Pretreatment IgE sensitization patterns determine the molecular profile of the IgG4 response during updosing of subcutaneous immunotherapy with timothy grass pollen extract

Long-term efficacy of house dust mite sublingual immunotherapy on clinical and pulmonary function in patients with asthma and allergic rhinitis

Background

A previous study reported that house dust mite (HDM) sublingual immunotherapy (SLIT) for 48 weeks was effective as add-on treatment for allergic asthma; however, data regarding its long-term efficacy are scarce.

Objective

We sought to evaluate the effect of HDM SLIT on asthma control, pulmonary function, and airway inflammation and remodeling throughout the 5-year treatment period.

Methods

A total of 140 patients with asthma and allergic rhinitis sensitized to HDM were randomized to receive either drugs alone or drugs plus SLIT for 5 years. The 5-item Asthma Control Questionnaire (ACQ-5), Asthma Quality of Life Questionnaire (AQLQ), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), spirometry, quantitative computed tomography, and type 2 biomarkers were assessed.

Results

An improvement in the ACQ-5, AQLQ, and RQLQ scores was observed in the SLIT group compared with the control group. HDM SLIT increased lung function and reduced the percentage of airway wall area. The levels of fractional exhaled nitric oxide (Feno), blood eosinophil, serum specific IgE for HDM, and total IgE decreased and were sustained during the 5 years. The change in type 2 biomarkers correlated with change in the AQLQ score. On the basis of receiver-operating characteristic analysis for predicting responders, the area under the receiver-operating characteristic curve in FEV1% predicted, airway wall area, Feno, and specific IgE was high. Multivariate regression analysis showed that the strongest predictor of responders was Feno.

Conclusions

HDM SLIT continued to provide sustained efficacy, improve lung function, and prevent progression of airway inflammation and remodeling in asthma throughout the 5-year treatment period.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Molecular Aspects of Allergen-Specific Immunotherapy in Patients with Seasonal Allergic Rhinitis

A systematic review and narrative synthesis of publications was undertaken to analyze the role of component-resolved diagnosis technology in identifying polysensitization for the provision of allergen-specific immunotherapy to patients with seasonal allergic rhinitis. A search of publications was carried out in electronic databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search helped to identify 568 publications, 12 of which were included in this review. Overall, 3302 patients were enrolled. The major finding was that component-resolved diagnostics change the choice of relevant allergens for allergen-specific immunotherapy in at least 50% of cases. Sensitization to allergen components differs with age, type of disease, and overall disease duration. Patients who had both bronchial asthma and allergic rhinitis were sensitized to a larger number of allergens than patients who had bronchial asthma alone.

Molecular reactivity profiling upon immunotherapy with a 300 IR sublingual house dust mite tablet reveals marked humoral changes towards major allergens

BACKGROUND

Molecular antibody reactivity profiles have not yet been studied in depth in patients treated by sublingual house dust mite (HDM) tablet immunotherapy. Humoral immune responses to a large panel of HDM mite allergens were studied using allergen microarray technology in a subset of clinically defined high and low responder patients from a double-blind placebo-controlled allergen-specific immunotherapy (AIT) trial using sublingual 300 IR HDM tablets.

METHODS

Serum levels of IgE, IgG and IgG₄ to 13 Dermatophagoides pteronyssinus molecules were measured at baseline and after 1-year AIT, using allergen microarrays in 100 subjects exhibiting high or low clinical benefit.

RESULTS

Der p 1, Der p 2 and Der p 23 were the most frequently recognized allergens in the study population. Patients with HDM-related asthma had significantly higher allergen-specific IgE levels to Der p 1 and Der p 23. No significant difference in the distribution of allergen sensitization pattern was observed between high and low responders. An increase in serum allergen-specific IgG and IgG₄ occurred upon AIT, in particular to allergens Der p 1, Der p 2 and Der p 23 (p < 0.0001).

CONCLUSIONS

We confirm for our study population that Der p 1- and Der p 23-specific IgE levels are associated with asthma. IgE reactivity profiles were not predicitive of sublingual AIT outcomes, with 300 IR tablets as efficacious in pauci- and multi-sensitized subjects. Our study is the first to demonstrate the induction of IgG and IgG₄  specific for the HDM allergens Der p 1, Der p 2 and Der p 23 by sublingual AIT.

Thermosensitive PLGA–PEG–PLGA Hydrogel as Depot Matrix for Allergen-Specific Immunotherapy

Allergen-specific immunotherapy (AIT) is the only currently available curative treatment option for allergic diseases. AIT often includes depot-forming and immunostimulatory adjuvants, to prolong allergen presentation and to improve therapeutic efficacy. The use of aluminium salts in AIT, which are commonly used as depot-forming adjuvants, is controversially discussed, due to health concerns and Th2-promoting activity. Therefore, there is the need for novel delivery systems in AIT with similar therapeutic efficacy compared to classical AIT strategies. In this study, a triblock copolymer (hydrogel) was assessed as a delivery system for AIT in a murine model of allergic asthma. We show that the hydrogel combines the advantages of both depot function and biodegradability at the same time. We further demonstrate the suitability of hydrogel to release different bioactive compounds in vitro and in vivo. AIT delivered with hydrogel reduces key parameters of allergic inflammation, such as inflammatory cell infiltration, mucus hypersecretion, and allergen-specific IgE, in a comparable manner to standard AIT treatment. Additionally, hydrogel-based AIT is superior in inducing allergen-specific IgG antibodies with potentially protective functions. Taken together, hydrogel represents a promising delivery system for AIT that is able to combine therapeutic allergen administration with the prolonged release of immunomodulators at the same time.

