Ambrosia artemisiifolia L. temperature-responsive traits influencing the prevalence and severity of pollinosis: a study in controlled conditions.

BACKGROUND: Ambrosia artemisiifolia L. is one of the most important sources of allergenic pollen in many regions of the world. Its health impact increased over the last decades and is expected to further increase in consequence of climate change. However little information is available on the specific role played by temperature on allergy rising. The aim of this work was to evaluate the effect of temperature on A. artemisiifolia growth, flowering and pollen allergenicity, the major plant functional traits influencing the prevalence and severity of pollinosis. RESULTS: Plants were grown in controlled conditions at three thermal regimes: "Low" (LT: 18-14 °C light-dark), "Intermediate" (IT: 24-20 °C light-dark) and "High" (HT: 30-26 °C light-dark). During plant development, plant vegetative and reproductive morpho-functional traits were measured and, at the end of plant life-cycle, mature pollen was collected and analyzed for its allergenic properties by slot blot, 1D- and 2D-western blot (by using a pool of sera from ragweed-allergic patients) and liquid chromatography-tandem mass spectrometry. A. artemisiifolia showed a great development plasticity leading to a broad temperature tolerance. Shoot architecture, growth rate, number of male inflorescence and pollen allergenicity were temperature-responsive traits. Pollen allergenicity increased in parallel with temperature and differences were related to allergen synthesis and Amb a 1-IgE-binding. Flavonoids whose concentration in pollen decreased with the increase of temperature, were recognized as the cause of the negligible Amb a 1-IgE binding in LT pollen. CONCLUSIONS: Results show that temperature governs plant development and pollen allergenicity influencing the temporal and spatial magnitude of subject exposure to allergens.

Evidence of Cross-Reactivity between Different Seed Storage Proteins from Hazelnut (Corylus avellana) and Walnut (Juglans regia) Using Recombinant Allergen Proteins.

Seed storage proteins are extremely stable allergens in nuts, seeds, and legumes and are responsible for the most severe allergic reactions to these foods. The cross-reactivity between seed storage proteins from different sources has not been studied at a molecular level so far. This study aimed to ascertain the cross-reactivity between walnut and hazelnut seed storage proteins using recombinant allergens. Sera from 13 consecutive patients with severe primary walnut and/or hazelnut allergy and hypersensitive to both nuts were studied. IgE specific for rCor a 9, rCor a 14, and rJug r 1 was measured, and inhibition experiments were carried out by measuring IgE reactivity after absorption of patients' sera with freshly prepared walnut extract. All 13 sera showed strong IgE reactivity against walnut 2S albumin, Jug r 1, 12 reacted to hazelnut 2S albumin, Cor a 14, and 8 to the hazelnut legumin, Cor a 9. In inhibition experiments, absorption of sera with whole walnut extract led to the complete disappearance of IgE reactivity to Jug r 1 in 12/13 cases, as expected, but also to the complete disappearance of specific IgE to Cor a 14 in 9/12 sera, and of IgE reactivity to Cor a 9 in 7/8. In the remaining cases a dramatic drop in IgE reactivity was observed. The study shows that patients primarily allergic to either walnut or hazelnut showing a skin or serological reactivity to the other nut also are potentially at risk of severe allergic reactions caused by cross-reactivity between 2S albumins and legumins.

IgE Cross-Reactivity between Humulus japonicus and Humulus lupulus.

PURPOSE: Japanese hop (Humulus japonicus) is a major cause of weed pollinosis in East Asia. However, supplies of commercial allergen extract from this plant have not met clinical demand. The pollen of common hop (Humulus lupulus), a closely related species, may provide an alternative source if there is strong IgE cross-reactivity between these two species. We aimed to compare the IgE cross-reactivity and allergenicity of common hop and Japanese hop pollen. MATERIALS AND METHODS: Cross-reactivity was measured by inhibition ELISA. One- and two-dimensional (2D) gel analyses combined with IgE immunoblotting and mass spectrometry [liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS)] were performed to detect IgE-reactive pollen components. RESULTS: Up to 16.7% of IgE reactivity to Japanese hop was inhibited by common hop. A 12-kDa protein component of Japanese hop pollen that showed the most potent IgE reaction was absent from common hop. Six IgE-reactive components from Japanese hop were detected by 2D gel electrophoresis and LC-ESI-MS/MS, but showed low Mascot scores, preventing positive identification. CONCLUSION: No significant IgE cross-reaction was observed for Japanese and common hop pollen allergens. Development of allergy diagnostic and immunotherapeutic reagents based on Japanese hop pollen are urgently needed.

