Immunologic specificity of isocyanate-induced IgE antibodies in serum from 10 sensitized workers

A procedure for the preparation of RAST disks used to assay isocyanate-specific IgE antibodies was developed. The outcome of the RAST was found to be strongly dependent on how the isocyanate test antigen was synthesized. Specific IgE from selected workers with isocyanate asthma reacted optimally to conjugates with less than or equal to 10 isocyanate molecules bound per molecule of human serum albumin. Further haptenization resulted in decreased specific binding and increased nonspecific binding because of high levels of total IgE. The hapten and carrier specificity of isocyanate-induced IgE antibodies were studied by direct RAST and RAST inhibition. The existence of new antigenic determinants related to both the isocyanate hapten and the carrier could be demonstrated. It was important to use a test antigen prepared from the same isocyanate as that to which the worker had been exposed, since the cross-reactivity between different isocyanate haptens was partial and varied from one patient to another. It was confirmed that isocyanate-specific IgE antibodies can be demonstrated only in a subgroup of workers with isocyanate-related bronchial asthma.     

Specific IgE antibodies to platinum salts in sensitized workers

A RAST has been developed for the measurement of IgE antibodies specific to platinum chloride complexes in sensitized workers. Human serum albumin covalently linked to Sepharose beads by the cyanogen bromide method was reacted with ammonium tetrachloroplatinite (II) (NH₄)₂PtCl₄. This conjugate was more suitable for the RAST, than conjugates of HSA and the platinum salt prepared in solution and then linked to the activated Sepharose, showing better sensitivity and giving lower levels of non-specific uptake of IgE from sera of non-exposed subjects with high total levels of IgE, e.g. allergic bronchopulmonary aspergillotics.     

The relationship between total serum IgE and castor-bean-specific IgE antibodies in castor-bean-sensitive patients from Marseilles

The relationship between serum IgE and castor bean (Ricinus communis)-specific IgE was studied in a group of dockworkers and other residents of Marseilles who were diagnosed as having castor bean allergy. The diagnosis was made because they had asthma or other allergic symptoms together with a positive skin test to castor bean. Total serum IgE was found to be higher in castor-bean-allergic patients (mean = 174 IU/ml) than in a control group of local blood donors (mean = 66 IU/ml). IgE levels were not as high as those found in the sera of a previously identified group of castor-bean-allergic dockworkers from Port Sudan (mean = 902 IU/ml). Castor-bean-specific IgE was demonstrated in the serum of 91% of the allergic group and there was some correlation with total IgE (r = 0.53, p less than 0.01). The proportion of IgE antibody specific for castor bean was determined in 20 castor-bean-sensitive patients using the radioallergosorbent test and was found to vary between 9 and 64% (mean = 38% or 265 ng/ml). No castor-bean-specific IgE antibody was detected in the control group.     

Positive ratio of allergen specific IgE antibodies in serum, from a large scale study

Incidences of allergen specific IgE antibodies in a large Japanese population(n = 4,797,158) were studied. Sera from patients were collected in our laboratories during 1994-1998, and assayed with Pharmacias CAP system FEIA. Values greater than 0.70 UA/ml(Score 2) were considered positive. Japanese cedar pollen showed the highest IgE response(positive ratio), followed by house dust, and dust mite. Among food allergens, apple had the highest response, followed by sesame seed, egg white, potato, and tomato. IgE response against Anisakis was significantly higher than that against seafood. Positive ratio varied significantly among regions and among seasons. For example, Hokkaido, compared to other regions, showed lower values for cedar and cypress, but higher for silver birch. Values used in this study were from patients who chose IgE testing, and thus do not represent the general population. However, our findings include positive ratios of rare allergens, and are useful for clinicians who do allergen testing.     

Total serum IgE and specific IgE antibodies in children with bronchial asthma

Correlation between total serum IgE levels and RAST scores in a total of 342 asthmatic children were evaluated. The median and range of serum IgE were 1,050 IU/mL and 20 to 10,000 IU/mL respectively. Positive rates of RAST were highest for mites and house dust (87% to 91%) and lowest for milk, dogs, buckwheat, and eggs (2% to 8%). In general, patients with higher RAST scores had higher serum IgE (P less than .05, Mann-Whitney test). In individual cases, however, serum IgE levels did not significantly correlate with RAST scores and RAST was mandatory to estimate the levels of specific IgE antibodies.     

