R. E. Rossi

Prevalence of Serum IgE Antibodies to the Staphylococcus aureus Enterotoxins (SAE, SEB, SEC, SED, TSST-1) in Patients with Persistent Allergic Rhinitis

Background: Enterotoxins produced by Staphylococcus aureus and their specific IgE antibodies were thought to be important in worsening atopic dermatitis. However, few studies have documented an association between S. aureus or its exotoxins and exacerbations of upper airway/nasal disease. In the current study, we determined the prevalence of serum-specific IgE towards staphylococcal enterotoxin A, B, C, D (SEA, SEB, SEC, SED) and toxic shock syndrome toxin 1 (TSST-1) in patients suffering from rhinitis and/or asthma due to allergy. Therefore, we examined whether SEA, SEB, SEC, SED and TSST-1 were important in worsening the clinical status of patients allergic to house dust mites by means of assessing serum eosinophil cationic protein (ECP), which is thought to be a reliable marker of asthma and rhinitis severity. Methods: 198 patients with persistent allergic rhinitis and/or asthma due to house dust mites were evaluated. Specific IgE towards SEA, SEB, SEC, SED, TSST-1, timothy grass and birch pollen recombinant allergens, and other aeroallergen extracts from common allergen sources were evaluated by the Pharmacia CAP System. Serum ECP was assessed, too. Results: The percentages of sensitization to staphylococcal enterotoxins of 198 house dust mite-allergic patients were as follows: TSST-1-specific IgE 24.7% (n = 49), SEC-specific IgE 22.2% (n = 44), SEB-specific IgE 15.1% (n = 30), SEA-specific IgE 9.1% (n = 18), and SED-specific IgE 5.5% (n = 11). Out of 198 individuals allergic to house dust mites 136 patients suffering from persistent rhinitis were subdivided into two subgroups: 53 patients with serum-specific IgE to at least one staphylococcal enterotoxin and 83 patients without specific IgE towards staphylococcal enterotoxins. Patients sensitive to staphylococcal enterotoxins had higher serum ECP levels than patients lacking specific IgE to SEA, SEB, SEC, SED and TSST-1(geometric mean 24.3 vs. 16.6 µg/100 ml; p = 0.029), as well as total IgE levels (geometric mean 564 vs. 161 kU/l, p = 0.00063) and specific IgE to Dermatophagoides pteronyssinus (geometric mean 16.7 vs. 6.6 kU/l; p = 0.0235) and Dermatophagoides farinae (geometric mean 18.6 vs. 7.8 kU/l; p = 0.0246). Conclusion: A status of sensitization to staphylococcal enterotoxins seems to be a factor increasing serum ECP, which is thought to be a reliable marker of clinical severity of allergic disease. Therefore, the evaluation of SEA, SEB, SEC, SED and TSST-1-specific IgE antibodies may have additional significance for the prognosis of persistent allergic diseases of the upper airway.

Measurement of IgE antibodies against purified grass-pollen allergens (Phl p 1, 2, 3, 4, 5, 6, 7, 11, and 12) in sera of patients allergic to grass pollen.

Background: Current allergy diagnosis is performed with allergen extracts which contain a variety of allergenic and nonallergenic components. The availability of highly purified and well‐characterized allergen molecules seems to be an advantage of component‐based diagnosis.

The IgE repertoire in children and adolescents resolved at component level: a cross-sectional study.

To cite this article: Melioli G, Marcomini L, Agazzi A, Bazurro G, Tosca M, Rossi GA, Minale P, Rossi R, Reggiardo G, Canonica GW, Passalacqua G. The IgE repertoire in children and adolescents resolved at component level: A cross‐sectional study. 
Pediatr Allergy Immunol 2012: 23: 433–440.

Detection of specific IgE antibodies in the sera of patients allergic to birch pollen using recombinant allergens Bet v 1, Bet v 2, Bet v 4: evaluation of different IgE reactivity profiles

Background:  Birch pollen is a significant cause of immediate hypersensitivity among susceptible subjects in temperate climates, affecting 5–54% of the population in western Europe. We examined the specific serum IgE antibodies towards recombinant allergens Bet v 1, Bet v 2 and Bet v 4 in birch‐sensitive patients from the province of Cuneo, north‐west Italy.

