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Results for “Radioallergosorbent Test”

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PubMed1981

Studies on alternaria allergens. II. Presence of two related antigens with contrasting allergenic properties in Alternaria tenius extracts.

Earlier, it was reported that most of the allergenic activity of Alternaria tenuis seemed to reside in the last Sephadex G-100 fraction (G3, molecular weight approximately 20,000). These conclusions were based on results obtained by the in vitro techniques of radioallergosorbent tests (RAST) and RAST inhibition. In the present studies, the allergenic activity of A. tenuis fractions was measured in vivo. It was found that fraction G3 was neither capable of inducing reaginic (IgE) antibodies in rats nor eliciting a skin reaction in rats sensitized with reagins against A. tenuis non-dialyzable fraction (MW greater than 12,000). On the other hand, subfractions G2D3 and G2D4 obtained from the middle fraction of G-100 (G2, MW approximately 30,000-40,000) followed by ion-exchange chromatography on DEAE-cellulose, showed the greatest allergenic activity in vivo, giving high titered reaginic antibodies in rats. When compared by RAST inhibition, the activities of fractions G2D3 and G2D4 were slightly lower than that of G3. Fraction G3 was immunogenic in rabbits. In immunodiffusion tests, G2D3, G2D4 and G3 appeared to be identical and they were cross-inhibiting in RAST inhibition tests. It was concluded that the sizes and multivalent properties of G2 and G3 antigens exerted a strong influence on their allergenic activities in rats (IgE antibody production) but this factor was of little importance for their antigenic activity in rabbits (precipitin antibody production) and their behaviour in the in vitro tests.

Alternaria↗

PubMed1995

Skin-prick test and RAST responses to cereals in children with atopic dermatitis. Characterization of IgE-binding components in wheat and oats by an immunoblotting method.

BACKGROUND: Hypersensitivity to cereals may occur via inhalation or ingestion. Although cereals are essential in the daily nutrition, only little information is available of the allergens causing symptoms in patients with atopic dermatitis (AD). OBJECTIVE: The purpose of the present study was to analyse the IgE immune-response to various cereals and specific cereal fractions of wheat and oats in children with severe AD and correlate the results with challenge studies. METHODS: Skin-prick tests (SPT) with a NaCl suspension of wheat, oats, rice, corn, millet and buckwheat and the ethanol soluble gliadin fraction of wheat were performed to 34 wheat/oats challenge positive or negative children with AD. Simultaneously serum total IgE and specific IgE antibody radioallergosorbent test (RAST), levels to wheat, oats and gluten were determined. In addition serum samples of these 34 AD patients and five age matched controls were analysed with IgE immunoblotting using neutral and acidic protein extracts of wheat and oats. RESULTS: From the 34 AD children 33 were SPT positive with wheat and 18 with oats. Positive RAST to wheat and oats could be detected in 32 and 30 samples respectively. From the oral wheat challenge positive children 12/14 appeared positive with gliadin SPT and revealed positive RAST to gluten, but each of the wheat challenge negative were negative in SPT with gliadin. In immunoblotting using neutral and acidic fractions of cereals the IgE binding with sera of challenge positive children showed the most intensive staining, but no correlation was found between different staining patterns and the clinical wheat sensitivity. The 26, 38 and 69 kDa bands in wheat and the 46 and 66 kDa in oats could be classified as major IgE binding proteins of these cereals (> 50% of the sera were positive). SPT with rice, corn, millet or buckwheat was positive in 16/34 patients. CONCLUSIONS: Intensive IgE staining to neutral/acidic soluble proteins in wheat and oats was seen, with major IgE binding to 26, 38 and 69 kDa proteins in wheat and 46 and 66 kDa in oats, but no specific IgE staining patterns correlating with clinical cereal sensitivity were found. The strong association between the positive oral wheat challenge and the positive SPT with the ethanol soluble gliadin suggests that also gliadin is an important allergen in wheat-allergic children with AD. The allergens in rice, corn, millet and buckwheat should be better studied before they can be recommended as alternatives for cereal allergic children.

