Presence Of Specific IgE Antibodies Research Articles

Case Report: Allergic bronchopulmonary aspergillosis in a 21-year-old female patient with no prior asthma

Hypersensitivity brought on by Aspergillus causes a lung illness known as allergic bronchopulmonary aspergillosis (ABPA). ABPA is a common fungal disease that affects individuals with uncontrolled asthma, cystic fibrosis, and immunocompromised patients. Aspergillus mould species are highly prevalent in the environment, especially in organic waste. There are more than a hundred different species of Aspergillus throughout the world, but the most common offenders are Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, and Aspergillus clavatus. Several Aspergillus species, most notably Aspergillus fumigatus, are responsible for human diseases. Depending on the amount and virulence of inhaled Aspergillus and the host’s genetic vulnerability and immunity, Aspergillus can produce allergic or allergic (Aspergillus-mediated allergies and asthma, hypersensitivity pneumonia, and ABPA pulmonary disorders. Because of its unique appearance, particularly when there is no medical history of asthma, it may be challenging to diagnose in some circumstances. Although side effects from treating ABPA are regularly described, cumulative medication toxicity caused by several compounds is uncommon. It’s essential to make a wise decision among the several compounds that are available and efficient against ABPA. We document a case of ABPA in a female patient who had no prior history of asthma. She had complained about having trouble breathing. The presence of specific IgE antibodies against Aspergillus fumigatus & an elevated eosinophil count were used to make the diagnosis of ABPA.

Пищевая аллергия у детей с атопическим дерматитом (возможности лабораторной диагностики)

Objective - determination of the frequency of manifestation of allergic reactions of reaginic and cellular types in vitro to food allergens in children with atopic dermatitis (AD). Materials and methods. We examined 284 children aged 0 to 14 years: 200 children with AD in 4 age groups and 84 control children. Investigated total IgE, histamine and serotonin in the blood. A semi-quantitative method in ELISA identified specific IgE antibodies to 67 food allergens, and in leukocyte migration capillary tube technique (LMCT) the presence of delayed-type sensitization to 42 food allergens. Results. The levels of total Ig E, histamine and serotonin in children with AD were significantly higher than the control. The average value of positive results for the presence of specific IgE antibodies to any food allergens was 46.2±4.57%. Banana, goat's milk, tomatoes, egg protein and cow's milk casein topped the ranking. According to the results of LMCT, delayed sensitization of the cell type was determined on average in 40.38±4.81% of tests. The leaders were allergens of hake, black coffee, glucose, peas, rye flour, orange, corn flour and peanuts. Conclusions.AD develops in children already at an early age (up to 3 years), with an excess of control values of total serum IgE by 4.8 times (p<0.01), histamine - by 1.3 times (p<0.01), serotonin - 1.2 times (р<0.001). Reaginic and cellular reactions are involved in the occurrence of food sensitization. Methods of laboratory diagnosis of food allergy are preferable to skin tests and allow young children to simultaneously determine sensitization to a large number of allergens.

REACTION OF NASAL POLYPS IN ALLERGEN-SPECIFIC IMMUNOTHERAPY WITH FUNGAL ALLERGENS IN PATIENTS WITH NASAL POLYPS ON THE BACKGROUND OF FUNGAL SENSITIZATION

