Rosa Codina

Preventing Asthma Epidemics Due to Soybeans by Dust-Control Measures

BACKGROUND The inhalation of soybean dust released during the unloading of soybeans into a silo caused outbreaks of asthma in Barcelona, Spain. This study was designed to determine morbidity due to asthma and serum IgE reactivity before and after the installation of filters in the silo. METHODS We measured soybean-allergen concentrations in 136 samples of air collected for 9 months before and 24 months after the installation of filters. We compared the number of days on which there was an unexpected increase in emergency room visits for asthma, the number of days on which the number of emergency room visits for asthma in one four-hour period was so high that it was unlikely to be due to chance, and the mean daily number of emergency room and intensive care unit admissions for asthma for a total of 60 months before and after filter installation. Serum IgE antibodies against soybean allergens were measured in 38 patients before and after filter installation. RESULTS The concentration of airborne soybean allergens on days when soybeans were unloaded decreased from 324 to 25 U per cubic meter after the installation of filters (P < 0.001). The number of days on which there was an unusually large number of visits to the hospital for asthma and the number of days on which asthma was epidemic both decreased significantly (both P < 0.001), from 29 to 6 and from 18 to 0, respectively. The mean daily number of emergency room and intensive care unit admissions for asthma on days when soybeans were unloaded decreased from 8.3 to 5.4 and from 0.26 to 0.01, respectively (both P < 0.001). The mean serum IgE antibody concentrations in the 38 patients studied decreased from 2 Pharmacia reference units per milliliter to 1 (P < 0.001). CONCLUSIONS Installing filters on silos to prevent airborne dissemination of allergenic soybean dust eliminates outbreaks of asthma caused by inhalation of the dust, thus supporting the idea that the avoidance of allergens helps prevent asthma.

Purification and characterization of a soybean hull allergen responsible for the Barcelona asthma outbreaks. II. Purification and sequencing of the Gly m 2 allergen

Background A low MW allergen from soybean hull, Gly m 1, with two isoallergens, Gly m 1 A and Gly m 1 B, was associated with the asthma outbreaks that occurred in Cartagena, Spain. Using sera of asthmatic epidemic patients (AEP) from Barcelona, three main soybean hull allergens, two of them with MWs atid pIs identical to those reported for Gly m 1 A and Gly m 1 B, were identified.

Neoallergens in Heated Soybean Hull

Background: During the process of harvest, transport and storage, microbial and mold contamination can raise the temperature of soybeans to 75°C or higher. The purposes of this study were (1) to evaluate the allergenicity of fresh and stored soybean hulls and (2) to ascertain whether heat alters the allergenicity of stored soybean hulls. Methods: Allergen extracts were prepared from (1) stored soybean hulls, (2) fresh soybean hulls and (3) stored soybean hulls heated to 37°C (E1), 55°C (E2) and 80°C (E3) or kept at room temperature (E4) for 16 h. Individual serum from 68 soybean asthmatic (SA) subjects, 30 nonallergic subjects and two serum pools made from 4 SA sera and 4 sera from asthmatics not sensitive to soybean were studied. All sera and serum pools were assayed for content of specific IgE (radioallergosorbent test) and IgG4 (ELISA). The following additional studies were done for extracts E1–E4: (1) SDS–PAGE, (2) SDS–PAGE/Western blot for specific IgE and IgG4 using both serum pools, and (3) study of the effects of heat on inhibiting activity of the extracts prepared from stored soybean hulls using the pool of SA sera. Results: Test results demonstrated a reduced binding of specific IgE and IgG4 to fresh soybean hull extract compared to stored soybean hull extract, and an increased binding for heated extracts (E1–E3) compared to unheated ones (E4). Moreover, there was an increase in potency for IgE and IgG4 bindings for the heated (E1–E3) compared to unheated (E4) extract, as measured by the amount of protein to produce 50% inhibition. Several protein bands with a molecular weight (MW) higher than 20 kD were absent from the SDS–PAGE for E3 but were present in E1, E2 and E4, and a new protein band (MW 15.3 kD) appeared for E3 only. Two new protein bands, with MWs of 15.3 and 10 kD, which bind specific IgE, were present on Western blot and one of the 3 main soybean hull allergens, probably Gly m 2, disappeared in E3. IgG4 Western blot showed similar results, but only the 10 kD protein band was present. Conclusion: The results demonstrate that soybean hull allergenicity is affected by heat, and suggest that the heat generated during storage and transport of soybeans could generate 2 new allergen determinants or increases in epitope exposure as a result of conformational changes. The significance of these new IgE and IgG4 binding proteins has yet to be determined.

