Studies on the osmophilic fungus Wallemia sebi as an allergen evaluated by skin prick test and radioallergosorbent test

Recently, Wallemia sebi, a species of osmophilic fungi, has been abundantly detected in house dust using low water activity media. In this study, allergenic activity of W. sebi was assessed by skin prick test and radioallergosorbent test (RAST) in 74 asthmatic patients ranging from 6 to 32 years of age. Aspergillus fumigatus and house dust were used for comparison. In skin prick test, W. sebi extract, A. fumigatus extract and house dust extract elicited positive reactions in 4 (5.4%), 4 (5.4%) and 51 (68.9%) patients, respectively. RAST showed positive results in 14 subjects (18.9%) for W. sebi extract, in 8 (10.8%) for A. fumigatus extract and in 59 (79.7%) for house dust extract. These results indicated that some asthmatic individuals showed immediate-type hypersensitivity to W. sebi, and which means this fungal species may be of importance to atopic diseases as a causative agent.     

Allergenic relationships between Aspergillus restrictus and Aspergillus fumigatus determined by radioallergosorbent test inhibition]

Recently Aspergillus restrictus, a species of osmophilic fungi, has been found to be widely distributed in our inhabited environment. The authors reported previously that the prevalence of hypersensitivity to this fungal species determined by skin prick test and radioallergosorbent test (RAST) was comparable with that to Aspergillus fumigatus. In this study, the allergenic relationships between the two fungi were examined by RAST and RAST inhibition tests in which A. restrictus extracts prepared from mycelial mats of two different strains cultured in M40Y liquid medium and A. fumigatus, one made from a mycelial mat cultured in YNB liquid medium containing 3% sucrose, were used. In the RAST inhibition tests using a serum pool obtained from five patients with highly positive RAST to these species, the two extracts of A. restrictus inhibited RAST to A. fumigatus by over 80%, and A. fumigatus extract inhibited RAST to the two strains of A. restrictus by approximately 75%. In A. fumigatus RAST inhibition tests using individual sera with positive A. fumigatus RAST, a strong inhibition (greater than 60%) elicited by each extract of A. restrictus was observed in 5 of 8 sera tested. In RAST, nine of 11 serum samples with positive RAST to A. fumigatus showed positive RAST to both strains of A. restrictus. There was a significant correlation between the RAST values of the two fungal species. These results give evidence of the presence of shared allergenic components between the two fungi, and indicate that these components may contain part of major allergens of A. fumigatus.     

Allergenic and antigenic activities of the osmophilic fungus Wallemia sebi asthmatic patients

Recently large amounts of Wallemia sebi, a species of osmophilic fungi, have been detected in house dust by low water activity media. The allergenic activity of W. sebi was examined by skin prick tests and radioallergosorbent tests (RAST) in 74 asthmatic patients (mean age 11.7, range 6-32). Aspergillus fumigatus and house dust were used for comparison. In the skin prick tests, W. sebi extract, A. fumigatus extract and house dust extract elicited positive reactions in 4 (5.4%), 4 (5.4%) and 51 (68.9%) patients, respectively. RAST showed positive results in 14 subjects (18.9%) for W. sebi extract, in 8 (10.8%) for A. fumigatus extract and in 59 (79.7%) for house dust extract. These results indicated that some asthmatic individuals showed immediate type hypersensitivity to W. sebi, which means this fungal species may be important as a causative agent in atopic diseases. Additionally, the authors measured W. sebi-specific IgG by enzyme-linked immunosorbent assay in asthmatic (n = 28) and non-atopic patients (n = 28). W. sebi-specific IgG was found in sera from all subjects in each group. W. sebi-specific IgG in asthmatics (mean +/- SD = 0.686 +/- 0.160) was significantly higher than that in non-atopics (mean +/- SD = 0.572 +/- 0.188) (p less than 0.01).     

