M2 Macrophages Upregulated by Allergen Exposure in Seasonal Allergic Rhinitis.

INTRODUCTION: Macrophages play a central role in balancing the immune response by switching phenotypes between the M1 and M2 profiles according to a delicate equilibrium. Based on a previous clinical trial (NCT03649139), this study aimed to evaluate the change in M2 macrophages during pollen exposure in seasonal allergic rhinitis (SAR). METHODS: Nasal symptom scores were recorded. Peripheral M2 macrophages were investigated according to cell surface markers, and M2-associated cytokine/chemokine release in serum and nasal secretion were assessed. In vitro pollen stimulation tests were performed, and polarized macrophage subsets were analyzed by flow cytometry. RESULTS: Compared to baseline, the percentage of peripheral CD163+ M2 macrophages in CD14+ monocytes increased during the pollen season (p < 0.001) and at the end of treatment (p = 0.004) in the SLIT group. The percentage of CD206+CD86- M2 cells in M2 macrophages during the pollen season was higher than that at baseline and at the end of SLIT. On the other hand, the percentage of CD206-CD86+ M2 cells in M2 macrophages significantly increased at the end of treatment in the SLIT group compared to baseline (p = 0.049), the peak pollen period (p = 0.017), and the placebo group (p = 0.0023). M2-associated chemokines CCL26 and YKL-40 were significantly increased during the pollen season in the SLIT group and remained higher at the end of SLIT than at baseline. Correspondingly, in vitro study demonstrated that Artemisia annua promoted M2 macrophage polarization in pollen-induced AR patients. CONCLUSION: Significant M2 macrophage polarization was promoted when patients with SAR were exposed to the allergen, either naturally exposed in pollen seasons or subjectively continuously exposed during the course of SLIT.

Ex Vivo Immunomodulatory Effects of Lactobacillus-, Lacticaseibacillus-, and Bifidobacterium-Containing Synbiotics on Human Peripheral Blood Mononuclear Cells and Monocyte-Derived Dendritic Cells in the Context of Grass Pollen Allergy.

Sensing of the intestinal microbiota by the host immune system is important to induce protective immune responses. Hence, modification of the gut microbiota might be able to prevent or treat allergies, mediated by proinflammatory Th2 immune responses. The aim was to investigate the ex vivo immunomodulatory effects of the synbiotics Pollagen® and Kallergen®, containing the probiotic bacterial strains Lactobacillus, Lacticaseibacillus and Bifidobacterium, in the context of grass pollen allergy. Peripheral blood mononuclear cells (PBMCs) from grass pollen-allergic patients and healthy controls were stimulated with grass pollen extract (GPE) and synbiotics and Gata3 expression and cytokine secretion analyzed. Monocyte-derived dendritic cells (MoDCs) cells were matured in the presence of GPE and synbiotics, co-cultured with autologous naïve T cells and maturation markers and cytokine secretion analyzed. GPE stimulation of PBMCs from grass pollen-allergic patients resulted in a significant higher production of the Th2 cytokines IL-4, IL-5, IL-9 and IL-13 compared to healthy controls. Gata3+CD4+ T cell induction was independent of the allergic status. The synbiotics promoted IL-10 and IFN-γ secretion and downregulated the GPE-induced Th2-like phenotype. Co-culturing naïve T cells with MoDCs, matured in the presence of GPE and synbiotics, shifted the GPE-induced Th2 cytokine release towards Th1-Th17-promoting conditions in allergic subjects. The investigated synbiotics are effective in downregulating the GPE-induced Th2 immune response in PBMCs from grass pollen-allergic patients as well as in autologous MoDC-T cell stimulation assays. In addition to increased IL-10 release, the data indicates a shift from a Th2- to a more Th1- and Th17-like phenotype.

Efficacy and safety of sublingual versus subcutaneous immunotherapy in children with allergic rhinitis: a systematic review and meta-analysis.