Efficacy of a house dust mite sublingual immunotherapy tablet as add-on dupilumab in asthma with rhinitis

BACKGROUND

HDM SLIT is one of the disease-modifying treatment for allergic asthma, and has demonstrated efficacy in clinical trials. Dupilumab, blocks IL-4 and IL-13 signaling, key drivers of type 2 inflammation, and is approved for patients with uncontrolled, moderate-to-severe asthma. The aim of this study was to evaluate outcomes after HDM SLIT initiation in asthma with rhinitis not optimally controlled with dupilumab in a real-world setting.

METHODS

At baseline and 48 weeks after treatment, asthma control questionnaire (ACQ)-5, asthma quality of life questionnaire (AQLQ) and rhinoconjunctivitis quality of life questionnaire (RQLQ) were assessed. Spirometry, type 2 inflammatory biomarkers and quantitative computed tomographic parameters of airway remodeling were also collected.

RESULTS

Of 47 patients received HDM SLIT and 41 completed the study. Combined HDM SLIT and dupilumab improved ACQ-5 (p < 0.05), AQLQ (p < 0.05), RQLQ (p < 0.05), and increased lung function and reduced FeNO (p < 0.05) and airway percentage wall area, and wall thickness (each, p < 0.05). The change in ACQ-5 and AQLQ score correlated with both changes in FeNO and FEV₁ percent predicted. Multiple regression analysis showed that the change in FEV₁ percent predicted was independent factor for improvement of AQLQ (r² = 0.510, p = 0.012). Based on ROC analysis for predicting SLIT responders, the baseline area under the curves in serum HDM specific-IgE, total IgE and FEV₁ percent predicted were high (>0.8).

CONCLUSIONS

These results support the benefits of adding HDM SLIT to pharmacotherapy plus dupilumab in uncontrolled asthma with rhinitis.

Exploring the role of basophil activation test in diagnosis of Dermatophagoides farinae sensitization and evaluation of therapeutic efficacy of subcutaneous immunotherapy in children

OBJECTIVE

It aims to detect basophil activation ratio (%CD63⁺ ) in peripheral blood of children with allergic asthma and rhinitis by using Flow cytometry (FCM) , so as to analyze the application values and clinical relevance of the Basophil Activation Test (BAT) in diagnosis of Dermatophagoides farinae (Derf) sensitization and monitoring therapeutic efficacy of subcutaneous immunotherapy (SCIT).

METHODS

It was a prospective study. From the newly diagnosed children with asthma and rhinitis in our pediatric clinic, 39 patients diagnosed Derf sensitization and 15 patients not allergic to Derf were enrolled; another 4 healthy children were taken as control group. Using Derf extracts in concentration of 1 μg/ml, 10 μg/ml and 100 μg/ml as the stimulus, BAT results were expressed as %CD63⁺ in diagnosis of Derf sensitization and its correlation with skin prick tests (SPT), serum total IgE (tIgE), specific IgE (sIgE), sIgE/tIgE, specific IgG4 (sIgG4), FEV1%pred in pulmonary ventilation function, exhaled nitric oxide (FeNO), children asthma control test (C-ACT) and visual analogue scale (VAS) were observed. In sensitization group, %CD63⁺ , sIgG4 and clinical indicators were detected again from patients who had received SCIT to analyze their internal connections.

RESULTS

The average levels of %CD63⁺ in three concentrations showed an increasing concentration-dependent trend overall. %CD63⁺ in sensitization group was significantly higher than that in the other two groups. The analysis of ROC for Derf sensitization showed the area under the curve (AUC) for BAT in three concentrations were higher than that for sIgE whose AUC is 0.893. %CD63⁺ was positively correlated with SPT grade, sIgE, sIgE/tIgE and VAS, and negatively correlated with C-ACT. In patients receiving SCIT, %CD63⁺ became lower and sIgG4 level became higher than pretreatment. There was no obvious change in sIgG4 in those who hadn't received SCIT.

CONCLUSIONS

BAT is a reliable and non-invasive tool for diagnosis of Derf sensitization in children with asthma and rhinitis. CD63-based BAT has clinical value to monitor outcome of SCIT, and the change of basophil activation is inherently related to induction of sIgG4.

Specific IgE and IgG4 Profiles of House Dust Mite Components in Allergen-Specific Immunotherapy

Background

Allergen immunotherapy (AIT) can induce immune tolerance to allergens by activating multiple mechanisms, including promoting IgG4 synthesis and blunting IgE production. However, the longitudinal data of sIgE and sIgG4 to allergen components during AIT are limited.

Objective

We sought to investigate the persistence and evolution of sIgE and sIgG4 against house dust mite (HDM) components during AIT and explore their correlation with clinical responses.

Methods

Sixty allergic rhinitis (AR) with/without asthma patients receiving AIT for HDM were enrolled in AIT group. Thirty AR patients without receiving AIT served as control group. Blood samples were collected for sIgE, sIgG4 to HDM components (Derp 1, Derf 1, Derp 2, Derf 2, Derp 7, Derp 10, Derp 21 and Derp 23) assay at baseline, Month 6 and Month 18 of AIT. Combined symptom and medication scores (CSMS) were obtained accordingly.