Allergens↗

PubMed1989

IgE antibody to sweat in atopic dermatitis.

Of 45 patients with atopic dermatitis skin-tested with their own sweat, 43 showed positive immediate-type skin reactions to titres between 1 and 256. Of 22 non-atopic patients 18 showed negative reactions. Skin reactivity of the atopic patients to the sweat and house dust did not run parallel. Radioallergosorbent test (RAST) using the sweat collected from a healthy subject detected IgE antibody in 24 atopic patients with a score from 0.5 to 3.5, whereas all the control subjects showed the score 0. This IgE antibody to sweat did not cross-react with the mite extract (Dermatophagoides farinae) or Staphylococcus aureus. These results indicate that atopic patients have specific IgE antibody to sweat.

Adolescent↗

PubMed1986

Pneumococcus-specific immunoglobulin E in cigarette smokers.

A relationship between elevated serum immunoglobulin E levels and smoking has been demonstrated in epidemiological studies. Allergy skin test data suggest that the excess immunoglobulin E of smokers is not specific for aeroallergens. It is possible that the excess immunoglobulin E is specific for microorganisms that often infect the lower respiratory tract of smokers. To investigate this possibility we utilized a radioallergosorbent test assay for detecting serum immunoglobulin E specific for Streptococcus pneumoniae, an organism commonly isolated from the respiratory tract of smokers with chronic bronchitis. We assayed sera of thirty smokers and thirty nonsmokers for immunoglobulin E specific for Streptococcus pneumoniae. Individual sera were considered positive for pneumococcus-specific immunoglobulin E if the binding was at least twice the non-specific binding at the total immunoglobulin E concentration of the particular serum. Eleven of the thirty sera of smokers and two of the thirty nonsmokers were positive for pneumococcus-specific immunoglobulin E. By chi-square analysis of these data, the prevalence of pneumococcus-specific immunoglobulin E was significantly greater in the smoking group compared with the non-smoking group (P less than 0.02). These results suggest that the excess immunoglobulin E of smokers is, at least in part, specific for microorganisms that infect the airways.

Adult↗

PubMedDate not supplied

[Latex sensitization in 28 patients].

We present a review of 28 cases of sensitization to latex. Skin prick test for latex was performed in subjects suspected of having allergy to latex and many fruits. Recently, many publications have evidenced the importance of sensitization to latex. There are well documented cases of intraoperatory anaphylaxis. Frequently, this happens to children with congenital urologic malformations, spina bifida or myelomeningocele, who undergo numerous surgical operations and vesical catheterizations. Latex-induced allergy also affects health professionals, since they are continuously in contact with latex-derived materials. There are other studies that relate latex-induced allergy to several fruit allergies (mainly chestnuts, bananas and avocados). In recent literature some discrepancy exists about the reliability of the prick test and the sensibility of in vitro diagnostic methods. We analyze 28 cases of latex sensitization from our clinic, comparing the most severe cases with the remaining subjects. Atopia antecedents were present in 82%, sub-clinical sensitization in 10 cases, urticaria/angioderma in 5, anaphylaxis in 9, and contact dermatitis in 4. Women were majority, with 22 cases versus 6 males. In patients with latex-induced anaphylaxis, the significantly most frequent feature was previous professional exposure to latex (p = 0.004). Specific IgE was measured by radioallergosorbent test (RAST), finding the highest values in the most severe clinical cases (p=0.0016), comparable to the results of the prick test, which still is the best diagnostic method. In our experience, banana and chestnut-induced allergies were the allergies most frequently associated to latex-induced allergy. There were no adverse reactions in any patient after the prick test.

Adolescent↗

PubMed1984

Allergen discs prepared from nitrocellulose: detection of IgE binding to soluble and insoluble allergens.

