Efficacy and safety of D. pteronyssinus immunotherapy in local allergic rhinitis: a double-blind placebo-controlled clinical trial

Local Allergic Rhinitis

Local allergic rhinitis (LAR) is defined by a clinical history suggestive of allergic rhinitis (AR), negativity of systemic IgE measurement and positive response to nasal allergen challenge (NAC). The term local respiratory allergy includes LAR, local allergic asthma (positive response in bronchial allergen challenge) and dual allergic rhinitis defined by the coexistence of AR and LAR. LAR worsens in severity and presence of comorbidities over time, and it is an independent entity from AR. Prevalence is higher in Mediterranean countries. LAR onset occurs during childhood in 36% of cases. Physiopathological features of LAR are: increased nasal eosinophilic inflammation, tryptase and eosinophil cationic protein, and presence of nasal specific IgE in secretions of 20-40% of subjects. A recent study demonstrated increase in sequential class switch recombination to IgE markers in mucosa of LAR with accumulation of IgE+ CD38+ plasmablasts. Moreover, there is increased expression in B cells of mucosal homing receptors CXCR3+ and CXCR4 in peripheral blood, with accumulation of Th9 and Th2 cells. NAC is the gold standard in the diagnosis of LAR. The measurement of specific IgE in nasal secretions basophil activation test or are still not suitable for diagnosis. There is ample evidence of the usefulness of allergen immunotherapy in the treatment in LAR after 4 DBPCRT in 152 patients. In conclusion, knowledge about LAR is continuously increasing, with detailed definition of physiopathological mechanisms and new phenotypes. More awareness of the disease should be promoted among different specialists, and NAC must be considered an essential diagnostic tool in any age group, including children.

Is allergen immunotherapy a model of personalized treatment in pediatric respiratory allergy?

PURPOSE OF REVIEW

To review recent evidence on allergen immunotherapy (AIT) as a model of personalized medicine in the treatment of children and adolescents with respiratory allergies.

RECENT FINDINGS

Meta-analysis and systematic review studies continue to point out that AIT is an effective treatment for children with respiratory allergies. Molecular allergy allows the understanding of patient sensitization profiles that frequently change the prescription of AIT. There is still a lack of evidence showing that this personalized prescription of AIT is associated with better clinical outcomes. The nasal allergen challenge has extended the indications of AIT for a new group of subjects with local allergic rhinitis. Patient selection of allergens involved in the increasingly personalized composition of extracts to be used in AIT increasingly characterizes it as personalized medicine.

SUMMARY

Despite the numerous studies carried out to identify the best biomarker to evaluate the response to AIT, there is still much disagreement, and clinical assessment (symptoms, quality of life, among others) continues to be the best way to evaluate the therapeutic success of AIT.

Local allergic rhinitis in children: Clinical characteristics and role of basophil activation test as a diagnostic tool

BACKGROUND

Local allergic rhinitis (LAR) is a condition involving a localized nasal allergic response in absence of systemic atopy. Most studies on LAR have been performed in adults. We aimed to describe clinical characteristics of LAR pediatric patients, its clinical evolution over a 7-year follow-up period and to study the role of basophil activation test (BAT), for its diagnosis.

METHODS

Forty-four children with non-allergic rhinitis (NAR) were included (24 males, 20 females, aged under 15 years). Nasal allergen provocation test (NAPT) and BAT were performed with Dermatophagoides pteronyssinus and Phleum pratense.

RESULTS

Seven patients (16%) were diagnosed of LAR. Six reacted to D pteronyssinus and one to P pratense. All LAR and 86% of NAR patients presented perennial symptoms. Fifty-seven percent of NAR and LAR patients referred persistent symptoms. Around half of NAR and LAR patients reported mild-moderate clinical manifestations. Three LAR patients associated conjunctival symptoms, proportionally more than NAR patients (19%, 7 out of 37). NAR patients presented bronchial asthma (n = 10) more frequently than LAR children (n = 1). More than half of LAR and NAR patients presented family history of atopy. BAT was negative in all LAR patients. On follow-up, 3 LAR patients and 10 of the 25 NAR patients who agreed to be retested, presented systemic sensitization. Dust mites were the most frequent allergen involved.

CONCLUSIONS

LAR should be ruled out in children with NAR. Almost half of children with LAR develop systemic sensitization over time. BAT shows low sensitivity for the diagnosis of LAR in children.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Omalizumab added to allergen immunotherapy increased the effect of therapy in patients with severe local allergic rhinitis

BACKGROUND

Allergen immunotherapy (AIT) is effective in patient with local allergic rhinitis (LAR). However, AIT may not always achieve the optimal treatment effect.

OBJECTIVE

To present short study with clinical cases of LAR combined therapy with sublingual immunotherapy (SLIT) and omalizumab in patients with house dust mite (HDM) allergy and compared it to therapy with omalizumab alone.

METHODS

Patients with severe LAR and hypersensitivity to HDMs were included. SLIT for HDMs was launched in a perennial protocol using SQ-HDM SLIT tablets with omalizumab. The total rhinitis symptom score (TRSS), total medication score (TMS) and combined total score (CTS) were assessed after one year.

RESULTS

After 12 months, significant improvements in all analyzed parameters in the patients on SLIT+ omalizumab therapy were observed: a reduction in the TRSS from 1.21 ± 0.33 to 0.6 ± 0.28 (p < .05), a reduction in the TMS from 2.25 ± 1.05 to 0.88 ± 0.31 (p < .05) and a reduction in the CTS from 3.46 ± 0.57 to 1.48 ± 0.51 (p < .05). This improvement in TRSS, TMS also in CTS was significantly greater than in the rest of the group with SLIT alone or omalizumab alone.

CONCLUSION

Omalizumab may be a valuable treatment that increases the effectiveness of immunotherapy in patients with severe LAR.

A Prospective Analysis of Systemic and Local Aeroallergen Sensitivity in Central Compartment Atopic Disease

OBJECTIVE

To compare systemic allergen sensitivity and local allergen sensitivity in the sinonasal tissue of patients with a recently identified subtype of chronic rhinosinusitis strongly associated with allergy: central compartment atopic disease (CCAD).

STUDY DESIGN

Prospective cohort study.

SETTING

Academic tertiary care rhinology clinic.

METHODS

Fifteen participants with endoscopic and radiographic evidence of CCAD underwent systemic allergy testing with skin testing and measurement of serum specific immunoglobulin E (sIgE) to 15 regionally common aeroallergens. Local allergen sensitivity was determined by measuring sIgE to these same 15 allergens in their sinonasal tissue. sIgE testing was performed by ImmunoCAP assay.

RESULTS

Of the 15 participants, 14 were sensitive to at least 1 allergen locally in the central compartment and systemically on skin or serum testing. Among all participants, 4 were sensitive to allergens on central compartment sIgE testing that they were not sensitive to on skin and serum sIgE testing (range, 1-8 discordant allergens). Comparisons between local and systemic aeroallergen sensitivity results showed statistically significant correlations (P < .05) ranging from weak to strong.

CONCLUSION

Systemic allergy testing is recommended in the initial workup for CCAD. Local allergen sensitivities may be present in a subset of patients with CCAD. Further study of the clinical significance of these sensitivities should be undertaken in CCAD, with evaluation of the role of medical therapies and allergen immunotherapy in the treatment of CCAD.

Sequential class switch recombination to IgE and allergen-induced accumulation of IgE+ plasmablasts occur in the nasal mucosa of local allergic rhinitis patients

BACKGROUND

The involvement of allergen-specific (s)IgE in local allergic rhinitis (LAR) has been debated. Here, we investigate the effect of nasal allergen challenge with Dermatophagoides pteronyssinus (NAC-DP) in mucosal and peripheral B-cell subpopulations in LAR patients.

METHODS

Nine LAR, 5 allergic rhinitis (AR), and 5 non-atopic healthy control (HC) individuals were subjected to a 3-day NAC-DP protocol, and nasal biopsies and blood samples were collected before and after provocation. Nasal biopsies were used for immunohistochemistry and gene expression studies, whereas the frequency of lymphocyte subsets and basophil activation test (BAT) were analyzed in blood samples by flow cytometry. sIgG was measured in sera.