Increased sensitivity and specificity of a sandwich ELISA for measurement of IgE antibodies

We have developed a sandwich enzyme-linked immunosorbent assay (ELISA) for measurement of IgE antibodies to the bee venom allergens phospholipase A2 (PLA2) and hyaluronidase (HYAL). The assay is 10-20 times more sensitive than conventional indirect ELISA or radioallergosorbent test (RAST). Furthermore, by using affinity purified rabbit antibodies to these allergens, the specificity of the test was increased compared to RAST. The use of antibodies to link the antigen to the solid phase removes the dependence on the individual protein's ability to bind to the microtitre plate. The increased sensitivity of the sandwich assay seems to be due to better presentation and retention of antigen on the solid phase.     

Food allergy: Specific binding of IgE antibodies from plant food sensitized individuals to carbohydrate epitopes

The presence of anti‐carbohydrate immunoglobulin E (IgE) antibodies was investigated in a group of 54 patients who were sensitive to at least two pollen species and at least five vegetable foods. Enzyme‐linked immunosorbent assays (ELISAs) and ELISA inhibition assays were performed with immobilized food‐related oligosaccharides (e.g. stachyose from legumes) and extracts of plant gums (e.g. gum arabic), as well as with allergen extracts from apples, celery and other fruits and vegetables. Furthermore, a combined procedure of immunoblotting and periodate treatment was applied to identify the epitope nature of glycans from vegetable food glycoproteins. The results suggested that 12/54 of the sera contained IgE antibodies against carbohydrate structures. The antibodies were also found to be highly cross‐reactive. For six patients, galactose may be an important epitope. The clinical relevance of the phenomenon requires further investigation.     

IgE antibodies against bovine serum albumin in a case of eosinophilic gastroenteritis

Eosinophilic gastroenteritis is a disease characterized histologically by an eosinophilic infiltration of the gut. The cause of this disease remains unclear, although both food allergy and food intolerance have been implicated in its pathogenesis. We report the case of a 22-year-old man in whom gastrointestinal symptoms first appeared in childhood, with involvement of mucosa and muscularis layers of stomach and bowel. He presented high IgE blood levels, and his prick test was positive to bovine, pig, and lamb sera. Immunoblots from calf, pig, and lamb sera, incubated with the patient's serum and revealed by autoradiography, demonstrated the presence of a 65-kDa protein band that was recognized by IgE antibodies but not by IgG. This band corresponded to bovine serum albumin, while IgE did not show reactivity with human albumin. These data suggest a possible role for IgE-mediated hypersensitivity mechanisms in the pathogenesis of eosinophilic gastroenteritis.     

Longitudinal study of specific IgE and IgG antibodies in a patient sensitized to ethylene oxide through dialysis

IgE and IgG antibodies to ethylene oxide (EO) were monitored by RAST and by ELISA in serum from a patient with hypersensitivity reactions during hemodialysis. Serum samples from the patient covering a 7-year period were analyzed. The changes in titers of IgE and IgG antibodies correlated to the time of EO exposure as well as to clinical symptoms. EO-specific IgG antibodies were, however, also found in sera from hemodialysis patients without any hypersensitivity symptoms. Assay of specific IgG antibodies will only indicate whether a patient has been exposed to, and immunostimulated by, EO, whereas specific IgE antibodies appear to be clearly related to hypersensitivity symptoms. The hapten and carrier specificity of EO-induced IgE antibodies was studied. The antibodies were found to be solely hapten specific because carriers of different types could be used in RAST without changing the outcome of the test. The existence of new antigenic determinants related to the carrier could not be demonstrated.     

Fine specificity and idiotype expression of anti-phosphorylcholine IgE and IgG antibodies

The immune response to the phosphorylcholine (PC) hapten elicited in BALB/c mice by PC-keyhole limpet hemocyanin (KLH) is composed of 2 groups of antibodies with specificity to PC and phenyl-PC, respectively. They were designated as group I and group II anti-PC antibodies. In this report we demonstrate that anti-PC IgE antibodies elicited by PC-KLH or PC-ovalbumin belong to the group II and do not express the T15 idiotype. Anti-PC IgG1, IgG2a and IgG2b antibodies express group I characteristics in the primary response and bear the T15 idiotype. Later, after 5 weeks and 3 injections of PC-KLH or PC-ovalbumin, a change in these isotypes to group II antibodies is observed. In contrast, anti-PC IgE is a group II antibody throughout progression of the immune response. The regulation of group I and group II antibody expression in serum is independent of the genetic background of the animals.     

