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Notes: IgE and IgG antibodies against Aspergillus fumigatus were detected by crossed radio immunoelectrophoresis (CRIE) on the sera of seven patients with aspergilloma, six patients with allergic broncho-pulmonary aspergillosis (ABPA) and 25 patients with extrinsic asthma with Aspergillus allergy. IgE-CRIE analysis indicated the presence of A. fumigatus-specific IgE in sera of patients with ABPA and Aspergillus asthma but not of aspergilloma patients. IgG-CRIE showed that both aspergilloma and ABPA patient sera contained high levels of circulating specific IgG antibodies in contrast to sera of Aspergillus asthma patients, which did not show detectable amounts of Aspergillus-specific IgG antibodies. Specific IgE binding could be demonstrated for the major allergens Ag-10 and AG-40 in all ABPA patients, in 80% of Aspergillus asthma patients but not in sera from aspergilloma patients. Specific IgG antibodies directed towards the major allergens could be detected in most of the aspergilloma patients, between 30–70% of the ABPA patients but not in sera from patients with Aspergillus asthma.

Notes: The content of IgE, specific to the unicellular green alga Chlorella sp., was analysed in sera from 46 atopic children sensitized to moulds, using radioallergosorbent test (RAST), immunoblotting and crossed immunoelectrophoresis/crossed radioimmunoelectrophoresis (CIE/CRIE). Chlorella-specific IgE was found in 23/46 sera by RAST, in 28/41 sera by immunoblotting and in 6/30 sera by CIE/CRIE. The Chlorella components most frequently binding IgE as analysed by gradient gel electrophoresis and immunoblotting were of molecular weights of approximately 13, 17, 19, 26 and 49 kD. Twenty-nine precipitating antigens, including seven IgE-binding precipitates were detected by CIE/CRIE. The study shows that low concentrations of specific IgE are formed to the green alga Chlorella in sera from atopic individuals sensitized to moulds.

Notes: The content of major allergens in biologically standardized allergenic preparations of birch, mite (Der p), cat, Alternaria (Alt a) and ragweed (Amb e) was determined. It was found fairly constant between species, i.e. varied within a factor of 2, with the exception of Alt a 1 in Alternaria alternata extract. This variation is allowed by authorities between different batches prepared from the same species of allergen. The method for biological standardization (BS) prescribed in the Nordic Guidelines has, for common inhalant allergens, been shown to give reproducible results between regions of Europe. However, it is difficult to define patients suitable for BS of most food allergens as well as less common inhalant allergens. Therefore we propose that, in the future, BS is replaced by determination of well-established major allergens and that 1 ng of major allergen is given the value of 1 Biological Unit. Clinical aspects Clinicians have had difficulties in understanding differences and similarities between units used by manufacturers for labelling of allergenic extracts. Biological standardization is time-consuming and expensive. Probably therefore, and to avoid comparison with extracts prepared by other manufacturers, most manufacturers have used their own units and few of them have used the biological units as defined by the Nordic Guidelines or FDA. Determination of the amount of major allergen by ELISA is simple and cheap. However, the biological relevance of major allergen content has not been established. Our results clearly indicate the possibility of replacing biological units by major allergen content, provided the composition of allergens is adequate. The major allergen content can easily be declared by all manufacturers. In the future, manufacturers should be forced to declare the major allergen content, thus making it easier for clinicians to compare extracts from different suppliers.