Evaluation of Basidiomycete and Deuteromycete (Fungi Imperfecti) extracts for shared allergenic determinants

Aqueous extracts of select members of the Basidiomycetes and Deuteromycetes (Fungi Imperfecti) were evaluated for the presence of shared allergenic determinants using skin prick and radio-allergosorbent test (RAST) inhibition. Twenty adults with perennial symptoms of rhinitis, with or without asthma, were skin-prick tested with six species of Deuteromycetes and seven species of Basidomycetes. Positive weal-and-flare reactivity to Pleurotus ostreatus was associated with Alternaria alternata, Fusarium solani and Epicoccum purpurescens. Positive skin reactivity to Calvatia cyathiformis was also associated with A. alternata and F. solani. Coprinus quadrifidus was associated only with F. solani, and Psilocybe cubensis was only associated with Aspergillus fumigatus. No other skin test associations were demonstrated. For every allergen tested by RAST inhibition, significant dose-dependent homologous inhibition was demonstrated. Although the ability of an individual heterologous extract to inhibit the direct RAST varied, inhibition was generally minimal. In the most extreme example, no heterologous allergen inhibited the A. alternata RAST. However, the Armillaria tabescens RAST was inhibited 52.6%, 38.1% and 25.1% by A. fumigatus, E. purpurescens, and Penicillium notatum, respectively, suggesting significant cross-reactivity. These results suggest that, although shared allergenic determinants exist between select species of Basidiomycetes and Deuteromycetes, crossreactivity is minimal and its clinical significance is not clear. These data confirm that for reliable diagnosis of fungal allergy, representatives of both major groups must be used.     

Specific IgE estimations by RAST in Japanese asthmatics compared with skin, passive transfer and bronchial provocation tests

198 asthmatics and twenty healthy persons were studied by RAST and in vivo tests with four common inhalant allergens, (a) Higher RAST classes were elicited with mite (Dermatophagoides farinae) extract and lower classes with other allergens. The agreement between positive RAST and skin or P-K tests was highest with the mite extract. RAST sensitivity was dependent on the kinds of allergens and was most sensitive to mite extract. Positive RAST was most closely related to the prick test reactions, (b) RASTs to house dust and mite extract were examined in terms of the threshold dosage of house dust and also the types of bronchial response (early, dual and late) induced by a certain amount of house dust; higher RAST classes were found in subjects with bronchial response of the dual or early type, elicited by a threshold dosage of diluted extract, while lower RAST classes were found in cases of the late-type response elicited by the threshold dosage of concentrated extract, (c) Changes in IgE antibodies to house dust and mite extract were estimated in patients with positive house dust provocation. A greater increase occurred in cases of dual or early response, a smaller increase in those with a late response. Despite discordances in skin tests and RAST between house dust and mite extracts, the increases in IgE antibodies to mite extracts as well as house dust were observed in all cases, presumably caused by an allergenic identity between the allergens.     

Allergen activity of xerophilic fungus, Aspergillus restrictus]

BACKGROUND AND PURPOSE: The typical xerophilic fungi, Aspergillus restrictus, have been very frequently detected in house dust by low water activity medium. Since the composition of fungal allergens are affected culture and extract condition, we considered the influence in A. restrictus in order to develop new allergen of xerophilic fungi. METHOD: The 4 different extract of A. restrictus were obtained from various fermentation and extraction methods. These extracts were studied for specific IgE in sera of patients with asthma. The cross-reactivity between A. restrictus and A. fumigatus were analyzed by enzyme-linked immunosorbent assay (ELISA) inhibition. Then, component analysis of A. restrictus allergens was examined by SDS-PAGE and Western Blotting. RESULT: In ELISA, IgE antibodies against four extracts of A. restrictus were found in sera of 20-48%. In ELISA inhibition using sera obtained from 11 asthma patients, A. fumigatus antigen solution inhibited the reaction of A. restrictus with 5 asthma patients. CONCLUSION: These results indicated that A. restrictus may be important as a causative agent in adult asthma patients. However, it was suggested that some preparation methods of an extract influence activity. Furthermore, cross-reactivity was found between A. restrictus and A. fumigatus.     

Association of features of atopy and diagnostic parameters in hymenoptera venom allergy.