RESULTS

NAC-DP induced an increase in IgE⁺ CD38⁺ plasmablasts in the nasal mucosa of LAR patients, but not in AR or HC individuals. Markers of sequential recombination to IgE (εCSR) (from IgG) were observed in 33% of LAR, 20% of AR, and 0% of HC subjects. NAC-DP increased the proportion of peripheral CD19⁺ CD20⁺ CD38⁺ plasmablasts in AR and LAR patients, but not in HC. Expression of the mucosal homing receptor CXCR3 in peripheral CD19⁺ CD20⁺ CD38⁺ plasmablasts from LAR, AR, and HC individuals was 7%, 5%, and 0.5%, respectively. In vitro DP stimulation increased proliferating CD19⁺ CD20⁺ CD38⁺ plasmablasts in LAR and AR patients, but not in HC. Serum DP-sIgG was higher in LAR and AR patients as compared to HC. BAT was positive in 33%, 100%, and 0% of LAR, AR, and HC subjects, respectively.

CONCLUSION

These results suggest that allergen exposure induces the sequential εCSR of IgG⁺ CD19⁺ CD20⁺ CD38⁺ plasmablasts in the nasal mucosa of LAR patients.

The Role of Allergen-Specific Immunotherapy in ENT Diseases: A Systematic Review

Previous studies have demonstrated that both subcutaneous (SCIT) and sublingual specific immunotherapy (SLIT) are effective in treating allergic rhinitis (AR). Further studies have evaluated the efficacy of allergen-specific immunotherapy (AIT) on different ear, nose, and throat (ENT) manifestations, in which allergy might have an etiopathogenetic role, such as local allergic rhinitis (LAR), rhinosinusitis (RS), otitis media (OM), and adenotonsillar (AT) disease. Nevertheless, the management of allergy in ENT diseases is still debated. To the best of our knowledge, this is the first systematic review assessing the efficacy of AIT in ENT diseases aside from AR. Literature data confirmed that AIT might be an effective therapeutic option in LAR, although its effect is restricted to studies with short-term follow-up. Furthermore, previous research demonstrated that AIT may improve symptoms and surgical outcomes of chronic rhinosinusitis when used as an adjunctive treatment. Few studies supported the hypothesis that AIT may exert positive therapeutic effects on recurrent upper airway infections as adenotonsillar disease. Finally, some clinical observations suggested that AIT may add some benefits in the management of otitis media with effusion (OME). The results of this systematic review allow us to conclude that the efficacy of AIT in ENT disorders has been only slightly investigated and additional studies are needed.

Risk of Chronic Rhinosinusitis With Nasal Polyps in Endotypes of Dermatophagoides pteronyssinus-Induced Rhinitis

BACKGROUND

Observation of the natural history of two emerging endotypes of allergic rhinitis, local-sensitization rhinitis (LAR) and dual-allergic rhinitis (DAR), compared with systemic-sensitization rhinitis (AR), could improve knowledge of the role of allergy in chronic rhinosinusitis with nasal polyps (CRSwNP).

OBJECTIVE

To test the hypothesis that endotypes of Dermatophagoides pteronyssinus (DP)-induced rhinitis were risk factors for CRSwNP and adult-onset asthma and to investigate whether delayed hypersensitivity to DP, assessed by atopy patch test, could be a contributing factor.

METHODS

We conducted a prospective observational study over 15 years on a cohort of 999 patients: 468 with AR, 333 with LAR, and 198 with DAR. The latter endotype was characterized by the coexistence of seasonal disease caused by systemic sensitization to pollen in patients with DP-induced LAR. The study design included a physical visit; ear, nose, and throat examination with anterior rhinoscopy; skin prick test; serum-specific IgE; DP-atopy patch test; nasal allergen provocation test with DP; paranasal sinuses computed tomography scan; nasal endoscopy; and spirometry.

RESULTS

During 15 years of follow-up, 194 patients developed CRSwNP with a higher rate of LAR (28.2%) and DAR (22.2%) than AR (12%). For LAR and DAR, 7.5% and 10.6% of patients developed adult-onset asthma temporally linked to CRSwNP in 68% and 71.4% of cases, respectively. A total of 858 patients with rhinitis had delayed hypersensitivity to DP. Moreover, DP-ATP was an independent predictive factor for CRSwNP and had elevated positive and negative predictive values for localized allergic disease of the nasal mucosa.

CONCLUSIONS

Endotypes of DP-induced allergic rhinitis represent risk factors for CRSwNP. Patients with local-sensitization rhinitis and DAR are more at risk than those with AR. In these emerging endotypes, progression toward CRSwNP is often associated with the development of adult-onset asthma. Chronic rhinosinusitis with nasal polyps shows several possible indicators for type 2 endotype. Delayed hypersensitivity to DP is an independent predictive factor for CRSwNP.

Diagnosis and Treatment of Local Allergic Rhinitis

Some patients with chronic rhinitis have a positive nasal allergen provocation test (NAPT) without systemic IgE sensitization by skin prick tests or serum allergen-specific IgE (sIgE). This novel concept is called local allergic rhinitis (LAR) and affects children and adults worldwide, but is underdiagnosed. LAR is not just the initial state of allergic rhinitis (AR), it is a unique form of chronic rhinitis that is neither classical AR nor non-AR. Many of the features of AR and LAR are similar, such as a positive NAPT, positive type 2 inflammatory markers, including the nasal discharge of sIgE, and a high incidence of asthma. A differential diagnosis of LAR needs to be considered in patients with symptoms suggestive of AR in the absence of systemic atopy, regardless of age. The diagnostic method for LAR relies on positive responses to single or multiple allergens in NAPT, the sensitivity, specificity, and reproducibility of which are high. The basophil activation test and measurement of IgE in nasal secretions also contribute to the diagnosis of LAR. Treatment for LAR is similar to that for AR and is supported by the efficacy and safety of allergen exposure avoidance, drug therapy, and allergen immunotherapy. This review discusses current knowledge on LAR.

Efficacy and Safety of Subcutaneous Immunotherapy for Local Allergic Rhinitis: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Subcutaneous immunotherapy (SCIT) has been used for treating local allergic rhinitis (LAR) patients. However, the clinical efficacy and safety were still questioned.

OBJECTIVE

This study was designed to estimate the efficacy and safety of SCIT for treating LAR patients through meta-analysis.

METHODS

We systemically searched MEDLINE, Cochrane Library, and Embase publications. Randomized, double-blind, clinical trials for the efficacy and safety of Allergen Immunotherapy (AIT) for LAR were included. A meta-analysis of 4 clinical endpoints (combined symptom and medication scores [CSMS], symptom scores [SS], medication scores [MS] and rhinoconjunctivitis quality of life questionnaire [RQLQ]) and adverse events (AEs)) was performed after bias and heterogeneity assessments. The immunologic response results were summarized.

RESULTS

Four RCTs with 134 patients were included. Four studies for analyzing primary outcomes (CSMS, SS, MS) and AEs, three for RQLQ results. The results indicated an important significant difference between SCIT and placebo groups, list as follows: CSMS (SMD = -2.42, 95% CI: -3.60 to -1.25, P < .0001), SS (SMD = -2.08, 95% CI -3.68 to -0.48, P = .01), MS (SMD = -1.43, 95% CI: -2.65 to -0.21, P = 0.02), RQLQ (SMD = -0.70, 95% CI -1.29 to -0.12, P = .02), Local AEs (RR = 4.13, 95% CI 1.08 to 15.77, P = .04). For immunologic response, significantly increased serum sIgG4 levels and improvements of allergen tolerance was observed after SCIT.

CONCLUSIONS

Our meta-analysis suggests that SCIT has a significant effect on improving symptoms and reducing medicine consumption for LAR patients. Larger and multicenter clinical trials are needed to clarify the safety and long-term efficacy.

Allergen-specific immunotherapy for local allergic rhinitis: a systematic review and meta-analysis

BACKGROUND

Local allergic rhinitis (LAR) is a phenotype of chronic rhinitis exhibiting a local Th2-driven inflammation without positive clinical markers of atopy. Immunomodulatory effects of allergen-specific immunotherapy (AIT) induce allergen-specific tolerance. However, AIT is not well-recognized as a treatment for LAR.