Aedes communis Reactivity Is Associated with Bee Venom Hypersensitivity: An in vitro and in vivo Study.

Mosquito bite is usually followed by a local reaction, but severe or systemic reaction may, in rare cases, occur. Allergic reactions to Aedes communis (Ac) may be underestimated due to the lack of reliable diagnostic tools. In this multicenter study, 205 individuals reporting large local reactions to Ac were enrolled and studied for cutaneous or IgE reactivity to Ac, Blattella germanica, Penaeus monodon, and Dermatophagoides pteronyssinus. Extract and molecular IgE reactivity to bees, wasps, hornets, and yellow jacket venoms were also studied in 119 patients with a clinical history of adverse reaction to Hymenoptera. Immunoblot (IB) analysis and immunoCAP IgE inhibition experiments were carried out in selected sera. Ac sensitization was recorded in 96 (46.8%) patients on SPT. Strict relationship between Ac and D. pteronyssinus, B. germanica, P. monodon, or Apis mellifera reactivity on SPT was observed. Ac IgE recognition was seen in 60/131 (45.8%) patients, 49 (81.6%) of them SPT positive, and 5/14 IB reactors. Ac IgE sensitization was associated with Tabanus spp, A. mellifera, Vespula vulgaris, and Polistes dominula reactivity. A strict relationship between Ac IgE reactivity and Api m 1, Api m 2, Api m 3, Api m 5, and Api m 10 was recorded. IgE reactivity to AC was inhibited in 9/15 cases after serum absorption with the A. mellifera extract. Both SPT and IgE Ac reactivity is observed in about half of patients with a history of large local reactions to mosquito bites. The significant relationship between Ac sensitization and either extract or single bee venom components is suggestive of a "bee-mosquito syndrome" occurrence.

Vitamin D3 improves the effects of low dose Der p 2 allergoid treatment in Der p 2 sensitized BALB/c mice.

BACKGROUND: Airborne allergens can induce an immunological chronic disease characterized by airway hyper responsiveness and inflammation, mediated by exaggerated Th2 immune response. Allergen-specific immunotherapy (AIT) is effective for treating this condition because it is able to modify its natural course by opposing the underlying pathogenic mechanisms and determining immune suppression, immune deviation and tolerance. The rational for the present study was to investigate the possibility of improving allergoid-based IT in terms of efficacy and safety. Recently, 1α,25-dihydroxyvitamin D3 (VD3), the active metabolite of vitamin D3, was described to be a potent inducer of T regulatory cells and to be a good adjuvant in AIT settings. METHODS: We investigated whether the co-administration of VD3 could potentiate the effect of AIT even when added to a low dose of chemically-modified monomeric allergoid of Der p 2 (d2-OID), in a Derp p 2 (d2)-sensitized BALB/c mice model. Control groups where treated with sham, VD3 alone or d2-OID only. RESULTS: The d2-OID alone was not fully successful, as expected for a low dose. VD3 administration was associated with some valuable, although limited, changes in the immunological parameters in the lung. On the contrary, the VD3 adjuvated allergoid vaccine induced the most prominent reduction of airway eosinophilia and Th2 cytokines and concomitant increase of T regulatory cells and IL-10 in the lung and Der p 2-specific IgG2a in the serum. CONCLUSIONS: The addition of VD3 to a conventional AIT protocol would allow the reduction of allergoid dose needed and therefore, the production costs. Moreover, beneficial immunomodulatory effects have been achieved by the oral administration which might favour the management of the therapy by the patients and their adherence, possibly enhancing the efficacy of the treatment.

Detection of pan-allergens in commercial pollen extracts for allergen immunotherapy.