Evaluation of Recombinant and Native Timothy Pollen (rPhl p 1, 2, 5, 6, 7, 11, 12 and nPhl p 4)- Specific IgG4 Antibodies Induced by Subcutaneous Immunotherapy with Timothy Pollen Extract in Allergic Patients

Background: Allergen immunotherapy is a widely accepted treatment for IgE-mediated allergies. The evaluation of immunotherapy-induced IgG4 antibodies based on allergen extract is questionable because the amount of allergen-extract-specific IgG4 to individual disease-eliciting allergens cannot be determined using crude allergen extracts. In this study, we examined the specific IgE and IgG4 serum binding profiles to individual Phleum pratense allergens in grass-pollen-sensitive patients who had received grass-pollen-specific immunotherapy (SIT). Methods: The study included 33 patients from North-West Italy. All suffered from seasonal rhinoconjunctivitis and/or asthma. A modified ‘cluster’ regimen of injections of a standardized aluminium-adsorbed P.pratense extract, with once-weekly visits and 10 injections for 5 weeks followed by 3 weeks of maintenance injections was instituted. Patients’ sera were analyzed for specific IgE and IgG4 reactivity to individual P. pratense allergens (recombinant Phl p 1, Phl p 2, Phl p 5, Phl p 6, Phl p 7, Phl p 11, Phl p12 and native Phl p 4) and natural P. pratense extract using the Pharmacia CAP system. Results: IgE reactivities to new allergen components were not detected by CAP in treated patients after 15 weeks and a cumulative dose of approximately 65 µg of the major allergen Phl p 5. Patients lacking specific IgE reactivity towards individual allergens at the start of SIT did not produce significant levels of specific serum IgG4 to serum IgE-negative allergens. On the other hand, an increase in specific IgG4 only to allergens to which patients were previously sensitized was observed. Significant increases in specific IgG4 levels to rPhl p 1 (p < 0.05), 2 (p < (0.01), 5 (p < 0.0001), 6 (p < 0.0001), 7 (p < 0.05), 11 (p < 0.05) and nPhl p 4 (p < 0.01) were observed after P. pratense extract immunotherapy. No significant rPhl p 12-specific IgG4 antibody increase was documented after treatment. Conclusion: These findings suggest that Phl p 12 was underrepresented in the extract used, as indicated by the low specific IgG4 response induced by this grass-pollen-specific vaccine. Thus, the simple detection of specific serum IgG4 antibodies a few weeks after the start of SIT could represent a valuable tool to estimate the presence of relevant allergens in a given immunotherapeutic allergen extract.

Effect of sublingual immunotherapy with grass monomeric allergoid on allergen-specific T-cell proliferation and interleukin 10 production

BACKGROUND Sublingual immunotherapy (SLIT) is safe and efficacious in the treatment of patients with allergic rhinitis. Although favorable clinical effects have been observed with controlled trials as early as a few months since the beginning of treatment, few biological changes induced by SLIT have been demonstrated. OBJECTIVE To investigate in grass-allergic patients the effect of a 2-month SLIT regimen, administered with a simplified protocol without up-dosing, on proliferation and production of cytokines characteristic of the regulatory T-cell phenotype (interleukin 10 [IL-10] and transforming growth factor beta [TGF-beta]) by allergen-specific T cells. METHODS Patients were recruited to the study in January 2006. SLIT was performed by self-administration and was continued for 60 days from February to April 2006. Eleven grass pollen-allergic patients with seasonal rhinitis were treated daily before the pollen season for 2 months with a modified allergen (monomeric allergoid) derived from a 3-grass pollen extract. Allergen-specific proliferation and production of IL-10 and TGF-beta were measured on peripheral blood mononuclear cells at baseline and treatment end. Tetanus toxoid served as the control antigen. RESULTS After SLIT, allergen-specific (P = .002) but not tetanus toxoid-specific proliferation decreased, whereas IL-10 transcription increased (P < .001). TGB-beta transcription was also increased after treatment, although not statistically significantly (P = .06). Changes in proliferation to allergen and in IL-10 transcription were correlated (r = -0.82, P = .003). CONCLUSIONS A short-term course of SLIT with modified allergen in grass-allergic patients is associated with the reduction of allergen-specific proliferation and with the up-regulation of the IL-10 regulatory cytokine.