METHODOLOGY

Systematic search on six electronic databases and registries was performed. Experimental and observational studies of AIT for LAR patients were retrieved. The primary outcomes were symptom score, medication score, combined symptom medication score, and disease-specific quality of life. Secondary outcomes were serum specific(s) IgG4, sIgE, and adverse events.

RESULTS

Four double-blind randomized controlled trials (156 patients) from two research units assessed the effects of subcutaneous immunotherapy (SCIT). Compared with placebo, SCIT showed significant reductions in symptom score, medication score, combined symptom medication score, disease-specific quality of life, and an increase in serum sIgG4. There was no significant change in serum sIgE. Likewise, two observational studies (one using SCIT and one using sublingual immunotherapy) improved post-therapeutic symptom score. No studies assessed the effects after discontinuation of treatment. AIT was safe without serious adverse events.

CONCLUSION

AIT has beneficial effects and safe for LAR. Its effects are restricted to studies with short-term follow-up. AIT may be considered in LAR patients.

Allergen immunotherapy against house dust mites in patients with local allergic rhinitis and asthma

METHODS

The study was a prospective, double-blind, placebo-controlled trial with patients diagnosed with LAR to HDMs and with concomitant asthma who underwent a 12-month treatment course of SLIT for HDM allergies. Seventeen patients were randomized to SLIT with the use of allergen extracts of D. pteronyssinus and D. farinae (50/50%) in SQ-HDM SLIT tablets and 15 patients were randomized to the placebo group. The total rhinitis score (TRSS), total asthma symptom score (TASS), combined total symptom score (TSS), total medication score (TMS), and FEV1 were analyzed.Results: In the final analysis, 16 patients who received SLIT and 14 who received placebo who completed the study protocol were included. Significant reductions in TRSS, TASS, TSS, and TMS after 12 months of treatment were observed in patients after SLIT (p < 0.05). A significant increase in the mean FEV1 between baseline and after 12 months of therapy was observed in the study, with p = 0.03 in the study group. Conclusion: SLIT can improve nasal and bronchial symptoms and reduce symptomatic treatment in patients with LAR and asthma and with hyperresponsiveness to HDMs.

The Importance of Nasal Provocation Testing in the Diagnosis of Dermatophagoides pteronyssinus-Induced Allergic Rhinitis

BACKGROUND

Allergen identification is the first step for allergen-specific immunotherapy (AIT) of allergic rhinitis (AR). Currently, the diagnosis of AR is based mainly on the positive results of the skin prick test (SPT) and/or serum specific immunoglobulin E (sIgE) measurement. However, the results of these two tests may not always directly correlate with AR.

OBJECTIVE

To investigate the importance of nasal provocation testing (NPT) in the diagnosis of Dermatophagoides pteronyssinus (Der p)-induced AR.

METHODS

Rhinitis patients willing to undergo AIT (n = 171) were enrolled. The correlations of Der p SPT, sIgE, NPT, and clinical symptom severity were assessed.

RESULTS

NPT-positive responses were more common in patients with higher SPT and sIgE levels. The optimal cut-off value for a NPT-positive response for SPT was 5.5 mm and for sIgE was 2.77 kUA/L, based on the respective receiver operating characteristic (ROC) curves. The area under the curve (AUC) of the ROCs was 0.814 (SPT only) and 0.794 (sIgE only) and increased to 0.828 with the combination of SPT and sIgE. The Der p-NPT concentration was inversely correlated with SPT and sIgE levels (r = -0.477, P < .001, and r = -0.461, P < .001, respectively), but none was correlated with the total nasal symptom score.

CONCLUSION

For patients who are willing to receive Der p AIT, NPT is a useful and safe test to confirm diagnosis prior to treatment initiation, especially in patients with lower levels of Der p SPT (< 5.5 mm) or sIgE (< 2.77 kUA/L).

Local Respiratory Allergy: From Rhinitis Phenotype to Disease Spectrum

Local respiratory allergy (LRA) is defined by the negativity of atopy tests, a clinical history suggestive of airway allergy and a positive response to the nasal and/or bronchial allergen challenge. The clinical spectrum of LRA is comprised of three conditions: local allergic rhinitis (LAR) and local allergic asthma in non-atopic patients, and dual allergic rhinitis (coexistence of allergic rhinitis and LAR) in atopic individuals. LRA is an independent disease phenotype not progressing to atopy over time, but naturally evolving to the clinical worsening and the onset of comorbidities. Published data suggests that LRA is mediated through the mucosal synthesis of allergen-specific (s)IgE, which binds to FcϵRI on resident mast cells, and in >50% of cases traffics to the blood stream to sensitize circulating basophils. To date, 4 clinical trials have demonstrated the capacity of allergen immunotherapy (AIT) to decrease nasal, conjunctival and bronchial symptoms, to improve quality of life, to increase the threshold dose of allergen eliciting respiratory symptoms, and to induce serum sIgG₄ in LRA individuals. Collectively, these data indicate that local allergy is a relevant disease mechanisms in both atopic and non-atopic patients with airway diseases.

The use of nasal allergen vs allergen exposure chambers to evaluate allergen immunotherapy

INTRODUCTION

Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment option for allergic rhinitis (AR) patients with persistent moderate-severe AR for whom traditional pharmacotherapies are ineffective. The nasal allergen challenge (NAC) and allergen exposure chamber (AEC) are two translational models of AR that can be used to investigate the properties, safety, and efficacy of AIT.

AREAS COVERED

Peer-reviewed, human-centered articles utilizing AEC or NAC models to investigate AIT between 2010 and 2020 were curated from PubMed, EMBASE, and OVID Medline databases. AECs have been used to evaluate traditional subcutaneous and sublingual administrations of AIT, including cross-protective effects and different dosing regimens. More recently, the effectiveness of novel AIT formulations has been evaluated. NACs are another model used to study AIT, including using novel intralymphatic routes of administration. It is an especially powerful and versatile tool to determine if basic science and animal model findings are clinically translatable.

EXPERT OPINION

The AEC and NAC models both produce clinically relevant and reproducible results. AECs are more effective for studying many participants but are limited because they require a specialized facility. As more AIT therapies and new formulations are developed over time, the versatility of the NAC will be especially useful.

Diagnosis and treatment of non-allergic rhinitis: focus on immunologic mechanisms

INTRODUCTION

Non-allergic rhinitis (NAR) is a heterogeneous nasal disease with high global prevalence. NAR can be subclassified as nonallergic rhinitis with eosinophilia syndrome (NARES), vasomotor rhinitis (VMR), and local allergic rhinitis (LAR). Although the precise factors involved in the etiology of NAR are not clear, there is evidence that immunological factors play an important role in the pathogenesis of NAR. This review provides a comprehensive overview of the immunological and neurogenic mechanisms involved in the diagnosis and treatment of NAR.

AREAS COVERED

This review provides a comprehensive overview of the immunological basis of diagnostic and treatment strategies for NARES, VMR, and LAR. In particular, recently documented molecular and immunological mechanisms of NAR are discussed, which may help to better understand the mechanisms underlying the pathologies of the different endotypes of NAR.

EXPERT OPINION

An increasing number of studies investigating the pathogenesis of NAR suggest that the immunological mechanisms underlying the different subtypes of NAR vary greatly, and are still not fully understood to accurately diagnose these subtypes. Thus, further studies should focus on making diagnosis and treatment of NAR more precise, safe, and effective. A better understanding of the immunological mechanisms involved in NAR should help in the discovery of new diagnostic and treatment strategies.

The role of the nasal allergen provocation test in local allergic rhinitis cases: a preliminary report

INTRODUCTION

The current state of knowledge is that allergic rhinitis can occur in two forms. One is allergic rhinitis as a manifestation of a systemic allergy with systemic atopy and positive results of skin prick tests or sIgE tests. The other is local allergic rhinitis (LAR) as a local allergic reaction affecting only the nasal mucosa without systemic atopy.

AIM

To attempt to assess the usefulness of the nasal allergen provocation test for the purposes of differential diagnosis and the qualification of LAR patients for therapy.