Results

In the AIT group, sIgG4 to the HDM components of Derp 1, Derf 1, Derp 2 and Derf 2, Derp 21 significantly increased at Month 18 compared to the baseline (36.2 U_A/mL vs 158.8 U_A/mL, 46.4 U_A/mL vs 94.6 U_A/mL, 80.5 U_A/mL vs 152.3 U_A/mL, 78.3 U_A/mL vs 205.1 U_A/mL, 42.3 U_A/mL vs 59.3 U_A/mL, all p<0.05), sIgE to HDM components didn’t see differences at baseline and at Month 18 (all p>0.05).The numbers of positive HDM component sIgE and sIgG4 increased from 4.5 to 5 and 0 to 1.5 respectively (both p<0.05). However, the changes of sIgE, sIgG4, sIgE/sIgG4 ratio and the numbers of positive HDM components had no correlations with the improvement of CSMS after AIT (all ρ<0.3). For the control group, the sIgE and sIgG4 did not change significantly during the observational period (all p>0.05).

Conclusion

AIT can induce the production of sIgG4 to HDM components. However, the increased sIgG4 levels of HDM component do not correlate with the corresponding sIgE levels at baseline or with AIT response. sIgG4 to HDM components do not qualify as a biomarker to evaluate the efficacy of AIT.

The role of allergen-specific IgE, IgG and IgA in allergic disease

Immunoglobulin E (IgE)‐mediated allergy is the most common hypersensitivity disease affecting more than 30% of the population. Exposure to even minute quantities of allergens can lead to the production of IgE antibodies in atopic individuals. This is termed allergic sensitization, which occurs mainly in early childhood. Allergen‐specific IgE then binds to the high (FcεRI) and low‐affinity receptors (FcεRII, also called CD23) for IgE on effector cells and antigen‐presenting cells. Subsequent and repeated allergen exposure increases allergen‐specific IgE levels and, by receptor cross‐linking, triggers immediate release of inflammatory mediators from mast cells and basophils whereas IgE‐facilitated allergen presentation perpetuates T cell–mediated allergic inflammation. Due to engagement of receptors which are highly selective for IgE, even tiny amounts of allergens can induce massive inflammation. Naturally occurring allergen‐specific IgG and IgA antibodies usually recognize different epitopes on allergens compared with IgE and do not efficiently interfere with allergen‐induced inflammation. However, IgG and IgA antibodies to these important IgE epitopes can be induced by allergen‐specific immunotherapy or by passive immunization. These will lead to competition with IgE for binding with the allergen and prevent allergic responses. Similarly, anti‐IgE treatment does the same by preventing IgE from binding to its receptor on mast cells and basophils. Here, we review the complex interplay of allergen‐specific IgE, IgG and IgA and the corresponding cell receptors in allergic diseases and its relevance for diagnosis, treatment and prevention of allergy.

A novel functional mast cell assay for the detection of allergies

BACKGROUND

Clinical management of allergic diseases has been hampered by the lack of safe and convenient tests to reliably identify culprit allergens and to closely follow changes in disease activity over time. Because allergy diagnosis is a complex and laborious multistep procedure, there is an urgent need for simpler but still functionally accurate ex vivo assays allowing objective diagnosis, substantiating treatment choices, and quantifying therapeutic responses.

OBJECTIVE

In this study, we sought to develop a novel functional cell-based assay that relies on passive sensitization of allergic effector cells with patient serum, circumventing current limitations in allergy diagnosis.

METHODS

We genetically engineered a conditional homeobox B8 (Hoxb8)-immortalized progenitor line from the bone marrow of mice that are transgenic for the human high-affinity IgE receptor (FcεRIα). These cells can be reproducibly differentiated into mature Hoxb8 mast cells within 5 days of culture in virtually unlimited numbers.

RESULTS

We demonstrate that the established Hoxb8 mast cell assay can be used to accurately measure total IgE levels, identify culprit allergens, longitudinally monitor allergen-specific immunotherapy, and potentially determine the time point of tolerance induction upon allergen-specific immunotherapy in patients with allergy. To facilitate the analysis of large testing volumes, we demonstrate a proof-of-concept for a high-throughput screening application based on fluorescent cell barcoding using the engineered Hoxb8 mast cells.

CONCLUSIONS

Our results indicate that this novel mast cell assay could represent a valuable tool to support clinicians in the identification of IgE-mediated allergies and in the quantification of treatment efficacy as well as duration of therapeutic response.

Basophils and their effector molecules in allergic disorders

Basophils are the rarest granulocytes which represent <1% of peripheral blood leukocytes. Basophils bear several phenotypic similarities to tissue-resident mast cells and therefore had been erroneously considered as blood-circulating mast cells. However, recent researches have revealed that basophils play nonredundant roles in allergic inflammation, protective immunity against parasitic infections and regulation of innate and acquired immunity. Basophils are recruited to inflamed tissues and activated in an IgE-dependent or IgE-independent manner to release a variety of effector molecules. Such molecules, including IL-4, act on various types of cells and play versatile roles, including the induction and termination of allergic inflammation and the regulation of immune responses. Recent development of novel therapeutic agents has enabled us to gain further insights into basophil biology in human disorders. In this review, we highlight the recent advances in the field of basophil biology with a particular focus on the role of basophils in allergic inflammation. Further studies on basophils and their effector molecules will help us identify novel therapeutic targets for treating allergic disorders.

