen might influence its allergenic activity and hence explain discrepancies between diagnostic test results based on IgE serology and provocation testing. It might also form a basis for the development of low allergenic vaccines.

Allergens↗
PubMed1998

Bronchial allergen challenge with isolated major allergens of Dermatophagoides pteronyssinus: the role of patient characteristics in the early asthmatic response.

BACKGROUND: The use of allergen extracts will hamper studies into quantitative aspects of allergic responses because the precise amount of relevant allergen for each patient is unknown. OBJECTIVE: We applied isolated IgE-binding components (major allergens) in the technique of bronchial allergen challenge to determine the role of patient characteristics in the early asthmatic response (EAR). METHODS: In 30 patients with mild-to-moderate asthma, the EAR was investigated after inhalation of an isolated major allergen of Dermatophagoides pteronyssinus (i.e., Der p 1 [n = 16] or Der p 2 [n = 14]). The degree of early-phase bronchial responsiveness to allergen (the cumulated dose of allergen causing a 20% fall in FEV1 [PD20allergen]) was related to the degree of nonspecific bronchial responsiveness (the concentration of histamine causing a 20% fall in FEV1 [PC20histamine]) and the level of specific IgE or allergen thresholds as found in skin tests and basophil histamine release assays. RESULTS: Twenty-seven patients with an immediate response during allergen and histamine challenges (deltaFEV1, > or = 20%) were analyzed. In these patients, a strong correlation was found between PD20allergen and PC20histamine (r = 0.81, p < 0.001). Weak correlations were found between PD20allergen and the level of specific IgE (r = -0.36, p = 0.07) or allergen thresholds as found in skin tests (skin prick test, r = 0.36 and p = 0.07; intracutaneous test, r = 0.49 and p = 0.01) or basophil histamine release assays (r = 0.37, p = 0.08). Moreover, no significant contribution of these indices of IgE-mediated hypersensitivity to the prediction of PD20allergen by multilinear regression models with PC20histamine was found. CONCLUSION: In asthmatic patients allergic to house dust mites the degree of nonspecific bronchial hyperresponsiveness is the main determinant of early-phase bronchial responsiveness to allergen. In these patients the degree of allergic sensitivity does not contribute to the prediction of the EAR after allergen inhalation.

Adolescent↗
PubMed2000

The high molecular mass allergen fraction of timothy grass pollen (Phleum pratense) between 50-60 kDa is comprised of two major allergens: Phl p 4 and Phl p 13.

BACKGROUND: More than 70% of the patients allergic to grass pollen exhibit IgE-reactivity against the high molecular mass fraction between 50 and 60 kDa of timothy grass pollen extracts. One allergen from this fraction is Phl p 4 that has been described as a basic glycoprotein. A new 55/60 kDa allergen, Phl p 13, has recently been purified and characterized at the cDNA level. OBJECTIVE: The relative importance of the two high molecular mass allergens has been characterized with respect to their IgE-binding frequency and capacity. METHODS: Both high molecular mass allergens were biochemically purified and subjected to nitrocellulose strips. About 306 sera obtained from subjects allergic to grass pollens were used to determine specific IgE-binding frequency to Phl p 4 and Phl p 13. IgE-binding of allergens was quantified by ELISA measurements. Pre-adsorption of sera with purified allergens and subsequent incubation of nitrocellulose-blotted timothy grass pollen extract was performed to determine whether or not Phl p 4 and Phl p 13 represent the whole high molecular mass allergen fraction. Proteolytic stability of both allergens was investigated by addition of protease Glu-C. RESULTS: More than 50% of 300 patients displayed IgE-binding with both allergens. Clear differences concerning the immunological properties of Phl p 4 and Phl p 13 were confirmed by individual IgE reactivities. Quantification of specific IgE for both allergens revealed comparable values. For complete inhibiton of IgE-binding in the high molecular mass range preincubation of sera with both allergens was necessary. Interestingly, inhibition of strong reacting sera with Phl p 13 eliminated not only reactivity of the 55/60 kDa double band, but in addition a 'background smear'. Whilst undenatured Phl p 4 was resistent to proteolytic digestion with Glu-C, native Phl p 13 was degraded rapidly. CONCLUSION: Phl p 4 and Phl p 13 are immunologically different and must both be considered as major allergens. They are judged to be important candidates for potential recombinant therapeutics that may provide a basis for improved immunotherapy.