MATERIAL AND METHODS

The subjects in the study were a group of 6 adults diagnosed with LAR on the basis of their medical history and the results of nasal allergen provocation tests, with the allergens being house dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae). The methods adopted in the study were a point-based rating scale as a measure of nasal/extranasal complaints and active anterior rhinomanometry.

RESULTS

Significant differences (p < 0.05) were observed, using the subjective rating scale, in relation to registered nasal and extranasal complaints in the early phase of the allergic reaction. Similarly, the rhinomanometry method revealed significant differences in nasal resistance values before and after the administration of an allergen.

CONCLUSIONS

The nasal allergen provocation test is the only testing tool that objectively measures the degree of the patient's allergic reactions and is useful in qualifying LAR patients for further therapy.

Precision Medicine in House Dust Mite-Driven Allergic Asthma

House dust mites (HDMs) are the allergenic sources most frequently involved in airway allergy. Nevertheless, not every sensitized patient develops respiratory symptoms upon exposure to HDM, and there is a clinical need to differentiate allergic asthmatics (AAs) from atopic non-allergic asthmatics with HDM sensitization. This differentiation sometimes requires in vivo provocations like the bronchial allergen challenge (BAC). Interestingly, recent data demonstrate that non-atopic patients with asthma can also develop positive BAC results. This novel phenotype has been termed local allergic asthma (LAA). The interest in identifying the allergic triggers of asthma resides in the possibility of administering allergen immunotherapy (AIT). AIT is a disease-modifying intervention, the clinical benefit of which persists after therapy discontinuation. Recently, new modalities of sublingual tablets of HDM immunotherapy registered as pharmaceutical products (HDM-SLIT tablets) have become commercially available. HDM-SLIT tablets have demonstrated a robust effect over critical asthma parameters (dose of inhaled corticosteroids, exacerbations, and safety), thus being recommended by international guidelines for patients with HDM-driven AA. In this review, we will summarize the current knowledge on the phenotype and endotype of HDM-driven AA, and LAA, address the difficulties for BAC implementation in the clinic, and discuss the effects of AIT in AA and LAA.

Coexistence of nasal reactivity to allergens with and without IgE sensitization in patients with allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) and local allergic rhinitis (LAR) are defined by nasal reactivity to aeroallergens with and without positive skin prick test (SPT), respectively. In this study, we aimed to investigate whether both types of allergen-specific reactivity can coexist in the same individual.

METHODS

Forty-eight patients with perennial rhinitis symptoms and positive SPT with seasonal allergens only (discrepant group) were subjected to consecutive nasal allergen challenges (NAC) with seasonal (NAC-S) and perennial allergens (NAC-P). A nasal lavage was collected before and after the NACs to measure eosinophil cationic protein (ECP). A basophil activation test (BAT) with seasonal and/or perennial allergens was performed in ten patients from the discrepant group and in six seasonal allergic rhinitis (SAR), eight perennial local allergic rhinitis (LAR), six nonallergic rhinitis (NAR), and six healthy control (HC) individuals.

RESULTS

All patients in the discrepant group tested positive in the NAC-S, and 41 of them (85.4%), also in the NAC-P (group A). Conversely, seven patients tested negative in the NAC-P (group B). ECP in the nasal lavage increased after the NAC-P in the group A (P = .004), but not in the group B. The BAT with seasonal allergens was positive in 100% of SAR and group A cases, whereas the BAT with perennial allergens was positive in 37.5% and 60% of LAR and group A cases, respectively. All NAR and HC subjects tested negative for the BAT.

CONCLUSION

This study shows that nasal reactivity to aeroallergens with and without positive SPT can coexist in the same patient. We propose the term dual allergic rhinitis for this rhinitis phenotype.

Different Development Forms of Local Allergic Rhinitis towards Birch

Background

Efficacy of allergen immunotherapy (AIT) in local allergic rhinitis (LAR) is a new subject of research. The presence of asthmatic symptoms in patients with LAR in the context of AIT is unexplored.

Objective

The efficacy and safety of AIT in patients with LAR towards birch pollen were investigated. The possibility of concomitant local allergic asthma in studied patients and the impact of AIT on it were examined.

Methods

36 patients with LAR towards birch were included in three years of AIT in a double-blind, placebo-control study. Primary outcome measurement was the mean changes in the combined symptom and medication scores (CSMSs) after AIT, and the second is the changes in the quality of life (QoL). Skin prick tests, serum, nasal allergen-specific IgE to birch, nasal and bronchial provocation challenge tests with birch allergen, methacholine tests, and spirometry were carried out at baseline and after AIT.

Results

Mean CSMSs of three years of AIT were significantly decreased in the active group from 5.88 (range: 4.11-9.01) to 1.98 (range: 1.22-4.51; p < 0.05). After three years of AIT, there was a significant increase of toleration for birch allergen from the mean concentration of 6250 ± 1200 SQ-U/ml up to 45000 ± 2500 SQ-U/ml (p = 0.02) during repeated nasal challenges. 16 patients with LAR had the positive results of methacholine tests, and 11 of them had a positive bronchial challenge to birch allergen. After AIT, the significant decrease of bronchial responsiveness to birch allergen in 5 from 7 patients was confirmed (p = 0.03). QoL assessed by the use of the RQLQ score was improved after AIT from 1.84 (95% CI: 1.53-1.97) to 1.45 (95% CI: 1.32-1.62) score in the active group after three years of AIT therapy (p = 0.03).

Conclusion

AIT to birch can be useful and safe in a patient with local allergic rhinitis and also with concomitant asthmatic symptoms. Further studies are needed.

Local Allergic Rhinitis Revisited

PURPOSE OF REVIEW

Local allergic rhinitis (LAR) represents a diagnostic and therapeutic challenge for clinicians. Even though it affects a considerable number of chronic rhinitis patients and a significant number of articles regarding prevalence, evolution, diagnosis, and treatment have been published, the condition remains still largely unrecognized and therefore misdiagnosed and mistreated.

RECENT FINDINGS

LAR is a unique form of chronic rhinitis; it is neither classical allergic rhinitis (AR) nor non-allergic rhinitis (NAR). The symptoms, duration, severity, and complications of LAR are similar to those of AR and can affect adults and children. Thus, a portion of patients diagnosed with NAR or chronic rhinitis of unknown etiology may have LAR. The relationship between LAR inflammation and systemic allergic inflammation is unclear. Patients are frequently misdiagnosed with idiopathic NAR, and distinguishing between both entities is difficult without specific diagnostic tests. Underdiagnosis of LAR has implications on the management of these patients, as they are deprived of allergen immunotherapy (AIT) that has been demonstrated to modulate the immune mechanisms underlying allergic diseases. This review aims to comprehensively summarize the current knowledge on LAR and address unmet needs in the areas of disease diagnosis and treatment.

Allergen Immunotherapy for Local Respiratory Allergy

PURPOSE OF REVIESW

Local respiratory allergy (LRA) is an eosinophilic phenotype of chronic airway disease. Three entities have been described within the LRA spectrum: local allergic rhinitis (LAR) and local allergic asthma (LAA) in non-atopic patients, and dual allergic rhinitis (DAR) in atopic patients (coexistence of LAR and allergic rhinitis). In this article, we aim to review the current evidence on the therapeutic options for LRA.

RECENT FINDINGS

No controlled study has assessed the effect of standard therapy (oral antihistamines, intranasal or inhaled corticosteroids, bronchodilators) in LRA subjects. Three randomized clinical trials and one observational study demonstrated that allergen immunotherapy (AIT) is able to control nasal and ocular symptoms, decrease the need for rescue medication, and improve quality of life in LAR individuals. Nasal or inhaled steroids can be expected to improve eosinophilic inflammation in LRA patients but cannot change the natural course of the disease. Moreover, the long-term and disease-modifying effects of AIT in LRA subjects need to be investigated.

Molecular profiling of allergen-specific antibody responses may enhance success of specific immunotherapy

BACKGROUND

House dust mites (HDMs) are among the most important allergen sources containing many different allergenic molecules. Analysis of patients from a double-blind, placebo-controlled allergen-specific immunotherapy (AIT) study indicated that patients may benefit from AIT to different extents depending on their molecular sensitization profiles.

