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Comparison of serum IgE determination by radioimmunoassay and by single radial immunodiffusion.

Two commercially available methods of total serum IgE determination have been evaluated, viz: the radioimmunosorbent test (RIST) and the assay by single radial immunodiffusion (RID). RIST was found a suitable and rapid method for the wide range of IgE concentrations to be expected in the sera of an allergic population. The RID method has a lower limit of detection of about 1000 I.U./ml; over this value, both techniques provided statistically correlated results. However, for technological reasons RID was considered less suitable for routine application.

Asthma↗

Comparison of ultrasensitive methods for the measurement of IgE.

Because the study of human IgE synthesis and regulation requires exquisitely sensitive and rapidly performed methods for assay of in vitro IgE production, we compared 4 methods for radiometric immunoassay (RIA) of human IgE: double antibody RIA (DARIA), ultrasensitive enzymatic RIA (USERIA), sensitive paper radioimmunosorbent test (SPRIST) and microtiter solid-phase RIA (MSPRIA). IgE protein was measured in serum samples and cord bloods. The USERIA and the MSPRIA consistently detected levels of IgE as low as 27-35 pg/ml. The DARIA and SPRIST were less sensitive. Comparison of the USERIA and the MSPRIA favored the latter because: (1) it is a more rapidly performed assay, (2) it involves fewer manipulations, and (3) it has less variability. We conclude that the MSPRIA for IgE is superior to the other methods both as a research tool for measuring minute quantities of IgE protein (as in tissue culture supernatants) and for measuring IgE in serum samples where concentrations fall below 1 ng/ml (0.42 IU/ml; 1 IU = 2.4 ng).

Humans↗

Allergic bronchopulmonary aspergillosis with low serum immunoglobulin E.

Elevated total serum IgE is helpful in making the diagnosis of ABPA and in monitoring the onset of exacerbations and response to therapy. ABPA occurs frequently in patients with CF, and in these instances a high total serum IgE is seen. This is the first case report of ABPA without an elevated total serum IgE level. At no time prior to this patient's first episode of ABPA, at the time of the illness, or at monthly intervals during follow-up did her total serum IgE level exceed 29 IU/ml.

Adult↗

Pollen-induced chemiluminescence: inhibition by serum from allergic individuals.

The interaction between pollen grains, polymorphonuclear leukocytes (PMNs) and serum results in the formation of "pollen rosettes" and the production of chemiluminescence (CL). Significantly more CL is produced by cells exposed ot pollen and sera from nonallergic individuals compared with sera from allergic individuals. The source of the PMNs, however, has no effect on the CL produced, When IgG is isolated from the sera of allergic individuals and added to the test system, a large CL response is seen that is inhibited by the IgG-depleted fraction. No similar inhibition is produced by the IgG-depleted fraction of sera from nonallergic individuals. The inhibitor of CL in sera from allergic individuals appears to be IgE, since its removal leads to an enhanced CL response. These results suggest that competition for a limited number of binding sites on pollen grains exists between pollen specific IgG and IgE antibodies in serum from allergic patients.

Granulocytes↗

IgE production in vitro by human blood mononuclear cells: a comparison between atopic and nonatopic subjects.

In vitro IgE synthesis by blood mononuclear cells from atopic patients and nonatopic subjects was examined. A total of 1 X 10(6) mononuclear cells cultured in RPMI-1640 and 10% fetal calf serum with or without cycloheximide was found to be optimal to detect de novo synthesis. A modified Phadebas IgE paper radioimmunosorbent test was employed for the quantitation of supernatant IgE concentration. Kinetic studies indicated that about half the peak amount of IgE is secreted within the first 2 days and the maximum concentration is reached at day 7. Mononuclear cells obtained from six of six atopic patients with eczema and elevated serum IgE levels and 22/33 atopic patients without eczema spontaneously synthesized significant amounts of IgE in vitro. We failed to detect de novo IgE synthesis by the cells obtained from 40 nonatopic controls. Polyclonal activators such as pokeweed mitogen. Staphylococcus aureus Cowan I, concanavalin A, and phytohemagglutinin failed to induce or enhance in vitro IgE synthesis in normal and atopic subjects. These findings indicate that the study of immunoregulation of IgE synthesis in man will be difficult to accomplish until new methods are developed that allow induction of the IgE response in vitro in nonatopic subjects.

Adolescent↗

Application of the dot immunobinding assay to allergy diagnosis.

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.

Antibody Specificity↗

Anaphylactic reactions to a psyllium-containing cereal.