Fungal flora is one of the causes of inflammation, including nasal polyposis. Therefore, researches aimed at reducing the impact of fungal sensitization (FS) on the course of chronic rhinosinusitis with nasal polyps (CRSwNP) are relevant.
 The research included 90 patients with chronic rhinosinusitis with nasal polyps combined with fungal sensitization. The patients were divided into two groups — the first clinical group (G1) and the second clinical group (G2). Group G1 received allergen-specific immunotherapy (ASIT) according to the scheme. Group G2 received basic treatment according to the protocol № 181 of 24.03.2009 (“Protocol for providing medical care to patients with chronic sinusitis”). Indications for allergen-specific therapy were hyperreactivity to fungi (positive allergy history of FS), the presence of specific IgE antibodies to fungal allergens, positive skin tests with fungal allergens, and high levels of total IgE. The research aimed to evaluate the effect of allergen-specific therapy on nasal polyps in patients with CRSwNP on the background of fungal sensitization. The specific oral treatment was carried out in two phases: the first — cumulative or initial, and the second — maintaining, in which the maximum tolerated dose was reached by gradually increasing the allergen concentration. The first phase duration was about 2.5–3 months. In the second phase, which lasted up to 6 months, the patient received the maximum allowable dose of the allergen to achieve a state of persistent hyposensitization. The therapeutic allergen was administered in the morning, 30 minutes before meals. The right amount of drops were dosed per teaspoon from the bottle with the allergen.
 Treatment was initiated during the period of clinical remission. ASIT was performed with basic anti-inflammatory treatment. The treatment efficiency was evaluated after 3, 6, and 12 months of treatment.
 Evaluation of the clinical efficiency of allergen-specific immunotherapy was made on the 4-point scale, where excellent results (4 points) — complete remission of the disease during the follow-up period (6-12 months); good results (3 points) — exacerbation of the disease 1-2 times per year, in mild form and removed by expectant treatment; fair results (2 points) — the number of exacerbations did not decrease, poor results (1 point) treatment is stopped due to lack of effect or the patient's symptoms constantly worsen after the introduction of an allergen. The size and distribution of nasal polyps were assessed by the results of nasal endoscopy using the IV-grade scale: I degree - polyps are not visible on endoscopic examination but present on CT scan; II degree - polyps visible in the middle nasal passages; III degree - polyps visible outside the middle nasal passages; IV - degree – nasal polyps obturate the nasal cavity.
 Improvement of nasal endoscopy picture (the number of G1 patients diagnosed with stage III of nasal polyps after 12 months decreased by 11.1%), reducing the volume of basic therapy. Satisfactory treatment results were determined in 13.8% of patients, in whom the number of exacerbations did not decrease, but the general well-being became much better than before specific immunotherapy, which indicates a stable effect after the treatment.
 Conclusions. The results conclude that the use of ASIT treatment is pathogenetically justified and significantly improves the clinical condition and quality of life in patients with chronic rhinosinusitis with nasal polyps and fungal sensitization.
 The severity of the polypous process in G1 patients was 1.6 times lower compared to G2, which contributed to the positive clinical effect of treatment in 86.1% of patients.
 The conducted research has shown high efficacy, good tolerability, and safety of the non-invasive method of treatment (ASIT) in chronic rhinosinusitis with nasal polyps and fungal sensitization.

Identification and molecular characterization of a novel non-specific lipid transfer protein (TdLTP2) from durum wheat.

Non-specific lipid transfer proteins (nsLTPs) are small, cysteine-rich proteins, a part of the pathogenesis-related protein family, and numerous of them act as positive regulators during plant disease resistance, growth, and reproduction. These proteins are involved also in the intracellular transfer of lipids, as well as in plant immune responses. Besides their differences in sequences, they show similar features in their structure. However, they show distinct lipid-binding specificities signifying their various biological roles that dictate further structural study. This study reports the identification, in silico characterization and purification of a novel member of the nsLTP2 protein family from durum wheat, TdLTP2. It was generated and purified using the combination of gel filtration chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). Its identity was detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry (MALDI-TOF). TdLTP2 had been expressed in different stress to detect its localization; therefore, fluor-immunolocalization studies accomplished this data. In this approach, to assess the allergenicity of TdLTP2, thirty patients with baker’s asthma were enrolled and ELISA to detect the presence of specific IgE antibodies tested their sera. Moreover, the lipid-binding properties of TdLTP2 were examined in vitro and validated using a molecular docking study. In summary, our results demonstrate a new addition of member in plant nsLTPs family, TdLTP2, which can develop a better understanding about its biological functions and shed light on future applications.

