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PubMed1991

Rice protein 16KD--a major allergen in rice grain extract.

The allergenic activity of Rice protein 16 KD (RP16KD) isolated from water soluble rice proteins was examined by radioallergosorbent test (RAST), RAST inhibition and histamine release assay. All of the 31 sera which showed positive RAST values for rice grain extract were positive for RP16KD RAST. Furthermore, there was a significant correlation (r = 0.56, p less than 0.01) between these RAST values. PR16KD effectively inhibited IgE binding to the rice grain extract disc in RAST inhibition assays using 4 sera with positive RAST values for both antigens. In 17 subjects with positive RAST values for rice grain extract, a significant positive correlation (r = 0.53, p less than 0.05) was found between the maximum percent histamine releases from their leukocytes by rice grain extract and RP16KD. These data strongly suggest that RP16KD is one of the major allergens of rice grain.

Allergens↗

PubMed1979

Allergenicity and lymphocyte-stimulating property of rice protein.

Two protein fractions of rice, grain, glutelin and globulin, were prepared by dilute alkali and salt extraction, respectively. The globulin fraction was separated into G1-1, G1-2, and G1-3 fractions by Sephadex G-200 column chromatography. The allergenic activities and lymphocyte-stimulating properties of these fractions were investigated by the radioallergosorbent test (RAST) with sera from 6 individuals who showed immediate skin reaction to soluble rice extract and by 3H-thymidine incorporation tests with 5 subjects with indurated skin reaction of delayed onset. All fractions were found to be reactive with specific IgE antibody, and G1-1 and G-2 revealed lymphocyte-stimulating activity. RAST inhibition revealed considerable cross-reactivity of IgE antibody with the glutelin and globulin fractions. When the glutelin and globulin fractions were heated at 60 degrees C for 1 hr, 100 degrees C for 2 min, or 100 degrees C for 10 min, RAST activities were reduced to 40%-70% of native. On the other hand, lymphocyte-stimulating activities of the globulin fraction heated at 60 degrees C for 1 hr or 100 degrees C for 2 min were enhanced up to 6 times of native activities, while those of identically treated glutelin fractions remained unchanged.

Adolescent↗

PubMed1980

Homology between roundworm (Ascaris) and hookworm (N. americanus) antigens detected by human IgE antibodies.

Utilizing the techniques of radioallergosorbent test (RAST), inhibition of RAST and isoelectric focusing on polyacrylamide gels, antigenic cross-reactivity has been shown between extracts of Ascaris lumbricoides. Ascaris suum and Necator americanus (hookworm). Antigenic homology is extensive between the two Ascaris preparations. The antigens common to hookworm and Ascaris, while representing a minor component of Ascaris body fluid, are nonetheless potent stimulators of IgE antibody production in subjects infected only with hookworm larvae. These shared antigens appear to have a pI of less than 5.1. The hookworm specific antigens also have a pI of less than 5.1, whereas those specific to Ascaris have pI values in the ranges of 5.0 to 6.0 and 7.0 to 8.6. These latter antigens, i.e. those with pI between 7.0 and 8.6, apparently elicit an immune response only during an active infection with Ascaris.

Antigens↗

PubMed1984

A collaborative study on RAST inhibition using a common method.

A collaborative study was carried out to determine the reproducibility of the inhibition form of the radioallergosorbent test (RAST). Seven laboratories were provided with three coded extracts of cocksfoot (Dactylis glomerata) pollen. All laboratories used a common method of RAST inhibition and were supplied with all reagents required to carry out the assays. In addition, four laboratories used local methods of RAST inhibition. Potency estimates were in reasonable agreement between laboratories when the study method was used but insufficient data were available to assess reproducibility when local methods were used. Two extracts prepared from the same source material were found to have parallel log dose-response lines but the line for the unrelated extract was steeper in all but one of the assays. This finding was an indication that the third extract differed qualitatively from the other extracts. It was concluded that the use of a study method of RAST inhibition resulted in good agreement between potency estimates obtained by different laboratories.

Allergens↗

PubMed1980

IgE and IgG antibodies to bee venom as measured by a modification of the RAST method.

The radioallergosorbent test (RAST) has been widely used in studying allergy to hymenoptera stings, but with variable results. We report here a modification of the RAST method which in a total of 157 bee keepers and family members, gave a close correlation between a positive RAST, and a history of generalized (100%) or localized (95%) allergic reactions. There was no positive RAST among forty-nine non-atopic control subjects but a striking finding was that 58% of non-allergic bee keepers had significant, but usually low, levels of IgE antibody to bee venom. IgG antibodies to bee venom have also been measured by a paper disc RAST which is quick and convenient. Levels were highest in non-allergic bee keepers. In the presence of high levels of IgG antibody, IgE antibody levels may be underestimated.

