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PubMedDate not supplied

Plantain allergy (Plantago lanceolata): assessment of diagnostic tests.

A study was made of 55 patients with skin prick test results for Plantago lanceolata of 3 mm2 or more. They were evaluated in relation to the response elicited by 10 mg/ml of histamine HCl. Patients with a response to Plantago less intense than the response to histamine were considered as having a "negative" response, whereas those whose response to Plantago was more intense than the response to histamine were considered as having a "positive" response. In 35 cases a radioallergosorbent test (RAST) was performed and in 22, nasal provocative testing (NPT). The frequency of positive response was 0.63 for skin tests, 0.11 for RAST and 0.72 for NPT. Among the patients with positive NPT, the frequencies of positive response to skin tests and RAST were 0.71 and 0.6 (p < 0.05), respectively. Results are discussed and study methods are proposed.

Adult↗

PubMed1987

Immunologic and functional consequences of chemical (tetrachlorophthalic anhydride)-induced asthma after four years of avoidance of exposure.

Seven patients with occupational asthma caused by a chemical, tetrachlorophthalic anhydride (TCPA), left their work in 1980. They have subsequently avoided TCPA exposure and have been followed until 1985. One patient died in 1981. The six living patients reported continuing symptoms suggestive of asthma, and five who were studied in 1985 demonstrated mild bronchial hyperresponsiveness (histamine concentration provoking a 20% fall in FEV1 range 2.7 to 12.5 mg/ml). Specific IgE antibody to TCPA conjugated with human serum albumin was measured by a radioallergosorbent test and detected in all patients. After avoidance of exposure, specific IgE fell exponentially with a half-life of 1 year. Specific IgE was still detectable in 1985, and throughout the follow-up period, prick tests with the conjugate elicited immediate skin responses. In 1981 four patients had inhalation tests with TCPA, and specific IgE rose afterward and then fell again.

Adult↗

PubMed1993

Skin prick tests with solutions of acid anhydrides in acetone.

Various low molecular acid anhydrides can act as haptens and induce type I allergies. Immunoglobulin E can be detected by radioallergosorbent test (RAST) with the protein conjugates of the respective anhydrides, which are commercially available for some substances. Being almost nonsoluble in water, these species cannot be applied in a skin prick test as a water solution. We will introduce a practicable skin prick test using acetonic solutions of the haptens. 136 persons were tested with acetone for negative control and histamine for positive control. Tests were carried out with 1 and 5% acetonic solutions of phthalic anhydride (PA). The RASTs with conjugates of the PA were performed with 111 subjects who had been exposed to acid anhydrides and with 5 people who possibly had been exposed. In 14 cases, when immediate-type allergy was suspected clinically, a test was performed in addition to the respective anhydride used at the workplace. In order to avoid unspecific histamine liberation, we tested 20 volunteer control persons who had not been occupationally exposed to acid anhydrides. In the prick test performed with acetonic PA solutions, 10 of the occupationally exposed subjects, who had also had a positive result in the RAST with protein conjugates of the PA, showed positive skin reactions, and in 2 further cases, in which the skin reaction was positive, the results of the RAST were just below the limit of a positive evaluation. The skin reaction was positive in 4 cases, in spite of a negative RAST result, while the prick test was reported to be negative in 3 cases although the RAST results were considered to be positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetone↗

PubMed1985

Analysis of tobacco leaf allergens by crossed radioimmunoelectrophoresis.

The reactivity of eleven 'tobacco smoke sensitive' and eight 'non-sensitive' individuals to tobacco leaf allergens was tested by Crossed Radioimmunoelectrophoresis (CRIE). All nineteen study subjects had IgE antibodies to tobacco leaf antigens as measured by Radioallergosorbent Test (RAST) and seventeen of the nineteen individuals were atopic. Of the thirty-seven tobacco leaf precipitins detected by Cross Immunoelectrophoresis (CIE), three were identified as allergens by CRIE. All nineteen subjects reacted to at least one of the three allergens detected. However, neither the intensity nor the incidence of reactivity with any of the three allergens correlated with smoking or 'smoke sensitivity'.

Allergens↗

PubMedDate not supplied

Performance of a fully automated in vitro allergy testing system.