Allergenicity to worldwide invasive grass Cortaderia selloana as environmental risk to public health

Allergies to grass pollen affects about 20% of the population worldwide. In the last few decades, the South American grass Cortaderia selloana (CS, Pampas grass) has expanded worldwide in a variety of countries including the USA, Australia and Western Europe. In many of these locations, CS has strikingly spread and has now been classified an invasive species. Many pernicious consequences of CS have been reported for local biodiversity, landscape and structures. However, the effect on human health has not been studied. To investigate this issue, we have chosen a European region on the northern cost of Spain where CS spread is overwhelming, Cantabria. We obtained CS pollen extract and analysed the allergenic reaction of 98 patients that were allergic to pollen of local grasses. We determined the skin reaction and the presence of specific IgE antibodies (sIgE) to CS or to a typical autochthonous grass, Phleum pratense. We also compared the seasonal symptoms with reported grass pollen counts in the area. The results strongly suggest that CS can cause respiratory allergies at a similar extent to the local grasses. Given that CS pollinises later than the local grasses, this would extend the period of grass allergies in the region for about three months every year, as stated by most of the patients. This is the first study reported on the effects of the striking expansion of CS on human health. Considering the strong impact that respiratory allergies have on the population, our results suggest that CS can currently constitute a relevant environmental health issue.

A novel MRGPRX2-targeting antagonistic DNA aptamer inhibits histamine release and prevents mast cell-mediated anaphylaxis

Anaphylaxis during general anaesthesia is a significant clinical challenge for anaesthesiologists. Approximately 50% of perioperative anaphylaxis cases lack the presence of specific IgE antibodies. Mas-related G-protein coupled receptor X2 (MRGPRX2) in humans and its mouse orthologue Mas-related G-protein coupled receptor B2 (Mrgprb2) are crucial receptors in non-IgE-dependent histamine release. Anaesthetics such as rocuronium and atracurium cause perioperative anaphylaxis by activating histamine release via the Mrgprb2 pathway. We hypothesized that antagonistic DNA aptamers that target MRGPRX2 can prevent perioperative anaphylaxis. Selection of a DNA aptamer that specifically binds MRGPRX2 was achieved by using our modified Systematic Evolution of Ligands by Exponential enrichment (SELEX) approach. Our SELEX process used MRGPRX2-proteoliposomes synthesised by a wheat germ cell-free system as templates. The activity of the selected aptamer to inhibit histamine release from MRGPRX2-activated mast cells and in an anaphylaxis rat model transplanted with this cell line was examined. Our selection process identified aptamer-X35 with the sequence 5′-ATGACCATGACCCTCCACACTGTAGGCACCACGGGTCCCTGGCAGTTAAAAGTACGTTTGTCAGACTGTGGCAGGGAAACA-3'. In silico 2D modelling of aptamer-X35 revealed a structure with a small loop and a long stem. Aptamer-X35 inhibited histamine release from mast cells by 70%. Subcutaneous injection of 30 nmol of aptamer-X35 inhibited the anaphylactic reaction in the rat anaphylaxis model.This study demonstrated that aptamer-X35 selected by the modified SELEX approach reduced histamine release by inhibiting the MRGPRX2 pathway. Overall, our findings establish aptamer-X35 as a potential therapeutic candidate against perioperative anaphylaxis.

EPIDEMIOLOGICAL ASPECTS OF CCD-POSITIVITY IN PATIENTS WITH CLINICAL MANIFESTATIONS OF ALLERGY IN THE SOUTH-WESTERN REGION OF UKRAINE

Patients with antibodies to CCD, when tested for the presence of specific IgE antibodies to allergen extracts, may exhibit a large number of positive reactions.Objective - to determine the epidemiological aspects of CCD-positivity in patients with clinical manifestations of allergy in the South-Western region of Ukraine.Material and methods. Results of serological examination of 500 patients with allergic manifestations were estimated and antibodies to different carbohydrate determinants using CCD blot determined.Results. It has been shown that antibodies to cross-reactive carbohydrate determinants are detected in 17.8±1.71% of patients with clinical manifestations of allergy. Antibodies to CCD are recorded in 10.71±2.20%, of patients aged 0-10 years, they are significantly higher in patients older than 10 years, on the average 22.00±5.45%. A direct correlation relationship (r=0.88) was determined between the class of reaction to CCD and the number of positive reactions to allergens. In the group of patients with multiple allergen reactions, 73.7±7.14% showed positive reactions to different CCD chains during additional examination on the linear CCD blot. In a separate analysis of CCD-positive patients on the linear CCD-blot, it was shown that antibodies to horse radish peroxidase were significantly higher than to bromelain (p<0.01) and ascorbate oxidase (p<0.05). The same pattern was observed in patients with multiple allergen reactions. Conclusions. The results of the studies indicate that it is necessary to take into account the possibility of non-specific reactions related to cross-reactive carbohydrate determinants and additionally test patients for the presence of antibodies to CCD, especially in the case of multiple reactions to allergens.

