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Serological and skin-test diagnosis of birch pollen allergy with recombinant Bet v I, the major birch pollen allergen.

BACKGROUND: Type I allergy represents a severe health problem in industrialized countries where up to 20% of the population suffer from allergic rhinitis, conjunctivitis and allergic asthma bronchiale and in severe cases from anaphylaxis, leading to death. OBJECTIVE: The aim of this study was to evaluate recombinant Bet v I, the major birch pollen allergen for in vivo and in vitro diagnosis of birch pollen allergy. METHODS: A group of 51 birch pollen allergic patients and eight non-allergic control individuals were tested for birch pollen allergy by skin-prick and intradermal testing, comparing commercial birch pollen extracts with recombinant Bet v I. Quantitative and qualitative serological testing was done with natural and recombinant allergens by radioallergosorbent test (RAST), enzyme-linked immunosorbent assay (ELISA) and immunoblotting. RESULTS: Recombinant Bet v I allowed accurate in vivo and in vitro diagnosis of tree pollen allergy in 49/51 patients tested. No false positive results were obtained in any in vitro assay system (ELISA, Western blot) or by skin testing (skin-prick, intradermal test) with recombinant Bet v I. CONCLUSION: Our results document that recombinant Bet v I produced in bacterial expression systems allows accurate in vitro and in vivo diagnosis of birch pollen allergy in > 95% of birch pollen allergic patients.

Adult↗

Specific IgE antibodies in nasal secretion from patients with allergic rhinitis and with negative or weakly positive RAST on the serum.

Nasal secretions from eighteen patients with allergic rhinitis with a positive case history, intradermal test and nasal provocation test, but with negative or only weakly positive RAST (radioallergosorbent test) on the serum against a total of thirty-five allergens, were studied. In the RAST an immunosorbent-purified anti-IgE with DE2 specificity was used, which raised the detection limit. Nasal secretion was collected by washing the nasal mucosa with 0-9% and 18% NaCl solution respectively, and the latter secretion was also luophilized and concentrated. In ten cases RAST was slightly positive on the nasal secretion, and in three of the concentrated secretions the RAST value was higher than on the serum. In none of the serum or nasal secretion samples was RAST positive according to the cut off value for a positive result defined by the reference system used in Phadebas Rast. From these results it is concluded that RAST analyses of nasal secretion from patients with allergic rhinitis is of no appreciable value in routine clinical allergological diagnosis. However, the increased sensitivity of RAST obtained with isotope-labelled anti-DE2 may be useful in the serological diagnosis of patients with low grade allergy having low levels of IgE antibodies in serum.

Adult↗

Diagnostic performance characteristics of the standard Phadebas RAST, modified RAST, and pharmacia CAP system versus skin testing.

Results from three in vitro assays for allergen-specific IgE, the standard Phadebas radioallergosorbent test (PhRAST), modified RAST (mRAST), and the new Pharmacia CAP System (CAP) were compared with skin prick testing (SPT) results in 104 patients with allergic rhinitis and/or asthma and 24 nonatopic controls. Five allergens were evaluated: cat, Dermatophagoides pteronyssinus, Alternaria, June grass, and short ragweed. Using SPT results as the reference standard, the PhRAST had the lowest sensitivity (62%) and highest specificity (99%). The CAP achieved higher sensitivity (74%) with comparable specificity (96%) while the mRAST had even higher sensitivity (90%) but lower specificity (87%). The overall frequency of positive results in controls was 0% for PhRAST, 1.7% for CAP, and 3.3% for mRAST. If the threshold for a positive mRAST was raised to greater than or equal to class 2, this assay achieved performance characteristics similar to the CAP. If the results of these in vitro tests are used as the sole guide to the prescription of environmental control and immunotherapy in unselected patients with rhinitis and asthma, the performance characteristics of the CAP make it the preferred test.

Adolescent↗

Improved in vitro diagnosis of allergy to Alternaria tenius and Cladosporium herbarum.

