RAST with animal dander, urine, saliva and serum

Binding of specific IgE antibodies from the sera of patients allergic to animals was investigated by direct RAST, using the animal's dander, urine, saliva or blood serum as insolubilized allergens. In allergy to rat, mouse, guinea pig, dog, cat or horse, the RAST results with the excretions of a particular animal were mutually well correlated. RAST with the animal blood serum was positive less often, and only in cases of a positive dander RAST. It is concluded that a RAST with animal dander precludes the use of other animal products.     

Study on the clinical significance of pharmacia rast RIA in animal allergy

To study the usefulness of Pharmacia animal allergen discs, the specific IgE antibodies in the sera of patients with allergy to pet or laboratory animals were measured with the use of those discs. The coincidental ratio between skin test to cat hair and RAST to cat epithelium was 73.3%, however between skin test to dog hair and RAST to dog epithelium or dog dander it was 66.7% or 60.0%, respectively. The rate of RAST positive do dog dander was higher than to dog epithelium, and so it seems to be the optimum allergen for screening. The correlation between RAST value to dog epithelium and dog dander was good, but there was no relationship between cat and dog epithelium, it seems that cross-antigenicity is low. In laboratory animals, the rate of RAST positive was in decreasing order: guinea pig, mouse, rabbit, rat, hamster. The rate of RAST positive to serum proteins of rat and mouse was lower than to epithelium and urine proteins. It seems not to be useful.     

Clinical associations with serum allergen-specific IgG4 antibodies

Serum total and allergen-specific IgE and IgG4 antibodies, were measured in eighty-seven atopic and nineteen non-atopic asthmatics. The allergens studied were: Dermatophagoides pteronyssinus, grass pollens, cat dander, dog dander, milk and egg. Sixty-eight atopic asthmatics and fourteen non-atopic asthmatics were found to have allergen-specific IgG4 antibodies, to at least one of the allergens tested. IgG4 antibodies to milk and egg were common in both groups of asthmatics, and to animal danders in the non-atopic asthmatics. Skin prick tests were always negative when allergen-specific IgG4 antibodies occurred alone, but in such cases, intradermal skin tests were positive. Seventy-five per cent ofa group of patients with normal levels of serum total IgG4, were found to have at least one positive IgG4 RAST.     

Incidence of IgG short-term sensitizing antibodies in an allergic population.

Heat-stable, immunoglobulin G, short-term sensitizing antibodies (IgG S-T S) were sought in serum from 149 allergic patients who had strongly positive immediate skin tests to inhalant allergens. The sera were tested by passive cutaneous anaphylaxis (PCA) in monkeys. No IgG S-T S antibodies were demonstrated in 169 tests with a variety of allergens. Antibody with the characteristics of IgE was demonstrated in 47% of monkey PCA tests and, in an additional 34% of sera. IgE antibody to the same allergen was demonstrated by radioallergosorbent testing (RAST).     

Breed-specific dog hypersensitivity in humans

The contribution of allergenic components of dander and serum from individual dog breeds in human hypersensitivity and the different responses to the various breeds in vivo and in vitro were examined. Differences in IgE antibodies directed against 13 individual dog breed danders and five different breed-specific sera were measured in groups sensitive and nonsensitive to dogs by the radioallergosorbent test (RAST). Cross-reactivity between dander extracts and sera was examined by RAST inhibition. Mean RAST binding to dog danders and sera was 15.9% and 14%, respectively, for the dog-sensitive group versus 0.6% for both danders and sera in the nonsensitive group. The mean difference in binding between groups was statistically different for all dander extracts and sera. The variances in binding were statistically greater for danders than sera in six of eight dog-reactive subjects. RAST binding and intradermal skin tests at a 1:10,000 $\text{w}\text{v}$ dilution correlated well (p < 0.05) for seven of nine breed-specific extracts. RAST inhibition studies showed that dog serum proteins were relatively poor inhibitors of dander extracts, and vice versa. Variability of skin test and RAST responses to different dog breed dander extracts support the existence of breed-specific allergens.     