Aim: To systematically compare the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in children with allergic rhinitis (AR). Methods: PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to March 2, 2023. Outcomes included symptom scores (SSs), medication scores (MSs), symptom and medication scores (SMSs), new sensitizations, development of asthma, improvement, and treatment-related adverse events (TRAEs). The quality of the included studies was assessed by the modified Jadad scale and Newcastle-Ottawa scale (NOS). Meta-regression was carried out to explore the source of heterogeneity. Subgroup analysis was further conducted in terms of study design [randomized controlled trials (RCTs), cohort studies], allergen [house dust mites (HDMs), grass pollen], treatment duration (≥ 24, 12-23 or < 12 months), allergen immunotherapy (AIT) modality (drops or tablets), and AIT protocol [continuous, pre-seasonal, co-seasonal, or after the grass pollen season (GPS)]. Sensitivity analysis was conducted for all outcomes. A Bayesian framework and a Monte Carlo Markov Chain (MCMC) model were developed for indirect comparison. Results: Totally 50 studies with 10813 AR children were included, with 4122 treated with SLIT, 1852 treated with SCIT, and 4839 treated with non-SLIT or non-SCIT therapy. For direct comparison, the SLIT group had a similar SS to the SCIT group [pooled standardized mean difference (SMD): 0.41, 95% confidence interval (CI): -0.46, 1.28, P = 0.353]. Comparable MSs were observed in the SLIT and SCIT groups (pooled SMD: 0.82, 95%CI: -0.88, 2.53, P = 0.344). For indirect comparison, no significant differences were found in SSs (pooled SMD: 1.20, 95% credibility interval (CrI): -1.70, 4.10), MSs (pooled SMD: 0.57, 95%CrI: -1.20, 2.30), SMSs (pooled SMD: 1.80, 95%CrI: -0.005, 3.60), new sensitizations [pooled relative risk (RR): 0.34, 95%CrI: 0.03, 3.58], and development of asthma (pooled RR: 0.68, 95%CrI: 0.01, 26.33) between the SLIT and SCIT groups; the SLIT group illustrated a significantly lower incidence of TRAEs than the SCIT group (pooled RR: 0.17, 95%CrI: 0.11, 0.26). Conclusion: Considering both efficacy and safety, SLIT might be a more favorable AIT than SCIT in the treatment of pediatric AR, which may serve as a decision-making reference for clinicians. Systematic review registration: PROSPERO (CRD42023460693).

Allergen Profile of London Plane Tree Pollen: Clinical and Molecular Pattern in Central Spain

Background: Platanus acerifolia (London plane tree) is a deciduous tree of the Platanaceae family. Sensitization to this plant varies withgeography. Madrid, located in central Spain, has one of the highest London plane tree pollen concentration levels on the Iberian Peninsula.Objectives: We evaluated both the clinical characteristics and the molecular sensitization pattern of patients with allergy to London planetree pollen in the region of Madrid.Patients and Methods: Thirty-eight patients allergic to London plane tree pollen were selected according to their clinical symptoms andpositive results in skin prick testing and/or specific IgE determination. Serum was collected, and allergen components were evaluatedusing immunodetection techniques as well as ImmunoCAP. The IgE-binding proteins detected were identified and characterized usingmass spectrometry.Results: Analysis of serum samples from allergic patients revealed 9 IgE-binding bands in London plane tree pollen extract. Among these,the 45-kDa protein, which corresponded to Pla a 2, was detected in 76.3% of patients. However, the 18-kDa (Pla a 1) and 9-kDa (Pla a 3)bands were detected in 44.7% and 23.7% of sera, respectively. These results were confirmed using purified proteins. Characterization ofthe allergen revealed the 27-kDa protein to be glutathione-S-transferase.Conclusions: The molecular profile of patients sensitized to London plane tree pollen differs from that reported in studies from otherlocations. In the population we studied, the prevalence of Pla a 2 was higher than that of Pla a 1 and Pla a 3. In addition, the minorallergen previously referred to as Pla a 4 was characterized as glutathione-S-transferase. (AU)