Basophil sensitivity reflects long-term clinical outcome of subcutaneous immunotherapy in grass pollen-allergic patients

BACKGROUND

Allergic rhinoconjunctivitis is a public health problem. Allergen Immunotherapy is an effective and safe treatment, that modifies the natural course of allergic disease and induces long-term tolerance.

OBJECTIVE

To correlate basophil and antibody biomarkers of subcutaneous immunotherapy to clinical outcomes and cellular changes in target tissue.

METHODS

Adults suffering from allergic rhinoconjunctivitis due to grass pollen allergy were randomized to receive subcutaneous immunotherapy (n = 18) or to an open control group (n = 6). Patients reported daily symptom and medication scores and weekly rhinitis related quality of life scores during four pollen seasons. Biomarkers were measured every 3 months for three years treatment and every 6 months in the follow-up year. Nasal and cutaneous allergen challenge tests were performed annually. Leukocyte subsets were assessed in nasal mucosa biopsies at baseline and after treatment.

RESULTS

Subcutaneous immunotherapy led to a 447-fold decrease in basophil sensitivity during the first treatment year. This remained 100-fold lower than baseline during the 3 year-treatment period and 10-fold lower during the follow-up year (n = 18, P = .03). Decrease in basophil sensitivity after three weeks of treatment predicted long-term improvement in seasonal combined symptom and medication scores (ῥ=-0.69, P = .0027) during three years of treatment. AUC of IgE-blocking factor correlated to nasal allergen challenge (ῥ = 0.63, P = .0012) and SPT (ῥ = 0.45, P = .03). Plasma cell numbers in the nasal mucosa increased during treatment (P = .02).

CONCLUSION

Decrease in basophil sensitivity after three weeks of subcutaneous allergen immunotherapy predicted the clinical outcome of this treatment.

Microarray-Based Allergy Diagnosis: Quo Vadis?

More than 30% of the world population suffers from allergy. Allergic individuals are characterized by the production of immunoglobulin E (IgE) antibodies against innocuous environmental allergens. Upon allergen recognition IgE mediates allergen-specific immediate and late-phase allergic inflammation in different organs. The identification of the disease-causing allergens by demonstrating the presence of allergen-specific IgE is the key to precision medicine in allergy because it allows tailoring different forms of prevention and treatment according to the sensitization profiles of individual allergic patients. More than 30 years ago molecular cloning started to accelerate the identification of the disease-causing allergen molecules and enabled their production as recombinant molecules. Based on recombinant allergen molecules, molecular allergy diagnosis was introduced into clinical practice and allowed dissecting the molecular sensitization profiles of allergic patients. In 2002 it was demonstrated that microarray technology allows assembling large numbers of allergen molecules on chips for the rapid serological testing of IgE sensitizations with small volumes of serum. Since then microarrayed allergens have revolutionized research and diagnosis in allergy, but several unmet needs remain. Here we show that detection of IgE- and IgG-reactivity to a panel of respiratory allergens microarrayed onto silicon elements is more sensitive than glass-based chips. We discuss the advantages of silicon-based allergen microarrays and how this technology will allow addressing hitherto unmet needs in microarray-based allergy diagnosis. Importantly, it described how the assembly of silicon microarray elements may create different microarray formats for suiting different diagnostic applications such as quick testing of single patients, medium scale testing and fully automated large scale testing.

Novel vaccines for allergen-specific immunotherapy

PURPOSE OF REVIEW

Allergen-specific immunotherapy (AIT) is a highly economic, effective and disease-modifying form of allergy treatment but requires accurate prescription and monitoring. New molecular approaches are currently under development to improve AIT by reducing treatment-related side effects, cumbersome protocols and patients' compliance. We review the current advances regarding refined diagnosis for prescription and monitoring of AIT and the development of novel molecular vaccines for AIT. Finally, we discuss prophylactic application of AIT.

RECENT FINDINGS

There is evidence that molecular allergy diagnosis not only assists in the prescription and monitoring of AIT but also allows a refined selection of patients to increase the likelihood of treatment success. New data regarding the effects of AIT treatment with traditional allergen extracts by alternative routes have become available. Experimental approaches for AIT, such as virus-like particles and cell-based treatments have been described. New results from clinical trials performed with recombinant hypoallergens and passive immunization with allergen-specific antibodies highlight the importance of allergen-specific IgG antibodies for the effect of AIT and indicate opportunities for preventive allergen-specific vaccination.

SUMMARY

Molecular allergy diagnosis is useful for the prescription and monitoring of AIT and may improve the success of AIT. Results with molecular allergy vaccines and by passive immunization with allergen-specific IgG antibodies indicate the importance of allergen-specific IgG capable of blocking allergen recognition by IgE and IgE-mediated allergic inflammation as important mechanism for the success of AIT. New molecular vaccines may pave the road towards prophylactic allergen-specific vaccination.

The use of microarray and other multiplex technologies in the diagnosis of allergy

OBJECTIVE

To give an overview and describe the strengths and weaknesses of immunoglobulin E (IgE) microarray and other multiplex assays that have been developed and are being used for allergy diagnostics.

DATA SOURCES

Queries for IgE microarray and multiplex assays were conducted with PubMed and Google Scholar, searching for primary articles and review papers.

STUDY SELECTIONS

We focused on articles written in English on commercially available IgE multiplex assays that were reported in the allergy and immunology literature.