BACKGROUND: Up to 50% of patients with pollen allergy are sensitized to at least 1 of the 2 pollen pan-allergens profilin and polcalcin. These allergens could have clinical relevance but the content of profilin and polcalcin in commercial extracts for allergen immunotherapy (AIT) is unknown. OBJECTIVE: To detect these pan-allergens in commercial pollen extracts for AIT from various sources. METHODS: Immunoglobulin E (IgE) reactivity to Phl p 7 and Bet v 2 of sera from 18 adults hypersensitive to profilin and/or polcalcin was investigated by enzyme-linked immunosorbent assay before and after absorption with grass, birch, ragweed, pellitory, and olive pollen extracts for AIT from different producers. Immunoblot inhibition experiments also were carried out using the same allergens. RESULTS: Birch, grass, ragweed, and olive pollen extracts for AIT contained large amounts of profilin, inducing 80% to 90% inhibition in most cases; Parietaria AIT extract appeared to contain little profilin. On immunoblot, grass and birch pollen extracts for sublingual AIT completely absorbed IgE specific for rBet v 2. Interestingly, only grass pollen extracts induced a significant inhibition of IgE binding to rPhl p 7 on enzyme-linked immunosorbent assay and immunoblot. A grass pollen allergoid lost most of its inhibitory potency, suggesting a much weakened affinity for specific IgE. CONCLUSION: With the exception of Parietaria, commercial extracts for AIT of most pollens are rich in profilin and, hence, potentially able to desensitize to this allergen; in contrast, only grass pollen extracts seem rich in polcalcin. These are the pollens to use in case of severe symptoms induced by pollen pan-allergens.

Immunotherapy: a new horizon for egg allergy?

Egg allergy is the second most frequent food allergy in children of the Western Countries, with an overall prevalence of 1-3%. Today strict avoidance diet is the only treatment, but its feasibility is difficult to obtain in childhood because of the large amount of egg proteins present in different foods. From 1998, a growing number of protocols on immunotherapy for egg allergy have been published, but all of them differ for patients' age, inclusion of high-risk patients, amount of allergen administered, duration of the protocols and presence of a control group. We reviewed the protocols performed in the last 15 years, to underline the most important issues in this kind of food immunotherapy, and the rates of tolerance or desensitization induction.

rBet v 1 immunotherapy of sensitized mice with Streptococcus thermophilus as vehicle and adjuvant.

Lactobacilli are able to induce upregulation of co-stimulatory molecules in DCs with Th1 cytokines production and increase in Treg activity. This could explain the observed effectiveness of the prolonged administration of lactobacilli in the prevention of allergic disorders in infants and envisage the possible use of bacteria expressing the allergen for the specific immunotherapy of allergic diseases. Hence, we evaluated Streptococcus thermophilus (ST) expressing rBet v 1 as allergen delivery tool and adjuvant factor for immunotherapy in Betv1-sensitized mice. rBet v 1 gene was introduced and expressed in ST (ST[rBet v 1]). BALB/c mice were sensitized with rBet v 1 and then treated with either ST alone, ST[rBet v 1], or the combination of ST and rBet v 1, for 20 days. After 2 aerosol challenges, Treg frequency, in vitro allergen-induced cytokines, rBet v 1-specific IgE and IgG2a, and bronchial histology were made in harvested spleen, sera, and lung. Results were compared with those obtained from not-treated/sensitized mice. ST[rBet v 1] induced immunological and histological changes typical of successful SIT: increased frequency of Tregs and expression of Foxp3; decreased allergen-specific IgE/IgG2a ratio; decrease of in vitro rBet v 1-induced IL-4 from spleen cells; increased allergen-induced IL-10 and IFN-γ; drop of bronchial eosinophilia. ST and ST+rBet v 1 combination, even though induced a slight increase in the frequency of Tregs and moderate allergen-induced IL-10, were ineffective in reducing bronchial eosinophilia, allergen induced IL-4 and rBet v 1-specific IgE/IgG2a ratio. ST[rBet v 1] has tolerogenic and Th-1 skewing properties and efficiently delivers the allergen to the gut immune-system restraining and readdressing the established specific Th2 response toward the allergen in mice.

Chloramine-induced anaphylaxis while showering: a case report.