OBJECTIVE

Our aim was to investigate in a real-life setting whether stratification of patients with HDM allergy according to molecular analysis may enhance AIT success.

METHODS

Serum and nasal secretion samples from patients with HDM allergy (n = 24) (at baseline, 7, 15, 33, and 52 weeks) who had received 1 year of treatment with a well-defined subcutaneous AIT form (Alutard SQ 510) were tested for IgE and IgG reactivity to 15 microarrayed HDM allergen molecules with ImmunoCAP Immuno-solid-phase Allergen Chip technology. IgG subclass levels to allergens and peptides were determined by ELISA, and IgG blocking was assessed by basophil activation. In vitro parameters were related to reduction of symptoms determined by combined symptom medication score and visual analog scale score.

RESULTS

Alutard SQ 510 induced protective IgG mainly against Dermatophagoides pteronyssinus (Der p) 1 and Der p 2 and to a lesser extent to Der p 23, but not to the other important allergens such as Der p 5, Der p 7, and Der p 21, showing better clinical efficacy in patients sensitized only to Der p 1 and/or Der p 2 as compared with patients having additional IgE specificities.

CONCLUSION

Stratification of patients with HDM allergy according to molecular sensitization profiles and molecular monitoring of AIT-induced IgG responses may enhance the success of AIT.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

Effect of Dermatophagoides pteronyssinus Immunotherapy on Upper and Lower Airway Eosinophilic Inflammatory Response to Nasal Allergen Challenge

Purpose

It remains unknown whether allergen-specific immunotherapy (AIT) could attenuate airway inflammatory response triggered by allergen exposure.

Methods

We performed Dermatophagoides pteronyssinus (Der-p) nasal provocation tests (NPTs) in allergic rhinitis (AR) and/or asthma patients without AIT (non-AIT), or at 16, 52, 104, or 156 weeks after Der-p AIT. Rhinitis and asthma visual analog scale (VAS; VAS of nasal symptoms [VAS-NS], VAS of asthma symptoms), the rhinoconjunctivitis quality of life questionnaire (RQLQ), nasal lavage, sputum induction, fractional exhaled nitric oxide (FeNO), nasal airway resistance, pulmonary function, and airway hyperresponsiveness were performed before and after NPT.

Results

Non-AIT subjects demonstrated significantly higher VAS-NS before and after NPT compared to AIT subjects (P < 0.05). NPT response was positive in 14 (100%) non-AIT, 7 (70%) 16 weeks-AIT, 6 (60%) 52 weeks-AIT, 6 (60%) 104 weeks-AIT, and 2 (20%) 156 weeks-AIT subjects. The NPT grade significantly correlated with AIT duration and baseline RQLQ score (r = −0.561, P < 0.001 and r = 0.525, P < 0.001, respectively). Sputum and nasal lavage eosinophil count, and FeNO in non-AIT subjects were significantly increased 6 hours after NPT (P < 0.05). AIT subjects did not change their sputum or nasal lavage eosinophil count before and after NPT. Subjects with 156 weeks-AIT demonstrated significantly lower levels of sputum and nasal lavage eosinophil count before and after NPT when compared with non-AIT patients (P < 0.05). Sputum eosinophil counts positively correlated with nasal lavage eosinophil counts at baseline and 6 hours after NPT (r = 0.719, P = 0.006 and r = 0.823, P < 0.001, respectively) in non-AIT patients.

Conclusion

Our results show that AIT can attenuate both upper and lower airway immune response to nasal allergen exposure in patients with AR and/or asthma.

Recent developments and highlights in allergic rhinitis

Allergic rhinitis (AR) is a disease with high prevalence all over the world and therefore needs to be thoroughly investigated and treated accordingly. The mechanisms underlying the pathology and treatment of AR have been widely studied, but many aspects remain unclear and warrant further investigations. This review presents an overview of recently published papers highlighting the risk factors, mechanisms, and treatment of AR. Additionally, recent studies discussing the role of single nucleotide polymorphism, DNA methylation, regulatory B cells, group 2 innate lymphoid cells, immunotherapy, and biologics in AR are also covered.

Advances in aeroallergen immunotherapy

PURPOSE OF REVIEW

Allergic rhinoconjunctivitis is the most common manifestation of allergic disease. This break in the normal natural function of the immune system to ignore harmless molecules such as pollen and pet dander to now aggressively react has lead to a substantial disease burden that is not always recognized and adequately treated.

RECENT FINDINGS

Individual molecular component testing may increase the predictive value of blood sIgE and clinical symptoms. Defining the most symptoms inducing allergenic protein has led to advances in peptide-based allergen immunotherapy. There have been steady consistent reports that allergy immunotherapy for children with symptomatic allergic rhinitis prevents the onset of asthma.

SUMMARY

Allergy immunotherapy is an effective disease-modulating treatment that alters the underlying immune dysfunction which is a currently underutilized therapy especially as it is likely effective in preventing the onset of asthma in children, at least in the short term.

Efficacy and safety of sublingual dust mite drops in children with mono- or polysensitized allergic rhinitis

OBJECTIVE

To explore the efficacy and safety of sublingual house dust mite (HDM) drops in children with mono- or polysensitized allergic rhinitis.

METHODS

We conducted a retrospective cohort study of 65 children with monosensitized AR and 118 children with polysensitized AR who were scheduled for sublingual administration of HDM drops from January 2015 to June 2016. Interleukin (IL)-2, IL-4, and IL-17α, transforming growth factor-β1 (TGF-β1), specific immunoglobulin E (IgE), and specific IgG4 were detected by ELISA. The efficacies were assessed using symptoms score and medication score. All the outcomes were measured 1 month before the study and 1 month after the end of the 2-year treatment.

RESULTS

The total nasal symptoms score (TNSS) decreased significantly from 11.27 (9.81 ± 12.73) at baseline to 3.48(1.98 ± 4.98) at the end of sublingual treatment for the monosensitized AP group (t = 30.00, P < 0.01), and from 11.54(10.04 ± 13.04) to 3.56 (2.00 ± 5.16) for the polysensitized AR group (t = 40.05, P < 0.01), respectively. IL-2 and TGF-β1 increased significantly after treatment in contrast with before treatment in both the monosensitized group and the polysensitized group (both P < 0.01). In contrast, IL-4 and IL-17α decreased significantly after treatment compared with the baseline in both groups (both P < 0.01). Sublingual HDM drops were generally safe and well tolerant in both groups.

CONCLUSIONS

This study confirmed the efficacy and safety of sublingual AIT in both monosensitized and polysensitized AR patients (Chinese children).

Bronchial asthma triggered by house dust mites in patients with local allergic rhinitis

BACKGROUND

Over 30% of local allergic rhinitis (LAR) patients self-report bronchial symptoms suggestive of asthma, but the relationship between the allergen exposure and the bronchial symptoms has not been studied.

OBJECTIVE

To investigate whether a bronchial counterpart of LAR exists.

METHODS

Patients were classified by clinical history, skin prick test/serum specific IgE (sIgE), and nasal allergen provocation test (NAPT) into the LAR, allergic rhinitis (AR), and nonallergic rhinitis (NAR) phenotypes. Twenty-eight LAR, 18 AR, and 19 NAR patients self-reporting bronchial symptoms suggestive of asthma and 8 healthy controls (HC) were subjected to a methacholine test (MT) before (Visit 1) and 24 hours after (Visit 3) a bronchial provocation test with Dermatophagoides pteronyssinus (BPT-DP) (Visit 2). Induced sputum and peripheral blood obtained after each MT were analyzed for immune cell populations, tryptase, ECP, and sIgE.

RESULTS

A positive MT was found in 50% of LAR, 83.3% of AR, 57.89% of NAR, and 0% of HC individuals (P = 0.022 AR vs LAR) at V1. BPT-DP was positive in 8 LAR and 15 AR patients (28% vs 83.3%, P < 0.001), with no positive responses in NAR and HC. All BPT-DP+ patients experienced a significant decrease of PC₂₀ at V3 vs V1 (P = 0.016 LAR, P ≤ 0.001 AR). BPT-DP+ patients also showed a significant increase of eosinophils, monocytes, and ECP in induced sputum at V3 compared with V1.