Animals↗

PubMed1979

Comparison of the atopic background between allergic and non-allergic beekeepers.

A study was carried out on beekeepers and their families. 34 subjects with a history of bee sting allergy and also a positive radioallergosorbent test (RAST) to honey bee venom were compared with 47 subjects with neither. 16 subjects in the bee allergy group (47%) had a history of atopic diseases as compared to 6 (13%) in the control group (p less than 0.01). 15 in the bee allergy group (44%) had at least one positive RAST to three common inhalant allergens as compared to 5 (11%) in the control group (p less than 0.01). These results suggest that, although bee sting allergy frequently affects non-atopic subjects, sensitization among beekeepers and their families occurs more readily in atopics. It is notable that a large proportion of patients injected with foreign proteins (the control group) either never develop venom-specific IgE antibodies or have suppressed their production.

Adult↗

PubMed1993

[Allergen analysis of buckwheat by the immunoblotting method].

Inhalation or ingestion of very small amounts of buckwheat allergen can initiate severe symptoms including wheezing, rhinorrhea, urticaria, vomiting and anaphylactic shock in patients with hypersensitivity against buckwheat. However, few studies of the immunological properties of buckwheat allergen have been made. The aim of the present investigation was to analyze the allergen in buckwheat antigen using the immunoblotting method, radioallergosorbent test (RAST) and RAST inhibition assay. Buckwheat 24 kilodalton protein (BW24KD) was shown by immunoblotting analysis to be the most frequently recognized allergenic component, binding to IgE antibodies from 100% of the patients' sera. There was a significant positive correlation (p < 0.001) between % bindings for BW24KD and buckwheat. In the RAST inhibition assay using patients' sera which showed positive IgE antibodies to buckwheat and BW24KD, there was effective inhibition in a dose-dependent manner between inhibition in a dose-dependent manner between BW24KD and buckwheat. These data indicated that BW24KD was a major allergen in buckwheat antigens. The experiments of SDS-PAGE using digestion buffer with or without 2-mercaptoethanol suggested that BW24KD was a component of heterodimer and the paired components had different molecular weights.

Adolescent↗

PubMed1996

Peripheral blood T lymphocytes and basophils, freshly isolated from house-dust-mite-sensitive patients, produce interleukin-4 in response to allergen-specific stimulation.

We examined the capacity of interleukin-4 (IL) production from lymphocytes and basophils, isolated from the peripheral blood of allergic patients sensitive to house dust mite, after stimulation with mite extract. IL-4 production was measured by a sensitive bioassay based on coculture with CT.h4S (a human IL-4-responsive cell line). Lymphocytes and basophils from patients with elevated serum IgE specific to mite allergen [radioallergosorbent test (RAST) score > 3] could produce detectable levels of IL-4 in response to mite extract, whereas those from patients with a RAST score of less than 2 or normal volunteers could not. The sensitivity of basophils to mite extract was high, so that a lower concentration of mite extract (1-10 ng/ml) could induce maximal IL-4 production. On the other hand, a higher concentration (10 micrograms/ml) was required for maximal IL-4 production from the lymphocytes. These findings demonstrate that allergen-specific IL-4-producing cells, lymphocytes and basophils, are generated in vivo in allergic patients and also that there exist characteristic differences between lymphocytes and basophils related to the in vivo source of IL-4.

Allergens↗

PubMed1977

Allergens in bee venom II. Two new high molecular weight allergenic specificities.

Two new allergenic specificites were detected in honeybee venom and the two corresponding protein substances isolated by gel filtration, immunoadsorption, and ion exchange chromatography. The first of these, allergen B, has a molecular weight ranging from 49,000 to more than 200,00 d and can be recognized by rabbit and guinea pig antisera as well as by human reaginic sera using the radioallergosorbent test (RAST). Allergen B gives a single line in immunodiffusion distinct from hyaluronidase, phospholipase A, melittin, and the other high molecular weight substances described and gives a single band at 49,000 d in sodium dodecyl sulfate (SDS) polyacrylamide gel. The second substance, allergen C, has a molecular weight of 105,000 d and was separated from allergen B by immunoadsorption with insoluble antibody. Allergen C was shown to be distinct from the other sustances in bee venom by immunodiffusion with animal antisera. One human reaginic serum was monospecific for allergen C. Two other minor components of 86,000 and 71,000 d are present in bee venom; their allergenic activities are unknown. The two specifities, B and C, comprise most of the reactivity of the previously described Sephadex G-75 fraction 1 and clearly are important allergens, reacting with 98% of sera from bee venom-allergic individuals.

Allergens↗

PubMed1985

Aluminium hydroxide adsorbed allergens used in modified RAST.