Notes: To investigate the capacity of chemical treatment of surfaces and the difference in capacity among common vacuum cleaners to reduce mite allergen content in house dust, we recruited 52 families with allergic children. Ten families used their central vacuum cleaners. Forty-two families were randomly divided into four groups with 10 or 11 families in each. These families used cither new vacuum cleaners with either HEPA (High Efficiency Paniculate Air) or micro-filters, or their own vacuum cleaners with either tannic acid or placebo. Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children at Days 0, 7, 21, and 35. Der p I and Der f I allergens were determined by sandwich ELJSA, After one week, tannic acid reduced the concentration of mite allergens/g of dust and the total amount/sampling area by 30% and 34%, respectively (p 〈 0.05), but there was no significant decrease in relation to placebo. After 5 weeks, central, HEPA- and micro-filter vacuum cleaners decreased the mite allergen concentration by 10–50% (p 〈 0.05) and the total amount of mite allergen from the investigated areas by 50–85% (p 〈 0.01). In relation to the placebo group the decrease was significant for HEPA-and micro-filter vacuums (p 〈 0.05), The total amount of mite allergens/ sampling area was more significantly (p 〈 0.05) reduced than the con-centration/g of dust. We conclude, that tannic acid reduces mite allergen concentrations in dust and total amount/sampling area for a short period of time. Central, HEPA- or micro-filter vacuum cleaners reduce mite ellergen concentrations and still more the total amount of mite allergen in house dust when used regularly for long periods. Therefore, when the total house is thoroughly cleaned, tannic acid should be applied to car pets and upholstery and low mite allergen levels maintained by using modern vacuum cleaners.

Notes: An in vitro model was established to study the stability of baker's yeast (Saccharomvces cerevisiae) allergens in conditions simulating the gastrointestinal tract. The protocol consisted of 2 hr incubation under gastric conditions (pH 1.2, +37°C and gastric enzymes) and 2 hr incubation under duodenal conditions (pH 6.8, + 37°C and duodenal enzymes). These were studied together and separately, as well as under pure acidic conditions without gastric enzymes. The yeast extracts contained equal amounts of allergen and were analysed by IgE-immunoblotting. The acidic conditions had partly an enhancing and slightly degrading effect on the yeast allergens, whereas the gastric enzymes destroyed several allergens, including the important intermediate allergens of 31 and 45 kD. After treatment under both gastric and duodenal conditions most of the yeast allergens were destroyed, except mannan and a 10 kD protein component. The findings suggest that the allergen exposure caused by baker's yeast lakes place mainly on the mucosal surfaces orally and oesophageally and through viable baker's yeast organisms that manage to pass the stomach and duodenum and possibly lead to intestinal growth of the organism. Patients with IgE production against the 10 kD allergen and mannan are, however, moderately exposed to allergens consisting of soluble antigenic material only.

Notes: Stability of Candida albicans allergens was studied under various storage conditions Lyophilized extract was reconstituted with human serum albumin glycerol-free and in the presence of 10% or 50% glycerol and stored at various temperatures for different time periods. All extracts were tested at the same time with immunoblotting using C albicans allergic patient sera and galactosidase-labelled anti-IgE. The highest number of detected allergens in the immunoblotting pattern was found in the presence of 50% glycerol at +6 C. The most important allergen of $$ the 46 kD protein allergen was stable up to 10 weeks at +6 $$ C in the presence of 50% glycerol but thereafter began to lose its IgE-binding capacity. After 30 weeks more than 50% of the IgE binding had disappeared. The 27 kD protein, another important allergen, was also labile but retained the allerg$$ better than the 46kD one. The 29kD protein allergen was stable at all storage conditions, except +3$$C tested even after one year. More than 6 months storage at +6C or higher temperature is however unacceptable even in the presence of the 50% glycerol. These findings have particular importance in the diagnosis and treatment of allergic diseases

Notes: The effect of storage and high temperatures on the stability of Saccharomyces cerevisiae allergens was studied by immunoblotting. Saccharomyces cerevisiae allergic serum pool and 125I- and galactosidase-labelled anti-IgE were used in the assays. Freeze-dried extracts were reconstituted with saline and with 50% glycerol and then stored at room (+ 20°C) and refrigerator temperature (+6°C) for different time periods.The stability was better in 50% glycerol at +6°C than at room temperature without glycerol. However, after 1 month, two of the most important allergens of S. cerevisiae, the 48 and 32 kDa protein allergens. lost their IgE-binding capacity even in the extracts stored with 50% glycerol al +6 C. The 45 kDa allergen was. on the other hand, quite stable after storage for 9 months at +6°C. Although the beneficial effect of 50% glycerol was clear, storage at +6°C, even with 50% glycerol should not exceed 1 month for S. cerevisiae extracts.Two commercially available S. cerevisiae extracts in solution with valid expiry dates were also analysed. They had only little allergenic potency, while a freeze-dried extract stored for 8 years showed good allergenic potency. Heating S. cerevisiae extracts resulted in precipitation., the precipitated fraction contained almost all the specific proteins as judged by electrophoresis and IgE detection. The supernatant fraction contained only a few allergens.