Nitrocellulose discs, 6 mm in diameter, are suggested as an alternative to cyanogen bromide-activated paper for the coupling of allergens in radio- or enzyme-linked assays to estimate allergen-specific IgE in serum. The preparation of allergen discs with nitrocellulose is simple, involving 3 steps: (a) drying allergen extract onto disc, (b) soaking discs in a 3% solution of bovine serum albumin, and (c) washing out the buffer. Very similar results (r = 0.94) were obtained using either paper or nitrocellulose discs for radioallergosorbent testing of sera from 15 bakers using allergens from mites, ryegrass pollen or wheat grain. The amount of protein (as radiolabelled albumin) actually bound to either type of disc or microtitre trays was similar, and low (5% of the protein applied for each media). However, when the protein was applied to nitrocellulose in 1% KOH up to 70% of it was bound. This solvent permitted better evaluation of IgE binding to insoluble allergens such as glutenin, which proved to be the most allergenic wheat-grain fraction tested by this method for a group of 9 bakers.

Allergens↗

PubMed1986

Immunoglobulin E antibodies against a reactive dye--a case report.

The presence of specific IgE (immunoglobulin E) antibodies against a conjugate between human serum albumin and a reactive azo dye (Levafix Goldgelb E-3GA, Reactive Orange 67) was demonstrated by the radioallergosorbent test (RAST), RAST inhibition, and skin prick tests in an occupationally exposed subject with symptoms of mainly rhinoconjunctivitis.

Adult↗

PubMed1997

Biological activity of recombinant Der p 2, Der p 5 and Der p 7 allergens of the house-dust mite Dermatophagoides pteronyssinus.

Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites.

Adult↗

PubMed1983

Allergic hypersensitivity to the insecticide malathion in BALB/c mice.

The widely used insecticide malathion (diethylmercaptosuccinate, S ester with O,O-dimethylphosphorodithioate) has been reported to cause allergic responses in some exposed people and in guinea pigs. In this study, IgE antibody-mediated and cell-mediated hypersensitivity to malathion was evaluated in female BALB/c mice. To elicit malathion-specific antibodies of the IgE class, a conjugate of the anhydride of the diacid metabolite of malathion (MMA) with keyhole limpet hemocyanin was administered ip with aluminum hydroxide as adjuvant. Sera collected following three sequential sensitizations were tested for specific IgE with the passive cutaneous anaphylaxis (PCA) test in Sprague-Dawley rats. MMA coupled to bovine serum albumin was used as the challenge antigen. Specific IgE was produced following the second and third sensitization in the mice receiving 10 and 100 micrograms of conjugate and following the third sensitization in the mice receiving 1 microgram of conjugate. A paper radioallergosorbent test (PRAST) was as sensitive as and showed a good correlation with the PCA assay for samples analyzed by both procedures. Malathion applied epicutaneously on 2 days or over 4 weeks failed to elicit delayed-type hypersensitivity as determined by change in ear thickness, 5-[125I]iodo-2'-deoxyuridine incorporation in the ear, and histology of the ear following ear challenge, with or without pretreatment of the mice with cyclophosphamide. MMA-specific IgE antibodies were not detected by the PCA test in the serum of mice treated epicutaneously for 4 weeks.

Animals↗

PubMed1995

Podocarpus gracilior and Callitris verrucosa--newly identified allergens that crossreact with Cupressus sempervirens.

Thirty-six symptomatic patients, with positive skin reactions to Cupressus sempervirens pollen extract were skin-tested with pollen extracts of Podocarpus gracilior and Callitris verrucosa, of these 17 (47%) had positive responses to P. gracilior, nine (25%) to C. verrucosa, and six (17%) to both. None of the non-atopic healthy controls had positive reactions to either of the extracts. Radioallergosorbent test (RAST)-inhibition studies were performed with pooled sera from three patients. Fifty per cent inhibition was obtained with 11 micrograms protein of C. sempervirens, 54 micrograms of P. gracilior, and 71 micrograms of C. verrucosa; however, when pollen extract of Olea europaea, an unrelated allergen, was tested, 265 micrograms protein were needed to obtain 50% inhibition. One-dimension sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of pollen extracts from the three species revealed that they had several very similar protein bands. Using Western blot analysis, several closely related IgE binding proteins were identified in the three species. It was concluded that the pollen grains of P. gracilior and of C. verrucosa are potentially allergenic. The presence of common allergenic proteins indicate partial crossreactivity with C. sempervirens.