Guide for interpreting reports from inspections/investigations of indoor mold

Inspections and testing of indoor environments for mold growth increased dramatically in the past decade. Allergists can now be presented copies of reports and laboratory data and asked to provide an interpretation, although allergists are seldom trained to review environmental data. There is no single sampling method that is both specific for mold growth and robust enough to reliably detect mold growth. There is no standard method for these inspections or testing and no widely recognized credential for investigators, and therefore reports also vary in quality, objectives, and thoroughness. Despite these issues, observations from informed inspections coupled with results from qualified analyses of samples that are collected with a useful strategy can usually indicate whether mold growth is present in a building, but the nature of the report should be assessed before any interpretation of the results and data are attempted. This rostrum discusses objectives of inspections, describes qualifications for investigators, outlines the limitations of various sampling methods applicable to mold and to some degree endotoxin, and provides guidance for data interpretation.

109 Partial characterization of the silk allergens in mulberry silk extract

Although there have been reports of allergic reactions such as asthma and hypersensitivity pneumonitis to silk allergens (especially in oriental countries), these allergens have not been characterized. We report an in vivo and in vitro study of subjects allergic to silk, as well as a partial characterization of the allergens involved. Forty-one subjects with a clinical history of silk allergy who had asthma, allergic rhinitis or both, and who had a positive intradermal skin test to mulberry silk extract, were evaluated in the study. Four asthmatic subjects with negative skin tests and RASTs to mulberry silk extract were used as controls. RAST specific lgE was present in 37/41 (90%) subjects. SDS-PAGE of mulberry silk extract demonstrated 13 protein bands of less than 21-95 kD. lgE which bound to protein bands was present in 13/32 (41%) sera, twelve of which bound to a single protein with a molecular weight between 35.1 and 50 kD. A pool made with the four control sera did not react with any protein band. The patients allergic to silk showed evidence of sensitivity to mulberry silk extract, both in vivo and in vitro, but sera from 19/32 (59%) subjects did not have antibodies reactive with the mulberry silk extract immunoblot protein bands. The low avidity of the lgE may be responsible for this discrepancy between in vivo and in vitro results.

Allergenicity of varieties of soybean

Background:  Soybean hulls (SHs) cause respiratory allergies. This study investigates the allergenicity of soybean varieties (SVs) by in vivo and in vitro tests.

Mollusk shell hypersensitivity pneumonitis.

Excerpt The shells of certain mollusks, as well as oyster shells, sea-snail shells, and others, provide the raw material used to manufacture nacre products. Weiss and Baur (1) suggested in 1987 a p...

Identification of the soybean hull allergens involved in sensitization to soybean dust in a rural population from Argentina and N-terminal sequence of a major 50 KD allergen.

Background Sensitization to soybean hull (SH) allergens occurs in subjects from Argentina, a soybean producer country. However, the causative allergens have not been identified. The purposes of this study are to: (i) identify the SH allergens using sera of 29 subjects with asthma and/or allergic rhinitis from Argentina exposed to soybean dust who have a positive (weal with SH/weal with histamine ≥ 0.5) skin prick test to SH; and (ii) determine the N‐terminal amino acid sequence of a major 50 K SH allergen that sensitizes this population.

Disodium octaborate tetrahydrate (DOT) application and vacuum cleaning, a combined strategy to control house dust mites

Background: The effectiveness of acaricides in homes is controversial.

Diagnosis of soybean-induced asthma

BACKGROUND The role of soybean dust as a causal agent of asthma has been clearly established since the Barcelona asthma epidemics in the 1980s. The large number of patients who were first seen with asthma symptoms during those epidemics provided an excellent opportunity to study the possibilities of different diagnostic tests. OBJECTIVE This study was designed to evaluate the usefulness of the skin test and amplified ELISA technique for quantifying specific IgE in the diagnosis of soybean asthma. PATIENTS AND RESULTS Ninety epidemic asthmatic patients and 95 nonepidemic asthmatic patients were studied 2 years after the last epidemic. Results of prick tests and ELISAs for specific IgE with hull and dust extracts showed a significant difference between the two groups of patients (p < 0.001). Sensitivity and specificity of glycerinated prick test with hull extract in epidemic asthmatic patients were 57.7% and 95.3%, respectively, and ELISA values were 56.6% and 93.7%, respectively. Similar results were obtained with dust extracts. CONCLUSION Glycerinated skin prick tests and ELISAs with soybean hull and dust extracts have proved effective in the diagnosis of soybean asthma, even 2 years after the epidemics. Taking into account the sensitivity (90.5%) and specificity (93.7%) of ELISA test results for epidemic asthmatic patients found when the epidemic occurred, data from this study suggest that both tests may be very useful for the diagnosis of soybean dust-induced asthma.