BACKGROUND: Since the development of the radioallergosorbent test (RAST) for quantification of allergen-specific IgE, numerous non-radoisotopic methods have been devised which combine the proven cellulose disc technology with enzyme-linked immunoassay methods. The HY.TEC EIA (Hycor Biomedical, Inc. Irvine, CA) was compared with Pharmacia CAP with respect to overall system features and assay performance characteristics. METHODS: The HY.TEC EIA and Pharmacia CAP were compared with respect to calibrator range, sensitivity, type of detection, type of solid phase, throughput, and mode of operation. To determine the assay sensitivity and specificity for a variety of allergens, a total of 2,447 tests were performed on both CAP and HY.TEC EIA. The samples were scored positive in both cases using a cutoff of 0.35 IU/mL. RESULTS: The general features of the HY.TEC EIA system are comparable to Pharmacia UniCAP, with the added advantage of higher throughput. Intra-assay precision was 7% and inter-assay precision was 9-15%. Using CAP as a comparative method, HY.TEC EIA has a sensitivity of 94.0% and a specificity of 94.4%. CONCLUSIONS: The HY.TEC EIA demonstrates excellent agreement with the Pharmacia CAP system in the determination of allergen-specific IgE. With the automation necessary in today's clinical laboratory, we conclude that the HY.TEC EIA is a state-of-the-art tool for the diagnosis of allergic disease.

Allergens↗

PubMed1996

Role of animal danders as inhalant allergens in bronchial asthma in India.

The etiological significance of animal danders in Indian patients with nasobronchial disorders has not yet been investigated. In the present study, the role of animal danders in the etiology of bronchial asthma was studied. Extracts of danders from 6 animals along with guinea pig whole pelt were prepared. Intradermal and bronchial provocation tests with these extracts were performed on (i) 68 asthmatics and (ii) 20 nonallergic healthy volunteers. In patients, significant positive skin reactions (2+ to 4+) ranged from 1.4% each with guinea pig whole pelt and ox dander to 8.8% with dog dander extracts. None of the healthy volunteers elicited such a response. On bronchial provocation, 20% and 53.8% of the tests were positive in asthmatics showing 1+ and 2+ skin reactivity, respectively. All the patients as well as controls eliciting negative intradermal responses demonstrated uniformly negative bronchial provocation tests to different dander extracts. Analysis of various clinical features of asthmatics with respect to skin positivity to dander/pelt extract was also carried out. Radioallergosorbent tests (RASTs) were performed to estimate dander-specific IgE levels in the sera of patients showing different grades of skin response to dander extracts of dog, horse, and goat. Sixty percent of sera from the patients showing 2+ to 4+ skin reactivity to various animal dander extracts showed positive RASTs. RAST positivity as well as RAST ratio increased with increase in the intensity of skin response. All the patients with positive cutaneous as well as positive bronchial responses also showed positive RASTs. Similarly, all the patients with positive skin and positive RASTs showed positive bronchoprovocation tests. These results suggested that animal danders play an important role in the etiology of bronchial asthma. Some of the clinical characteristics of asthmatics, such as (i) early age at onset of asthma, (ii) positive family history, and (iii) asthma with associated allergies, have significant bearing on the cutaneous response to various dander extracts.

Adult↗

PubMed1988

Laboratory animal allergy in a pharmaceutical company.

A cross sectional survey was carried out on 138 workers exposed to laboratory animals. Sixty (44%) had symptoms in a self completed questionnaire that were consistent with laboratory animal allergy (LAA) of whom 15 (11%) had chest symptoms. There was a positive skin prick test to one or more animal urine extracts (rat, mouse, guinea pig, rabbit) in 13% and 38% had a positive radioallergosorbent test to urine extract. LAA chest symptoms were almost five times more common in atopic than non-atopic subjects (who were distinguished by skin test response to common, non-animal aeroallergens). A positive skin test to animal urine was associated with LAA chest symptoms and with atopy. Nose, eye, or skin symptoms without chest symptoms were not associated with atopy. There was an inverse relation between duration of employment at the firm and LAA chest symptoms, suggesting selection of affected people out of employment with animals.

Adult↗

PubMed1991

Factors relating to the development of respiratory symptoms in coffee process workers.