In a total of 525 patients with hypersensitivity reactions to hymenoptera stings diagnostic parameters of hymenoptera venom (HV) allergy (severity of reactions, skin test threshold and RAST for bee and vespid venoms) were investigated for their relationship to the following indicators of atopy: positive history of atopic diseases, elevated (less than or equal to 100 kU/l) total serum IgE and positive prick test reactions to common inhalant allergens (CIA) (grass pollen, cat epithelium, house dust mite). There was a conclusive history of atopic disease in 25%, a total serum IgE greater than or equal to 100 kU/l in 48%, and at least one positive reaction to CIA in 53%. Total IgE greater than or equal to 100 kU/l correlated with a higher frequency of RAST classes greater than or equal to 2 (P less than 0.01) and with less severe reactions to hymenoptera stings (P less than 0.05). In the presence of at least one positive reaction to CIA, there were more frequently skin test thresholds less than or equal to 10 micrograms/ml (P less than 0.05) and RAST classes greater than or equal to 2 (P less than 0.01) for HV than in CIA prick test negative individuals. There was no significant, relationship between the other pairs of parameters evaluated. Thus, reactivity to HV in diagnostic tests is increased in the presence of certain indicators of atopy. This has to be considered in the interpretation of skin test and RAST results obtained with HV.     

Diagnosis of food allergy by the radioallergosorbent test

The radioallergosorbent test (RAST) was positive in 52.5% of 200 sera representing 200 food hypersensitivities from 108 patients with a history of definite immediate-type reactions to foods. Corresponding prick test was performed for 170 of the sera. The latter test was positive in 70%, the RAST was positive in 52%, and either prick test or RAST was positive in 74%. It is concluded that the RAST is positive less frequently than the prick test in the diagnosis of immediate-type food allergy in clinically sensitive patients, but that the performance of both tests increases slightly the possibility of confirming the diagnosis. However, the RAST is useful for further evaluating positive prick tests with foods that do not correlate with clinical hypersensitivity.     

Relationship of Allergen-Specific IgE Antibodies, Skin Prick Tests and Allergic Disorders in Unselected Adolescents

The relationship between serum levels of allergen-specific IgE (RAST) and skin prick test reactivity and allergic disorders was evaluated in 137 subjects randomly selected from an adolescent population. All subjects were prick tested with six common allergens, interviewed and physically examined. In addition, serum was collected for RAST analysis with three to six allergens. At least one positive RAST result (score 1-4) was observed in 40% and at least two positive RASTs in 22% of the subjects. Boys experienced more RAST reactions and generally with higher scores than girls. For instance, 26% of boys but only 11% of girls were RAST positive to timothy grass pollen. The correlation between prick test and RAST results was better with pollens than with house dust and animal epithelia. When the test results were discordant, the skin test was usually positive and RAST negative. Many of the small skin reaction (weal diameter 3-4 mm) were accompanied by a negative RAST. Respiratory allergy was closely connected with both positive skin test and RAST reactivity, while atopic dermatitis was less related. In 17% of the adolescents positive skin tests and in 14% positive RASTs occurred in the absence of any allergic symptoms. We conclude that a positive RAST score 3-4 to inhaled allergens is a strong indicator of clinical allergy but low scores 1-2 are frequently found in healthy young people.     

An approach to fungal antigen relationships by radioallergosorbent test inhibition

Antigenic relationships among three species of Aspergillus (A. fumigatus, A. glaucus, and A. flavus) were examined by paired cross-radioallergosorbent test (RAST) inhibition analysis, an in vitro technique based on human IgE antibody specificity. Alternaria tenuis was found to be antigenically unrelated to each of the three species of Aspergillus and was used as a negative control. A single test serum yielded uninhibited RAST indices of 6, 7.4, 8.1, and 7.8 for A. fumigatus, A. glaucus, A. flavus, and Alternaria tenuis, respectively. At a concentration of 10 mg/ml, A. fumigatus inhibited A. glaucus RAST by 63% and A. flavus RAST by 62%. A. glaucus inhibited A. fumigatus RAST by 36% and A. flavus RAST by 63%. A. flavus inhibited A. fumigatus RAST by 44% and A. glaucus RAST by 81%. Each species of Aspergillus produced significant but only partial inhibition of RAST to each of the other two species analyzed. Results indicate the existence of both shared and unique antigens among these three species of Aspergillus. Paired cross-RAST inhibition may be used as an approach to study species relationships among genera of several classes of clinically relevant fungi. Unless many strains are employed, data obtained do not represent a definitive analysis of species, because of possible different degrees of inhibition by various strains of a particular species. They do, however, allow for the antigenic comparison of two or more crude, poorly characterized preparations thought to be important in human allergic disease.     

