Search

We have developed a new technique for the direct local administration of test solutions to the nasal mucosa and for quantification of nasal secretory responses. This technique, a variation on several published reports of filter paper use, allows simple and rapid determination of drug effects and facilitates the analysis of ipsilateral and contralateral responses to local challenge of the nasal mucosa. We have used this technique to investigate the secretory responses of the nasal mucosa to methacholine and histamine and to determine the effects of atropine and ipratropium bromide (Atrovent nasal spray) on these secretory responses.

We have used the RAST-inhibition technique in homologous and heterologous inhibitions of the Aspergillus fumigatus, Alternaria tenuis, and Cladosporium herbarum RAST assays followed by the immunoblot technique to assess the degree of shared allergenic determinants in these extracts. In the Aspergillus RAST, there was little or no inhibition with Cladosporium and Alternaria, but considerable cross-reactivity was found between Alternaria and Cladosporium. Inhibition by Alternaria of the Cladosporium RAST was found in a dose-dependent fashion in one serum, whereas all four sera in the Alternaria RAST were inhibited by Cladosporium in this fashion. Logit transformation of the Alternaria RAST-inhibition curves produced common slopes with Alternaria and Cladosporium in three of the four sera, indicating their immunologic identity. The immunoblot technique confirmed the degree of cross-reactivity found by RAST inhibition among the molds. This evidence of common allergenic determinants in these fungi could help to explain the observation that mold-allergic patients often have skin test reactions to several fungi.

Bermuda grass-pollen proteins were electrophoretically separated on polyacrylamide gels and transferred to nitrocellulose where IgE-binding components were detected by reaction with individual patient's serum and 125I-labeled antihuman IgE. Seventeen pollen components (in the molecular weight (MW) range of 8000 to 94,000 daltons), separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, bound IgE antibodies from a panel of 44 sera from allergic patients. The spectrum of Bermuda grass-pollen IgE-binding components detected is greater in number and wider in MW range than has previously been described. A component of MW 34,000 daltons (fraction 9) bound IgE from 100% of atopic sera tested. This component also bound the greatest quantity of IgE. Electrophoresis and transfer under nondissociating conditions revealed a component of MW 100,000 daltons that also bound IgE antibodies in all 44 sera tested. This component may be an aggregated form of fraction 9. A comparison of the electroblotting results obtained under dissociating and nondissociating conditions suggests once again that allergenic proteins in crude extracts may aggregate or associate during in vitro studies. Electrophoretic transfer analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis may thus be the method of choice for allergen separation and identification.

The recently developed dot immunobinding assay is operationally simple and facilitates performance of multiple simultaneous assays. Here, its use as the basis for determination of total and allergen-specific IgE is established. For total IgE, the same commercially available polyclonal anti-human IgE was used on the solid phase and as a peroxidase conjugate in the liquid phase. After incubation with a chromogenic substrate, IgE was determined from the color intensity of the resulting dots with a scanning reflectance densitometer. The limit of sensitivity was 50 pg/ml of IgE. Standardized conditions gave the dynamic range 50 to 2500 IU/ml in serum. The IgE measured was not subject to interference by serum components, was labile at 56 degrees C, was soluble at 30% saturation (NH4)2SO4, and was unaffected by anti-human immunoglobulins of other specificity. Coefficients of variation were 0.05 within run, and were 0.1 between run. Comparison with data on sera obtained with the PRIST method yielded a correlation coefficient of 0.96 and a linear regression of slope 1.15. Assays for allergen-specific IgE were established with bee venom and dust mite allergens in the solid phase. The same peroxidase-conjugated antibody was used as for total IgE. Comparisons with comparable RAST assays were performed.

A history of respiratory and allergic disorders was obtained in a white, rural population with ages 20 to 65 yr. Allergy skin testing was performed, and total IgE was measured by PRIST method. One thousand eight hundred and fourteen subjects were studied. Those subjects with positive allergic skin reactions and a history of allergic disorders and smoking were excluded to provide a reference group to derive "normal" values of total IgE. The mean level of the total IgE of this reference group was 12.1 U/ml. The upper limit of the normal range of total IgE levels was estimated at 87.3 U/ml. IgE levels did not differ between the sexes or with age in our adult population.