A method is described in which the conventional radioallergosorbent test (RAST) for determination of allergen-specific IgE in serum has been modified by displacing the solidphase sorbent by a gel of aluminium hydroxide (Al(OH)3). The optimum conditions for this new analysis (AlRAST) are determined, taking into account speed, costs and the ratio between responses of patients and normal individuals. The AlRAST fulfills the criteria for validity: it is specific and shows parallelism between serum dilution curves. The sensitivity and reproducibility are slightly lower than in the conventional RAST, but sufficient for most routine and screening procedures. The preparation of allergosorbents in AlRAST can be accomplished within 1 h, thus making it convenient for fast screening of patients against unusual allergen extracts, as well as for allergen standardization from dose-response curves. Further, it is possible to standardize aluminium hydroxide adsorbed extracts used for immunotherapy by using the products directly as allergosorbents in the AlRAST.

Allergens↗

PubMed1990

IgE antibodies to Pityrosporum orbiculare in children with atopic diseases.

IgE antibodies to Pityrosporum orbiculare and 16 other species of fungi were measured with the radioallergosorbent test (RAST) in sera of 131 children. The children were 7-18 years old, suffered from atopic diseases and showed a varied allergic profile on a skin prick test (SPT). IgE antibodies to P. orbiculare were found in the sera of 26 of the 131 children. A higher proportion of the P. orbiculare RAST positive children than of the negative ones had current eczema (p less than 0.0001). In a stepwise logistic regression analysis of SPT and RAST data, the occurrence of serum IgE antibodies to P. orbiculare had the highest explanatory value for current eczema. Ten of 15 children with current atopic eczema and total serum IgE of greater than 500 kU/l had serum IgE antibodies to P. orbiculare. Twenty-four of the 26 P. orbiculare RAST positive children harboured serum IgE antibodies to other fungi. The strong relationship between atopic eczema and the occurrence of IgE antibodies to P. orbiculare indicates that these antibodies may be pathogenetically important in at least some patients with atopic eczema and this gives another dimension to this common skin disease.

Adolescent↗

PubMed1999

Increased mast cell tryptase in sudden infant death - anaphylaxis, hypoxia or artefact?

BACKGROUND: Increased concentrations of mast cell tryptase in post mortem blood have frequently been observed in sudden infant deaths but the cause of this has not yet been clarified. OBJECTIVE: The aim was to evaluate factors (immunological, morphological and anamnestic data) behind the observed increase in mast cell tryptase in sudden infant deaths with elevated tryptase. METHODS: Mast cell tryptase and total immunoglobulin (Ig) E were measured in post mortem sera from 44 infants younger than 1.5 years. Radioallergosorbent tests were performed for possible allergens (mixture for relevant food allergens, Phadiatop and latex). IgG subclasses, IgM, and complement factors (C3, C4 and factor B) were measured with radial immunodiffusion. Mast cells, labelled with antibodies against mast cell tryptase, were counted in the lungs and heart. The circumstances of death and medical history of the deceased infant and family were obtained through police and hospital records. RESULTS: In 40% of the SIDS cases tryptase was elevated (>10 microg/L). Total IgE in serum was increased in 33% compared with clinical reference values but showed no association with mast cell tryptase. RAST tests were positive in three cases. In one of these cases both tryptase and total IgE were elevated. The only variable that was associated with high tryptase values was prone position at death (P < or = 0.05 ). Allergy or asthma in the family were alleged in 50% of the cases, but was not associated with elevated tryptase or IgE. Children with elevated total IgE also displayed high concentrations of IgG1 and IgG2. Infants who died in the spring had significantly higher IgE than the others (P < or = 0.05). CONCLUSION: The results do not support the hypothesis that the elevated tryptase concentrations in sudden infant death are caused by allergy. The association between prone position at death and elevated tryptase could hypothetically be explained by mast cell degranulation due to, for example, a hypoxic stimulus in these infants.

Anaphylaxis↗

PubMed1975

In vitro diagnosis of atopic allergy. The occurrence and clustering of positive RAST results as a function of age and total IgE concentration.

Specific IgE antibodies were determined on a routine basis in patient sera using the radioallergosorbent test (RAST) with a panel of ten common allergens. Total IgE was also assayed. Of all positive RAST reactions observed, 74% were against the following allergens: horse and cat epithelium, birch and timothy pollen, and house dust. Clustering (occurrence together with significantly elevated frequencies) accompanied both positive reactions to some animal danders and food allergens. Children in all age groups had significantly more positive food RAST results than adults, and this explains the clustering among food allergen results. Children aged 0-4 years had few positive pollen results. Among those with at least one positive RAST result, the mean number of positive results was 3.3, a figure which did not vary with age. In the present patient population 37% had a total IgE above the upper reference (normal) limit, and of these 95% had at least one positive RAST result. A normal or low IgE value was found to be less informative.