To improve the in vitro diagnosis of mould allergy 22 children suffering from allergic asthma caused by Alternaria tenius and/or Cladosporium herbarum as proven by bronchial provocation test were investigated. Partially purified, standardized mould preparations were used in radioallergosorbent test (RAST) with conventional and new update mould discs, mould-induced histamine release and immunoblotting. Updated RAST discs were found to be superior to the old-type discs for the detection of Alternaria but not Cladosporium sensitivity. In all patients except one, specific IgE-antibodies to the respective mould were demonstrated by immunoblotting. Mould-induced histamine release failed to prove sensitization in only two patients. No differences were found comparing histamine release from whole blood with release from isolated cells. The results demonstrate a high sensitivity of in vitro tests when purified and standardized extracts are used.

Allergens↗

Allergens from plantain (plantago lanceolata). Studies with pollen and plant extracts.

There has been unjustified neglect of dicotyledonous (dicot; 'weed') pollens in research directed at isolating pure allergens, since dicot pollens are widespread and frequently important in provoking immediate allergic reactions. Sera from patients who showed positive skin prick test reactions to plantain pollen generally also reacted in the radioallergosorbent test (RAST) with at least one other species of dicot pollen. Fractionation of plantain pollen extracts by ultrafiltration and molecular sieving and examination of the fractions by the RAST revealed a spread of allergenic activity. Using crossed immunoelectrophoresis, at least 16 different antigens were detected in plantain pollen and at least 6 of these antigens may be allergenic. Allergenic glycoproteins that react with concanavalin A were isolated and their complexity examined by electrophoresis and electro-focusing. IgE-binding components were found widely distributed in plantain plants and not confined to the pollen.

Allergens↗

Further observations on the role of IgE-mediated hypersensitivity in recurrent otitis media with effusion.

One hundred young patients with recurrent otitis media with effusion (OME) were evaluated for IgE-mediated hypersensitivity by critical analysis of history, physical findings, skin testing for selected antigen, laboratory determination of total IgE, and radioallergosorbent testing (RAST) for six inhalant and two food allergens. The patients could be divided into allergic rhinitis and nonallergic groups. Allergic rhinitis patients had higher total IgE in their serum, and middle ear effusion (MEE). IgE was elevated in 16 of 35 allergic patients. In 8 of these 16 (23% of the allergic group), the IgE/mg protein was higher in the MEE than in the corresponding serum, suggesting local production of IgE. Nasal IgE was substantially increased in the allergic patients; however, in many patients there was no correlation between the corresponding MEE IgE and elevated nasal IgE, suggesting that local production of nasal and middle ear IgE is independent. We conclude that IgE-mediated allergic reactions may play a role in the pathogenesis of OME in about 23% of young allergic patients.

Adolescent↗

The role of cow milk allergy in increasing the severity of atopic dermatitis.

Previous studies have shown that up to 33% of children with atopic dermatitis have experienced food hypersensitivity and among different kinds of food allergens Cow Milk (CM) has almost always been one of the most common food allergens in children. The aim of this study is to evaluate the cow milk allergy (CMA) as an increasing factor of severity of atopic dermatitis. One hundred and nineteen children (between 1.5 months and 12 years of age) with atopic dermatitis in the sense of Hanifin and Rajka's criteria entered this study and the severity of atopic dermatitis was identified via the SCORAD index. In order to make the diagnosis of cow milk allergy, a careful history, and a familial history of allergy was taken and the results of skin prick test (SPT) with CM and 4 other food allergen extracts, Radioallergosorbent test (RAST) with CM allergens and a food challenge test with cow milk (fresh or dried) were used. Also a total serum IgE determination and an eosinophil count (with a stool exam) were accomplished. The clinical manifestations of atopic dermatitis in patients was started from their first day of life up to 10 years of age. The family history in 83% of the patients was positive. Positive skin prick test and RAST with CM allergens were positive in 37.9% and 29.3% of cases respectively and the response to challenge test with cow milk was positive in 35 out of 40 patients and in total 44.5% had CMA according to a positive history of cow milk allergy and a positive outcome of the IgE tests (SPT and/or RAST) or a positive challenge test with CM allergens. The results showed that the most common food allergens in patients with atopic dermatitis are certainly cow milk allergens (44.5%) whereas other food allergens are tomato (29.41%), egg (28.57%), nuts (9.24%) and wheat (3.36%) according to the skin prick test. The mean total serum IgE was 307.11 +/- 6.56 IU/ml (range = 6-5000) in children with CMA and 81.04 +/- 5.97 IU/ml (range = 1-5000) in children without CMA while the mean eosinophil count was 569.52 +/- 3.02 count/ml (range = 67-8500) and 314.22 +/- 2.94 count/ml (range = 5-5000) respectively. The mean severity of atopic dermatitis according to the SCORAD index was 60.76 in children with CMA and 44.29 in children without CMA. The severity of atopic dermatitis in patients with CMA was significantly higher than patients without CMA (p < 0.0001). Also the mean total serum IgE and mean eosionophil counts in children with CMA were significantly higher than in children without CMA (P < 0.01 and p < 0.0001, respectively). It shows the important role of CM allergen proteins in the induction and in increasing the severity of AD in children.

