Dust Mite Antigen Research Articles

Indoor air pollution and childhood asthma: effective environmental interventions.

Exposure to indoor air pollutants such as tobacco smoke and dust mites may exacerbate childhood asthma. Environmental interventions to reduce exposures to these pollutants can help prevent exacerbations of the disease. Among the most important interventions is the elimination of environmental tobacco smoke from the environments of children with asthma. However, the effectiveness of reducing asthmatic children's exposure to environmental tobacco smoke on the severity of their symptoms has not yet been systematically evaluated. Dust mite reduction is another helpful environmental intervention. This can be achieved by enclosing the child's mattresses, blankets, and pillows in zippered polyurethane-coated casings. Primary prevention of asthma is not as well understood. It is anticipated that efforts to reduce smoking during pregnancy could reduce the incidence of asthma in children. European studies have suggested that reducing exposure to food and house dust mite antigens during lactation and for the first 12 months of life diminishes the development of allergic disorders in infants with high total IgE in the cord blood and a family history of atopy. Many children with asthma and their families are not receiving adequate counseling about environmental interventions from health care providers or other sources.

Correlates of recurrent wheezing in school-age children. The Physicians of Raleigh Pediatric Associates.

Correlates of recurrent wheezing were examined in a case-control study involving 343 children ranging from 7 to 12 yr of age and recruited from a general pediatric practice. Positive skin tests for allergy were observed in 35% of a random sample of children without recurrent wheezing, and in 77% and 90% of children who had experienced from two to four episodes and five or more episodes, respectively, of recent wheezing. By logistic regression analysis, sensitization to dust mite (odds ratio [OR]: 5.2; 95% CI: 3.0 to 9.0), cat (OR: 15.5; 95% CI: 3.4 to 70.8), and Alternaria (OR: 6.8; 95% CI: 2.1 to 21.5) antigens was consistently associated with recurrent wheezing. Sensitization to pollen antigen(s), observed in 60% of allergic children, was not associated with wheezing. A family history of asthma was a significant predictor of recurrent wheezing (OR: 3.2; 95% CI: 1.7 to 5.9) after adjusting for its association with positive skin tests. Environmental tobacco smoke (ETS) exposure was associated with an increased risk of recurrent wheezing in nonallergic children and in allergic females, but not in allergic males. ETS exposure was not associated with positive skin tests for allergy. A history of wheezing with respiratory illness before 2 yr of age was associated with a modest risk of recurrent wheezing between 7 and 12 yr of age (OR: 2.3; 95% CI: 1.2 to 4.6), a risk that did not differ by allergic status or gender. Theoretically, the prevalence of recurrent wheezing in this population could be reduced approximately 65% by controlling exposure to indoor allergens and ETS.

The effect of prolonged exposure to NO2 from birth on airways responsiveness in rabbits sensitized at birth.

Our aim was to determine whether daily exposure to 4 ppm nitrogen dioxide (NO2) from birth until 3 months of age influenced the development of airways hyperresponsiveness and atopic sensitivity in immunized rabbits. Littermate New Zealand white (NZW) rabbits were immunized within 24 h of birth by i.p. injection of house dust mite antigen in AI(OH)3 gel, and exposed to either ambient air or 4 ppm NO2 for 2 h.day-1, 5 days.week-1. At 3 months, bronchoalveolar lavage (BAL) and serum samples were obtained. Airways responsiveness was measured as the provocative concentrations (mg.ml-1) of histamine or methacholine required to elicit a 50% increase in airway resistance (RLPC50) and a 35% decrease in dynamic compliance (CdynPC35). There were no differences in total cell or differential cell counts recovered in BAL fluid between control and NO2 exposed animals. Airways responsiveness did not differ between groups of animals (histamine RLPC50 values: air (n = 15) versus NO2 (n = 13), respectively, 9.98 +/- 1.32 versus 16.43 +/- 1.45 mg.ml-1; CdynPC35 values: 16.60 +/- 1.44 versus 14.95 +/- 1.43 mg.ml-1; methacholine RLPC50 values: air (n = 14) versus NO2 (n = 12), respectively, 2.18 +/- 1.51 versus 2.21 +/- 1.32 mg.ml-1; CdynPC35 values: 2.64 +/- 1.41 versus 2.85 +/- 1.31 mg.ml-1). There was no difference in sensitization between groups of animals exposed to air or NO2, evaluated either by cutaneous responsiveness to intradermal antigen, or serum immunoglobulin E (IgE) levels assessed by the passive cutaneous anaphylaxis (PCA) reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of IL-4 and IL-5 secretion by histamine and PGE2.