Comparison of results of skin tests, RAST, and double-blind, placebo-controlled food challenges in children with atopic dermatitis

Forty children with atopic dermatitis were evaluated for clinical evidence of hypersensitivity to foods by double-blind, placebo-controlled food challenges. Twenty-four children (60%) experienced 33 positive challenges, manifested by cutaneous symptoms in 31 (94%), gastrointestinal symptoms in 14 (42%), nasal symptoms in nine (27%), and respiratory in six (18%). Results of prick skin tests (STs) and RASTs to eight food antigens frequently eliciting hypersensitivity reactions were compared with those from food challenges to determine the diagnostic accuracy in children with atopic dermatitis. Defining a positive ST as a wheal 3 mm larger than the negative control wheal and a positive RAST as a Phadebas RAST score of 3 or 4, the sensitivity, specificity, and predictive accuracies of these tests were found to be comparable except in the case of wheat antigen where the ST was clearly superior to the RAST. Accepting a RAST score of 2 or more as a positive slightly improved sensitivity in some cases but dramatically decreased specificity. Combining results of STs and RASTs did not improve significantly the diagnostic accuracy over results of the tests used individually. These studies demonstrate no advantage of RAST alone or in combination with prick skin testing over prick skin testing alone in the evaluation of food hypersensitivity in children with atopic dermatitis. Furthermore, skin testing should be considered a good test for excluding immediate food hypersensitivity but only a suggestive positive indicator of hypersensitivity due to the high rate of clinically insignificant positive STs.     

Allergic bronchopulmonary aspergillosis does exist in Brazil

A case of allergic bronchopulmonary aspergillosis is presented. The patient had corticosteroid-dependent asthma, recurrent pulmonary infiltrates clearing with oral prednisone bursts, positive dual (immediate and late) skin test (prick and intradermal) reactivity to Aspergillus fumigatus, 11% blood eosinophilia, elevated total serum IgE, positive precipitating antibody against Aspergillus fumigatus, and elevated specific serum antibodies to Aspergillus fumigatus (positive IgE and IgG antibody indices, and elevated IgE levels by both RAST and FAST). To our knowledge this is the first immunologically documented case of allergic bronchopulmonary aspergillosis in Brazil. Future survey studies are required.     

Coffee worker's asthma: A clinical appraisal using the radioallergosorbent test

Eight coffee workers with job-related respiratory symptoms were studied with water-soluble green coffee bean (GCB), castor bean (CaB), and factory dust (FD) antigens. Six workers described occupationally related asthma, rhinitis, conjunctivitis, and urticaria or pruritis and demonstrated positive wheal and flare skin tests with GCB and FD antigens. Serum radioallergosorbent test (RAST) indices ranged from 3 to 15 for GCB and 28 to 60 for CaB specificities. The other 2 coffee workers, who denied allergic symptoms, and 8 atopic and sex-matched control subjects demonstrated negative skin tests and RAST indices <2 with these same antigens. Provocative inhalation challenge (PIC) with GCB in 2 skin test-and RAST-positive subjects resulted in significant immediate asthmatic reactions, while PIC in a skin-and RAST-negative asthmatic subject failed to produce an airway response. GCB and CaB antigen characteristics and industrial sources were studied by RAST inhibition analysis. Lack of crossed RAST inhibition with GCB and CaB preparations showed these antigens to be distinct. Several industrial dust and sack samples produced significant RAST inhibition for GCB or CaB determinants. Chlorogenic acid produced no RAST inhibition for either determinant. The results indicated that coffee workers with occupational allergic disease demonstrate serum IgE antibodies specific for etiologic GCB and CaB antigens and that these antigens are distinct, unrelated to chlorogenic acid, present in certain industrial dust and sack samples, and capable of producing asthma in sensitized subjects.     