INTRODUCTION: Sodium-N-chlorine-p-toluene sulfonamide, commonly known as chloramine-T, is a derivative of chlorine which is widely used as a disinfectant. For many years, chloramine-T has been described as a cause of immediate-type hypersensitivity, especially with regard to asthma and rhinitis, and as a cause of occupational dermatoses in cleaning personnel in hospitals, although no anaphylactic reaction has yet been reported. Hence, to the best of our knowledge we present the first case of anaphylaxis to chloramine-T with evidence of specific immunoglobulin E antibodies. CASE PRESENTATION: We describe the case of a 25-year-old Caucasian woman who was in good health and with a negative history for atopy, including no respiratory symptoms of rhinitis or asthma, and with no professional exposure to chloramine-T. She, while showering, applied a chloramine-T solution to a skin area with folliculitis on her leg, and within a few minutes developed generalized urticaria and angioedema, followed by vomiting and collapse with loss of consciousness. A skin prick test with a chloramine-T solution at 10mg/mL concentration was positive, and specific immunoglobulin E to chloramine-T was quantified at a value of 2.9 optical density as measured by the enzyme allergosorbent test technique. CONCLUSION: The strict cause-effect relationship and the results of the skin test and the in vitro test make certain the causative role of chloramine-T in this case of anaphylaxis. This suggests that chloramine-T, based on its wide use as a disinfectant, should be considered a possible cause in anaphylaxis of unknown origin.

Innate and lymphocytic response of birch-allergic patients before and after sublingual immunotherapy.

Functional imbalance in Th1/Th2 cell response toward allergens is a recognized hallmark of allergic patients and a major role of dendritic cells (DCs) in redirecting T-cell phenotypes after specific immunotherapy has been suggested. This study investigates the proliferative and cytokine responses of T cells cocultured with monocyte-derived DCs (MoDCs) after allergen stimulation in birch-allergic patients compared with controls and investigates whether sublingual immunotherapy (SLIT) could change the DC-driven immune response. T cells were stimulated with the major birch pollen allergen (nBet v1) and MoDCs from eight birch-allergic patients with seasonal allergic rhinitis and eight nonallergic controls. Proliferation and cytokine production were measured before and after one course of SLIT with birch allergoid. Significantly lower levels of proinflammatory (IL-1beta, p = 0.027; IL-6, p = 0.030; TNF-alpha, p = 0.019) and Th1 (interferon gamma, p = 0.032; IL-12, p = 0.05) cytokines were measured in supernatants of T cells and MoDCs cultures from allergic patients compared with nonallergic controls. After SLIT, significant increase in IL-12 (p = 0.039), IL-1beta (p = 0.040), IL-6 (p = 0.041), TNF-α (p = 0.048), and IL-10 (p = 0.048) and significant decrease in IL-13 (p = 0.001) were observed. MoDCs/T-cell cocultures, pulsed with the specific allergen, produced lower quantities of proinflammatory and Th1 cytokines in allergic patients compared with healthy subjects, suggesting an allergen-specific impairment of natural immunity and Th1 immune response. A single course of SLIT was able to enhance allergen-specific innate immunity and to modify lymphocyte response, promoting Th1 and T-cell regulatory activity.

Isoform identification, recombinant production and characterization of the allergen lipid transfer protein 1 from pear (Pyr c 3).

Non-specific lipid transfer proteins belonging to LTP1 family represent the most important allergens for non pollen-related allergies to Rosaceae fruits in the Mediterranean area. Peach LTP1 (Pru p 3) is a major allergen and is considered the prototypic allergenic LTP. On the contrary, pear allergy without pollinosis seems to be under-reported when compared to other Rosaceae fruits suggesting that the as-yet-uncharacterized pear LTP1 (Pyr c 3) has in vivo a low allergenicity. We report here on the identification of four cDNAs encoding for LTP1 in pear fruits. The two isoforms exhibiting amino acid sequences most similar to those of peach and apple homologues were obtained as recombinant proteins. Such isoforms exhibited CD spectra and lipid binding ability typical of LTP1 family. Moreover, pear LTP1 mRNA was mainly found in the peel, as previously shown for other Rosaceae fruits. By means of IgE ELISA assays a considerable immunoreactivity of these proteins to LTP-sensitive patient sera was detected, even though allergic reactions after ingestion of pear were not reported in the clinical history of the patients. Finally, the abundance of LTP1 in protein extracts from pear peel, in which LTP1 from Rosaceae fruits is mainly confined, was estimated to be much lower as compared to peach peel. Our data suggest that the two isoforms of pear LTP1 characterized in this study possess biochemical features and IgE-binding ability similar to allergenic LTPs. Their low concentrations in pear might be the cause of the low frequency of LTP-mediated pear allergy.