Immunological specificity of monoclonal antibodies to Chlamydia psittaci ovine abortion strain

Fifty-one monoclonal antibodies were prepared by two different techniques against Chlamydia psittaci strain A22 isolated from an ovine abortion. These antibodies were tested for reactivity by the indirect immunofluorescent antibody technique with eleven reference Chlamydia strains (nine C. psittaci, one Chlamydia trachomatis and one Chlamydia pneumoniae). Four classes of specificity were recognized for monoclonal antibodies: genus, species, subspecies and type specificity. The type-specific monoclonal antibodies were non-reactive with ovine arthritis isolates. Twenty monoclonal antibodies were specific for two mammalian strains: ovine abortion A22 and K mouse. Some monoclonal antibodies were reactive with C. pneumoniae strains and non-reactive with C. trachomatis strains. All these monoclonal antibodies were very useful for improving the diagnosis of chlamydial infection, the antigenic analysis and the serotyping of C. psittaci.     

Assay of specific IgE antibodies to disodium cromoglycate in serum from a patient with an immediate hypersensitivity reaction

A 29-year-old man with pollen allergy had experienced immediate adverse reactions, such as itching of the eyes, rhinitis, wheezing, and general urticaria, after using disodium cromoglycate (DSCG) eye drops. The local symptoms were reproducible, and skin tests were strongly positive. With serum from the patient, a RAST was developed for the assay of IgE antibodies. The uptake on RAST disks was 6% of the total activity added, which was a significantly higher level than was found in sera from 35 randomly selected blood donors or in sera from 25 patients tolerating DSCG. By addition of DSCG to the patient's serum, 95% of the binding to paper disks could be inhibited. The induction of specific IgE antibodies was proposed to be a result of a combination of electrostatic and hydrophobic interaction of DSCG and a protein carrier. The substance would thus act as a hapten without any covalent binding to the carrier. DSCG may serve as a model for other nonreactive low-molecular-weight substances suspected to elicit type I-like adverse reactions.     

Allergy to castor bean in The Sudan: measurement of serum IgE and specific IgE antibodies

Allergy to castor bean was diagnosed in thirty-nine dockworkers from Port Sudan, on the basis of rhinitis and/or asthma provoked by castor bean dust, together with a positive prick test to a high dilution of castor bean extract. These were compared to twelve non-allergic dockworkers from Port Sudan and forty-three other Port Sudan residents. The castor bean allergic group had significantly higher IgE levels (mean 902 iu/ml) than the non-allergic dock workers (mean 245 iu/ml) or the Port Sudan residents (mean 404 iu/ml) P<0.01, IgE antibody to castor bean was detected in all the castor bean-allergic group, and also in 25-35% of the Port Sudan resident group, but at a much lower level. No evidence was found to support the view that parasitic infestation (evidenced by IgE antibodies to Ascaris lumbricoides) prevented sensitization to castor bean or any other allergen. There was a higher incidence of IgE antibodies to Dermatophagoides pteronyssinus in the castor bean-allergic dockworkers (18/36) than in the non-allergic Port Sudan residents (5/43), although we were unable to show that sensitivity to other inhalant allergens pre-disposed to castor bean allergy.     

Antigenic specificity of serum antibodies in mice fed soy protein

BACKGROUND: Soybean protein is used in a number of food products but unfortunately is also a common cause of food allergy. Upon ingestion of soy protein, healthy mice like other animals and humans generate a soy-specific antibody response in the absence of signs of illness. Not much is known about the relationship between the immunogenic proteins involved in this nondeleterious antibody response and the pathological response associated with food allergy.The objective of the present study was to characterize the antigenic specificity of the soy protein-specific antibody response generated in healthy mice ingesting soy protein. METHODS: Blood from mice fed a soy-containing diet was analyzed using ELISA and immunoblot for antibody reactivity towards various soy protein fractions and pure soy proteins/subunits. Mice bred on a soy-free diet were used as controls. RESULTS: The detectable antigenic specificity of the serum antibodies of soy-consuming mice comprised glycinin and beta-conglycinin. Immunoblots with soy protein extract demonstrated antibody reactivity towards both the basic and the acidic chains of glycinin and the beta-conglycinin subunits with an individual response pattern among mice. Moreover, antibody reactivity was found towards the native quaternary structure of glycinin. CONCLUSIONS: Mice ingesting soy protein generate an antibody response with reactivity towards glycinin and beta-conglycinin. Antibody reactivity found towards the native quaternary structure of glycinin indicates an oral immunogenicity of the highly processing-resistant oligomerized glycinin.     