Systemic reactions to peach are associated with high levels of specific IgE to Pru p 3

Allergy to fruits belonging to the Rosaceae family is common in the adult population of the Mediterranean area, with peach and apple being the fruits more frequently responsible. The main allergenic proteins involved are Bet v 1 omologues, profilins, and lipid transfer proteins (LTPs) (1, 2). Plant LTPs are basic polypeptides of 9 kDa (91–95 amino acid), which have been identified as relevant allergens in several foods and pollens (3). Of note, LTPs are highly resistant to both gastric digestion and heat, and seem therefore to be associated to more severe and/or systemic symptoms, and capable of inducing sensitization in fruit-allergic patients without an associated pollinosis (4). This study was aimed to verify whether the severity of the clinical reactions to peach fruits is associated to sensitization towards allergenic LTP molecules, namely the LTP Pru p 3, the Bet v 1-related protein Pru p 1, and the profilin Pru p 4. Among outpatients referred to our Allergy Unit, subjects with adverse reactions due to the ingestion of fresh peaches and/or peach juices were identified. Those patients were divided, according to the severity of reaction into: subjects with systemic symptoms including urticaria, angioedema, asthma rhinitis or anaphylaxis and subjects with oral allergy syndrome (OAS) only. A control group of patients with respiratory allergy and no symptom of food allergy was also included. All patients underwent a complete diagnostic work-up including skin prick tests with a panel of common food/ inhalant commercial extracts and CAP assay (Phadia Diagnostics, Milan, Italy). The CAP assay was carried out with the following recombinant (r) or natural (n) allergens: rBet v 1, rBet v 2, rBet v 4, rPhl p 1, 2, 5b, 6, 7, 11, 12, nPhl p 4, rArt v 1, rPar j 2, rAmb a 1, rAlt a 1, rFel d 1 and Dermatophagoides pteronissinus extract. A statistical analysis was carried out in order to verify if the three groups of patients displayed significant differences in the LTP-specific IgE. Forty-six patients were studied, according to the criteria mentioned above. Seventeen patients (mean age 25.8 years, 7 male, total IgE 722 ± 101 kU/l) had systemic symptoms with peach, 12 patients (mean age 26.9 years, 8 male, total IgE 408 ± 280 kU/l) had OAS, and 17 subjects (mean age 29.1 years, 6 male, total IgE 311 ± 180 kU/l) suffered from respiratory allergy. Only the concentrations of Pru p 3 specific IgE were significantly higher in the 17 patients with systemic reactions after fruit or fruit-juice ingestion, than in patients with OAS and patients with respiratory allergy, as shown in Fig. 1. Six patients of the OAS group and four of the systemic symptoms group had measurable specific IgE to Pru p 4 (profilin), whereas a co-sensitization to Pru p 1 was present in four patients of the OAS group and three of the systemic symptoms group. Specific IgE to Par j 2 (another LTP) were detected only in three patients, two of whom were controls. A complementary observation was that specific IgE against Bet v 1 were detected in four of the patients with OAS. Those patients, in fact have had OAS also with cherry, apple or pear. LTPs are potent panallergens, and their biological activity is favoured by the resistance to heat and gastric digestion (5), since they can persist in the native form even in processed food such as fruit juices. Pru p 3, a compact protein stabilized by four disulfide bonds, has been identified as the major allergen of peaches (6), capable of inducing clinical symptoms in sensitised subjects. In the AL LERGY 2 0 0 9 : 6 4 : 1 7 9 5 – 1 7 9 8 • a 2009 JOHN WILEY & SONS A/S • CONTRIBUT IONS TO THIS SECT ION WILL NOT UNDERGO PEER REVIEW, BUT WILL BE REV IEWED BY THE ASSOCIATE EDITORS •

Evaluation of IgE antibodies to recombinant pollen allergens(Phl p 1, Phl p 2, and Phl p 5) in a random sample of patients withspecific IgE to Phleum pratense

Background: We measured specific IgE levels against the recombinant allergens (RAs) rPhl p 1, rPhl p 2, rPhl p 5 in patients allergic to grass pollen, and examined the existence of different patterns of IgE production to RAs. The seasonal variations of IgE levels to rPhl p 1, rPhl p 2, and rPhl p 5 were considered, too.