Interference in ragweed pollen and honeybee venom radioallergosorbent tests

We studied sera from patients sensitive to short ragweed (SRW) and honeybee venom (HBV) to investigate serum factors able to interfere with the measurement of IgE antibody levels by the radioallergosorbent test (RAST). We heated sera to destroy IgE antibodies and tested them for interference in the RAST. Heating sera for 4 hr at 56 °C destroyed up to 98% of the IgE antibody activity. After immunotherapy sera from patients sensitive to SRW and HBV produced striking interference in the RAST. The interference was most marked in the RAST employing 50-μg quantities of microcrystalline cellulose—linked allergens, but it was also evident in the RAST employing 500-μg quantities of such allergens and in the commercial RAST in which allergen is linked to paper disks. The interfering substance eluted from diethylaminoethyl (DEAE) cellulose in the IgG fraction. The interference could be eliminated by increasing the relative quantity of solid-phase allergen; RAST interference was not detected when SRW extract was linked to Sepharose 4B. The results indicate that serum factors, presumably IgG antibodies, produce interference in the RAST. Thus immunotherapy studies that measure IgE antibody levels by the RAST must consider the possibility that IgG antibodies can appear to depress IgE antibody levels. Furthermore, because commercially available RAST disks are susceptible to RAST interference, they must be used with caution for the diagnosis of allergy in patients whose sera may contain significant quantities of IgG antibodies.     

Relationship between IgG1 and IgG4 antibodies to foods and the development of IgE antibodies to inhalant allergens. II. Increased levels of IgG antibodies to foods in children who subsequently develop IgE antibodies to inhalant allergens

In the present investigation we have tested the hypothesis that children with a high IgG antibody response to foods have an increased risk of developing IgE antibodies to inhalant allergens. Sera from 106 children with an increased risk of developing IgE-mediated allergy were analysed. During the follow-up, in 54 of these children IgE antibodies to inhalant allergens appeared. A positive/negative IgG1 and IgG4 anti-food score was determined as described previously: sera from age-clustered unselected children were tested for the levels of IgG1 and IgG4 antibodies to common foods. For each IgG RAST and each age group, the 75-percentile was chosen as cut-off value. Each antibody level was thus converted into a positive (higher than the 75-percentile of the age group) or negative value. The number of positive tests was used as the score. High-risk children with a high IgG1 anti-food score more often developed inhalant-specific IgE antibodies than high-risk children with low IgG1 titres: 50% of the children with a high IgG1 anti-food score developed IgE antibodies to grass pollen. Fifty per cent of the children with a high and 14% of the children with a low IgG1 anti-food score developed IgE antibodies to cat dander. For the prediction of the development of IgE anti-mite (house dust mite), the IgG4 anti-food scores appeared less useful than the IgG1 anti-food scores; 46% of the IgG4 high responders versus 22% of the IgG4 low responders acquired IgE anti-mite, whereas for IgG1 these percentages were 73 and 19, respectively.     

IgE synthesis in man. II. Comparison of tetanus and diphtheria IgE antibody in allergic and nonallergic children.

Specific IgE and IgG antibodies were quantitated in 91 allergic and 80 nonallergic age- and sex-matched children between 4 and 17 yr of age. Statistically significant increased antidiphtheria and antitetanus IgE antibodies (p < 0.01) measured by the radioallergosorbent test (RAST) were noted in allergic compared with nonallergic subjects. Of the allergic children with total serum IgE >500 U/ml, 19 of 52 (37%) and 25 of 52 (48%) had elevations (>2 SD above nonallergic control mean) of serum antitetanus or antidiphtheria IgE antibody, respectively, whereas only 2 of 35 allergic children with serum IgE <500 U/ml had elevation (>2 SD) of these antibodies. Antitetanus and antidiphtheria IgG antibodies were measured by passive sheep red blood cell (SRBC) hemagglutination. Geometric mean antitetanus IgG antibodies were higher in allergic (4.9 AU/ml) as compared to nonallergic (1.7 AU/ml) children (p < 0.001). Geometric mean antidiphtheria IgG antibodies were higher (0.31 AU/ml) in nonallergic and lower in allergic (0.10 AU/ml) subjects (p < 0.01). These data suggest that allergic individuals with markedly elevated total serum IgE have unique antibody responses following routine immunization with tetanus-diphtheria (Td) toxoids and tetanus-pertussis-diphtheria (DPT) which are manifest by enhanced specific IgE synthesis.     

Inhalant allergy to wild animals (deer and elk)

We studied 15 highly atopic persons with historic and/or skin test evidence of allergy to deer or elk. All 15 were also reactive to domestic animal danders (dog, cat, or horse). Twelve patients had elevated IgE antibody levels to deer hair/dander and six patients had elevated IgE antibody levels to elk hair/dander. Elevated IgE antibody levels to serum or urine from deer or elk were found in six persons. By using individual patient sera in RAST inhibition experiments we showed that IgE antibodies were directed to allergens common to hair/dander, urine, and serum. One individual reacted to an allergen common to both deer and cat hair/dander. We concluded that atopic individuals sensitive to domestic animals may develop IgE-mediated reactions to deer or elk allergens following recreational or professional hunting contact with these animals.     