RESULTS

Several commercial IgE assays that use microarray or other multiplex technology have been developed, and some have been implemented into clinical practice in Europe and Asia, with the Immuno Solid-Phase Allergen Chip being the most widely studied. Results of these assays generally correlate with results using "singleplex" IgE assays (eg, ImmunoCAP), though there can be variability among products and among allergens. A strength of the microarray technology is that IgE to a large number of allergens can be detected simultaneously in a single test, and only a small amount of patient serum is required. Cost, inadequate sensitivity under some scenarios, and difficulties with data interpretation, in some cases of 100 or more allergens, can be limitations.

CONCLUSION

IgE microarray assays are already a valuable tool in research applications. These assays, and also other forms of IgE multiplex assays, are likely to play an important role in the clinical practice of allergy in the future. Additional studies focused on clinical outcomes, and the development of more targeted allergen panels could facilitate increased clinical use.

Serum Periostin as a Biomarker for Predicting Clinical Response to House Dust Mite Sublingual Immunotherapy in Allergic Rhinitis

BACKGROUND

House dust mite (HDM) sublingual immunotherapy (SLIT) has proven to be effective for allergic rhinitis (AR), but its efficacy varies among patients. No candidate biomarkers for prediction of response to SLIT are available. Periostin, a matricellular protein, is involved in pathophysiology of AR, and its serum levels reflect airway allergic inflammation.

OBJECTIVE

To evaluate the relationship between serum periostin levels and current rhinitis control before and after standardized quality (SQ)-HDM SLIT, and to investigate the role of periostin in predicting clinical response.

METHODS

One hundred eleven subjects with HDM-induced AR were randomized to receive either SLIT plus pharmacotherapy or pharmacotherapy alone, for 48 weeks. At enrollment and the end of study, clinical characteristics and biomarkers that included serum periostin, serum HDM-specific IgE (s-IgE), total IgE, blood eosinophil counts, and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) were measured. The association between clinical indices or biomarkers and clinical response to SLIT was analyzed.

RESULTS

A response to SLIT was recorded in 64% (32 of 50) patients. High serum periostin levels (>30.2 ng/mL) were associated with an effective response to SLIT, and the magnitude of RQLQ improvement was correlated with the level of serum periostin. The sensitivity and specificity based on receiver operating characteristic analysis for periostin were higher than those of s-IgE. Multivariate regression analysis showed that serum periostin was an independent factor for SLIT responders.

CONCLUSIONS

Serum periostin appears to be a useful biomarker for predicting the response to SQ-HDM SLIT in patients with AR.

Leukotriene A4 Hydrolase Is a Candidate Predictive Biomarker for Successful Allergen Immunotherapy

Background

Allergic rhinitis is a common disorder that affects 10% to 40% of the population worldwide. Allergen immunotherapy (AIT) represents the only therapy that has the potential to resolve clinical symptoms of allergic rhinitis. However, up to 30% of patients do not respond to AIT. Biomarkers predicting the clinical efficacy of AIT as early as possible would significantly improve the patient selection and reduce unnecessary societal costs.

Methods

Artemisia pollen allergic patients who received at least 1-year AIT were enrolled. Clinical responses before and after 1-year AIT were evaluated to determine AIT responders. Artemisia specific IgE and IgG4 levels were measured by using ImmunoCAP and enzyme-linked immunosorbent assay (ELISA) separately. Stepwise regression analysis was performed to identify which rhinitis-relevant parameters explained the most variability in AIT results. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics was applied to identify the potential candidate biomarkers in the sera of responders and non-responders collected before and after 1-year therapy. The diagnostic performance of the potential biomarkers was then assessed using enzyme-linked immunosorbent assay (ELISA) in 30 responders and 15 non-responders.

Results

Artemisia specific IgE and IgG4 levels were elevated only in the responders. Regression analysis of allergic rhinitis-relevant parameters provided a robust model that included two most significant variables (sneeze and nasal congestion). Thirteen candidate biomarkers were identified for predicting AIT outcomes. Based on their association with allergy and protein fold change (more than 1.1 or less than 0.9), four proteins were identified to be potential biomarkers for predicting effective AIT. However, further ELISA revealed that only leukotriene A₄ hydrolase (LTA₄H) was consistent with the proteomics data. The LTA₄H level in responders increased significantly (P < 0.001) after 1-year therapy, while that of non-responders remained unchanged. Assessment of LTA₄H generated area under curve (AUC) value of 0.844 (95% confidence interval: 0.727 to 0.962; P < 0.05) in distinguishing responders from the non-responders, suggesting that serum LTA₄H might be a potential biomarker for predicting the efficiency of AIT.

Conclusion

Serum LTA₄H may be a potential biomarker for early prediction of an effective AIT.

Advances in IgE Testing for Diagnosis of Allergic Disease

Since its discovery in 1967, IgE antibody detection in skin and blood has identified a state of allergic sensitization and served as a necessary but not sufficient risk factor that requires objective symptoms to make the definitive diagnosis of human allergic disease. More recently, quantitative IgE antibody levels in serum against allergenic extracts, molecules, and epitopes have pushed its application into more accurately identifying the specificity of the allergic response for targeting immunotherapy, predicting allergic symptom severity after allergen exposure, and attempting to distinguish tolerance from food allergy. This review examines new in vivo and in vitro developments in the design, performance, interference, and application of the methods used to identify allergic sensitization. The increasing accepted applications of molecular allergen and allergen epitope-based IgE antibody measurements, especially as applied to food allergy diagnosis and management, are highlighted as state-of-the-art advances. Despite these major advances in allergic sensitization documentation, their ultimate value requires integration by the clinician with the patient's history and pretest probability of disease.