Historical data were obtained by questionnaire and telephone survey on 20 of 24 women with reported allergic reactions to a psyllium-containing cereal, Heartwise. Protein fractions from this new cereal, as well as from psyllium mucilloid and a psyllium-containing laxative, Metamucil, were extracted, quantitated, and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Patients' sera were collected, and specific IgE and IgG antibodies to these psyllium antigens were detected by immunoblotting techniques. Of the 20 women evaluated, all but six were nurses. Eighteen (90%) of the women had historical and/or laboratory evidence of atopy. Exposures included ingestion or dispensing of psyllium-containing products. Only three women denied prior exposure to psyllium. Symptoms developed shortly after small amounts of the cereal were ingested and most commonly included moderate to severe wheezing, throat and chest tightness, and urticaria. All the women required medical therapy, 11 (55%) in an emergency room. Specific IgE and IgG antibodies to various psyllium protein fractions were documented in all the subjects. It was concluded that individuals sensitized by occupational exposure to psyllium dust are at high risk for allergic reactions to ingested psyllium-containing products.

Adult↗

Screening of bone marrow and kidney transplant donors and recipients for cytomegalovirus antibody by commercial latex agglutination or competitive enzyme-linked immunosorbent assays.

A commercial competitive enzyme-linked immunosorbent assay and a sensitive in-house radioimmunosorbent test detected cytomegalovirus (CMV) antibody in similar numbers of serum specimens (66 and 67 of 152, respectively) obtained from bone marrow and renal transplant donors and recipients. In contrast a commercial latex agglutination assay for CMV antibody apparently gave false positive results when testing serum specimens obtained from organ donors. The implications for CMV screening of organ transplant donors and recipients are discussed.

Antibodies, Viral↗

A critical search for evidence of changes in levels of circulating IgE in patients with cancer.

Serum-IgE levels in 95 patients with various advanced malignant conditions were determined by the radioimmunosorbent test. The results obtained did not support the claims of other workers that a high proportion of untreated cancer patients have extremely high circulating IgE levels, attributable to the release of a tumour constituent which interferes with this radioimmunoassay procedure.

Blood Donors↗

Immunobiological aspects of acute subglottic laryngitis in children.

In the pathogenetic evaluation of acute subglottic laryngitis (ASL) the anatomy of the child's larynx should be taken into consideration: its absolute size need not necessarily be smaller than that of the adult, but its relative size with respect to the developmental stage of other organs, is. The most frequently seen anaphylactic reaction of the larynx in ASL is edema. Since 1975, 284 children with ASL have been treated in our Department of Otorhinolaryngology. They have been divided into the following groups: Group A--196 children with diseases of unknown etiology; Group B--20 children with identified viral infections; and Group C--68 children with allergic reactions. All children had their histories taken and they were all submitted to clinical examination, endoscopy, laboratory tests and allergy tests. Immunological and serological determinations, as well as lung function tests markedly facilitate the identification of etiologic factors in ASL and are of considerable help in planning a therapy and preventing any relapse of the disease.

Acute Disease↗

Specific IgE antibodies to Leishmania braziliensis in patients with mucocutaneous leishmaniasis.

A total of 116 sera of patients suffering from South American mucocutaneous leishmaniasis were analysed using the RAST (L. braziliensis-specific) and RIST techniques. Results of total and specific IgE levels were correlated with different clinical stages of the disease. The level of total and specific IgE appeared to be higher among patients with cutaneous ulcers than among those presenting mucocutaneous lesions, i.e. espundia. Furthermore, non-treated patients presented higher concentrations of total and specific IgE than did treated ones.

Antibody Specificity↗

Sensitivity to the house dust mite and airway hyperresponsiveness in a young adult population.