Adolescent↗

PubMed1980

Allergenicity of major component proteins of soybean.

Allergenic activities of major component proteins of soybean 11S-, 7S- and 2S-globulins were examined by the radioallergosorbent test (RAST) and by RAST inhibition experiments with the sera from soybean-sensitive patients. The reactivity with specific IgE antibody was found in all fractions. There was considerable cross-reactivity among three fractions, and 2S-globulin had the highest allergen potency to inhibit the RAST against 11S, 7S- and 2S-globulin. When the fractions were heat-treated at 80, 100 and 120 degrees C for 30 min, the RAST reactivity of 2S-globulin heated at 80 degrees C for 30 min was slightly enhanced, while that of others was reduced to 39--75% of that of the native globulin. IgE antibody could be produced in BALB/c mice only with one of the three fractions, i. e. 2S-globulin, and the produced IgE antibody lacked reactivity with 11S- and 7S-globulin.

Allergens↗

PubMed1985

Allergens in the white and yolk of hen's egg. A study of IgE binding by egg proteins.

The radioallergosorbent test (RAST) was used to compare the IgE binding of egg white and yolk, and allergenic proteins were detected by immunoelectrotransfer ('Western blotting'). The main allergens were found in egg white, but for a large proportion of the egg-sensitive patients, yolk contained specific IgE-binding constituents. For blood sera from 36 patients, there was a positive correlation between the results of RAST for egg white and for yolk. Lysozyme was found to be an allergen for some patients. The effect of heating on the allergenicity of egg white was examined and the allergenicity of hen egg white was compared with that of a duck egg. The allergens in yolk were associated with each of the three yolk fractions, and several of the proteins in the low-density lipoprotein fraction bound IgE.

Adolescent↗

PubMed1997

Immune response to food antigens: kinetics of food-specific antibodies in the normal population.

The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to beta-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.

Animals↗

PubMed1996

Enhanced IgE response to Candida albicans in postoperative invasive candidiasis.

BACKGROUND: Invasive candidiasis is a life-threatening complication problem in post-operative and immunocompromized patients, e.g. those treated by intensive care. Candida is frequently cultured from the mucous membranes of hospital patients and fungal cultures offer little diagnostic help. Other diagnostic methods, such as blood cultures, serology and diagnostic imaging techniques produce results too late and, if positive, low sensitivity. OBJECTIVE: To study the value of Candida-specific antibodies, especially those of IgE class, in diagnosing invasive Candida infection. METHODS: The immunoglobulins IgE, IgG and IgM responses to antigens of Candida albicans in the sera of 14 patients with culture, biopsy and/or autopsy proven postoperative invasive candidiasis and of 11 colonized and 19 non-colonized operated patients were studied by mannan radioallergosorbent test (RAST), mannan enzyme-linked immunosorbent assay (ELISA) and immunoblotting. RESULTS: Detection of IgE antibodies to C. albicans polysaccharide (mannan) and protein antigens proved specific and sensitive in diagnostics of invasive candidiasis after major abdominal surgery. IgE rose early in the course of the infection and the method made a clear distinction between invasive infection and mucous colonization. Immunoblotting for protein antibodies was most sensitive while nitrocellulose-RAST for mannan antibodies was most specific. The combined use of immunoblotting and RAST increased the sensitivity and the specificity. Determinations of anti-Candida IgG and IgM antibodies had low sensitivity and specificity. CONCLUSION: Critically ill patients with invasive candidiasis develop IgE antibodies to Candida antigens probably because of disturbed TH1/TH2 responses. Determination of specific IgE antibodies can be used as a diagnostic aid in the early stage of invasive Candida infection.

Adult↗

PubMed1987

[Studies on the RAST method using tray added disc].

The radioallergosorbent test (RAST) provides a reliable method for detecting of specific IgE antibodies against a wide variety of antigens. The method using tube added disc for the estimation have been widely used in routine assay. In this study, the method using tray added disc has developed in our laboratory. The results were as follows; (1) The method using tray showed good correlation to the original method. (2) Characteristics of the method are rapidity, simplicity and economics. (3) The reaction well of tray is flat bottomed and is good for disc reaction. (4) Coefficients of variation for intra assay were; (d1): 9.40-9.68%, inter assay were 10.39-12.15% respectively. (5) The seasonal variation of positive allergens and the correlation of d to h, g1 to g3 were estimated. The method using tray seems to be one of the most useful routine methods of RAST assay and checking the seasonal variation of RAST will give good advantages to estimate the regional pollution of pollens allergy.

Antibodies, Anti-Idiotypic↗