Lack of neo-sensitization to Pen a 1 in patients treated with mite sublingual immunotherapy

BackgroundSome studies reported the possible induction of food allergy, caused by neo-sensitization to cross-reacting allergens, during immunotherapy with aeroallergens, while other studies ruled out such possibility.ObjectivesThe aim of this study was to evaluate the development of neo-sensitization to Pen a 1 (tropomyosin) as well as the appearance of reactions after ingestion of foods containing tropomyosin as a consequence of sublingual mite immunization.Materials and methodsSpecific IgE to Tropomyosin (rPen a 1) before and after mite sublingual immunotherapy in 134 subjects were measured. IgE-specific antibodies for mite extract and recombinant allergen Pen a 1 were evaluated using the immunoenzymatic CAP system (Phadia Diagnostics, Milan, Italy).ResultsAll patients had rPen a 1 IgE negative results before and after mite SLIT and did not show positive shrimp extract skin reactivity and serological rPen a 1 IgE conversion after treatment. More important, no patient showed systemic reactions to crustacean ingestion.ConclusionsPatients did not show neo-sensitization to tropomyosin, a component of the extract (namely mite group 10) administered. An assessment of a patients possible pre-existing sensitisation to tropomyosin by skin test and/or specific IgE prior to start mite extract immunotherapy is recommended.Trial RegistrationThis trial is registered in EudraCT, with the ID number of 2010-02035531.

Possible Relationship between Systemic Side Effects and Sensitization to rPar j 2 in Allergic Patients Submitted to an Ultra-Rush (20 min) Sublingual Immunotherapy and Selected by Component Resolved Diagnosis

Background: The pollen of Parietaria spp., a weed of the Urticaceae family, is a major cause of respiratory allergy in the Mediterranean area, where the most common species are Parietaria judaica and Parietaria officinalis. In this study, we evaluated the specific serum IgE-binding profiles to individual P. judaica pollen recombinant major allergen, and Phleum pratense cytoskeletal profilin and a 2-EF-hand calcium-binding allergen homologous to cross-reactive Parietaria pollen allergens, in patients allergic to pollen with positive skin test towards Parietaria spp. extract. Methods: The present observation included 220 patients from the province of Cuneo, north-west Italy, all suffering from rhino-conjunctivitis and/or asthma selected on the basis of skin test positive to P. judaica extract. The sera were evaluated for specific IgE reactivity to P. judaica pollen major recombinant(r) allergen Par j 2, Phleum pratense pollen allergens rPhl p 7 (2-EF-hand calcium binding protein) and rPhl p 12 (profilin), both identified as cross-reactive Parietaria spp. allergens, using Pharmacia CAP System. Out of 220 patients, 37 patients with IgE reactivity to rPar j 2 and 105 patients sensitized to at least one timothy pollen major allergen (i. e. rPhl p 1, rPhl p 2, natural Phl p 4 and rPhl p 6) were submitted to an ultra-rush protocol of sublingual immunotherapy (SLIT). The occurrence of adverse reactions were evaluated in both groups. Results: All 220 patients with pollinosis and positive in vivo skin prick tests had in vitro positive CAP results to P. judaica natural extract. On the contrary, in these patients the prevalence of Par j 2-specific IgE was only 33.2% (73/220). In fact, 116/220 (52.7%) patients with serum specific IgE to crude Parietaria pollen extract had specific IgE to Phl p 12, 18/220 (8.1%) subjects with specific IgE to rPhl p 12 also exhibited specific IgE to Phl p 7 and 26/220 (11.8%) subjects had specific IgE against rPhl p 7. Particularly, geometric mean (25th–75th percentile) of specific IgE to rPar j 2 were as follows: 2.87 kUA/l (1.005–7.465). Out of 73 patients with specific IgE to rPar j 2, 7 subjects (9.6%) had also specific IgE to rPhl p 7, 12 (16.4%) had specific IgE to rPhl p 12 and 4 (4.1%) patients had specific IgE to both recombinant allergens. Of 37 patients under an ultra-rush protocol of SLIT, 3 subjects (8.1%) experienced generalized urticaria, and 1 of them also had diarrhea 3 h after the last dose of Parietaria judaica extract oral-vaccine administration. On the contrary, no systemic reactions were observed in 105 patients after Phleum pratense extract oral intake after a similar ultra-rush SLIT protocol (p = 0.0046). Conclusions: In the light of present findings, allergen extract-based diagnosis, in vivo and in vitro, cannot discriminate allergic patients that are genuinely sensitized to Parietaria spp. major allergens or to other major allergens to which current immunotherapeutic allergy extracts are standardized. Therefore, in vitro component resolved diagnosis is the unique tool to define the disease eliciting molecule(s). Finally, during sublingual immunotherapy, not only the dose of allergen, but also the biochemical characteristic of the major allergen administered may be an important factor in determining possible systemic reactions.