BACKGROUND: The pathogenic mechanisms of airway hyperresponsiveness (AHR) in asthma are unknown and only a few studies have examined the importance of sensitivity to antigens in AHR in young adults. OBJECTIVE: We investigated the correlation between AHR and sensitivity to specific antigens, atopy, history of childhood asthma and spirometry in a young adult population. METHODS: Based on the results of interviews with 447 students at our university, 308 non-smoker students were classified into six groups. Group 1 comprised subjects with intermittent mild bronchial asthma; group 2, subjects with history of childhood asthma; group 3, subjects with atopic disease, and a RAST score for Dermatophagoides farinae (Def) of > or = 2; group 4, normal subjects with a RAST score for Def of > or = 2; group 5, subjects with cedar pollinosis; and group 6, normal subjects. We measured AHR to methacholine (MCh), spirometry, immunoglobulin E-radioimmunosorbent test (IgE-RIST), IgE-radioallergosorbent test to six common antigens, eosinophil cationic protein (ECP), and eosinophil count in peripheral blood in each subject. RESULTS: Airway hyperresponsiveness to MCh did not correlate with IgE-RIST, eosinophil count, or ECP. The highest AHR to MCh was present in groups 1 and 2 and lowest in groups 5 and 6. Multiple regression analysis showed that sensitivity to Def was the only factor that significantly influenced AHR to MCh. Airway hyperresponsiveness to MCh of groups with a RAST score for Def of 0/1 was lower than groups with a RAST score of 2 to 6. Airway hyperresponsiveness to MCh did not correlate with the degree of positivity to Def antigen among positive sensitized groups (RAST score 2 to 6). CONCLUSIONS: Sensitivity to mite antigen may be important in the pathogenesis of AHR and Def is a major contributing antigen in young adults in Japan. Once asthma occurs, AHR remains positive for a long time even after the disappearance of asthma-related symptoms.

Adult↗

[Visagnost--a strip test for in vitro allergy diagnosis in comparison with Magic Lite and Cap-FEIA: I. Total IgE determination].

The diagnosis of allergic airway diseases, especially allergic rhinitis, is based on medical history, clinical examination and further tests. Since the detection of IgE, total IgE in serum has become a major tool in the diagnosis of immediate allergy. Although in-vivo-tests like skin prick test are performed in almost every allergologist's practice, the capability of determining IgE was restricted to special laboratories. As shown for semiquantitative glucose dipsticks, a rapid and easy method has advantages for both patient and doctor. A recently developed dipstick test (Visagnost, in U.S. Quidel allergy screen) for allergy screening now enables every practitioner to determine total IgE levels within less than one hour. For the evaluation of the diagnostic value of this dipstick test, we compared the total IgE levels in the sera of 56 patients with two modern methods (Magic Lite, Ciba-Corning, and Cap-FEIA, Pharmacia). Visagnost is an enzyme-immuno-assay with the solid phase on the dipstick. It can be performed in serum, plasma or whole blood, in this study the test was performed in serum. Magic lite is a combined solid-liquid-phase immuno-assay with a final chemiluminescent reaction, the incubation time is about two hours. Cap-FEIA is a solid phase sandwich ELISA with a fluorescent reaction and an incubation time of at least four hours. Patient's sera were shock-frozen in liquid nitrogen and stored at -80 degrees C until examination. Visagnost gave results in four ranges of minor 20 U/ml, 21-50 U/ml, 51-100 U/ml and more than 100 U/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme-Linked Immunosorbent Assay↗

The association of atopy with a gain-of-function mutation in the alpha subunit of the interleukin-4 receptor.

BACKGROUND: Atopic diseases are very common, and atopy has a strong genetic predisposition. METHODS: Using single-strand conformation polymorphism analysis and DNA sequencing, we searched for mutations in the a subunit of the interleukin-4 receptor that would predispose persons to atopy. We examined the prevalence of the alleles among patients with allergic inflammatory disorders and among 50 prospectively recruited adults. Subjects with atopy were identified on the basis of an elevated serum IgE level (> or = 95 IU per milliliter) or a positive radioimmunosorbent test in response to standard inhalant allergens. The signaling function of mutant interleukin-4 receptor a was examined by flow cytometry, binding assays, and immunoblotting. RESULTS: A novel interleukin-4 receptor alpha allele was identified in which guanine was substituted for adenine at nucleotide 1902, causing a change from glutamine to arginine at position 576 (R576) in the cytoplasmic domain of the interleukin-4 receptor alpha protein. The R576 allele was common among patients with allergic inflammatory disorders (found in 3 of 3 patients with the hyper-IgE syndrome and 4 of 7 patients with severe atopic dermatitis) and among the 50 prospectively recruited adults (found in 13 of 20 subjects with atopy and 5 of 30 without atopy; P=0.001; relative risk of atopy among those with a mutant allele, 9.3). The R576 allele was associated with higher levels of expression of CD23 by interleukin-4 than the wild-type allele. This enhanced signaling was associated with a change in the binding specificity of the adjacent tyrosine residue at position 575 to signal-transducing molecules. CONCLUSIONS: The R576 allele of interleukin-4 receptor alpha is strongly associated with atopy. This mutation may predispose persons to allergic diseases by altering the signaling function of the receptor.

Adult↗