This study was designed to study the effects of autacoids on IL-4 and IL-5 secretion. IL-4 and IL-5 are secreted by TH2 cells. TH2 cells were generated by the culture of peripheral blood lymphocytes from atopic individuals in the presence of ragweed or dustmite antigen. The cloned TH2 lymphocytes were then stimulated with PMA (10 ng/ml) and alpha-CD3 (50 ng/ml) in the presence and absence of histamine (10(-4) - 10(-8)M) and PGE2 (10(-6) - 10(-8)M) for 48 hours. Other cAMP elevating agents were used as control. The supernatants were then assayed for the presence of IL-4 and IL-5 by ELISA. Both histamine and PGE2 suppressed the secretion of IL-4 in a dose dependent manner. Other cAMP elevating agents did not affect IL-4 secretion. In contrast, histamine upregulated the secretion of IL-5, whereas the effects of PGE2 on IL-5 secretion were not conclusive. Chloride channels have been implicated in the secretory processes. The effects of a chloride channel blocker, DIDS, were studied on histamine-induced suppression of IL-4 secretion. DIDS (10(-7) - 10(-12)M) abrogated the inhibitory effects of histamine on IL-4 secretion. The observations suggest that histamine may inhibit IL-4 secretion via activation of chloride channels.

Practical approaches to the treatment of atopic dermatitis.

Atopic dermatitis is a chronic pruritic cutaneous disease that occurs in 0.5% to 1% of the general population and affects almost 10% of all children. Since this is a disease that is associated with both a very high level of total IgE and a high incidence of allergic respiratory disease, it behooves the practicing allergist to become familiar with the diagnosis and treatment of atopic dermatitis. This following discussion will focus on the identification of major and minor clinical features of the disease and review the spectrum of immune dysregulation that is frequently seen with these patients. The primary focus of this review will be directed at the identification of treatment options available to allergists within the published practice guidelines of the American Academy of Dermatology and practice guidelines that are currently being developed by the American Academy of Allergy & Immunology. Atopic dermatitis is an "itch which rashes and not a rash which itches" and therefore, any patient treatment program should address the multiplicity of potential trigger factors that provoke this itching. These factors include heat, humidity, and perspiration, in addition to the ingestion of certain food allergens and the topical exposure to both dust mite antigen and animal dander. Recent studies suggest that the pathogenesis of allergic disease entails a complex inflammatory process in which the TH2 lymphocyte might play a major role in shifting the immune response in favor of disease. Accordingly, recent immunomodulating treatments, such as interferon gamma and cyclosporine, might offer therapeutic options to the physician beyond the standard topical forms of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Skin disease-related T cells bind to endothelial selectins: expression of cutaneous lymphocyte antigen (CLA) predicts E-selectin but not P-selectin binding.

Cutaneous lymphocyte antigen (CLA), defined by the HECA-452 antibody, is a cell surface glycoprotein found on a subset of T cells in peripheral blood that binds specifically to E-selectin. This marker is present on the majority of T cells at sites of cutaneous inflammation and immune responses. Based upon such evidence, an association between T cell CLA expression and skin homing has been proposed. To understand better this relationship, we asked whether putative disease-related, antigen-specific T cells expressed CLA. In this study, we employed T helper type 2 (TH2) T cell clones specific for house dust mite (Dermatophagoides pteronyssinus) antigens. These cells were derived from challenged skin of an individual known to react positively to epicutaneous challenge with this agent. In this study, we show that these cloned T cells showed very high homogeneous expression of CLA (nearly 500-fold higher than T cell clones derived from peripheral blood) and bound specifically to recombinant E-selectin. The CLA molecule on these cells was identified not only by HECA-452, but also by CSLEX-1, indicating that it contained sialyl-Le(x) (S-Le(x)) determinants. T cells cloned under similar conditions from peripheral blood were CLA negative or low and bound poorly to E-selectin. Surprisingly, both skin and blood clones bound comparably to P-selectin. This binding was independent of S-Le(x) or CLA expression. We conclude that in sensitized individuals, antigen-specific T cells expressing high levels of CLA localize in skin promptly after epicutaneous challenge. This localization is likely to involve the interaction of S-Le(x) determinants on the CLA molecule with E-selectin on the dermal microvasculature. We further conclude that T cells can interest with P-selectin on endothelium and that S-Le(x) does not appear to be necessary for this interaction.