A preseason booster prolongs the increase of allergen specific IgG4 levels, after basic allergen intralymphatic immunotherapy, against grass pollen seasonal allergy

BACKGROUND

Allergen specific IgG4 levels have been monitored as a surrogate marker for the tolerance inducing effect of subcutaneous immunotherapy (SCIT) in many studies. Its accuracy at group level has been well established, but IgG4 has not yet found its place in the daily care of immunotherapy patients.

METHODS

Intralymphatic immunotherapy (ILIT) is a novel route for allergy vaccination against pollen allergy, where an ultrasound-guided injection of 1000 SQ-U Alutard is given directly into a groin lymph node. The suggested standard dosing so far has been one injection with 4 weeks in-between. In total 3000 SQ-U with the treatment completed in 2 months. IgG4 was measured with Immulite technique and rhinoconjunctivitis symptoms were estimated with daily online questionnaires. Mann-Whitney U-test and Wilcoxon Signed Rank test were applied for comparisons between groups and within groups, respectively.

RESULTS

The present study demonstrates that a single, preseason ILIT booster of 1000 SQ-U Alutard 5-grasses®, re-increases the allergen specific timothy-IgG4 levels, in patients already treated with ILIT before the previous pollen season. It also shows the feasibility of the ILIT-route for allergy vaccination of rhinitis patients, with or without concomitant asthma, with low degree of side effects and reconfirms high and sustained patient satisfaction.

CONCLUSIONS

It is tempting to suggest that the allergen specific IgG4 levels can be used to build an intuitive algorithm for future clinical guidance of ILIT patients.Trial registration Is Intralymphatic Allergen Immunotherapy Effective and Safe?, ClinicalTrials.gov Identifier NCT04210193. Registered 24 December 2019-Retrospectively registered, https://clinicaltrials.gov/ct2/show/study/NCT04210193?term=NCT04210193&draw=2&rank=1.

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.

Allergen-specific subcutaneous immunotherapy for Japanese cedar pollinosis decreases the number of metachromatic cells and eosinophils in nasal swabs during the preseason and in season

Background and objective

Nasal symptoms of allergic rhinitis can be reduced with allergen‐specific subcutaneous immunotherapy (SCIT). However, the mechanisms underlying the effectiveness of SCIT for Japanese cedar pollinosis are not well understood. We studied changes in the numbers of metachromatic cells, eosinophils and neutrophils in nasal swabs following SCIT for Japanese cedar pollinosis.

Methods

Subjects were either untreated or given SCIT for 0.5 to 13 years duration. For the 2019 seasons, nasal swabs were taken in the pollinosis preseason (immunotherapy n = 36; untreated control, n = 62) and in the pollinosis season (immunotherapy n = 45; untreated control n = 46) and the numbers of mast cells, eosinophils and neutrophils assessed by microscopy.

Results

There were significant improvements in symptom severities following SCIT in comparison to untreated subjects (P < .0003, the Mann‐Whitney U test) in preseason, and (P < .00001) in season. Metachromatic cell counts from nasal swabs of SCIT subjects in preseason and in the season were lower than those of untreated subjects (P = .0029 and P = .031, respectively). Eosinophil numbers in nasal swabs of subjects given SCIT were lower than in untreated subjects (P = .0031) in season, but not in preseason. There were no significant differences in degrees of neutrophilia between untreated and SCIT subjects in preseason and in season.

Conclusion

One mechanism underlying the effectiveness of SCIT for Japanese cedar pollinosis involves a reduction in the number of metachromatic cells in nasal swabs in the preseason and an inhibition of increases in the number of metachromatic cells and eosinophils in season.

A WAO - ARIA - GA2LEN consensus document on molecular-based allergy diagnosis (PAMD@): Update 2020

Precision allergy molecular diagnostic applications (PAMD@) is increasingly entering routine care. Currently, more than 130 allergenic molecules from more than 50 allergy sources are commercially available for in vitro specific immunoglobulin E (sIgE) testing. Since the last publication of this consensus document, a great deal of new information has become available regarding this topic, with over 100 publications in the last year alone. It thus seems quite reasonable to publish an update. It is imperative that clinicians and immunologists specifically trained in allergology keep abreast of the new and rapidly evolving evidence available for PAMD@.

PAMD@ may initially appear complex to interpret; however, with increasing experience, the information gained provides relevant information for the allergist. This is especially true for food allergy, Hymenoptera allergy, and for the selection of allergen immunotherapy. Nevertheless, all sIgE tests, including PAMD@, should be evaluated within the framework of a patient's clinical history, because allergen sensitization does not necessarily imply clinical relevant allergies.

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen.

Is it worthy to take full-course immunotherapy for allergic rhinitis? About efficacy biomarker of allergen immunotherapy

Nowadays, people pay more attention to biomarkers that can predict clinical efficacy of immunotherapy for allergic rhinitis. As the only recognized aetiological treatment, the efficacy of allergen immunotherapy (AIT) has been proved by many studies. However, treatment success depends on compliance and persistence greatly, which can be impaired by the lengthy duration of AIT and socioeconomic status of patients. Besides, ineffectiveness is another factor that accounts for non-adherence. If the clinical efficacy can be predicted in the early stage of immunotherapy, it can help patients choose appropriate treatment plans, increase patient compliance and optimize the allocation of medical resources. This paper mainly focuses on five candidate biomarkers, the sIgE/tIgE ratio before treatment, serum inhibitory activity for IgE, decreased basophil activation, upregulation of Tregs and tolerogenic DCs, reviews the time when potential biomarkers can predict or monitor the efficacy of AIT, discusses the reason why these indicators could serve as efficacy biomarkers and interactions among potential biomarkers.