Allergens↗

Tetrachlorophthalic anhydride asthma: evidence for specific IgE antibody.

We describe seven women with asthma induced by occupational exposure to an acid anhydride, tetrachlorophthalic anhydride (TCPA), an epoxy resin hardening agent. Inhalation tests with TCPA at atmospheric concentrations of less than one tenth of a manufacturer's recommended exposure limit provoked asthmatic reactions in the four women tested. None had evidence of pretest bronchial hyperreactivity. Immediate skin prick test reactions were elicited in the seven subjects by a conjugate of TCPA with human serum albumin (TCPA-HSA) but not in others tested. Specific IgE antibody levels to TCPA-HSA, measured by radioallergosorbent test scores, were significantly elevated in the seven, but not in TCPA-exposed and unexposed comparison groups. These results imply that occupational asthma caused by TCPA is an allergic reaction mediated by specific IgE antibody.

Adult↗

Immunoglobulin E specific to wheat and rye flour proteins.

We have used the radioallergosorbent test (RAST) to determine IgE antibodies specific to wheat flour proteins in the sera of seven groups of patients. In some cases rye-specific IgE was also determined. Wheat and rye RAST scores showed a good correlation, presumably due to cross-reactions. Among bakers with asthma, positive scores, 0.5-3, occurred with a prevalence of 43%, and among children with eczema, scores in the range 0.5-4 were found with a prevalence of 54%. A score of 0.5 was a marginal value which was also occasionally encountered with sera from patient groups with no history of immediate hypersensitivity to wheat or rye. These groups included adults and children with allergic rhinitis and asthma, children from the general population and children with coeliac disease. The RAST appeared useful in the diagnosis of allergy to inhaled flour dust among bakers. Among children with eczema, positive wheat and rye RAST results were a common finding, which only occasionally could be linked to strong and unequivocal reactions to the foods in question. Both in bakers and children with eczema, wheat and rye RAST results showed good agreement with intracutaneous skin test results.

Adult↗

The significance of cell-bound antigen-specific IgE in chronic urticaria.

Radioallergosorbent test (RAST) was performed on the sera obtained from chronic urticarial patients from whose leucocytes significant histamine release by mite antigen was observed. In 14 out of 19 cases investigated, no mite-antigen-specific IgE was detected in their sera by RAST, in spite of significant mite-antigen-induced histamine release from their leucocytes. The results suggest that type I reaction may be involved in chronic urticaria and the cell-bound, antigen-specific IgE may be important rather than the circulating antigen-specific IgE in this disease.

Adolescent↗

The role of IgE-mediated hypersensitivity in otitis media with effusion.