After several cases of occupational asthma had been reported in a coffee processing factory in England, 197 coffee workers representing 80% of the production workforce were studied to determine the factors affecting the development of work related respiratory symptoms of wheeze, cough, and dyspnoea. Two computer administered questionnaires concerning the presence of respiratory symptoms and the occurrence of work related respiratory symptoms were used. Workers underwent skin prick testing to green coffee bean extract (GCB) and 11 common inhalant allergen extracts and bronchial provocation testing with methacholine. The presence of specific immunoglobulin E (IgE) antibodies to GCB and castor bean extract (CAB) were determined by a radioallergosorbent test (RAST). The prevalence of work related respiratory symptoms was 12.7%, bronchial hyperresponsiveness 30%, atopy 54%, positive GCB skin prick test 14.7%, positive GCB RAST 14%, and positive CAB RAST 14.7%. None of the workers was sensitised to fungi present in the factory and the numbers of certain species of fungi, despite being greater than may be found out of doors or in an uncontaminated indoor environment, were fewer than are generally associated with the presence of work related respiratory symptoms among agricultural workers. Storage mites were not isolated. Green coffee bean extract and CAB RAST were significantly correlated using the McNemar test but there was limited allergenic cross reactivity in RAST inhibition studies of the two extracts. The only factors that were significantly and independently associated with work related symptoms were CAB RAST and duration of employment. Bronchial hyperresponsiveness was not independently associated with work related respiratory symptoms. The significant independent associations of bronchial hyperresponsiveness included GCB RAST, duration of employment, and resting forced expiratory volume in one second. Exposure to CAB, a highly potent antigen, may be overriding the effects of other factors such a GCB, atopy, bronchial hyperresponsiveness, and smoking. This study suggests that CAB contamination remains a potential problem in the coffee processing industry and all efforts to eliminate it from the working environment should continue.

Adolescent↗

PubMed1977

Detoxified hymenoptera venoms: preliminary studies of in vitro cytotoxicity and antigenicity of Apis mellifera 'venomoid'.

The preparation of detoxified venom (venomoid) of Apis mellifera is described. The venomoid obtained by formaldehyde detoxification retained significant antigenicity. Radioallergosorbent test (RAST) inhibition studies indicated a loss of the affinity of the venomoid for the venom-specific human IgE antibody. In rabbits the venomoid was capable of producing precipitating antibodies which cross-reacted with the original venom. Cytotoxic activity of venomoid as measured by nonimmunological histamine release and hemolytic activity with human cells was not detectable in vitro. Further studies seem warranted for the establishment of a venomoid as a diagnostic and/or therapeutic agent in the management of the hypersensitivity reactions to venom.

Animals↗

PubMed1984

Allergens of Schistosoma mansoni. II. Fractionation and characterization of S. mansoni egg allergens.

The interaction of Schistosoma mansoni crude soluble egg antigen (SEA) with IgE antibodies in sera from S. mansoni-infected mice, rats and humans has been studied by the radioallergosorbent test (RAST) and the Prausnitz-Küstner (PK) technique. IgE antibodies recognizing egg antigens were present as early as day 21 after the infection in the mouse sera and day 28 in rat sera. IgE in sera of infected humans reacted with antigenic components in the Mr range 70,000-150,000 and focusing as a broad peak in the pH range 4.5-6.5 as measured by RAST. SDS-PAGE followed by western blotting showed the presence of major components at molecular weights of 117,000 and 35,000-43,000. In the PK test, using mouse sera, components focusing in the alkaline pH range also gave a positive reaction. Most of the allergenic activity was bound by concanavalin A-Sepharose and by wheat germ agglutinin-Ultrogel. IgE in serum from an infected non-permissive host (the Fischer rat) apparently recognized egg-stage-specific allergen as indicated by differences in the time course of the IgE response to egg allergens compared to the adult material. When analyzed by SDS-PAGE and western blotting with day 45-infected rat serum, SEA showed some qualitative and quantitative differences to adult worm antigen. Molecules at molecular weights between 25,000 and 30,000 and at about 43,000 in SEA reacted with rat serum IgE and were absent from adult worm antigen. The allergenic similarities between egg and adult worm are discussed.

Allergens↗

PubMed1984

Occupational asthma due to poultry mites.