P060A MICA typing by NGS revealed the association of MICA GENE polymorphism with specific IgE production in cedar pollen allergy

Aim We have found the association of Japanese Cedar Pollinosis (JCPsis) with SNPs near MICA gene by SNPs typing in HLA gene region. In this study, the association was clarified by MICA gene typing using amplicon sequenceing method by NGS. Methods DNAs from 178 JCPsis patients, 185 healthy controls were tested allele types of MICA and HLA by HLA and KIR typing Kit (Scisco Genetics Inc) on MiSeq (Illumina Inc,). Serum samples from them were titrated for the presence of specific IgE antibodies to Japanese cedar pollen(JCP), orchard grass pollen, mugwort pollen, & house dust mite by radioallergosorbent test. Results Though all controls were selected not to have any symptom of pollinosis, only 101 in 185 individuals were specific IgE negative to all allergens tested, and 84 individuals were positive to one or more allergens including JCP. Therefore, the control group was divided into two groups, specific IgE negative and positive to allergens. The significant association of MICA with JCPsis was found only in analysis using IgE negative control group. IgE positive control group showed no association. MICA*008((P = 0.0036, odds = 0.5) & MICA*027 (P = 0.016, odds = 0.55) showed strong reverse association. Conclusions MICA*008 is lacked a part of trans-membrane region and produce soluble protein. Furthermore, 008 and 027 has the haplotype of 175Gly, 213 Ile, 251Arg which are reported to relate with MICA shedding. This haplotype associate with JCPsis strongly (P = 0.0000399, Odds = 0.46). It is speculated that soluble MICA may suppress IgE production by binding NKG2D and inactivating NK cell, and suppress pollinosis. This speculation is also supported by the report that NKG2D is critical for allergy.

Dissociation between skin test reactivity and anti-aeroallergen IgE: Determinants among urban Brazilian children.

BackgroundThe dissociation between specific IgE and skin prick test reactivity to aeroallergens, a common finding in populations living in low and middle-income countries, has important implications for the diagnosis and treatment of allergic diseases. Few studies have investigated the determinants of this dissociation. In the present study, we explored potential factors explaining this dissociation in children living in an urban area of Northeast Brazil, focusing in particular on factors associated with poor hygiene.MethodsOf 1445 children from low income communities, investigated for risk factors of allergies, we studied 481 with specific IgE antibodies to any of Blomia tropicalis, Dermatophagoides pteronyssinus, Periplaneta americana and Blatella germanica allergens. Data on demographic, environmental and social exposures were collected by questionnaire; serum IgG and stool examinations were done to detect current or past infections with viral, bacterial, protozoan and intestinal helminth pathogens. We measured atopy by skin prick testing (SPT) and specific IgE (sIgE) to aerollergens in serum (by ImmunoCAP). SIgE reactivity to B. tropicalis extract depleted of carbohydrates was measured by an in-house ELISA. Total IgE was measured by in house capture ELISA. SNPs were typed using Illumina Omni 2.5.ResultsNegative skin prick tests in the presence of specific IgE antibodies were frequent. Factors independently associated with a reduced frequency of positive skin prick tests were large number of siblings, the presence of IgG to herpes simplex virus, Ascaris lumbricoides and Trichuris trichiura infections, living in neighborhoods with infrequent garbage collection, presence of rodents and cats in the household and sIgE reactivity to glycosylated B. tropicalis allergens. Also, SNP on IGHE (rs61737468) was negatively associated with SPT reactivity.ConclusionsA variety of factors were found to be associated with decreased frequency of SPT such as unhygienic living conditions, infections, total IgE, IgE response to glycosylated allergens and genetic polymorphisms, indicating that multiple mechanisms may be involved. Our data, showing that exposures to an unhygienic environment and childhood infections modulate immediate allergen skin test reactivity, provide support for the “hygiene hypothesis”.