CONCLUSION

The results suggest the existence of a new asthma phenotype (local allergic asthma) defined by absence of systemic atopy and positivity to BPT with allergen.

Nasal challenges in allergen immunotherapy trials

PURPOSE OF REVIEW

The nasal allergen challenge (NAC) model can be a valuable diagnostic tool for allergic rhinitis. Alongside its clinical use, NACs can be used as primary and secondary endpoints in studies evaluating allergen immunotherapy (AIT) products for allergic rhinitis treatment. This review will discuss the technical aspects of the NAC model and provide a summary of recent studies using NACs to assess existing and new AIT treatments.

RECENT FINDINGS

Over the last 2 years, both titrated and single-dose nasal challenge protocols have been used to evaluate immunotherapies targeting grass, birch, house dust mite, and cat allergens. Early efficacy and dose-finding trials showed improvements in allergic symptoms and nasal tolerance to allergens after AIT treatment with standardized extracts or modified forms of whole allergen. NACs were also used in two proof-of-concept studies to illustrate the efficacy of intralymphatic immunotherapy with two concomitant allergens and subcutaneous immunotherapy with Fel d 1-specific IgG-blocking antibodies.

SUMMARY

Along with existing therapies, nasal challenges are useful in evaluating AIT treatments in the very early stages of clinical development. However, because of the variety in challenge techniques and symptom assessments available, special attention must be placed in the protocol design in order to compare the study results with existing NAC publications.

How to Diagnose and Treat Local Allergic Rhinitis: A Challenge for Clinicians

Chronic rhinitis is a very common disease that can be divided in various phenotypes. Historically, the condition has been classified into the allergic rhinitis (AR) and non-allergic non-infectious rhinitis (NAR) forms, based on the results of the classical biomarkers of atopy: skin prick test and serum allergen-specific IgE However, this classification does not reflect the complexity of the rhinitis syndrome, as illustrated by the existence of non-atopic rhinitis patients who display a nasal reactivity to environmental allergens. This new phenotype has been termed local allergic rhinitis (LAR) and can be only recognized if an additional test such as the nasal allergen challenge (NAC) is integrated in the diagnostic algorithm for chronic rhinitis. Recent data shows that the NAC is a very safe and reliable technique ready for the clinical practice. LAR is a differentiated rhinitis phenotype which often commences during childhood and quickly progresses towards a clinical worsening and the association of comorbidities in other mucosal organs. Recent evidence supports the existence of a bronchial counterpart of LAR (local allergic asthma), which highlights the pathophysiological links between the upper and lower airways and reinforces the united airways concept. Importantly, several controlled studies have demonstrated the ability of allergen immunotherapy to control LAR symptoms while the therapy is being administered. This review emphasizes the need to implement the NAC in the clinical practice in order to facilitate the recognition of LAR patients, allowing for an early prescription of specific therapies with disease-modifying potential.

Safety and reproducibility of nasal allergen challenge

BACKGROUND

The nasal allergen challenge (NAC) is a useful tool for the diagnosis of allergic rhinitis (AR) and local allergic rhinitis (LAR) and might serve to design and monitor allergen immunotherapy. Nevertheless, data about its safety and reproducibility are scarce.

OBJECTIVE

To investigate the safety and reproducibility of NAC in pediatric and adult rhinitis patients with/without asthmatic symptoms, and in healthy controls.

METHODS

A retrospective evaluation of the NACs conducted in our Unit for 2005-2017 and monitored by acoustic rhinometry and nasal-ocular symptoms was performed to analyze the safety of two methods for allergen application (metered spray & micropipette) and NAC protocols (NAC with single or multiple allergens/session [NAC-S & NAC-M]). The adverse events (AEs), spirometry values, and rescue medication required for AE were recorded. The reproducibility was examined by a prospective analysis of three repeated NAC-S performed at 1-2-month interval in AR, LAR and nonallergic rhinitis patients, and in healthy controls.

RESULTS

A total of 11 499 NACs were performed in 518 children and 5830 adults. Only four local AE occurred, and 99.97% of NACs were well tolerated. The reproducibility and positive and negative predictive values of three consecutive NAC-S performed in 710 subjects were 97.32%, 100%, and 92.91%, respectively. There were no false-positive results in the 710 analyzed subjects. Safety and reproducibility were comparable between the methods of allergen application and the rhinitis phenotypes.

CONCLUSION

The NAC is a safe and highly reproducible diagnostic test ready to be used in the clinical practice in both children and adults with or without asthma.

Is the evidence of local allergic rhinitis growing?

PURPOSE OF REVIEW

To examine the recent advances on epidemiological studies, diagnostic approach and clinical management of local allergic rhinitis (LAR) in adults and children.

RECENT FINDINGS

Evidence about LAR is growing especially in pediatric and Asian populations. The prevalence of LAR is lower in Asian countries compared with western countries in both children and adults. LAR is considered a chronic condition and an independent rhinitis phenotype that affects up to 26.5% of nonatopic rhinitis patients. The disease rapidly progress toward the clinical worsening with associated onset of asthma and conjunctivitis, which further impairs patient's quality of life. Nasal Allergen Provocation Test is the diagnostic gold standard that can be complemented by basophil activation test and the detection of specific IgE in nasal secretions. Allergen immunotherapy induces a significant and early improvement in both clinical symptoms and quality of life in LAR patients.

SUMMARY

LAR is a common entity, with different prevalence depending on geographical locations. LAR has to be considered in the process of differential diagnosis in children and adults with rhinitis. Diagnosis of LAR is crucial in order to start an etiologic treatment such as allergen immunotherapy, which has proven to be very effective in these patients.

Efficacy and safety of birch pollen immunotherapy for local allergic rhinitis

BACKGROUND

Local allergic rhinitis (LAR) is a relatively new disease.

OBJECTIVE

To ascertain the effects of allergen-specific immunotherapy in LAR.

METHODS

A randomized, double-blind, placebo-controlled trial of birch subcutaneous allergen immunotherapy (AIT) for LAR was performed in 28 patients. The therapy was performed for 24 months in 15 patients with AIT and 13 patients given placebo. The primary end point was decrease in symptom medication score (SMS). In addition, we monitored serum-specific immunoglobulin E (IgE), serum-specific immunoglobulin G4, nasal-specific IgE to Bet v 1, and safety and quality-of-life parameters.

RESULTS

After 24 months of treatment, there was a significant decrease in the median area under the curve for SMS of the active group vs the placebo group: 2.14 (range, 1.22-4.51) vs 6.21 (range, 5.12-7.89), at the P < .05 level. During AIT, the active group showed a significant decrease in SMS of up to 65% vs baseline. A significant increase in immunoglobulin G4 and decrease in nasal-specific IgE were observed in the active group during AIT compared with the placebo group. AIT was well-tolerated and without systemic reactions.

CONCLUSION

This study demonstrates that AIT for birch pollen in patients with LAR was clinically effective and exhibited good tolerance.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03157505.

Recent developments and highlights in rhinitis and allergen immunotherapy

This review paper aims to provide an overview of recent developments in the field of allergic and non-allergic rhinitis, as well as allergen immunotherapy. Recent advances in phenotyping and endotyping various forms of rhinitis have brought us one step closer towards tailoring treatment more appropriately for a given patient. Updates on local allergic rhinitis are also covered. Allergen immunotherapy (AIT) is an area of significant interest, with multiple original papers and recent position papers and guidelines published. Evidence related to the application of AIT in seasonal and perennial allergic rhinitis (AR), local allergic rhinitis and novel and expanded applications is discussed in the publication.

Recent developments and highlights in biomarkers in allergic diseases and asthma

The potential of precision medicine in allergy and asthma has only started to be explored. A significant clarification in the pathophysiology of rhinitis, chronic rhinosinusitis, asthma, food allergy and drug hypersensitivity was made in the last decade. This improved understanding led to a better classification of the distinct phenotypes and to the discovery of new drugs such as biologicals, targeting phenotype-specific mechanisms. Nevertheless, many conditions remain poorly understood such as non-eosinophilic airway diseases or non-IgE-mediated food allergy. Moreover, there is a need to predict the response to specific therapies and the outcome of drug and food provocations. The identification of patients at risk of progression towards severity is also an unmet need in order to establish adequate preventive or therapeutic measures. The implementation of precision medicine in the clinical practice requires the identification of phenotype-specific markers measurable in biological matrices. To become useful, these biomarkers need to be quantifiable by reliable systems, and in samples obtained in an easy, rapid and cost-efficient way. In the last years, significant research resources have been put in the identification of valid biomarkers for asthma and allergic diseases. This review summarizes these recent advances with focus on the biomarkers with higher clinical applicability.