Forty-one children with recurrent otitis media with effusion (OME) were evaluated for IgE mediated allergy by critical analysis of history, physical findings, skin testing for selected antigens, and laboratory determination of total IgE and radioallergosorbent testing (RAST) for six inhalant and two food allergens. The children were divided into an allergic and nonallergic group. The allergic group clearly had higher total IgE in their serum. There was an elevation of middle ear effusion (MEE) IgE in 5 of 20 allergic cases. In three of these five patients or 15% of the allergic group, the IgE/mg protein was higher in the MEE than in the corresponding serum, suggesting the possibility of local production of IgE. Specific IgE antibody as measured by RAST was noted in 9 of 20 MEE and 5 of 20 nasal washings in the allergic group and in only 2 of 21 MEE and in 10 nasal washings of the nonallergic group. Nasal IgE was substantially increased in three patients of the allergic group; however, the corresponding MEE IgE was not increased in proportion to the nasal IgE. The MEE RAST was positive in 22% of the allergic group and in less than 1% of the nonallergic group. Nasal RAST was positive in 20% of the allergic group and in none of the nonallergic group. We conclude that IgE-mediated allergic reactions may play a role in the pathogenesis of OME in only about 15% of children defined as allergic on the basis of clinical and laboratory evidence. Allergy investigation as a diagnostic procedure in children with recurrent OME, but without a history of allergy on the basis of history, family history, or laboratory testing is likely to be nonproductive.

Adolescent↗

The spectrum of IgE-mediated responses to latex.

A spectrum of IgE-mediated allergic responses to latex is presented in this report of 14 patients, including health care workers, sensitized by exposure to latex gloves. Symptoms often occurred immediately after exposure to latex, and manifestations varied according to the route of latex antigen presentation. Skin exposure usually caused contact urticaria. Exposure to latex in the air elicited allergic rhinitis, conjunctivitis, and asthma. Systemic effects from latex occurred intraoperatively due to the surgeon's latex gloves. Anaphylactic shock included the above symptoms with the addition of tachycardia and hypotension. All patients had positive latex skin tests. Serum IgE antibody to latex was found with a latex radioallergosorbent test in all but one tested patient. Physicians should be aware that latex allergy can present as anaphylaxis during surgery, barium enema, or dental work. Latex skin tests are a satisfactory method of diagnosis. Nonlatex gloves are available and are tolerated by affected people.

Adolescent↗

Decrease of specific and total IgE levels in allergic patients after BCG vaccination: preliminary report.

BACKGROUND: A systemic reaction to mycobacteria biases the balance of T helper cell types 1 and 2 toward T helper cell type 1. BCG vaccination mimics some characteristics of mycobacterial infection. Children who have undergone tuberculin conversion after BCG vaccination seem to be more likely to lose their atopic symptoms. Inhibition of both allergic response and airway hyperreactivity after vaccination for mycobacteria has been observed in animal experiments. OBJECTIVE: To evaluate the effects that BCG vaccination has on the serological status of allergic people. PARTICIPANTS AND METHODS: This study included 20 volunteers with a history of allergic rhinitis who were required to undergo BCG vaccination by Italian law. Epicutaneous allergy testing with a panel of common seasonal and perennial inhalational allergens and 2 blood withdrawals were performed. The serum total IgE levels and the serum allergen-specific IgE levels of each individual were measured just before BCG vaccination and again 4 months later. Total IgE levels were determined using the paper radioimmunosorbent test, and allergen-specific IgE levels were determined using the radioallergosorbent test. RESULTS: Total IgE and allergen-specific IgE levels were significantly decreased after BCG vaccination (P =.004 and P<.001, respectively). CONCLUSION: BCG, an effective stimulus for cell-mediated immunity, deserves further study to evaluate its ability to modulate the immune response associated with allergic rhinitis.

Adult↗

Food allergy in children with hyperactivity, learning disabilities and/or minimal brain dysfunction.

Ninety hyperactive children, 22 children with learning disability and eight emotional-inattentive children were tested for allergy to 43 food extracts using the in vitro radioallergosorbent test (RAST). Fifty-two percent of all children exhibited allergy to one or more of the foods tested. Within the hyperactive group a statistically significant association was found between the number of allergies and teachers' (Conners) scores of hyperactivity. This association was statistically significant only in those hyperactive children who also had learning disability and minimal brain dysfunction. A statistically weak association was also found between a small number of children clinically diagnosable as hyperactive and the number of allergies or total allergy scores. A causal relationship between food allergy and a small subgroup of children with a primary diagnosis of hyperactivity is suspected.

Attention Deficit Disorder with Hyperactivity↗

Association between the MB system and asthma in the Japanese.