Inhibiting phosphatase SHIP-1 enhances suboptimal IgE-mediated activation of human blood basophils but inhibits IgE-mediated activation of cultured human mast cells

IgE-mediated activation of basophil granulocytes and mast cells follows a bell-shaped dose-response curve. The decreased activation at supraoptimal allergen stimulation is thought to be associated with SH2-containing inositol-5'-phosphatase 1 (SHIP-1). SHIP-1 phosphorylation is inversely related to IgE-mediated releasability of basophils. This study sought to clarify the regulatory role of SHIP-1 in degranulation of basophil granulocytes and mast cells by selective inhibition of the phosphatase function of SHIP-1with 3-α-aminocholestane (3-α-AC). Six grass pollen allergic patients, six non-responder patients and six cultured human primary mast cell lines were included. The effect of 3-α-AC (1-60 μM, 30 min, 37 °C) was analyzed at individual suboptimal, optimal and supra-optimal allergen concentrations. The activity, upregulation of CD63, measured at different conditions was compared to evaluate the maximal effect of selective SHIP-1 inhibition. Basophils of five non-responder patients were treated with 3-α-AC (10 μM, 30 min, 37 °C). At high concentrations (>60 μM) of 3-α-AC, cells appeared to enter apoptosis. The median reactivity increased from 27.1% to 44.9% CD63⁺ basophils at 10 μM of 3-α-AC and suboptimal allergen stimulation (p = 0.0153). There was no effect on blood basophils of 3-α-AC at optimal or supra-optimal allergen concentrations. In contrast, treatment with more than 6 μM 3-α-AC significantly inhibited mast cell reactivity. 10 μM 3-α-AC reduced median reactivity from 32.85% to 16.5% CD63+ mast cells (p = 0.0465). Treatment with 3-α-AC did not increase response of basophils of non-responder patients. Modulating blood basophils with 3-α-AC enhanced reactivity only at suboptimal allergen concentration, and basophils from non-responders did not regain responsiveness to IgE stimulation. 3-α-AC inhibited the IgE response of mast cells in a dose dependent manner.

Specific IgG4 antibodies to cow's milk proteins in pediatric patients with eosinophilic esophagitis

BACKGROUND

Allergen-specific IgG₄ (sIgG₄) antibodies are often associated with tolerance, but sIgG₄ antibodies to causally relevant foods have been reported recently in adults with eosinophilic esophagitis (EoE). Prevalence and levels of food sIgG₄ are not well established in the general pediatric population.

OBJECTIVE

We sought to investigate serum food sIgG₄ with component diagnostics in children with EoE and children from an unselected birth cohort and to explore the effects of sex, age, and milk consumption on sIgG₄ levels.

METHODS

Sera from 71 pediatric patients with EoE and 210 early adolescent children from an unselected birth cohort (Project Viva) were assayed for sIgG₄ and specific IgE (sIgE) to major cow's milk (CM) proteins (α-lactalbumin, β-lactoglobulin, and caseins) and to wheat, soy, egg, and peanut proteins.

RESULTS

In the EoE cohort high-titer sIgG₄ (≥10 μg/mL) to CM proteins was more common than in control sera and achieved odds ratios for EoE ranging from 5.5 to 8.4. sIgE levels to CM proteins were mostly 4 IU/mL or less in patients with EoE, such that sIgG₄/sIgE ratios were often 10,000 or greater. When adjusted for age and milk consumption, high-titer sIgG₄ to CM proteins was strongly associated with EoE, with an odds ratio of greater than 20 to all 3 CM proteins in boys.

CONCLUSIONS

sIgG₄ to CM proteins are common and high titer in children with EoE. Although it is not clear that this response is pathogenic, sIgG₄ levels imply that these antibodies are an important feature of the local immune response that gives rise to EoE.

An analysis of factors related to the effect of sublingual immunotherapy on Japanese cedar pollen induced allergic rhinitis

BACKGROUND

Sublingual immunotherapy (SLIT) can improve the symptoms of allergic rhinitis and modify its natural history; however, its efficacy varies among patients. This study aimed to determine which factors modify the effect of SLIT through post hoc analysis of a previous phase 3 trial of standardized Japanese cedar (JC) pollen extract (CEDARTOLEN^®).

METHODS

The study included 482 patients who had previously completed a phase 3 trial during two seasons. The SLIT and placebo groups each contained 241 subjects. Because pollen dispersal differed in the two seasons, we identified good and poor responders from the SLIT group in the 2nd season. We compared patient baseline characteristics, changes in serum immunoglobulin, and severity of symptoms in the 1st season between good and poor responders, as well as between SLIT and placebo groups.

RESULTS

When we compared the baseline characteristics of good and poor responders, a significant difference was observed in body mass index (BMI) such that the patients with BMI ≥25 presented with lower treatment efficacy. No significant difference was observed in correlation with any other factors or treatment-induced alterations of serum immunoglobulin levels. We found that 75.3% of the patients with moderate symptoms and 50.9% of the patients with severe or very severe symptoms in the 1st season met our criteria for good responders in the 2nd season.