Antecedentes: Platanus acerifolia es un árbol de hoja caduca de la familia Platanaceae. La sensibilización frente a esta planta varía enfunción de la zona geográfica. Madrid, ubicada en el centro de España, tiene uno de los mayores niveles de concentración de polen deeste árbol en la Península Ibérica.Objetivo: Evaluar las características clínicas y los patrones moleculares de sensibilización en pacientes con alergia al plátano de sombraen la región de Madrid.Pacientes y Métodos: Treinta y ocho pacientes alérgicos al polen del plátano de sombra fueron seleccionados de acuerdo con los síntomasclínicos, pruebas cutáneas positivas y/o IgE específica. El suero se recogió y se evaluaron los componentes alérgicos mediante técnicas deinmunodetección, así como ImmunoCAP. Las proteínas que unían IgE fueron identificadas y caracterizadas por espectrometría de masas.Resultados: El análisis de los sueros de los pacientes alérgicos reveló 9 bandas que captaban IgE en los extractos de polen de plátano desombra. Entre estas, la proteína de 45 kDa, correspondiente a Pla a 2, se detectó en el 76,3% de los pacientes. Sin embargo, las bandasde 18 kDa (Pla a 1) y 9 kDa (Pla a 3) fueron reconocidas en el 44,7% y 27,3%, respectivamente. Estos resultados se confirmaron usandoproteínas purificadas. La caracterización de los alérgenos identificó la proteína de 27 kDa como una glutatión S-transferasa.Conclusiones: El perfil molecular de los pacientes sensibilizados al polen del plátano de sombra varía respecto al descrito en estudios deotras localizaciones. Nuestra población muestra una mayor prevalencia de Pla a 2 comparado con Pla a 1 y Pla a 3. Además, el alérgenominoritario previamente denominado Pla a 4 fue caracterizado como una glutatión-S-transferasa. (AU)

Eosinophilic Esophagitis due to Aeroallergens: A Systematic Review and Update

Eosinophilic esophagitis is a chronic antigen-mediated esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by TH2 inflammation (at least 15 eosinophils/high power field) when other secondary systemic and local causes of esophageal eosinophilia are excluded. Although this disease was initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that aeroallergens may also play a role in pathogenesis and disease course. Some studies support seasonal variations in the diagnosis of eosinophilic esophagitis and disease exacerbations owing to the increase in aeroallergens to which patients are sensitized. It is also known that this disease can be caused by extensive, identifiable exposure to aeroallergens and after treatment with specific immunotherapy based on food or aeroallergens. It was recently postulated that treatment of allergic rhinoconjunctivitis can improve the symptoms of eosinophilic esophagitis, although data are limited to case reports and small series. Currently, biomarkers and biologic therapies are not helpful for diagnosis or inducing clinical and histological remission of the disease. Nevertheless, there are high hopes for dupilumab. This review aims to give visibility to the involvement of aeroallergens in the triggering and exacerbation of eosinophilic esophagitis, since many of them, in addition to being airborne and inhalant, can also be ingested as food. Clearly, we must try to identify the cause of the disease to ensure remission. (AU)

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.

Dosing intact birch pollen grains at the air-liquid interface (ALI) to the immortalized human bronchial epithelial cell line BEAS-2B.

In real life, humans are exposed to whole pollen grains at the air epithelial barrier. We developed a system for in vitro dosing of whole pollen grains at the Air-Liquid Interface (ALI) and studied their effect on the immortalized human bronchial epithelial cell line BEAS-2B. Pollen are sticky and large particles. Dosing pollen needs resuspension of single particles rather than clusters, and subsequent transportation to the cells with little loss to the walls of the instrumentation i.e. in a straight line. To avoid high speed impacting insults to cells we chose sedimentation by gravity as a delivery step. Pollen was resuspended into single particles by pressured air. A pollen dispersion unit including PTFE coating of the walls and reduced air pressure limited impaction loss to the walls. The loss of pollen to the system was still about 40%. A linear dose effect curve resulted in 327-2834 pollen/cm2 (± 6.1%), the latter concentration being calculated as the amount deposited on epithelial cells on high pollen days. After whole pollen exposure, the largest differential gene expression at the transcriptomic level was late, about 7 hours after exposure. Inflammatory and response to stimulus related genes were up-regulated. We developed a whole pollen exposure air-liquid interface system (Pollen-ALI), in which cells can be gently and reliably dosed.

Does the reaction size of skin prick test associated with the allergic rhinitis symptom severity?