Sensitising effects of genetically modified enzymes used in flavour, fragrance, detergence and pharmaceutical production: cross-sectional study

ObjectivesThe use of genetically engineered enzymes in the synthesis of flavourings, fragrances and other applications has increased tremendously. There is, however, a paucity of data on sensitisation and/or allergy to...

IgE in the diagnosis and treatment of allergic disease

Traditionally, the concept of allergy implied an abnormal response to an otherwise benign agent (eg, pollen or food), with an easily identifiable relationship between exposure and disease. However, there are syndromes in which the relationship between exposure to the relevant allergen and the "allergic" disease is not clear. In these cases the presence of specific IgE antibodies can play an important role in identifying the relevant allergen and provide a guide to therapy. Good examples include chronic asthma and exposure to perennial indoor allergens and asthma related to fungal infection. Finally, we are increasingly aware of forms of food allergy in which the relationship between exposure and the disease is delayed by 3 to 6hours or longer. Three forms of food allergy with distinct clinical features are now well recognized. These are (1) anaphylactic sensitivity to peanut, (2) eosinophilic esophagitis related to cow's milk, and (3) delayed anaphylaxis to red meat. In these syndromes the immunology of the response is dramatically different. Peanut and galactose α-1,3-galactose (alpha-gal) are characterized by high- or very high-titer IgE antibodies for Ara h 2 and alpha-gal, respectively. By contrast, eosinophilic esophagitis is characterized by low levels of IgE specific for milk proteins with high- or very high-titer IgG4 to the same proteins. The recent finding is that patients with alpha-gal syndrome do not have detectable IgG4 to the oligosaccharide. Thus the serum results not only identify relevant antigens but also provide a guide to the nature of the immune response.

Allergenic pollen in the atmosphere of Rohtak city, Haryana (India): a pioneer study

An attempt has been made in the present study to assess the allergenicity of dominant pollen types recorded from the atmosphere of Rohtak city. Skin prick test was performed with the antigenic extracts of 22 pollen types on 150 local patients who visited Asthma Clinic, University of Health Sciences, Rohtak. Markedly positive skin reactions (2+ and above) varied from 4.6 to 20.6 % to various pollen antigens. Cenchrus ciliaria (20.6 %), Zea mays (20 %) and Pennisetum typhoides (19.3 %) were the pollen allergens exhibiting maximum sensitivity. Antigenic extract of Cassia occidentalis, Cynodon dactylon and Ricinus communis showed marked skin reactivity in 18.6 % of patients. Prosopis juliflora, Chenopodium murale, Amaranthus spinosus, Cassia fistula and Cassia siamea showed 2+ and above reactions in 16.6, 15.3, 14.6 and 14.0 % of the local patients, respectively. Least reactivity (4.6 %) was shown to the antigenic extract of Cyperus rotundus. Out of 52 sera screened for the presence of specific IgE antibodies against different antigenic extracts, only 5.5 % showed >60 % binding. About 30 % and above binding was shown to the antigenic extracts of Z. mays, A. spinosus, R. communis and Xanthium strumarium. The concordance between positive skin reaction and serum-specific IgE antibodies ranged from 15 to 69 %.

Low sensitivity of commercially available rApi m 1 for diagnosis of honeybee venom allergy

Low sensitivity of commercially available rApi m 1 for diagnosis of honeybee venom allergy

Immunoglobulin E antibody reactivity to bacterial antigens in atopic dermatitis patients