Activation of human blood lymphocytes by house dust mite protein and Mycobacterium tuberculosis purified protein derivative: effects of interferon-gamma, interleukin-4, dexamethasone and cyclosporin A.

Peripheral blood mononuclear cells (PBMC) from nonatopic donors sensitive to Mycobacterium tuberculosis purified protein derivative (PPD) and from atopic donors sensitive to PPD and house dust mite antigen (HDM), were stimulated in vitro to proliferate in response to exogenous IL-2. In the presence of exogenous IFN-gamma, the response of cells from atopic donors to PPD was either unaffected or slightly enhanced, whereas the response to HDM was inhibited in a dose-dependent manner. The response of cells from nonatopic donors to PPD remained unchanged or was only slightly inhibited and this was not dose-dependent. Exogenous IL-4 did not reverse the inhibitory effects of IFN-gamma and a neutralizing antibody to IL-4 did not inhibit the proliferative response of cells to HDM and IL-2. Dexamethasone inhibited the IL-2-mediated response of cells from atopic donors stimulated with HDM, whereas the IL-2-mediated response of cells induced by PPD was either unchanged or stimulated by dexamethasone. Cyclosporin A inhibited the response of cells to both HDM and PPD. These results suggest that IFN-gamma can exert a selective effect on the response of T lymphocytes to different antigens and that it is possible to identify compounds able to regulate this activity.

In vivo clonal dominance and limited T-cell receptor usage in human CD4+ T-cell recognition of house dust mite allergens.

Sensitivity to house dust mite antigens in atopic individuals is a major cause of allergic diseases, ranging from asthma to rhinitis and dermatitis. We have studied the T-cell receptor (TCR) usage of house-dust-mite-specific CD4+ T-cell clones isolated from an atopic individual, by using the anchored polymerase chain reaction, and have analyzed the peripheral TCR repertoire of the same individual. Several T-cell clones had identified TCRs at the sequence level, despite the fact that they had been independently isolated, in some cases, in different years. These data suggest the presence in vivo of long-lived T-cell clones. We have also shown that junctional sequences identical to these clones are present in peripheral blood T cells taken 6 years after the isolation of the T-cell clones. The analysis of TCR genes used by the panel of clones reveals oligoclonality, with the variable (V) region gene segments V alpha 8 and V beta 3 being dominant, although there is minimal conservation of junctional sequences. The results have implications for understanding the TCR recognition of an environmental aeroallergen and the life span of T-cell clones in vivo during a chronic immune response.

House dust mite antigen induced Fce receptor II(CD23) expression in mite-sensitized atopic dermatitis patients

House dust mite antigen induced Fce receptor II(CD23) expression in mite-sensitized atopic dermatitis patients

Infant feeding, wheezing, and allergy: a prospective study.

The determinants of wheezing and allergy were investigated in 453 children with a family history of allergic disease. A randomised controlled trial examined the effects of withholding cows' milk protein during the first three months of life and replacing cows' milk with soya milk. The children were followed up to the age of 7 years. Withholding cows' milk did not reduce the incidence of allergy or wheezing. Children who had ever been breast fed had a lower incidence of wheeze than those who had not (59% and 74% respectively). The effect persisted to age 7 years in the non-atopics only, the risk of wheeze being halved in the breast fed children after allowing for employment status, sex passive smoking, and overcrowding. Allergic disease was not associated with exposure to tobacco smoke, house dust mite antigen, or cats. Breast feeding may confer long term protection against respiratory infection.

ACAROSAN AND THE ACAREX TEST IN THE CONTROL OF HOUSE DUST MITE ALLERGENS IN THE HOME

SUMMARYHouse dust mites are believed to be major triggers for allergic disease in atopic individuals. As part of a programme controlling dietary and aero‐allergen exposure in high‐risk infants, an acaricidal foam and powder (Acarosan) was applied to bedroom and main living room carpets, as well as upholstered furniture, on four occasions in the first year of life. Dust was assayed for mite antigen (Der p1) and these results compared with the semi‐quantitative assay of guanine content (Acarex Test). After nine months mean Der p1 levels had decreased by 70% in the treatment group. Proportionally, the greatest fall occurred in those items that had the highest initial mite antigen content. The Acarex score does show a correlation with Der p1 levels, but cannot replace antigen assay when accurate data is required. A chemical acaricide may help reduce house dust mite antigen levels, but is not by itself sufficient to reduce levels below that considered critical for sensitisation.