BACKGROUND: Skin prick test (SPT) has the best positive predictive value to diagnose respiratory atopic diseases, including allergic rhinitis (AR), but the association of severity of allergic symptom and SPT reaction size has not been clearly determined yet. METHODS: In this a cross- sectional investigation, the severity of disease is classified using a visual analog scale for main symptoms, and SPT was conducted according to the principles of the European Academy of Allergy and Clinical Immunology. RESULTS: Thirty seven percent of the participants had at least one severe symptom. Patients with sensitivity to Alternaria (common allergens in humans) or tree pollens had more severe symptoms. We found that in patients who had sensitivity to Russian thistle pollen, wheal size >6 mm, was associated with more severe symptoms. CONCLUSION: Despite previous conflicts to rely on SPT test for starting immunotherapy, we recommend this test especially for patients sensitive to Alternaria, weed pollens, and tree pollens, considering the size of wheal in association with AR symptom severity.

The Relationship between Aeroallergen Sensitization and Chronic Cough in School-Aged Children from General Population.

OBJECTIVE: Determining sensitivity to allergens is an essential step in diagnosing children with allergic diseases. Chronic cough has remained poorly understood with causative triggers. The purpose of our study was to shed light on the relationship between sensitization to aeroallergens and chronic cough. METHODS: This population-based study examined children (aged 7 years to 13 years) between June and July 2016. The 1,259 children, 72 of whom (5.7%) had a chronic cough, and 1,187 of whom (94.3%) did not (controls), completed the questionnaire, but 1,051 children completed skin prick tests (SPTs) with eight aeroallergens. RESULTS: There were positive SPT results to at least 1 allergen in 549 children (52.2%). Sensitization to house dust mite (HDM) was most common (chronic cough = 46.9%; controls = 47.2%), followed by pollen (chronic cough = 21.9%; controls = 16.5%) in both groups, but there was no difference in allergic profile and sensitization to aeroallergen (P > 0.05 for all comparisons). Multivariable analysis with adjustment for confounding indicated that children who were in sensitization to pollen had an increased risk of chronic cough (aOR = 2.387; 95% CI: 1.115 to 5.111; P = 0.025). Multivariable analysis with adjustment for confounding indicated that children who were exposed to current smoking (aOR = 4.442; 95% CI: 1.831 to 10.776; P = 0.001) and mold (aOR = 1.988; 95% CI: 1.168 to 3.383; P = 0.011) were associated with chronic cough. CONCLUSION: Sensitization to pollen should be considered as a potential contributing factor to the development of chronic cough in school-aged children.

The Flagellin:Allergen Fusion Protein rFlaA:Betv1 Induces a MyD88- and MAPK-Dependent Activation of Glucose Metabolism in Macrophages.

TLR5 ligand flagellin-containing fusion proteins are potential vaccine candidates for many diseases. A recombinant fusion protein of flagellin A and the major birch pollen allergen Bet v 1 (rFlaA:Betv1) modulates immune responses in vitro and in vivo. We studied the effects of rFlaA:Betv1 on bone marrow-derived macrophages (BMDMs). BMDMs differentiated from BALB/c, C57BL/6, TLR5-/-, or MyD88-/- mice were pre-treated with inhibitors, stimulated with rFlaA:Betv1 or respective controls, and analyzed for activation, cytokine secretion, metabolic state, RNA transcriptome, and modulation of allergen-specific Th2 responses. Stimulation of BMDMs with rFlaA:Betv1 resulted in MyD88-dependent production of IL-1ß, IL-6, TNF-α, IL-10, CD69 upregulation, and a pronounced shift towards glycolysis paralleled by activation of MAPK, NFκB, and mTOR signaling. Inhibition of either mTOR (rapamycin) or SAP/JNK-MAPK signaling (SP600125) resulted in dose-dependent metabolic suppression. In BMDM and T cell co-cultures, rFlaA:Betv1 stimulation suppressed rBet v 1-induced IL-5 and IL-13 secretion while inducing IFN-γ production. mRNA-Seq analyses showed HIF-1a, JAK, STAT, phagosome, NLR, NFκB, TNF, TLR, and chemokine signaling to participate in the interplay of cell activation, glycolysis, and immune response. rFlaA:Betv1 strongly activated BMDMs, resulting in MyD88-, MAPK-, and mTOR-dependent enhancement of glucose metabolism. Our results suggest macrophages are important target cells to consider during restauration of allergen tolerance during AIT.

Specific gut microbiome signatures and the associated pro-inflamatory functions are linked to pediatric allergy and acquisition of immune tolerance.