Specific IgE antibodies in atopic eczema

Radioallergosorbent tests (RAST'S) with 35 antigens and total serum IgE levels were performed on sera from 25 patients with atopic eczema, ranging from mild to very severe, who had been evaluated clinically and, when possible, skin-tested to inhalant allergens. IgE levels varied from 95 to 112,000 I.U., with a geometric mean of 2,200 I.U. Individual patients' sera gave an average of 8.4 positive RAST's to 14 inhalant allergens with a range of from 1 to 14 positive tests. The correlation of RAST with skin tests averaged 55 per cent with no difference observed with either the scratch or the prick methods. The degree of correlation was not related to severity of eczema. In eczema patients the great majority of noncorrelating tests were RAST positive and skin-test negative, unlike the noncorrelating tests found in children with asthma and allergic rhinitis, where there are more positive skin tests with negative RAST. The 25 sera were tested by RAST with 18 food antigens and the various sera gave from 1 to 18 positive tests, with an average of 9.7. IgE antibodies reacting with at least one of the DPT antigens were found in 10 of the 25 sera. Sera from 4 of the patients studied contained IgE antibodies that combined with all 35 antigens studied. Control RAST's with these sera were negative. This study shows that much of the elevation of serum IgE observed in atopic eczema represents specific IgE antibodies that can combine with common antigens with relatively high affinity.     

Allergen-specific IgE and IgG4 antibody levels in sera and the capacity of these sera to sensitize basophil leucocytes in vitro

Leucocytes from normal non-allergic donors were passively sensitized with sixty-five atopic sera that contained IgE directed against house dust mite (HDM) or guinea-pig dander (GPD). In no serum was there any IgE with an abnormal basophil anaphylactic-sensitizing activity. In sera from patients hypersensitive to GPD, both GPD-specific IgE and IgG4 were measured. A significant correlation was found between the GPD-IgE RAST and the basophil-sensitizing capacity of GPD-positive sera, but no correlation was found between this sensitizing capacity and the GPD-lgG4 RAST. Leucocytes were passively sensitized with serum mixtures that contained the same amounts of total and HDM-specific IgE; these mixtures differed as to sensitizing activity. It is unclear whether this variation is due to differences in IgE or to influences of other factors in serum.     

Humoral and Cell-Mediated Immune Responses to Dog Dander and Hair in Asthmatic Children

Dog dander and hair (DDH) specific IgA, IgG and IgE antibodies from serum samples Of 202 asthmatic children, and in nasal secretion from 4 to 15 years were measured by enzyme-linked immunosorbent assay. The results were compared with clinical history, and with allergy test (skin prick test, provocation test and RAST) using the same DDH extract. A blood sample for the in vitro lymphocyte stimulation test was obtained from 40 children, and a nasal secretion sample for analysis of the local DDH-specific IgA, IgG and IgE antibody levels was collected form 35 of them. In children of dog-keeping families, higher serum levels of DDH-specific antibodies, especially IgE antibodies, were observed if the dog had been in the home already during the first years of the child's life. The serum levels of DDH-specific antibodies, however, did not correlate with the degree of the present exposure to dogs. The serum levels of DDH-specific or total IgE, or with the results of skin prick or provocation test. The serum levels of DDH-specific IgA were highest in children who were subjectively most sensitive to dogs. Nasal levels of DDH-specific IgE correlated positively with serum specific IgE levels. The correlation was weaker between nasal and serum titers of specific IgG, and not significant between nasal and serum IgA antibody levels, Specific IgE antibody levels were higher, while specific IgA and IgG antibody levels were lower, in nasal secretion form subjects with nasal symptoms on contact with dogs, when compared with subjects with other complaints (asthma, conjunctival or skin reactions). DDH-specific IgG levels correlated negatively with specific IgE level in the nasal secretion from subjects with a positive provocation test result, while the correlation was positive in subjects with a negative provocation test. The in vitro lymphocyte response to DDH did not correlate with the results of allergy test, or with the levels of DDH-specific antibodies in serum or in nasal secretion.     

Dissociation of house dust allergies. A comparison between skin tests, inhalation tests, specific IgE and basophil histamine release measurements.