Twenty-three unrelated Japanese patients with asthma who showed a high total serum IgE level, a strong skin test response to Dermatophagoides farinae, and a high score on a radioallergosorbent test (RAST) using Dermatophagoides farinae were typed for HLA-A locus, -B locus, and -D region antigens. No significant difference in the frequencies of HLA-A, -B, and -DR antigens were observed between the asthma patients and the healthy controls. A significant difference in the frequency of MB3', however, was found between the asthma patients and the healthy controls (corrected p = 0.04, relative risk = 18.5).

Asthma↗

Trichophyton-specific IgE in patients with dermatophytosis is not associated with aeroallergen sensitivity.

BACKGROUND: It has been proposed that Trichophyton infection is associated with atopy and allergy. OBJECTIVES: Our purpose was (1) to confirm whether atopy predisposes to chronic dermatophytosis and (2) to investigate whether Trichophyton infection induces atopic disease. METHODS: Patients attending dermatology clinics and suspected of having dermatomycosis underwent in a prospective manner fungal culture and Trichophyton and inhalant skin tests, and blood serum was collected for total IgE and Trichophyton radioallergosorbent testing. Personal and family history of atopic diseases was also investigated. RESULTS: According to mycologic culture, atopic history, and inhalant skin test results, patients were classified into 4 groups: (1) atopy plus mycosis (n = 28), (2) atopy (n = 26), (3) mycosis (n = 35), and (4) no atopy, no mycosis (n = 33). Patients with active mycosis (groups 1 and 3) demonstrated significantly increased positivity of Trichophyton skin tests compared with patients without fungal infection (groups 2 and 4), regardless of their atopic status, whereas atopic patients (those in groups 1 and 2) had significantly increased levels of total serum IgE compared with nonatopic subjects. Trichophytosis was not more prevalent in atopic than in nonatopic subjects, and atopic diseases were not more frequent in culture-positive than in culture-negative patients. CONCLUSIONS: Our results indicate that Trichophyton -specific IgE is observed in patients with trichophytosis regardless of atopy.

Adolescent↗

IgE antibody response of smokers, nonsmokers, and "smoke-sensitive" persons to tobacco leaf and smoke antigens.

Serum samples from cigarette smokers, nonsmokers, and persons reporting "smoke sensitivity" were tested for IgE antibodies to tobacco leaf and smoke extracts by the radioallergosorbent test. Results indicated that none of the serum samples tested contained detectable IgE antibodies to smoke extracts. Occasionally, serum specimens from smokers or nonsmokers demonstrated reactivity to leaf antigen. The most significant reaction to leaf antigens was detected in serum from one of the 7 smoke-sensitive subjects tested. These results demonstrate that smoking, nonsmoking, and clinical "smoke sensitivity" are not correlated with the presence of IgE antibodies to tobacco leaf or smoke antigen.

Antibody Formation↗

Coughing in pre-school children in general practice: when are RAST's for inhalation allergy indicated?

To identify patterns of clinical history associated with extreme (high or low) probabilities of allergic sensitization in coughing children so as to restrict allergy testing to those with an intermediate probability of sensitization. A total of 752 children, aged 1-4, visiting their GPs for coughing (>or=5 days), were tested for IgE-antibodies to house dust mite, cat and dog [RadioAllergoSorbent Test (RAST)]. Parents completed a questionnaire on family history of atopy, breastfeeding, smoking, pets, and floor covering. Data of 640 children could be analyzed, 83 (13%) were IgE-positive. In a logistic regression analysis, a scoring formula for the prediction of being IgE-positive was constructed using variables from the patient's history. Significant contributors for sensitization were: age (3-4 yr), infantile eczema, positive family history of mite-allergy, sibling(s) with pollen-allergy, and smoking by parents. If only one of these characteristics is present, the probability of sensitization is < 25%. In such cases watchful waiting may be preferred over allergy testing. In other cases, a negative RAST may help to exclude sensitization, whereas a positive RAST helps to establish the diagnosis. Thus, acting on clinical history alone may save approximately 80% of RAST's. Patient history-derived information contributes to distinguishing children who are at low risk for sensitization to house dust mite, cat, and dog. The scoring formula may help GPs to identify children with a low probability of being sensitized. This may form the basis for watchful waiting. In others, allergy testing may be useful to gain more diagnostic certainty.

Allergens↗