New onset wheezing in an older male population: Evidence of allergen sensitization in a longitudinal study: Results of the normative aging study

Background: Thirty-nine male subjects, with new-onset wheezing, were selected from participants in the Department of Veterans Affairs Normative Aging Study and compared with 74 age-matched controls. Wheezing was defined by responses to a standardized and regularly administered questionnaire. The subjects with wheezing had a reduced FEV 1 compared with controls ( p = 0.005), but most had values above 80% predicted. Current smoking was more common in subjects with wheezing (36.8% vs 8.11% in controls, p < 0.001). The mean age of both subjects and controls was 64 years. Methods: Allergen-specific IgE antibodies were measured, starting with sera at the time of the most recent questionnaire, and on the average 3.1, 7.6, and 12.3 years before that, with use of stored serum samples. Results: Total IgE did not differ significantly between the groups. IgE binding to dust mite antigen was detected in 13% to 15% of the subjects with wheezing compared with fewer than 7% of the controls over four time intervals ( p = 0.014). IgE binding to cat and ragweed antigens did not differ significantly between groups. If current nonsmokers were analyzed separately, IgE binding to cat allergen was also slightly greater in subjects with wheezing compared with controls ( p = 0.054). Sequential analysis of IgE antibody levels to mite antigen, over time, indicated that IgE antibody antedated the onset of wheezing. Conclusions: New-onset wheezing in an older adult male population is significantly associated with allergic sensitization to dust mite. There was a borderline association with sensitization to cat in noncurrent smokers only. This supports the hypothesis that a subgroup may have allergic triggers to their symptoms.

Secretion of IL‐2, IL‐4, and IFN‐γ for Dust Mite Antigens in a Patient with Atopic Dermatitis

In a 21-year-old female with severe atopic dermatitis, the secretion of interleukin-2 (IL-2), interleukin-4 (IL-4), and interferon-gamma (IFN-gamma) by her peripheral blood mononuclear cells (PBMC) was measured after incubation with/without antigens extracted from Dermatophagoides pteronyssinus (Dp), to which the patient had developed a positive patch-test reaction. Incubation with Dp antigen produced marked secretion of IL-2 and IFN-gamma, but not IL-4. This may suggest that Dp-specific T lymphocytes present in the circulating blood cells are capable of producing IL-2 and IFN-gamma, which may be relevant to the delayed-type allergic reaction occurring in the skin lesion.

Effect of environmental control in reducing house dust mite antigen in asthmatic child&apos;s house

Effect of environmental control in reducing house dust mite antigen in asthmatic child&apos;s house

Combination of patch test and IgE for dust mite antigens differentiates 130 patients with atopic dermatitis into four groups

Background: Patients with atopic dermatitis sometimes have positive responses to patch testing (PT) with dust mite antigens, which is believed to correlate with the elevated levels of specific IgE for those antigens. Objective: The purpose of this study is to identify the correlation between the PT and serum IgE concerning the mite antigens. Methods: We studied 130 patients with atopic dermatitis by the PT reaction and the serum level of specific IgE for Dermatophagoides pteronyssinus antigens. Results: Fifty-one of the 130 patients assessed as PT-positive had either high (32 of 130 patients;24.6%) or low or no (19 of 130 patients; 14.6%) levels of mite-specific IgE; there was a significant difference between the groups with elevated and low IgE. Similarly, a total of 79 PT-negative patients also showed an elevated or low mite-specific IgE (42 of 130 patients [32.3%] or 37 of 130 patients [28.5%], respectively). It was noted that clinical morphologic findings were peculiar to three of the four groups;however, the patients who were PT-negative with a low IgE (37 of 130 patients) showed no particular clinical lesions. Conclusion: Comparing the results from our 130 patients, there was no correlation between the serum IgE level and the PT reaction for dust mite antigens. Conversely, the results of PT and mite-specific IgE could be used to divide these patients into four distinct groups, each with its own particular clinical morphology, suggesting the heterogeneity of this disease.