The health effects of both indoor and outdoor air pollutants are of increasing concern. The health effects of outdoor air pollutants traditionally have been assessed through measurements of lower respiratory tract changes. However, it has been shown that one outdoor air pollutant, sulfur dioxide, decreases nasal mucus flow and increases nasal airway resistance. Along with cigarette smoke, indoor air pollutants such as formaldehyde, cadmium, and ammonium or sulfate ions have been shown to alter upper airway mucociliary function. Emissions from wood stoves are known to irritate the upper airways. Measurement of nasal airway resistance using posterior rhinomanometry allows quantification of nasal function. This technique recently has been used to demonstrate that adolescents with allergic asthma have increased work of breathing after inhalation of 0.5 ppm sulfur dioxide. Another study using posterior rhinomanometry showed that clerical workers had increased work of breathing after exposure to carbonless copy paper as compared with bond paper. This brief review of upper respiratory tract changes after pollutant exposure should serve as a reminder that a complete clinical history must include questions designed to ascertain the patient's exposure history to both outdoor and indoor air pollutants. These exposures can have a major impact on the health of the upper respiratory system.

Allergenic proteins were extracted from one silk batch that was imported to be used as filling material for bed mattresses and rugs. IgE and IgG antibodies to the extracted silk proteins were measured by RAST in sera of nine silk-sensitive persons as well as in sera of healthy control donors. Silk proteins were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis into 12 polypeptides of molecular weights between 14 and 70 kilodaltons. By means of the immunoblot technique, IgE and IgG antibodies to the individual silk polypeptides could be detected. Sera of silk-sensitive persons contained high titers of IgE and low titers of IgG antibodies to the separated silk polypeptides. Sera of control donors contained low IgG antibody titers to a limited number of these polypeptides.

Because of conflicting reports in the literature concerning the value of various procedures for measurement of IgE in serum and secretions, we compared four different methods, the radioimmunosorbent test (RIST), the double-antibody radioimmunoassay (RIA), the paper disc immunosorbent test (PRIST), and radial immunodiffusion (RID). The standards used in the assays were tested initially in the double-antibody RIA with the use of the reference from the World Health Organization. The results showed that RID as expected was relatively insensitive and IgE was reliably measured only above approximately 1,000 international units (IU). Moreover, certain sera containing low levels of IgE by the other procedures gave distinct precipitin zones and presumably falsely high levels of IgE protein. Thus RID may yield apparently erroneous results when used as a screening procedure for measurement of IgE levels. Among the other procedures PRIST and the double-antibody RIA showed the best agreement. With serum samples RIST yielded values for IgE in the low level range higher than those given by the PRIST and double-antibody RIA. With breast milk and colostrum, values of IgE between 120 and 690 ng/ml were found by RIST, whereas IgE was not detected by double-antibody RIA and PRIST. No evidence of an inhibitor of IgE was found in breast milk, so that the apparent elevation of IgE in breast milk by the RIST is likely false. These findings confirm prior reports of spurious elevations of IgE with the RIST and indicate the usefulness of the PRIST and double-antibody RIA for the measurement of IgE in sera and secretions.

Recent studies have implicated soybeans as one of the major food allergens in children. Serum from eight patients with atopic dermatitis and positive double-blind, placebo-controlled food challenges to soy were used to investigate allergen-specific IgE and IgG antibody to soy protein and its fractions. ELISA and immunoblotting techniques were used for this purpose. A crude soy extract, as well as the 7S, 11S, and whey fractions, were isolated and purified for the in vitro studies from commercial defatted soy flakes. ELISA results demonstrated a statistically significant increased IgE and IgG response to the crude soy extract compared to that of normal control subjects. There was also an increase in IgE specific for 7S and IgG specific for 11S in the atopic group. The immunoblots reveal that IgE and IgG are present in varying amounts to multiple fractions of the soy protein. These results indicate that IgE and IgG specific to crude soy are elevated in patients with positive double-blind, placebo-controlled food challenges to soy but that no one fraction is clearly more antigenic.