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting up to 20% children and 9% adults world-wide. AD patients are often sensitized against a broad variety of allergens and more than 90% of them suffer from skin superinfections with Staphylococcus aureus.In this study, we searched for the presence of specific IgE antibodies against S. aureus and Escherichia coli antigens in AD patients.Sera from AD patients (n=79), patients suffering only from allergic rhinoconjunctivitis (n=41) or allergic asthma (n=37) were tested for IgE reactivity to nitrocellulose-blotted S. aureus, E. coli and gut bacterial antigens. IgE-reactive bacterial antigens were affinity purified and identified by mass spectrometry.More than 30% of AD patients but not patients suffering only from allergic rhinoconjunctivitis and asthma or non-allergic persons exhibited IgE binding to several protein antigens among them DNA-binding and ribosomal proteins and flagellin. Patients with severe skin manifestations showed more frequently IgE reactivity to S. aureus compared with AD patients with mild symptoms. Positive immediate and late skin test reactions could be induced in sensitized AD patients with S. aureus extract.Specific IgE reactivities against a variety of bacterial antigens were observed in a subgroup comprising a third of AD patients and may contribute to allergic inflammation.

Presence Of Specific IgE Antibodies To Ovomucoid In Infants With High Levels Of Egg White-specific IgE; A Marker For Persistence Of Egg Allergy?

RATIONALE: The majority of children with egg allergy develop tolerance in early childhood. The purpose of this study was to determine the immunological differences between the infants who developed egg tolerance and the children with persistent egg allergy. In our previous study, the cutoff point for the egg white (EW) specific IgE level at initial evaluation for outgrowing the allergy at age 5 years was 23.25 KUA/L.

Identification of Covalent Binding Sites of Phthalic Anhydride in Human Hemoglobin

Phthalic anhydride (PA) is a reactive low molecular weight compound used in the chemical industry. The exposure of PA may lead to work-related airway diseases such as rhinitis, chronic bronchitis, and asthma. The exposure gives rise to an increase in hapten-specific IgG antibodies in workers but with a low presence of specific IgE antibodies. In this study, the binding of PA to human hemoglobin (Hb) in vitro was investigated. Trypsin and Pronase E digestion, LC, LC/MS/MS, GC/MS analysis, and nanoelectrospray hybrid quadrupole time-of-flight MS were used to identify the adducted amino acids of the synthesized PA-Hb conjugates. In the conjugate with the molar ratio 1:0.1, a total of six adducted amino acids were identified. N-Terminal valine was found adducted in both the alpha- and the beta-chains as well as a total of four lysines, Val 1, Lys 16, and Lys 61 on the alpha-chain and Val 1, Lys 66, and Lys 144 on the beta-chain. Two types of lysine adducts were found, a phthalamide and a phthalimide. It was also found that PA differs in its binding site as compared to hexahydrophthalic anhydride. The result of this study suggests several interesting applications of biological monitoring.

Evaluation of the Levels of Specific IgE against Cryptococcus diffluens and Cryptococcus liquefaciens in Patients with Atopic Dermatitis

Cryptococcus diffluens and Cryptococcus liquefaciens, 2 basidiomycetous yeasts, frequently colonize the skin of patients with atopic dermatitis (AD). In this study, we investigated the presence of specific IgE antibodies against C. diffluens and C. liquefaciens in the sera of AD patients by using an enzyme immunoassay . Of the 122 AD serum samples tested, 43 (35.2%) and 50 (41.0%) were positive for specific IgE antibodies against C. diffluens and C. liquefaciens, respectively. The levels of specific IgE against the C. diffluens antigen and that against the C. liquefaciens antigen were strongly correlated (r=0.96). In contrast, no remarkable correlation was observed between the levels of specific IgE against the 2 Cryptococcus species and that of specific IgE against Malassezia restricta. Competitive enzyme-linked immunosorbent assay (ELISA) inhibition tests revealed that C. diffluens and C. liquefaciens shared common antigens. This finding was consistent with the IgE immunoblotting data which demonstrated that several IgE-binding proteins with molecular masses of 77, 54, and 30 kDa were recognized in both C. diffluens and C. liquefaciens antigens . These results suggest that fungal components from C. diffluens and C. liquefaciens may act as allergens and play a role in the pathogenesis of AD.