The present study was undertaken to identify the most dominating allergens giving positive reactions both in vivo and in vitro, in patients with house dust (HD) hypersensitivity. Among 655 subjects with positive skin test reactions for HD, 469 (i.e., 71%) had positive reactions for Dermatophagoides pteronyssinus (D.pt.), and 186 (i.e., 28%) had negative reactions for D.pt.; among these 186 patients, 96% reacted to other different allergens, especially to animal epithelia. Challenge tests were performed in 52 patients. In 40 subjects with positive skin tests to HD and D.pt., all gave positive reactions to both tests. Among 12 patients, negative to D.pt. but positive to animal dander, provocation tests confirmed hypersensitivity to animal dander and absence of reaction after inhalation of D.pt. extract. Laboratory studies used specific IgE determinations (RAST Phadebas) and histamine release from human leukocytes. Of 240 HD-hypersensitive patients with serum IgE to HD, 204 also had positive RAST results for D.pt. and 36 for other allergens, there was a high incidence of cat dander (29/36). In a total of 13 dust-allergic people with positive skin tests for HD and D.pt., the relative cell sensitivity for these two extracts was determined from the allergen concentrations, which elicited 50% histamine release. The same biological parameters were determined in a group of 10 patients with positive skin tests to HD and cat dander, and negative skin tests to D.pt., for D.pt., HD, and cat dander extracts. Patients having positive skin tests to HD and D.pt. were also good histamine releasers for these two allergens. On the other hand, we could demonstrate that leukocytes from patients negative to D.pt. were really hypersensitive to cat dander. Our results demonstrate that neither HD skin tests nor HD RAST can characterize the effective allergens responsible for HD hypersensitivity. Identification of the major allergens present in HD, variable in each individual case, could aid toward more specific diagnosis.     

Quantitative Immunoelectrophoretic Analysis of Extract from Cow Hair and Dander

Quantitative immunoelectrophoresis used for the analysis of a diabased, centrifuged and freeze-dried extract from cow hair and dander revealed 17 antigens. Five of these were identified as serum proteins. Partial identity to antigens of serum and extract from hair and dander of goat, sheep, swine, horse, dog, cat and guinea pig, and to antigens of house dust was demonstrated. Sera from 36 patients with manifest allergy to cow hair and dander selected on the basis of case history, RAST, skin and provocation test, were examined in crossed radioimmunoelectrophoresis (CRIE); sera from five persons with high serum IgE, but without allergy to cow hair and dander, and sera from five normal individuals were controls 31/36 of the sera contained IgE with specific affinity for two of the antigens of the extract. Further, two major and six minor allergens were identified. The control sera showed no specific IgE binding. A significant positive correlation was found between RAST and CRIE for the first group of patients. The approximate molecular weights of the four major allergens obtained by means of gel chromarography were: 2.4 × 10⁴, 2 × 10⁴, 2 × 10³ dalton, respectively. Using Con-A and Con-A Sepharose in crossed immunoaffinoelectrophoresis, eight of the antigens were revealed to contain groups with affinity for Con-A.     

The irritable bowel syndrome and food hypersensitivity

Ten patients with irritable bowel syndrome were evaluated for food hypersensitivity with skin testing (IgE) and IgG serum antibodies (RAST panel) to common food antigens. Patients also underwent an open elimination diet for 2 weeks followed by a 48-hour challenge of each food that was considered to be suspicious from patients diary, positive skin prick test, and/or positive IgG antibodies. Six patients had positive skin scratch test results and only one patient had RAST IgG food antibodies greater than 3,000 cpm which is a marked increase above normal. None of the patients however had an exacerbation of their irritable bowel symptoms with a food challenge. We conclude therefore that positive skin testing and IgG serum antibodies are not reliable indicators of food hypersensitivity in irritable bowel syndrome and that food hypersensitivity does not seem to play a role in the symptoms related to the irritable bowel syndrome.     

Allergy to guinea pigs: I Allergenic activities of extracts derived from the pelt, saliva, urine and other sources

Guinea pig-sensitive patients with asthma and rhinitis were skin test positive to extracts of several materials derived from guinea pigs. A radioallergosorbent test (RAST) was developed to measure serum IgE specific for the dander, urine, saliva and also for dust from the air-vent filters of a room housing guinea pigs. A strong correlation was found between positive skin test reactions, and raised serum IgE to these extracts. Furthermore, the relative allergenic potency of extracts was similar when determined by skin-prick testing and by inhibition of the RAST to guinea pig dust. Non-guinea pig-derived extracts such as the hay, sawdust and diet had negligible activity in skin testing and RAST inhibition; and preparations of Dermatophagoides pteronyssinus, house dust and rat dust did not inhibit the RAST for guinea pig room dust. The guinea pig dust, dander, fur, urine and saliva were the more potent extracts; while whole pelt, faces and serum were considerably less active. Extracts from different sexes were not appreciably different in potency. The results of skin testing. RAST and RAST inhibition suggest cross-allergenicity between the various extracts. Although material shed from the pelt may have been derived from saliva, or even urine, allergenic activities of urinary and salivary preparations were found to be less than those of the dander, fur or dust. This suggests that allergens have become concentrated on the pelt.     