The possible role of the northern fowl mite (NFM) in occupation-related respiratory disease of poultry workers was examined. The study population included 16 poultry workers with workplace-associated asthma and rhinitis, 27 atopic individuals with similar symptoms but no occupational exposure to poultry, and 12 asymptomatic nonatopic poultry-exposed controls. Ten of the 16 atopic poultry workers had immediate wheal-and-flare reactions to NFM, as compared with two of 27 non-poultry-exposed controls (p less than 0.001). In cutaneous testing with five poultry-related antigens, the NFM was the most reactive. On skin tests, four atopic poultry workers were positive for NFM and negative for Dermatophagoides farinae; four workers were negative for NFM and positive for D. farinae. Radioallergosorbent test (RAST) showed specific IgE levels for NFM, with positive RAST scores in 60% of poultry workers having positive skin tests. A provocative bronchial test with NFM extract in a poultry worker having positive NFM skin test and RAST score resulted in an immediate 25% reduction in the FEV1 and a 62% fall in forced expiratory flow volume at 25% of vital capacity. Collectively, the established presence of NFM in the poultry workplace, associated clinical histories, positive cutaneous tests, positive specific-IgE assays, and positive bronchial challenge combine to establish a role for NFM in occupational allergic respiratory disease of poultry farmers.

Adolescent↗

PubMed1996

Crossreactivity between allergens in natural rubber latex and banana studied by immunoblot inhibition.

BACKGROUND: An association between allergic reactions to natural rubber latex and to banana has been reported but the immunochemical properties of the putative cross-reacting allergens remain unknown. OBJECTIVE: To study extracts of banana and natural rubber latex and sera from latex-allergic patients for possible crossreacting allergens and IgE antibodies. METHODS: Sera from 22 latex-allergic patients and 22 control subjects with no evidence of allergy to latex or to banana were studied. All patients had positive and controls negative reactions in skin-prick testing using an eluate of latex gloves. IgE antibodies to natural rubber latex and to banana were evaluated by immunoblotting and by radioallergosorbent test (RAST) and crossreactivity between allergens in banana and natural rubber latex by immunoblot inhibition. Skin-prick testing was used to examine in vivo reactivity to banana. RESULTS: Ten of the 22 (45%) latex-allergic patients sera recognized altogether 14 allergens in banana by immunoblotting. The most frequently identified banana allergens were 23, 32, 36, 39 and 47 kDa proteins. The banana skin-prick test was positive in 14 of 18 (78%) latex-allergic patients studied and banana RAST in 12 of 14 patient sera tested. Fourteen of 21 interviewed patients reported symptoms from eating or handling bananas. In immunoblot inhibition studies a dose-dependent inhibition of IgE binding to banana extract with natural rubber latex proteins was observed in all five patient sera tested and, likewise, the binding of IgE to natural rubber latex extract was inhibited with banana proteins in four of the five patient sera. CONCLUSIONS: The present results confirm the existence of crossreacting allergens in natural rubber latex and banana and provide new information on the immunochemical nature and heterogeneity of these allergens.

Adult↗

PubMed1978

Reutilization of 125I-labelled anti-IgE antibody and paper discs in PRIST and RAST IgE determination.

In the paper radioimmunosorbent test (PRIST) anti-human IgE coupled paper discs are used for the estimation of total IgE in blood serum: in the radioallergosorbent test (RAST) allergen-coupled paper discs are used for the estimation of specific IgE in blood serum. The bound IgE or specific IgE is quantified by a 125I-labelled anti-human IgE. The non-bound 125I-labelled anti-human IgE can be collected and used in new assay. By a 4-h incubation of the used paper discs with 1 M glycine-HCl buffer (pH 2.7) the IgE-labelled anti-IgE complex can largely be removed. The paper discs treated in this manner can be used in a new assay.

Antibodies, Anti-Idiotypic↗

PubMed1977

Allergy testing: comparison of skin and in vitro tests of allergic reagin.

Skin tests have been used for many years to detect reaginic antibodies in the investigation of allergic patients. Recently in vitro assays of allergic reagins, including the radioallergosorbent test (RAST) and the rat mast cell test (RMCT) have become available. A comparison of the clinical usefulness of these tests suggested that skin tests and the RAST are of comparable diagnostic accuracy and reliability. The RMCT was found to be poorly reproducible and unreliable. For routine cases skin tests should continue to be the procedure of choice. The RAST may reasonably be used when skin tests are unreliable, impractical or contraindicated. The RAST may also be helpful in some cases in resolving discrepancies between skin test results and the clinical history.