IgE Test in Secretions of Patients with Respiratory Allergy

PURPOSE OF REVIEW

IgE is a key player in multiple inflammatory airway diseases. Ample literature demonstrates its presence in mucosa of patients with allergic rhinitis (AR), local allergic rhinitis (LAR), asthma, or chronic rhinosinusitis with nasal polyposis (CRSwNP).

RECENT FINDINGS

Current evidence shows that high-affinity IgE in blood stream of allergic individuals derives mainly from the mucosae. Also, mucosal synthesis of IgE can occur in the absence of systemic atopy, and may be relevant in atopic and non-atopic phenotypes of rhinitis as demonstrated in LAR. Specific IgE (sIgE) detection varies depending on technique used for sample collection and its measurement. sIgE detection is highly specific for diagnosis of LAR. Moreover, measurement of sIgE in secretions could be useful in monitoring response to allergen-specific immunotherapy in both AR and LAR phenotypes. This review will focus on recent developments in the role of IgE in respiratory diseases, and the clinical implications of its measurement in secretions.

Recent advances in allergic rhinitis

Allergic rhinitis affects 20 to 30% of adults in both the United States and Europe and perhaps a somewhat higher percentage of children. In addition to nasal and ocular symptoms directly related to the allergic process, interference of these symptoms with sleep leads to daytime sleepiness and impaired quality of life. Patients miss work because of symptoms but an even greater problem is interference with work productivity, or presenteeism, which has been reported to be the biggest contributor to the total economic cost of allergic rhinitis. There has been increasing awareness that many patients with either seasonal or perennial symptoms but negative skin and in vitro tests for allergen sensitivity have local nasal allergy, diagnosable by the presence of allergen-specific IgE in their nasal secretions or a positive nasal allergen challenge or both. The pharmaceutical management of allergic rhinitis rests on symptomatic treatment with antihistamines that perhaps are more effectively administered intranasally than orally and intranasal corticosteroids. Allergen immunotherapy is very effective, even for local allergic rhinitis, and the shortcomings of subcutaneous immunotherapy of inconvenience and safety are reduced by the introduction of sublingual immunotherapy (SLIT). Use of the latter is currently somewhat limited by the lack of appropriate dosing information for SLIT liquids and the limited number of allergens for which SLIT tablets are available.

EAACI Position paper on the standardization of nasal allergen challenges

Nasal allergen challenge (NAC) is an important tool to diagnose allergic rhinitis. In daily clinical routine, experimentally, or when measuring therapeutic success clinically, nasal allergen challenge is fundamental. It is further one of the key diagnostic tools when initiating specific allergen immunotherapy. So far, national recommendations offered guidance on its execution; however, international divergence left many questions unanswered. These differences in the literature caused EAACI to initiate a task force to answer unmet needs and find a consensus in executing nasal allergen challenge. On the basis of a systematic review containing nasal allergen challenges of the past years, task force members reviewed evidence, discussed open issues, and studied variations of several subjective and objective assessment parameters to propose a standardized way of a nasal allergen challenge procedure in clinical practice. Besides an update on indications, contraindications, and preparations for the test procedure, main recommendations are a bilaterally challenge with standardized allergens, with a spray device offering 0.1 mL per nostril. A systematic catalogue for positivity criteria is given for the variety of established subjective and objective assessment methods as well as a schedule for the challenge procedure. The task force recommends a unified protocol for NAC for daily clinical practice, aiming at eliminating the previous difficulty of comparing NAC results due to unmet needs.

Prevalence and clinical characteristics of local allergic rhinitis to house dust mites

PURPOSE OF REVIEW

Local allergic rhinitis (LAR) is a recently classified subtype of rhinitis defined by a nasal allergic response in patients without systemic evidence of atopy. Recent studies have reported the prevalence, clinical course, culprit allergens, diagnostic methods and treatment outcomes of LAR. The purpose of this review is to summarize the most relevant and updated scientific evidence for LAR, especially focusing on its prevalence and clinical characteristics.

RECENT FINDINGS

LAR is found in a significant proportion (3.7-61.9%) of patients previously diagnosed with nonallergic rhinitis, but the prevalence may differ among ethnic groups and countries. Common allergens of LAR are similar to those of allergic rhinitis, in which house dust mites are the most common cause, followed by grass pollen, tree pollen, weed pollen and animal dander confirmed by provocation tests. Although the nasal provocation test to a single allergen is considered the gold standard method, the detection of allergen-specific IgE and other inflammatory mediators from nasal secretions and the basophil activation test can assist in the diagnosis of LAR. Conjunctivitis and asthma are the most common comorbid conditions, and the occurrence rate of asthma increases over period. However, the conversion rate to allergic rhinitis was not significantly different between LAR and healthy controls.

SUMMARY

LAR is a well-differentiated entity of rhinitis, which should be considered in patients with persistent and severe symptoms without any systemic evidence of atopy. Further research is needed to investigate the long-term outcome, and geographic and ethnic differences of LAR.

Local allergic rhinitis: Implications for management

A significant proportion of rhinitis patients without systemic IgE-sensitisation tested by skin prick test and serum allergen-specific IgE (sIgE) display nasal reactivity upon nasal allergen provocation test (NAPT). This disease phenotype has been termed local allergic rhinitis (LAR). LAR is an underdiagnosed entity affecting children and adults from different parts of the world, with moderate-to-severe symptoms, impairment of quality of life and rapid progression to symptom worsening. LAR is a stable phenotype and not merely an initial state of AR. Allergic rhinitis and LAR share many clinical features including a positive NAPT response, markers of type 2 nasal inflammation including sIgE in nasal secretions and a significant rate of asthma development. LAR should be considered as a differential diagnosis in those subjects of any age with symptoms suggestive of AR but no evidence of systemic atopy. Although LAR pathophysiology is partially unknown, in some patients sIgE can be demonstrated directly in the nasal secretions and/or indirectly via positive responses in basophil activation test (BAT). LAR can coexist with other rhinitis phenotypes, especially AR. The diagnosis currently relies on the positivity of NAPT to a single or multiple allergens. NAPT has high sensitivity, specificity and reproducibility, and it is considered the gold standard. BAT and the measurement of nasal sIgE can also contribute to LAR diagnosis. LAR patients benefit from the same therapeutic strategies than AR individuals, including the avoidance of allergen exposure and the pharmacotherapy. Moreover, several recent studies support the effectiveness and safety of allergen immunotherapy for LAR, which opens a window of treatment opportunity in these patients.

Specific immunotherapy in local allergic rhinitis: A randomized, double-blind placebo-controlled trial with Phleum pratense subcutaneous allergen immunotherapy

BACKGROUND

Allergen immunotherapy has been shown to be an effective treatment for local allergic rhinitis (LAR) to house dust mites. Studies with pollen allergen immunotherapy are limited to observational studies. The aim of this study was to evaluate the clinical efficacy and safety of Phleum pratense subcutaneous immunotherapy (Phl-SCIT) in LAR.

METHODS

In a randomized double-blind placebo-controlled study, 56 patients with moderate-severe LAR to grass pollen received Phl-SCIT with a depigmented polymerized pollen vaccine or placebo for the first year, and Phl-SCIT the second one. The blind was maintained throughout the study. Primary outcome was combined symptom medication score (CSMS) during grass pollen season (GPS). Secondary clinical outcomes included organ-specific symptoms, medication-free days, rhinitis severity and asthma control. Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), nasal allergen provocation test (NAPT), skin testing, serum levels of specific IgG4 and specific IgE and safety were also evaluated.