Milk whey-specific immune complexes in allergic and non-allergic subjects

We developed an antigen- and isotype-specific ELISA for the rapid detection of native serum immune complexes (IC). It is a sandwich assay, in which a solid phase antigen-specific capture antibody selectively binds the antigen-specific IC via the antigen. The isotype of the bound IC is then identified using an enzyme-labelled indicator antibody. Using this sensitive assay system, we were able to detect native serum milk whey-specific immune complexes (SMIC) of the IgG, IgE and IgA isotypes. Detectable amounts of native serum SMIC of all three isotypes were found in sera of the majority of both atopic and non-atopic subjects. The ELISA was then used to compare the levels of native IgE SMIC in sera of milk RAST positive atopic patients with those found in milk RAST negative atopic patient sera. Milk RAST positive patient sera were found to have significantly higher mean levels (P less than or equal to 0.005) of native IgE SMIC than milk RAST negative sera. Sera of other atopic individuals were also found to contain significantly higher mean levels (P less than or equal to 0.005) of native IgG and IgA SMIC than non-atopic donors. IgE IC may specifically be involved in adverse symptoms seen in milk allergic patients.     

Monkey dander asthma

We recently cared for two patients who experienced acute asthma with exposure to dander of the cotton top tamarin, a species of New World monkey. Both patients had serologic evidence for an IgE antibody to monkey dander as determined by RAST and a positive immediate skin test response to an extract prepared from monkey dander. Furthermore, by RAST we were able to determine that cotton top tamarin urine and newborn cotton top tamarin dander had antigens that reacted with IgE in the serum of the affected patients. Thus we report two patients with asthma to monkey dander that appears to be mediated by an IgE mechanism. We also found that serum from a subject exposed to another species of New World monkey, the capuchin, yielded a positive RAST to the cotton top tamarin, suggesting that allergenic cross-reactivity may exist between the two species.     

Measurement of antigen-specific IgE in nasal secretions of patients with perennial rhinitis

Sixteen of 53 patients with rhinitis had positive skin tests corresponding with serum-specific IgE (RAST). Concomitant positive nasal secretion (NS) RAST was found in 10/16. Four patients with both negative skin tests and serum RAST had positive NS RAST. In a subset of patients with perennial rhinitis, specific IgE may be detected only in NS. Further studies are necessary to document the clinical relevance of such NS IgE antibodies.     

Measurement of IgG, IgA and IgE antibodies to Dermatophagoides pteronyssinus by antigen-binding assay, using a partially purified fraction of mite extract (F4P1).

An extract of Dermatophagoides pteronyssinus culture has been fractionated by chromatography on Sephadex G-100 and Pevikon block electrophoresis to obtain a partially purified allergen (F4P1). This preparation has a molecular weight of between 15--25,000 Dalton, migrates slowly on electrophoresis, and is colourless in solution. The skin-test reactivity of F1P1 was comparable to that of crude D. pteronyssinus extract. F4P1 was radio-labelled with 125I and used in an antigen-binding radioimmunoassay to measure IgG, IgA and IgE antibody (ab) to D. pteronyssinus. IgG, ab was detected in serum from 32/34 (94%) mite-allergic persons, and from 10/31 (30%) nonallergic persons. IgA ab and IgE ab were found in sera from 22/34 (65%) and 37/34 (79%) allergic persons respectively. Neither IgA nor IgE ab could be detected in sera from non-allergic persons. An excellent correlation was found between radioallergo-sorbent technique (RAST), using crude D. pteronyssinus extract and IgE-binding activity (BA) for F4P1, (r=0.94, P less than 0.001). The antigen-binding assay for IgE BA was as sensitive as RAST, but less sensitive than PK testing. There was a very good quantitative correlation between IgG BA and IgE BA (r = 0.84, P less than 0.001). IgG BA was shown to rise in the serum of three patients treated with injections of D. pteronyssinus extract.