Understanding the functional potential of the gut microbiome is of primary importance for the design of innovative strategies for allergy treatment and prevention. Here we report the gut microbiome features of 90 children affected by food (FA) or respiratory (RA) allergies and 30 age-matched, healthy controls (CT). We identify specific microbial signatures in the gut microbiome of allergic children, such as higher abundance of Ruminococcus gnavus and Faecalibacterium prausnitzii, and a depletion of Bifidobacterium longum, Bacteroides dorei, B. vulgatus and fiber-degrading taxa. The metagenome of allergic children shows a pro-inflammatory potential, with an enrichment of genes involved in the production of bacterial lipo-polysaccharides and urease. We demonstrate that specific gut microbiome signatures at baseline can be predictable of immune tolerance acquisition. Finally, a strain-level selection occurring in the gut microbiome of allergic subjects is identified. R. gnavus strains enriched in FA and RA showed lower ability to degrade fiber, and genes involved in the production of a pro-inflammatory polysaccharide. We demonstrate that a gut microbiome dysbiosis occurs in allergic children, with R. gnavus emerging as a main player in pediatric allergy. These findings may open new strategies in the development of innovative preventive and therapeutic approaches. Trial: NCT04750980.

Reduced anaphylactic potential of denatured pullulan-conjugated Cry j 1.

Japanese Cedar (JC) pollinosis is the most common seasonal allergic rhinitis in Japan. Throughout the JC pollen season, patients suffer from the allergic symptoms, resulting in a reduction of quality of life. Allergy immunotherapy (AIT) is an established treatment option for a wide range of allergens that unlike symptomatic treatments (e.g. antihistamines) may provide sustained immune tolerance. However, AIT, especially subcutaneous immunotherapy (SCIT) has a fatal anaphylaxis risk due to the use of crude allergen extracts. Consequently, development of allergen derivatives with substantially reduced anaphylactic potential is desirable. An allergen derivative that showed reduced IgE-binding and anaphylactic potential was developed through conjugation of native Cry j 1 (n Cry j 1), a major JC allergen, to the polysaccharide pullulan followed by chemical but non-covalent denaturation. The resulting Cry j 1 allergen derivative, Dn p-Cry j 1, showed reduced IgE-binding and IgE-mediated effector cell activation in vitro using an ELISA competition assay and a mast cell activation model (EXiLE). Reduced anaphylactic potential of Dn p-Cry j 1 in vivo was demonstrated using the rat passive cutaneous anaphylaxis (PCA) assay. The difference in anaphylactic potential of Dn p-Cry j 1 compared to n Cry j 1 in wild-type rats was of the same magnitude as the difference seen in the anaphylaxis reactions obtained with n Cry j 1 in wild-type rats and mast-cell deficient rats, indicating a dramatic reduction in anaphylactic potential of Dn p-Cry j 1. These results indicate that Dn p-Cry j 1 is a promising candidate for next-generation JC AIT.

Design of peptides with high affinity binding to a monoclonal antibody as a basis for immunotherapy.

About half of the US population is sensitized to one or more allergens, as found by a National Health and Nutrition Examination Survey (NHANES). The most common treatment for seasonal allergic responses is the daily use of oral antihistamines, which can control some of the symptoms, but are not effective for nasal congestion, and can be debilitating in many patients. Peptide immunotherapy is a promising new approach to treat allergic airway diseases. The small size of the immunogens cannot lead to an unwanted allergic reaction in sensitized patients, and the production of peptides with sufficient amounts for immunotherapy is time- and cost-effective. However, it is not known what peptides are the most effective for an immunotherapy of allergens. We previously produced a unique monoclonal antibody (mAb) E58, which can inhibit the binding of multiple groups of mAbs and human IgEs from patients affected by the major group 1 allergens of ragweed (Amb a 1) and conifer pollens (Jun a 1, Cup s 1, and Cry j 1). Here, we demonstrated that a combined approach, starting from two linear E58 epitopes of the tree pollen allergen Jun a 1 and the ragweed pollen allergen Amb a 1, and residue modifications suggested by molecular docking calculations and peptide design could identify a large number of high affinity binding peptides. We propose that this combined experimental and computational approach by structural analysis of linear IgE epitopes and peptide design, can lead to potential new candidates for peptide immunotherapy.

Safety and Effectiveness of a Single Multiallergen Subcutaneous Immunotherapy in Polyallergic Patients.