Allergens↗

PubMed1983

Bacteria-specific IgE in patients with nasal polyposis. A preliminary report.

Sixty-one patients exhibiting chronic nasal polyposis had their conditions evaluated by radioallergosorbent tests to determine the presence of bacteria-specific serum IgE. Fifty-nine patients exhibited positive serum IgE to at least one of 11 bacteria tested. There are several implications of the collected data.

Antibodies, Bacterial↗

PubMed1989

Measurement of the absolute level of specific IgE to Dermatophagoides farinae by dot radioimmunoassay: relationship between the ratio of specific IgE to total IgE and skin reactivity.

Allergen dot radioimmunoassay (dot-RIA), employing nitrocellulose filter paper (NFP) as the solid phase, and a Phadebas RAST tracer as the detecting antibody was used to measure the absolute amount of specific IgE to Dermatophagoides farinae (D. farinae) in forty-five D. farinae-sensitive patients and ten negative controls. These results with dot-RIA were compared with those with D. farinae radioallergosorbent test (RAST). When the elution of D. farinae-specific IgE from antibody-dotted NFP complex by alkaline buffer (pH 11.0) was done and followed by measurement of IgE contents in various dilutions of eluate to construct a standard curve, D. farinae-RAST exhibited greater binding than dot-RIA. There was a similar high degree of correlation of specific IgE levels between the ratio of specific IgE to total IgE by dot-RIA and RAST when compared with the wheal size on skin prick test to D. farinae. It was suggested that dot-RIA using NFP as the solid phase-a simple, less expensive, and reproducible method-is applicable for measuring the absolute level of specific IgE to D. farinae and for determining the relationship between the ratio of specific IgE to total IgE and the wheal size on skin prick test in D. farinae-sensitive patients.

Allergens↗

PubMed1986

Fractionation and immunochemical characterization of Prosopis juliflora pollen allergen.

Prosopis juliflora pollen grain crude extract gave six different molecular weight fractions varied from 81,000 to 13,000 dalton on Sephadex G-100 gel filtration. The purity of fractions of Prosopis juliflora pollen extract were checked by polyacrylamide gel electrophoresis. The fraction had an molecular weight 20,000 dalton showed four absorption maxima whereas other fractions had single absorption maxima. Allergenic activity and nature of allergens were evaluated by in vitro Radioallergosorbent test and in vivo Passive Cutaneous Anaphylaxis test. All these tests indicated that most allergenic fractions were in the 20,000 molecular weight.

Allergens↗

PubMedDate not supplied

IgE antibodies to Malassezia furfur, M. sympodialis and Pityrosporum orbiculare in patients with atopic dermatitis, seborrheic eczema or pityriasis versicolor, and identification of respective allergens.

Malassezia yeasts may be a trigger factor for atopic dermatitis. Following the recent reclassification of the genus, the presence of specific IgE antibodies was examined in the sera of patients with atopic dermatitis (n = 223), pityriasis versicolor (n = 83), seborrheic eczema (n = 50) and hymenoptera allergy (n = 39) and in controls without skin diseases (n = 50). In addition to using the commercially available radioallergosorbent test (RAST) for Pityrosporum orbiculare couplings were also made against the reference strains for M. furfur and M. sympodialis. To characterize the specificity and molecular weight of corresponding epitopes identical material was used for production of an immunoblot. Despite high total levels of IgE, controls and patients with pityriasis versicolor showed no specific IgE antibodies. Six patients (12%) with seborrheic eczema were positive while 78 patients (35%) with atopic dermatitis had specific IgE antibodies in higher RAST classes that differed between the Malassezia species. The molecular weights of the main antigens of M. sympodialis and M. furfur were determined to be 15, 22, 30, 37, 40, 58, 79, 92, 99 and 124 kDa and 15, 25, 27, 43, 58, 92, 99 and 107 kDa, respectively. Evaluated according to the location of their disease, patients with head and neck lesions most frequently showed Malassezia-specific IgE antibodies. However, there were differences between the Malassezia species tested, the previously used strain P. orbiculare being assignable to the species M. sympodialis.