Notes: To investigate the capacity of common vacuum cleaners and chemical treatment to reduce cat (Fel d I) and dog (Can f I) allergen content in house dust, 52 families with allergic children and no pets at home were recruited. Five groups of 10–11 families used their central vacuum cleaners (n = 10), their own old vacuum cleaners plus either tannic acid (n = 10) or placebo (n = 10) applied to carpets and upholstry after the first sample was collected on Day 0 or new vacuum cleaners equipped with either HEPA (high efficiency particulate air)- (n = 11) or micro-filters (n= 10). Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children on Days 0, 7, 21, and 35. Fel d I and Can f I allergens were determined by sandwich ELISA methods. Central, micro-filter and HEPA-filter vacuum cleaners did not reduce the concentrations nor the total amount/sampling area of Fel d I or Can f I. Tannic acid initially reduced (p 〈 0.05) both the concentration and the total amount of Fel d I by 30% and Can f I by 10%, but only for one week. The levels increased to base-line after 21–35 days. The concentrations of Fel d I increased 10–30 times in homes visited by cats or cat owners. We conclude, that tannic acid treatment reduced pet allergen concentrations and total amounts in dust for one week only. Central vacuum cleaners or vacuum cleaners equipped with HEPA- or micro-filter did not reduce the pet allergen load in homes of allergics. Indirect contacts with cats caused a pronounced increase in cat allergen levels.

Notes: Allergenicity and antigenicity of various commercially available cow milk hydrolysates intended for infant feeding were analysed in 45 children with cow milk allergy. The hydrolysates included the whey hydrolysates Beba HA® (Good Start HA®) and Profylac®, and the casein hydrolysates Alimentum® and Nutramigen®. Positive skin prick tests were recorded against Beba HA in 10 of 41 tested children (24%), against Profylac® in 5/34 (15%) and in one each (2.5%) against Alimentum and Nutramigen. Double-blind placebo-controlled oral challenge tests were performed in 11 children with cow milk allergy using Alimentum, cow milk (positive control) and their regular well-tolerated formula (Nutramigen or soy) used as negative control. One child reacted to Alimentum. This patient was the only one with circulating antibodies against the product, as indicated by a positive RAST. High density SDS-PAGE electrophoresis showed that Beba HA contained a number of unresolved proteins, and non-degraded or partially degraded whey proteins in the range of 5–20 kD. Profylac contained strongly stained protein material in the low molecular weight region 1–10 kD. No protein bands could be identified in the casein-based hydrolysates. Residual antigenicity was tested by measuring the content of betalactoglobulin in the hydrolysates. Three of the hydrolysates contained 〈 0.06 μg/g dry weight, while the concentration in Beba HA was 200 μg/g dry weight. Positive RAST against Beba HA was detected in 11/45 sera (24%) compared to 7–13% against the other hydrolysates. RAST inhibition with the hydrolysates using cow milk discs was very low for all of them. Using dot immuno-binding assay a weak IgE binding with Alimentum was detected in 4 sera, Beba HA and Profylac in each 2 sera and with Nutramigen in one. The data taken together show that all 4 tested hydrolysates retain some allergenicity. There were differences between the products, one of the whey hydrolysates being substantially more allergenic and antigenic than the other tested formulas. The casein hydrolysate Alimentum showed few reactions in vivo and in vitro in this selected group of children but one child reacted when challenged with Alimentum, indicating that there is a risk for general reactions when using any hydrolysed product in subjects allergic to cow milk.