Allergens↗
PubMed2000

Mouse allergen. I. The prevalence of mouse allergen in inner-city homes. The National Cooperative Inner-City Asthma Study.

BACKGROUND: Although mouse allergen is a well-defined cause of IgE-mediated hypersensitivity in occupational settings, it has not been well studied in the general population. OBJECTIVE: We sought to determine the prevalence of mouse allergen in inner-city homes. METHODS: A subset of 608 homes from the National Cooperative Inner-City Asthma Study population had dust samples adequate for analysis of mouse allergen. In addition, data regarding the demographics and housing of the subjects were related to the mouse allergen levels. RESULTS: Ninety-five percent of all homes had detectable mouse allergen (Mus m 1) in at least one room, with the highest levels found in kitchens (kitchen: range, 0-618 microg/g; median, 1.60 microg/g; bedroom: range, 0-294 microg/g; median, 0.52 microg/g; television-living room: range, 0-203 microg/g; median, 0. 57 microg/g). By city, 100% of the kitchens in Baltimore had detectable mouse allergen, with the lowest percentage (74%) in Cleveland. Mouse allergen levels correlated among rooms (R = 0.65-0. 75). Forty-nine percent of the homes had reported problems with mice within the last year, and 29% of the homes had evidence of mice in one or more rooms on home inspection and had higher levels of mouse allergen (P =.0001). Higher allergen levels were also associated with evidence of cockroach infestation in any room (P =.006). None of the other subject or housing demographics evaluated were associated with a higher prevalence or level of mouse allergen. CONCLUSIONS: We conclude that mouse allergen is widely distributed in inner-city homes and that cockroach infestation is associated with high mouse allergen levels.

Allergens↗
PubMed2003

Exposure to endotoxin and allergen in early life and its effect on allergen sensitization in mice.

BACKGROUND: Exposure to endotoxins, allergens, or both in early life might regulate the development of tolerance to allergens later in life. OBJECTIVE: We investigated whether continuous exposure of infant mice to aerosolized endotoxin, allergen, or both inhibits subsequent allergen-induced immune and inflammatory responses. METHODS: Infant BALB/c mice were pre-exposed to aerosolized endotoxin, ovalbumin (OVA), or both (3 times a week for the first 4 weeks of life) before systemic sensitization (days 1-14) and repeated airway challenge (days 28-30) with OVA. RESULTS: Compared with that seen in negative control animals, systemic sensitization and airway allergen challenges induced high serum levels of allergen-specific IgE (0.7 +/- 0.09 vs 0.02 +/- 0.01 OD units), predominant T(H)2-type cytokine production (IL-5 by splenic mononuclear cells in vitro, 1.2 +/- 0.2 vs 0.04 +/- 0.06 ng/mL), airway inflammation (bronchoalveolar lavage fluid leukocytes, 125 +/- 15 vs 64 +/- 7/microL; eosinophils, 28 +/- 5 vs 1 +/- 0/microL) and development of in vivo airway hyperreactivity (maximal enhanced pause, 11 +/- 1.9 vs 4 +/- 0.2). Pre-exposure with LPS before sensitization increased production of specific IgG2a (67 +/- 10 vs 32 +/- 5 U/mL) but failed to prevent T(H)2-mediated immune responses. Pre-exposure with OVA or with OVA plus LPS completely suppressed allergen sensitization, airway inflammation, and development of in vivo airway hyperreactivity; values were similar to those of negative control animals. Inhibition was due to allergen-specific T-cell anergy indicated by omitted allergen-specific T(H)2 and T(H)1 immune responses. In addition, combined exposure to endotoxin and allergen induced a general shift toward an unspecific T(H)1 immune response. CONCLUSION: Exposure with endotoxins before allergen sensitization is not able to induce unresponsiveness but might decrease the susceptibility for sensitization to a variety of common allergens.

Aerosols↗