RESULTS

Subcutaneous immunotherapy (SCIT) had a short-term and sustained effect with significant improvements of all primary and secondary clinical outcomes and RQLQ score. SCIT significantly increased serum sIgG4 levels and allergen tolerance, from the 6th to 24th months of treatment. At the end of the study, 83% of patients treated with ≥6 months of SCIT tolerated a concentration of P. pratense over 50 times higher than baseline, and 56% gave a negative NAPT. SCIT was well tolerated; six mild local reactions occurred, and there were no serious adverse events related to the study medication.

CONCLUSIONS

Subcutaneous immunotherapy with depigmented polymerized allergen extracts is a safe and clinically effective treatment for LAR to P. pratense.

Local allergic rhinitis is an independent rhinitis phenotype: The results of a 10-year follow-up study

BACKGROUND

The knowledge about the natural history of local allergic rhinitis (LAR) is limited. One unmet question is to demonstrate whether LAR should be considered the first step in the development of allergic rhinitis (AR) or an independent phenotype. The aim of this study was to prospectively evaluate the natural history of a population with LAR, the potential conversion to AR with systemic atopy and the development of asthma during 10 years.

METHODS

This is the second phase of a 10-year follow-up study of a cohort of 176 patients with LAR of recent onset and 115 age- and sex-matched healthy controls prospectively evaluated from 2005 to 2016. Clinical-demographic questionnaire, spirometry, skin prick test and specific IgE were evaluated yearly. Nasal allergen provocation tests (NAPT) with Dermatophagoides pteronyssinus, Alternaria alternata, Olea europaea and grass pollen were performed at baseline, and after 5 and 10 years.

RESULTS

After 10-year LAR, patients experienced a significant and clinically relevant worsening of the rhinitis, with increase in emergency assistance, development of asthma, loss of allergen tolerance and impairment of the quality of life. This worsening became significant after 5 years and progressed throughout 10 years. A similar rate of development of AR with systemic atopy was detected in patients and controls (9.7% vs 7.8%, log-rank P=.623). In 5 patients, conversion to systemic atopy occurred >10 years (3%).

CONCLUSIONS

LAR is a well-differentiated clinical entity with a low rate of development of systemic atopy, a natural evolution towards worsening and a risk factor for suffering asthma.

Direct intranasal application of the solid phase of ImmunoCAP® increases nasal specific immunoglobulin E detection in local allergic rhinitis patients

BACKGROUND

The measurement of nasal specific IgE (NsIgE) in local allergic rhinitis (LAR) patients is challenging and shows variability. The objective of this work was to evaluate a minimally-invasive method of direct detection of NsIgE in patients with LAR to Dermatophagoides pteronyssinus (DP) using an automated immunoassay.

METHODS

Fifty patients participated (LAR, n = 14; allergic rhinitis (AR), n = 20; healthy controls [HC], n = 16). Detection of NsIgE was performed by direct application of the solid phase of a commercial DP ImmunoCAP® test 24 hours after DP nasal provocation.

RESULTS

There was no difference in the median volume of secretion absorbed by the solid phase of the ImmunoCAP test in the 3 studied groups (p = 0.17). According to receiver operating characteristic (ROC) curve analysis, NsIgE ≥0.1450 was the optimal cutoff point, obtaining in LAR patients 42.86% sensitivity with the highest specificity (100%), and 75% sensitivity and 100% specificity for AR.

CONCLUSION

This study demonstrates the detection of NsIgE to DP in LAR by using a simple, commercial device with high specificity.

Local allergic rhinitis: evolution of concepts

The discovery of an exclusive local production of IgE antibodies dates back to the 1970s, but only recently the pathophysiology of such phenomenon was deeply investigated, leading to the concept of local allergic rhinitis (LAR). Currently, LAR is defined by the occurrence, in patients with symptoms clearly suggesting allergic rhinitis but with negative results to common allergy testing, of allergen specific IgE in the nasal mucosa. Most studies investigating LAR were based on the development of rhinitis symptoms following nasal provocation test (NPT) with the suspected allergens, but such test may be performed by a number of options, none of them being as yet acknowledged and recommended in consensus document. On the other hand, also the mere detection of IgE in the nasal mucosa indicates, as for IgE measurement in blood or other tissues, allergic sensitization but cannot give the certainty of clinical allergy. Therefore, the combination of IgE detection in nasal mucosa and a positive result of NPT should be used to diagnose LAR. Recent data on the use for in vitro testing of molecular allergy diagnostics in place of whole allergen extracts suggest that this method could improve the sensitivity and specificity of laboratory tests, and an appraisal of the basophil activation test as a third level technique, to be implemented when the results of local IgE testing and NPT are uncertain, is currently ongoing.

Dermatophagoides pteronyssinus immunotherapy changes the T-regulatory cell activity

Subcutaneous specific immunotherapy (SCIT) has been shown to modify the Dermatophagoides pteronissinus (DP) allergic response, characterized by generation of Treg cells. However, studies have reported no changes in the proportion of Treg cells after immunotherapy, indicating that the effects may be due to modifications in their regulatory activities. We aimed to determine whether Tregs generated by DP-SCIT can switch the allergic response to tolerant and study the involvement of suppressive cytokines on it. Twenty-four DP-allergic rhinitis patients were recruited, 16 treated with DP-SCIT and 8 untreated. Treg and T effector cells were isolated before and after DP-SCIT, and cocultured in different combinations with α-IL-10, α-TGF-β blocking antibodies and nDer p 1. Treg cells after DP-SCIT increased Th1 and decreased Th2 and Th9 proliferation. Similarly, they increased IL-10 and decreased IL-4 and IL-9-producing cells. α-IL-10 affected the activity of Treg cells obtained after DP-SCIT only. Finally, DP-specific IgG4 levels, Treg percentage and IL-10 production were correlated after DP-SCIT. These results demonstrate that DP-SCIT induces Treg cells with different suppressive activities. These changes could be mediated by IL-10 production and appear to play an important role in the induction of the tolerance response leading to a clinical improvement of symptoms.

Local Allergic Rhinitis in Adult Patients with Chronic Nasal Symptoms

BACKGROUND

Local allergic rhinitis (LAR) remains an underdiagnosed condition characterized by the local production of IgE antibodies during the natural exposure to aeroallergens. The prevalence of LAR in adult patients with a previous diagnosis of non-AR was assessed.

MATERIAL AND METHODS

Eighty-four patients with perennial nasal allergy symptoms but a negative skin prick test and specific IgE antibodies against common inhalant allergens were included in the study. Nasal provocation tests were performed with the inhalant allergens Dermatophagoides pteronyssinus, Alternaria, and cat allergen, followed by the detection of nasal-specific IgE antibodies in the lavage during the challenge.

RESULTS

LAR was confirmed in 21 (25%) study patients. In the remaining 63 (75%) patients, non-AR was diagnosed. In addition, LAR was found following exposure to D. pteronyssinus in 19 (22.6%) patients, Alternaria in 3 (3.6%) patients, and the cat allergen in 1 (1.2%) patient. In 2 patients, concomitant allergies to D. pteronyssinus and Alternaria were observed.

CONCLUSION

LAR can be a form of chronic perennial rhinitis that has previously been considered to be non-AR.

Nonallergic rhinitis and lower airway disease

In the past years, several investigators have demonstrated the existence of local nasal responses in some patients with typical allergic rhinitis symptoms but without atopy and have defined a new phenotype called local allergic rhinitis (LAR) or 'entopy'. In a percentage of LAR subjects, the upper airway disease is also associated with lower airway symptoms. After the description of this phenotype, the differential diagnosis between LAR and nonallergic rhinitis (NAR) has become a challenge for the clinician. To correctly identify LAR patients is of high importance for treatment and management of these patients, and for an appropriate inclusion of patients in clinical trials and genetics studies. The treatment of LAR patients, in contrast with NAR, is oriented to allergen avoidance and specific treatment. Allergen immunotherapy, the aetiological treatment for allergic respiratory diseases, has demonstrated to be an effective and safe treatment in LAR, increasing immunological tolerance, and reducing the clinical symptoms and the use of medication. In this article, the important and novel aspects of LAR in terms of mechanisms, diagnosis and treatment will be discussed. Also, the involvement of the lower airway and the potential role of IgE in the bronchial disease will be also reviewed.