Adult↗

PubMed1990

Antigen-induced histamine release from peripheral leukocytes of "Konnyaku asthmatic patients".

Histamine release from peripheral leukocytes of "Konnyaku asthmatic patients," patients with a unique occupational bronchial asthma in Japan, was measured after challenge with the antigen. There was an antigen concentration-dependent response with highly significant correlations between the maximal histamine release and the ratio of the radioallergosorbent test (RAST) of the antigen to human serum albumin. These results suggest that the histamine release test from peripheral leukocytes as well as RAST can be a useful diagnostic test in patients with bronchial asthma.

Adult↗

PubMed1977

Diagnosis of reaginic allergy with house dust, animal dander and pollen allergens in adult patients. II. A comparison between skin tests and provocation tests.

The results of skin tests (ST) were compared with those of 2,055 provocation tests (PT) in 403 patients with asthma and/or allergic rhinitis. The overall agreement between ST and PT results was 77%. Various correlation figures were found for different allergens. In patients with pronounced allergy in the shock organ the prportion of positive ST was higher than in those with low-grade allergy. It is concluded that only strong ST reactions should be relied upon. In other cases additional diagnostic methods are reccommended. The diagnostic precision of ST is of the same order of sizes as that of the radioallergosorbent test.

Adolescent↗

PubMed1997

Laboratory analyses in the diagnosis of human allergic disease.

The clinical immunology laboratory provides support to the allergist in the diagnosis and management of human allergic diseases. Following a clinical history, the detection of allergen-specific immunoglobulin E (IgE) in serum can be useful in the definitive diagnosis of an IgE antibody-mediated hypersensitivity. Total serum IgE, the multiallergen screen, and mast cell tryptase are less commonly measured analytes in the work-up of the allergic patient. More recently, the clinical laboratory has employed monoclonal antibody based-enzyme immunoassays to quantify dust mite, cat, dog, and cockroach indicator aeroallergen levels in indoor home and work environments. Levels of allergenic proteins in environmental and medical/consumer products are measured by other assays such as the competitive inhibition radioallergosorbent test. Methods of quantification, internal quality control, and external proficiency testing programs are emphasized in this report.

Allergens↗

PubMed1983

Fire ant venom hypersensitivity. I. Comparison of fire ant venom and whole body extract in the diagnosis of fire ant allergy.

Levels of IgE antibody to fire ant whole body extract (FA-WBE) and fire ant venom (FAV) were evaluated in 60 patients with clinical histories of fire ant sting hypersensitivity and 11 frequently stung individuals without significant clinical reactivity to fire ant. An overlap of levels of IgE antibody to FA-WBE and FAV was seen between groups of patients with increasingly severe clinical reactivity; however, the group mean IgE antibody level of patients without significant clinical reactivity differed markedly from the group means of patients with more severe clinical reactivity (p less than 0.001). In 31 patients a good correlation (r = 0.6935) was found comparing FA-WBE IgE antibody level with FA-WBE skin tests, and in 26 patients a good correlation (r = 0.8564) was obtained comparing FAV IgE antibody levels with FAV skin tests. An excellent Spearman rank correlation coefficient (r = 0.9197) was found on comparison of FAV and FA-WBE IgE antibody levels in 71 individuals. Cross-reactivity of FAV and FA-WBE was demonstrated by the ability of these reagents to competitively inhibit the binding of IgE antibody to solid-phase FA-WBE and FAV in the radioallergosorbent test (RAST). From these results we conclude that FAV and FA-WBE both contain relevant allergens important in fire ant-allergic individuals and that skin tests and RAST are both valid as diagnostic tests for fire ant allergy. Finally, there is a good correlation between RAST and skin tests using FA-WBE or FAV as test reagents, since these reagents are highly cross-reactive as demonstrated by their ability to inhibit each other in the RAST.

Adolescent↗