Continued need of appropriate betalactam‐derived skin test reagents for the management of allergy to betalactams

Immediate allergic reactions to betalactams (BLs) are due to IgE antibodies that recognize the ring-derived penicilloyl determinant or side-chain structures of common BLs. The presence of specific IgE antibodies can be demonstrated by skin testing, the determination of specific IgE antibodies in sera or their binding to basophils with subsequent activation upon contact with penicillins in vitro. Skin tests are still the most sensitive technique followed by in vitro tests, which may sometimes yield useful complementary information. The diversity of the response to BLs has meant that in some instances, in addition to benzylpenicillin-derived determinants, testing for amoxycillin, cephalosporins or other BLs may also be required to establish the diagnosis. The recent withdrawal from the market of BL-derived materials for skin testing will have a serious effect on public health, resulting in a return to the pre-1960 era before these reagents became available. Because of their greater sensitivity, these skin tests cannot yet be replaced by in vitro tests. Furthermore, skin tests are the most readily available form of allergy testing for physicians. This paper reviews the results of skin tests in BL allergy and provides evidence for their continued need.

Food allergy: nuts and tree nuts

Nuts are a well-defined cause of food allergy, which affect approximately 1 % of the general population in the UK and the USA. There do appear to be differences in the frequency of nut allergy between different countries because of different dietary habits and cooking procedures. For example, in the USA and France, peanuts are one of the most frequent causes of food allergy, but in other countries, it seems to be less common. Genetic factors, in particular, appear to play a role in the development of peanut allergy. While the majority of nut allergens are seed storage proteins, other nut allergens are profilins and pathogenesis-related protein homologues, considered as panallergens because of their widespread distribution in plants. The presence of specific IgE antibodies to several nuts is a common clinical finding, but the clinical relevance of this cross-reactivity is usually limited. Allergic reactions to nuts appear to be particularly severe, sometimes even life-threatening, and fatal reactions following their ingestion have been documented. Food allergy is diagnosed by identifying an underlying immunological mechanism (i.e. allergic testing), and establishing a causal relationship between food ingestion and symptoms (i.e. oral challenges). In natural history investigations carried out in peanut-allergic children, approximately 20 % of the cases outgrew their allergy or developed oral tolerance. The treatment of nut allergies should include patient and family education about avoiding all presentations of the food and the potential for a severe reaction caused by accidental ingestion. Patients and families should be instructed how to recognise early symptoms of an allergic reaction and how to treat severe anaphylaxis promptly.

Immunological characterization of a recombinant tropomyosin from a new indoor source, Lepisma saccharina

The presence of specific IgE antibodies to invertebrates is common among patients with rhinitis and asthma. Tropomyosin has been described as an invertebrate cross-reactive allergen. We have recently characterized an allergenic extract from silverfish (Lepisma saccharina). Since this insect could be a new source of tropomyosin in the indoor environment, we have thought important to clone and characterize the tropomyosin from it. Recombinant tropomyosin was cloned and characterized by means of immunoblotting with tropomyosin-specific monoclonal antibodies, rabbit polyclonal antibodies and IgE from allergic patients. Its allergenic activity was investigated in histamine release assays. Immunoblotting and ELISA inhibition were carried out to identify the natural tropomyosin in the silverfish extract and to study the cross-reactivity among other arthropod tropomyosins. Tropomyosin-specific antibodies recognized in immunoblotting the natural tropomyosin in the insoluble fraction of silverfish extract. The silverfish tropomyosin (Lep s 1) was cloned and fully expressed. It shared high homology with other arthropod tropomyosins. rLep s 1 was recognized by tropomyosin-specific monoclonal and polyclonal antibodies and by IgE of allergic patients. It was able to inhibit the IgE binding to the insoluble fraction of silverfish extract, and to induce histamine release by an arthropod-allergic serum. Inhibition experiments revealed IgE cross-reactivity between rLep s 1 and other arthropod tropomyosins. rLep s 1 is the first allergen cloned and characterized from silverfish extract. It enabled us to identify the natural counterpart in the insoluble fraction of silverfish extract, suggesting that the tropomyosin is not readily extractable with a classic aqueous extraction procedure. rLep s 1 displayed biological activity, suggesting that it could be regarded as a useful tool to study the role of silverfish tropomyosin in the sensitization to invertebrate allergic sources.