The nature of melon allergy in ragweed-allergic subjects: A study of 1000 patients.

Previous studies suggest cross-reactivity between specific ragweed pollen and melon allergens. This study was designed to clarify the origin of the cross-reactivity between ragweed pollen and the gourd family. One thousand ragweed-allergic subjects were interviewed about the presence of oral allergy syndrome (OAS) induced by melon or watermelon and were divided into reactive to ≤3 seasonal allergen sources or >3 seasonal allergen sources. Patients reporting melon and/or watermelon allergy underwent a skin-prick test (SPT) with fresh melon and, after 2006, also with profilin-enriched date palm pollen extract. Because no IgE reactivity to melon extract was detected in vitro, ELISA was performed using date palm pollen extract, and inhibition experiments were performed using grass pollen, date palm profilin, and bovine serum albumin (BSA) as inhibitors. Six hundred forty-six and 354 subjects reacted to ≤3 seasonal allergens or >3 seasonal allergens, respectively; 4/646 (1%) and 81/354 (23%) reported a history of melon/watermelon-induced OAS (p < 0.0001). Forty-three of 46 (93%) melon reactors scored positive on SPT with the profilin-enriched extract, which was positive in 0/2 (0%) versus 43/44 (98%) reactive to ≤3 or >3 seasonal allergen sources, respectively (p < 0.0001). in vitro, serum from melon-allergic subjects showed a strong IgE reactivity to the profilin-enriched date palm pollen extract, which was abolished by preabsorption with both grass pollen extract and date palm pollen extract, but not by BSA. In ragweed pollen-allergic subjects, melon allergy is most likely associated with cross-sensitization to the plant pan-allergen profilin and not to specific ragweed pollen allergens. This study confirms the association between profilin sensitization and melon allergy.

Molecular cloning and characterization of Cup a 4, a new allergen from Cupressus arizonica.

Sensitization to Cupressaceae pollen has become one of the most important causes of pollinosis in Western countries during winter and early spring. However, the characterization of the extracts, the allergens involved and the cross-reactivity with other pollen sources still remain poorly studied; in the case of Cupressus arizonica only two allergens have been described so far. A new allergen from C. arizonica pollen, Cup a 4, was cloned and expressed in Escherichia coli as an N-terminally His-tag recombinant protein that was characterized biochemically, immunologically and by circular dichroism spectroscopy. The new allergen has high sequence identity with Prickly Juniper allergen Jun o 4 and contains four EF-hand domains. The recombinant protein has structural similarities with other calcium binding allergens such as Ole e 3, Ole e 8 and Phl p 7. Cup a 4 is expressed in mature pollen grains and shares antigenic properties with the recombinant form. Sera from 9.6% C. arizonica allergic patients contain specific IgE antibodies against recombinant Cup a 4.

Olea sublingual allergoid immunotherapy administered with two different treatment regimens.

Sublingual immunotherapy (SLIT) with monomeric carbamylated allergoid administered in accordance with the standard regimen has proven to be effective and safe. Achieving clinical benefit, however, requires a lengthy period of time so it is not very suitable for short-lasting allergies. We thus performed this study to compare an administration protocol starting in the coseasonal period (with a 4-day build-up phase) with a precoseasonal scheme to verify if the former regimen provides the same benefit in a shorter period of time. The prospective, randomized, drug therapy-controlled study was conducted in 33 rhinitic patients monosensitized to Olea with or without asthma. Ten patients were assigned to the coseasonal therapy with 5000 allergic units (AU)/week for 6 weeks, 11 to the precoseasonal therapy with 3000 AU/week for 10 weeks, and 12 to drug therapy. They were treated from April or May to June 2008. A visual analog scale (VAS) was performed at baseline and after treatment to assess the well being of the patients. Drug consumption was evaluated by means of a monthly diary. There was greater VAS improvement in both the SLIT groups versus the controls, but it was statistically significant only in the coseasonal group (p < 0.01). Furthermore, there was a reduction in the rescue medication only in the coseasonal SLIT (p < 0.05 versus drug therapy). One mild adverse event was observed. The allergoid SLIT was shown to be effective and safe in Olea allergy in particular when a coseasonal regimen was used.