Diagnostic value of a glass fibre-based histamine analysis for allergy testing in children

The aim of this study was to compare the diagnostic value of common allergy tests with basophil histamine release in 124 children with symptoms of asthma. The patients were evaluated by case history, skin prick test, RAST-analysis, and basophil histamine release using a glass fibre-based histamine assay to 10 common inhalant allergens. The bronchial provocation test was used as a reference of "true" IgE-mediated asthma. To compare the various diagnostic parameters each absolute test value was classified into a scoring system. The concordance between the tests varied between 85-97%. In general, the best concordance was found between basophil histamine release and RAST. Sensitivity, specificity and predictive values were calculated on the basis of 104 bronchial provocation tests. It was found that histamine release was the best single analysis, followed by RAST and prick testing. The sensitivity of RAST and histamine release was very high (1.00) for pollen and house dust mites. Histamine release showed a predictive value between 0.91 and 1.00 for pollen and house dust mites, thus indicating the possibility of omitting the bronchial provocation test. In the dander group histamine release gave the best sensitivity (0.91), however at the expense of specificity (0.64), whereas RAST and skin prick test gave a specificity of 1.00. In the mould group histamine release also showed the best diagnostic value. The combination of skin testing with histamine release or RAST was of no additional diagnostic help. It is concluded that the glass fibre-based histamine analysis, which makes routine histamine release testing possible, is a reliable diagnostic test in children.     

Influence of hyposensitization with Dermatophagoides pteronyssinus extract on clinical score, total and specific IgE levels, and skin test in asthmatic patients

To evaluate the effects of immunotherapy on clinical response, on IgE serum level, on radioallergosorbent test (RAST), and on skin tests, a prospective study was performed by a follow-up of 73 asthmatic patients allergic for house dust during hyposensitization with Dermatophagoides pteronyssinus extract. No relationship could be found between the evolution of clinical score, skin tests and RAST, but 91% of the patients with a decreasing IgE serum level had satisfactory clinical results. Serial determinations of serum IgE levels during hyposensitization showed two patterns of evolution with a favourable prognostic value: a continuously decreasing serum IgE or a primary increase followed by a late decrease.     

A study of skin test with regard to age differences and agreement with positive results from the RAST and ELISA methods]

Skin tests of the scratch type were performed on 132 asthmatic patients with 28 allergens. The threshold titers of skin test, RAST and ELISA of house dust, HD mites, Japanese cedar pollen, ragweed pollen and orchard grass pollen were included. The main skin-positive allergens among the patients were as follows: house dust, HD mites, Japanese cedar pollen, orchard grass pollen, timothy grass pollen and ragweed pollen. There are age differences on skin-positive rates among 4 age groups of the patients; 90% of the patients under 40 years old groups reacted positively to any of 28 allergens, while half number of the patients groups over 40 years old reacted positively to the allergens. According to the quantitative analysis between threshold titers of skin test and RAST titers using house dust and HD mites allergens, specific IgE production shall be decreased in the patients over 40 years old. Using 5 main allergens above mentioned, the agreements of positive responses between three methods were compared. RAST positive responses correlated well with the skin test results, while ELISA positive responses correlated rather poorly with the skin test results. However, correlation between RAST and ELISA results was relatively good. The correlation of positive responses to house dust and HD mites by the three methods was very good, but there were some cases where positive responses were obtained by only one of the methods.     

Immunologic analysis of steroid-dependent asthma

In order to analyze steroid-dependent asthma immunologically, IgE antibodies to mite (Dermatophagoides farinae), Candida albicans, and Aspergillus fumigatus were measured in 112 asthmatic patients. IgG and IgG subclass antibodies to mite were also measured. The rate of patients who were positive to candida IgE RAST was higher in atopic steroid-dependent patients than in atopic steroid-independent patients (P less than .01). The rate of mite-sensitive patients who had not received immunotherapy with mite or house dust was higher than in the atopic steroid-dependent patients than in atopic steroid-independent patients (P less than .05). IgG1 and IgG4 antibodies to mite were higher in mite-sensitive steroid-independent patients than in mite-sensitive steroid-dependent patients. IgE antibodies to A. fumigatus were detected only in patients with allergic bronchopulmonary aspergillosis (ABPA). Based on these results, we were encouraged to try immunotherapy with house dust mite or C. albicans if patients were steroid-dependent and sensitive to these allergens except when the patients had ABPA.     