Class and subclass-associated specificity differences of anti-gliadin antibodies from mucosa and serum.

The class and subclass distribution of antibodies against gliadin in intestinal lavage fluid, saliva and serum was investigated in individuals with coeliac disease. Serum antibodies against gliadin were mainly or even exclusively of the IgA1 subclass. In intestinal lavage fluid and saliva, antibodies of both IgA1 and IgA2 subclasses were found. In patients with and without IgA deficiency, an IgG response was detected both in serum and intestinal lavage fluid with a predominance of IgG1 in selected patients. Specific IgG2, IgG3 and IgG4 antibodies were also detected in intestinal lavage fluid, while no specific IgG2, IgG3 or IgG4 antibodies were found in serum, suggesting a local production of specific IgG antibodies. In Western blot analysis, intestinal lavage fluid and serum IgA antibodies reacted against gliadin components with a MW between 33,000 and 42,000. Serum IgA1 antibodies directed against a gliadin component with a MW slightly higher than 42,000 were also observed. Specific IgG and IgM antibodies in both the secretion and serum against gliadin components with a MW between 33,000 and 42,000 were also detected. This study shows that mucosa-derived gliadin-specific IgA and IgG antibodies may be produced even when there is an absence of specific antibodies of the corresponding immunoglobulin subclass in serum. Furthermore, the specificity of serum and intestinal lavage fluid anti-gliadin IgA1 antibodies may differ.     

Multidisc RAST: a reliable method for screening of specific IgE antibodies in serum?

"Multidiscs" (md) are cellulose discs to which several allergens are coupled, allowing the simultaneous screening of several specific IgE antibodies. We compared RAST performed with md to RAST performed with the corresponding individual allergens coated on single discs (sd). One hundred and twenty-two RAST positive samples were analyzed for four different allergen groups: moulds, cereals, weed pollens and tree pollens. We found lower RAST sensitivity when screening with mds than with the individual sds in all allergen groups except cereals. In 30 to 70% of the samples, the results were concordant. In 25.5 to 66.7%, md values were lower and in 1.3 to 26.3% higher than sd values. When only qualitative results were considered, the loss of sensitivity appeared acceptable: only 6.7 to 16.7% of the sd positive samples were not detected by md screening. A cost-benefit analysis, calculated on local data, confirmed economic advantages.     

Production of monoclonal mouse IgE antibodies with DNP specificity by hybrid cell lines

IgE anti-DNP antibody-secreting hybridomas were obtained by polyethylene glycol fusion of murine myeloma cells with spleen cells from mice, primed with DNP-KLH and challenged with DNP-Nippostrongylus brasiliensis extract. The in vivo and in vitro continuously growing hybridomas are producing high amounts of monoclonal IgE anti-DNP antibodies, which are heat-labile, hapten-specific and have rat mast cell sensitizing capacity.     

A multicentric study on sensitivity and specificity of a new in vitro test for measurement of IgE antibodies

The sensitivity and specificity of the Pharmacia CAP System, a new in vitro assay for measuring IgE antibodies, were evaluated in a multicentric study on 286 allergic patients and 243 normal subjects. Sensitivity was 95.5%, with results significantly better than RAST for some allergens, and specificity was excellent, 98.1%.     

Quantitation of IgE antibodies by radioimmunoassay in the presence of high concentrations of non-IgE antibodies of the same specificity

Radioimmunoassays for mouse IgE antibodies, based on adherence to an antigen-coated surface, are precise and sensitive, but errors can be introduced by the presence of relatively high concentrations of non-IgE antibodies of the same specificity. Such errors are caused by competition for the limited number of antigenic determinants on the antigen-coated surface. In this paper we explore further the quantitative aspects of the 'competition effect'. An easily applied method is described, based on preferential precipitation of non-IgE antibodies by ammonium sulfate, that permits analysis of IgE antibodies in the presence of large amounts of non-IgE antibodies (that are principally IgG). For IgE anti-Ar, the maximum permissible ratio is extended from approximately 1500:1 to at least 40,000:1. We have also determined the effect of IgG antibodies or whole mouse serum on PCA reactions of mouse IgE antibodies, carried out in rats.