BACKGROUND: As the number of allergic sensitizations increases the severity of allergic respiratory diseases worsens. Multiple monoallergen immunotherapy can be accompanied by poor treatment adherence and high costs, single multiallergen immunotherapy needs to prove efficacy whilst maintaining a good safety profile. METHODS: Observational, retrospective, multicenter study using a 2-pollen single undiluted multiallergen subcutaneous immunotherapy (SCIT) in routine clinical practice in Spain. Patients with rhinoconjunctivitis, with/without controlled asthma, sensitized to grass, olive, Parietaria, Cupressus, plane tree and/or Salsola pollen were included. Primary and secondary clinical efficacy endpoints were quality of life (mini Rhinitis Quality of Life Questionnaire (miniRQLQ)) and visual analogue scale (VAS) respectively. All adverse events were documented. RESULTS: Ten centers included 97 patients, median age 32 years. SCIT treatment included combinations of grass mix with olive, Parietaria, Cupressus, plane tree or Salsola or olive with Parietaria, Cupressus or Salsola. The mean duration of SCIT was 1.8 years with a high treatment adherence (73%). Significant improvement in quality of life, nasal and ocular symptoms, activity limitations and practical problems (p< 0.0001) and other symptoms (p= 0.024) was observed. Most patients did not develop asthma-like symptoms and a significant improvement of all allergic symptom severity was perceived. VAS showed a significant improvement in rhinoconjunctivitis and asthma by patients and physicians. Twenty-nine patients experienced adverse reactions, 25 had local and 6 had systemic reactions. CONCLUSIONS: Single undiluted multiallergen SCIT treatment of two different pollens is efficacious and safe in both children and adults, showing that it is a suitable option for the treatment of polyallergic patients.

Case Report: Safe and Effective Sublingual Birch Allergen Immunotherapy in Two HIV-Positive Patients.

Allergen-specific immunotherapy (AIT) is a safe, effective treatment for respiratory allergies (such as moderate-to-severe allergic rhinoconjunctivitis) that are not controlled by symptomatic medications. The indications and contraindications for AIT have been defined in international guidelines and consensus statements. However, some of these contraindications are not evidenced- based but have been deduced from the theoretical risk of an interaction between AIT disease-modifying effect and immune or inflammatory comorbidities. In the absence of clinical trial evidence, the accumulation of experience as case reports can narrow the spectrum of absolute contraindications. The majority of international guidelines list HIV infection as a contraindication to AIT. Here, we describe two cases of safe, effective sublingual birch pollen AIT in HIV-positive patients undergoing concomitant antiretroviral therapy. A 32-year-old female and a 63-year-old male sensitized to tree pollen and with clinically confirmed birch pollen allergy underwent pre- and co-seasonal sublingual birch pollen AIT for three and two pollen seasons, respectively. The therapy was associated with a marked reduction in the frequency and intensity of allergic symptoms, and the reduced use of (symptomatic) rescue medication. Mild, local, treatment-emergent adverse events were noted throughout the course of treatment but resolved spontaneously. No serious adverse events were reported. In particular, there were no obvious harmful effects on the patients' immune status or viral load. Hence, sublingual birch pollen AIT proved to be effective and safe in two HIV-positive patients.

Cloning and immunobiochemical analyses on recombinant chymopapain allergen Cari p 2 showing pollen-fruit cross-reaction.

Papaya is reported to trigger food and respiratory allergy. Here, we identified chymopapain Cari p 2 as an allergen that can sensitize atopic individuals through fruit consumption followed by respiratory hazards through pollen exposure. Recombinant Cari p 2 displayed IgE-reactivity with 78% of papaya allergic sera. rCari p 2 also displayed allergenic activity through basophil degranulation. rCari p 2 is correctly folded and showed irreversible denaturation in the melting curve. rCari p 2 displayed IgE-cross-reactivity with homologous cysteine proteases from kiwi and pineapple. Cari p 2 transcript was also detected in papaya pulps. rCari p 2 was resistant to pepsin digestion and retained IgE-reactivity after 60 minutes of pepsin digestion. In mouse model, rCari p 2 was found to elicit inflammatory responses in the lung and gastrointestinal epithelium. Hence, Cari p 2 is a newly characterized allergen with diagnostic and immunotherapeutic potential for managing allergic disorders in papaya sensitized individuals.