Animals↗

PubMed1982

Specific IgE antibodies in workers with occupational asthma due to western red cedar.

The presence of specific IgE antibodies in the serum of patients with occupational asthma resulting from exposure to western red cedar (RCA) was studied by a radioallergosorbent test (RAST). The antigen matrix used in the RAST was either a conjugate of Sepharose particles with antigens in a crude cedar extract or with plicatic acid, the major haptenic component of cedar antigens. Of eighteen patients with clinical RCA and positive reaction to antigenic bronchoprovocation, eight were found to have abnormal RAST values. By appropriate absorption experiments, the serum RAST activity was shown to represent cedar antigen-specific IgE antibodies. No significant RAST activity was detected in the serum specimens from sixteen control subjects or from ten patients with negative bronchoprovocation-reaction to antigenic challenge. These results suggest that IgE antibody-mediated allergic reaction may be an important pathogenetic factor in RCA.

Allergens↗

PubMed1980

Comparison of cord blood immunoglobulin E concentrations and maternal allergy for the prediction of atopic diseases in infancy.

Total serum IgE levels were determined in 136 newborns and their mothers and in 54 of their fathers, using the paper radioimmunosorbent test (PRIST) technique. IgE specific antibodies for house dust (Dermatophagoides pteronyssinus), orchard grass, timothy grass, and cow's milk were measured with the radioallergosorbent test (RAST). One hundred thirty-three RAST assays were negative in newborns, and in three cases RAST for cow's milk was positive. Cord blood IgE ranged from 0 to 5.5 IU/ml (mean 0.32 +/- 0.54 IU/ml); levels were significantly (p less than 0.05) higher when maternal IgE was over 100 IU/ml and when mothers had received progesterone therapy during the pregnancy. Salbutamol administration or tobacco smoking during pregnancy did not influence newborn IgE. A clinical follow-up study was conducted in 83 infants for 9 mo. Nine infants developed definite atopic disease, and possible allergic diseases were noted in eight other infants. The IgE level at birth appeared to be more predictive for the development of allergy in infancy than the family history.

Albuterol↗

PubMed1981

Evaluation of total and specific IgE determinations in normal children and children suffering from asthmatic bronchitis with suspected allergic disease.

In young children with suspected allergic disease skin testing might to some extent be replaced by total and specific IgE determinations. Total IgE levels could be determined in these cases by the paper radioimmunosorbent test (PRIST) and be related to one's own reference values. Elevated total IgE levels have some predictive meaning for the occurrence of positive radioallergosorbent tests (RAST) in allergic disorders. Therefore, if total IgE and specific IgE determinations are performed routinely, the RAST panel applied should be minimized to three or four allergens and should be performed only when related to the clinical history. This will be exemplified with the sera of children suffering from asthmatic bronchitis with suspected allergic disease.

Adolescent↗

PubMed1985

Skin test and RAST responses to wheat and common allergens and respiratory disease in bakers.

Interrelationships between skin and humoral tests for immediate hypersensitivity to wheat and indicators of respiratory disease were examined in 176 male bakers. Skin tests were assessed by measuring the diameter of the weal resulting from prick innoculation of allergen extract and circulating allergen-specific IgE by radioallergosorbent test (RAST). Fifteen per cent of subjects showed positive skin-prick test responses to wheat extracts. These subjects demonstrated an increased prevalence of respiratory symptoms and of measurable bronchial responsiveness to methacholine. Thirty per cent of subjects had positive skin test responses to common allergens but negative responses to whole wheat. Compared to subjects with no positive skin test responses they had an increased prevalence of bronchial responsiveness to methacholine but a similar prevalence of respiratory symptoms. There was a significant association between skin test responses to whole wheat and skin test responses to common allergens suggesting that bakers with pre-existing sensitivity to common allergens are at increased risk of developing wheat flour sensitization. There was no significant difference between skin-prick test and RAST responses to wheat, water-soluble wheat protein and common allergens. Both tests showed similar relationships with indices of respiratory disease. The associations between skin test and RAST responses to wheat extracts and indices of respiratory disease was stronger for the water-soluble wheat proteins than for other wheat grain extracts. These results suggest that immediate hypersensitivity to wheat flour is important in the development of non-specific bronchial hyperreactivity in bakers and that the water-soluble fractions of wheat flour are the most important allergenic components.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