The relationship between eosinophils, OKT6-positive cells and house dust mite (HDM) antigens in naturally occurring lesions of atopic dermatitis

To determine the role of eosinophils in naturally occurring lesions of atopic dermatitis, we observed the distribution of eosinophil cationic protein (ECP) and the relationship between eosinophils, OKT6-positive cells and house dust mite (HDM) antigens. Some specimens showed many EG2-positive stains, although the accumulation of tissue eosinophils was not prominent. EG2 stains were seen not only in eosinophils but also in extracellular granules. Some macrophage-like cells of the dermis showed EG2 stains in the form of phagocytized eosinophil granules. Some EG2-positive eosinophils were in close contact with OKT6-positive cells in the epidermis and dermis. Furthermore, in three patients sensitive to house dust mite (HDM) antigen, HDM antigens invaded the skin with many EG2-positive stains. These results suggest that eosinophils play an active role in the development of eczematous lesions of atopic dermatitis.

House dust mite (HDM) antigen in naturally occurring lesions of atopic dermatitis (AD): The relationship between HDM antigen in the skin and HDM antigen-specific IgE antibody

To elucidate the etiological role of house dust mite (HDM) antigen in the pathogenesis of atopic dermatitis (AD), we conducted immunohistochemical studies on the localization of HDM antigen in naturally occurring lesions of AD. HDM antigens were found in the epidermis and dermis in 19 of 38 cases. All of the 19 patients had HDM antigen-specific IgE antibody, but HDM antigen was not detected in the lesions of patients without HDM antigen-specific IgE or in control skin specimens. Most HDM antigens were located on Langerhans cells (LCs) or near helper T cells. Our findings suggest that HDM antigen is the causative factor in the development of eczematous lesions of AD, and thus we hypothesized that IgE-mediated allergic contact sensitivity to HDM antigen plays an important role in the pathogenesis of AD.

Extreme dietary measures in the management of atopic dermatitis in childhood.

Of 63 children with severe atopic dermatitis who were treated with a diet eliminating all but 6 foods for a 6-week period, 9 (14%) abandoned the diet, 21 (33%) completed the diet but did not benefit, and in 33 (52%) there was significant benefit. However, the outcome at 12 months was the same regardless of the response to the diet because of the tendency for dermatitis to markedly improve in all three groups. Of 37 children with exceptionally severe atopic dermatitis treated with an antigen avoidance regimen comprising hospitalization, exclusive feeding with an elemental formula for a median duration of 30 days, and measures to reduce exposure to pet animal and dust mite antigens at home, 10 (27%) either failed to respond to the regimen or relapsed within 12 months, and sustained improvement was seen in 27 (73%) patients. A few-food diet or a strict anti avoidance regimen may be associated with improvement of atopic eczema where conventional treatments have failed.

House-dust mite allergy and eosinophilia in patients with asthma in Rangoon (Yangon).

Skin tests were done by prick and intradermal techniques, using house dust mite (Dermatophagoides pteronyssinus) antigen on 35 patients with early onset asthma, 33 with late onset asthma, 43 with asthma and frequent cough with sputum production (chronic bronchitis) and 30 control subjects. Absolute blood eosinophil and sputum eosinophil (as percentage of leukocytes) counts were performed on each patient. Positive skin tests to house dust mite antigens were significantly more frequent in each of the patient groups (35-75%) than in control subjects (0%), but were not significantly different among the three groups of asthmatics. All three groups of asthmatics had significantly higher mean blood absolute eosinophil counts and sputum eosinophil counts than control subjects, eosinophilia being most frequent in patients with early onset asthma. These findings suggest the importance of exposure to house dust mite antigens in the development of asthma in patients in Rangoon (Yangon), Burma (Myanmar).

韓国, ソウル市の屋内塵中のダニ相とダニ抗原量

The mite fauna of 74 house dust samples collected by season from 3 apartment houses and 4 separate houses in Seoul, Korea was examined microscopically. House dust mite antigen content was measured by the use of enzymelinked immunosorbent assay (ELISA) inhibition method. Of 9,638 collected mites, pyroglyphid mites comprised 70.5% and Dermatophagoides farinae was the dominant species (55.5%). Mite density and mite antigen content were highest in autumn and lowest in winter. These were higher in separate houses than in apartment houses. Positive correlation between mite density and mite antigen content was observed (r=0.45). The relatively low density of house dust mites in dust samples in apartment houses and in Korea was discussed in relation to family density, habitable floor area and use of "Ondol" floor heating system.