Hypersensitivity to trimethoprim

We present two patients who experienced life-threatening immediate reactions and one patient who developed generalized urticaria following oral administration of trimethoprim (TMP) and sulfamethoxazole (SMX) combination. Skin prick tests with TMP were positive in the three patients. No patients reacted to skin prick tests with SMX. No significant levels of IgE antibodies to TMP were found by RAST in the serum of the patients. Normal subjects used as controls did not react to any of these tests. Single-blind, placebo-controlled oral challenges were positive with TMP and negative with SMX in all patients. These results suggest that the three patients developed type I hypersensitivity reactions to TMP. In our patients skin prick tests with TMP were useful in TMP hypersensitivity diagnosis.     

Discrepancies between the skin test and IgE antibody assays: study of histamine release, complement activation in vitro, and occurrence of allergen-specific IgG

Intracutaneous skin tests (STs) and RAST with the common allergens, grass pollen, house dust mite, and cat dander, were performed on 660 adult patients. In 117 patients (18%), we found 140 discordances (7%) in a total number of 1980 ST and RAST combinations. In agreement with studies in the literature, greater than 80% of the discordances consisted of positive skin reactions without detectable allergen-specific IgE antibodies in serum. The percentages of discordant results were similar for the three allergens. Reproducibility of both the RAST and the ST was evaluated in the discordant group. Repetition of the routine RAST procedure elicited results similar to those in the first test in 81% (105/130). A second ST elicited identical results in 89% (47/53). In addition to the routine IgE antibody assay, sera of patients with a positive ST but without detectable IgE antibodies were tested in two other RAST systems: (1) a RAST with allergen extracts from the same production batch as the ST reagents, and (2) the Pharmacia RAST. In spite of having a clearly positive ST, sera from 68 (80%) of 85 patients remained completely negative in all three RAST systems. Histamine release (HR) in vitro from washed leukocytes was studied in 35 patients with a reproducible positive ST and negative RAST results with serum. Interpretation of this test was possible in 28 patients. In 82% (23/28) of these patients, clearly detectable HR was found with the relevant allergen extract. A role of IgE in the skin reactions and HR tests was confirmed by positive RAST results with IgE that was affinity purified from serum of seven of these patients. Allergen-specific IgG4 antibodies are unlikely to be implicated, since no antibodies against grass pollen and house dust mite were detectable in sera of these patients. Only 18% of the patients with an unexplained skin reaction with cat dander have detectable IgG4 antibodies, but these antibodies were found in a similar frequency in a nonallergic, ST negative control group. Low total IgG responses precluded false negative RAST results caused by competition of IgG antibodies with IgE antibodies. There were no significant differences in the degree of complement activation in vitro by house-dust extracts between healthy control subjects, nonallergic patients, and patients with unexplained skin reactivity. It is concluded that a high proportion of the positive skin reactions with common inhalant allergens, which are not accompanied by a positive RAST, are probably caused by IgE antibodies that are not detectable in serum with any of the RAST procedures.(ABSTRACT TRUNCATED AT 400 WORDS)     

A New, Purified Dermatophagoides farinae Allergen Preparation

A purified, standardized and characterized allergen preparation of the house dust mite Dermatophagoides farinae (Df) was evaluated by skin prick test (SPT) and radioallergosorbent test (RAST) in 88 subjects. Skin reactions to the purified Df preparation and a corresponding crude Df preparation were compared. SPT was also performed with a crude Dermatophagoides pteronyssinus (Dpt) preparation to compare reactions obtained with the two mite preparations. By SPT the purified Df allergen preparation was representative of the crude Df preparation (r = 0.78) and the correlation between skin reactions to Df and Dpt was high (r = 0.78). The concordance between results obtained with RAST and SPT techniques with the purified Df preparation was high (84%). The purified D. farinae preparation was well tolerated and is well suited for SPT.