CONCLUSIONS

BMI might modify the effect of SLIT; however, other factors were not related clearly. The severity of symptoms in the 1st season of treatment does not predict that in the 2nd season.

[Molecular-allergological aspects of allergen-specific immunotherapy]

Allergen-specific immunotherapy (SIT) does not achieve 100% efficacy, nor is there a reliable marker for therapy failure. However, advances in molecular allergology over the past few years have allowed a significantly improved characterization of the patients using molecular-allergological analysis methods (molecular phenotyping). Thus, major and minor allergens can be identified. In addition, the marker allergens for the severity of an allergic reaction, the pathological and therapeutic predictive marker allergens, and sensitization patterns are identified.

Biomarkers for monitoring clinical efficacy of allergen immunotherapy for allergic rhinoconjunctivitis and allergic asthma: an EAACI Position Paper

BACKGROUND

Allergen immunotherapy (AIT) is an effective treatment for allergic rhinoconjunctivitis (AR) with or without asthma. It is important to note that due to the complex interaction between patient, allergy triggers, symptomatology and vaccines used for AIT, some patients do not respond optimally to the treatment. Furthermore, there are no validated or generally accepted candidate biomarkers that are predictive of the clinical response to AIT. Clinical management of patients receiving AIT and efficacy in randomised controlled trials for drug development could be enhanced by predictive biomarkers.

METHOD

The EAACI taskforce reviewed all candidate biomarkers used in clinical trials of AR patients with/without asthma in a literature review. Biomarkers were grouped into seven domains: (i) IgE (total IgE, specific IgE and sIgE/Total IgE ratio), (ii) IgG-subclasses (sIgG1, sIgG4 including SIgE/IgG4 ratio), (iii) Serum inhibitory activity for IgE (IgE-FAB and IgE-BF), (iv) Basophil activation, (v) Cytokines and Chemokines, (vi) Cellular markers (T regulatory cells, B regulatory cells and dendritic cells) and (vii) In vivo biomarkers (including provocation tests?).

RESULTS

All biomarkers were reviewed in the light of their potential advantages as well as their respective drawbacks. Unmet needs and specific recommendations on all seven domains were addressed.

CONCLUSIONS

It is recommended to explore the use of allergen-specific IgG4 as a biomarker for compliance. sIgE/tIgE and IgE-FAB are considered as potential surrogate candidate biomarkers. Cytokine/chemokines and cellular reponses provided insight into the mechanisms of AIT. More studies for confirmation and interpretation of the possible association with the clinical response to AIT are needed.

Basic science for the clinician: Mechanisms of sublingual and subcutaneous immunotherapy

OBJECTIVE

To discuss the general immunologic changes that occur during immunotherapy, focusing on the differences between subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT).

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

Articles pertaining to SCIT and SLIT, with specific emphasis on those that included immune mechanistic studies.

RESULTS

Both SCIT and SLIT are characterized by the induction of regulatory B and T cells, decreased allergen-specific T-cell proliferation, a shift from a TH2 to TH1 cytokine milieu and from an IgE to an IgG4/IgA antibody response. These changes are accompanied by clinical improvement in symptoms.

CONCLUSION

Immunotherapy using allergen extracts administered via both subcutaneous and sublingual approaches have demonstrated efficacy in the treatment of allergic rhinoconjunctivitis and other allergic conditions. There are subtle differences between the approaches, and understanding these differences may help clinicians select a preferred route of therapy for particular patients or allergens, depending on the immune response that is being targeted.

Pros and Cons of Clinical Basophil Testing (BAT)

PURPOSE OF REVIEW

We review basophil testing by flow cytometry with an emphasis on advantages and disadvantages.

RECENT FINDINGS

There are many tools available to assess the presence and severity of allergic diseases in patients. For 50 years, peripheral blood basophils have been used as tools to study these diseases. It is a very accessible cell that binds IgE antibody and secretes the classical mediators responsible for the symptoms of allergic reactions. In the last decade, an even more accessible methodology, using flow cytometry, has been developed to enhance the ability to use basophils for both mechanistic and clinical diagnostics. Basophil testing has been included in diagnostics for different forms of allergies as well as to monitor disease status. A variety of studies have begun to establish both precise methods and their clinical relevance for disease diagnosis, but there remain some important questions on how to take optimal advantage of the behaviours of basophils.

Endotype-driven treatment in chronic upper airway diseases

Rhinitis and rhinosinusitis are the two major clinical entities of chronic upper airway disease. Chronic rhinosinusitis (CRS) and allergic rhinitis (AR) affect respectively up to 10 and 30% of the total population, hence being associated with an important socio-economic burden. Different phenotypes of rhinitis and CRS have been described based on symptom severity and duration, atopy status, level of control, comorbidities and presence or absence of nasal polyps in CRS. The underlying pathophysiological mechanisms are diverse, with different, and sometimes overlapping, endotypes being recognized. Type 2 inflammation is well characterized in both AR and CRS with nasal polyps (CRSwNP), whereas type 1 inflammation is found in infectious rhinitis and CRS without nasal polyps (CRSsNP). The neurogenic endotype has been demonstrated in some forms of non-allergic rhinitis. Epithelial barrier dysfunction is shown in AR and CRSwNP. Emerging therapies are targeting one specific pathophysiological pathway or endotype. This endotype-driven treatment approach requires careful selection of the patient population who might benefit from a specific treatment. Personalized medicine is addressing the issue of providing targeted treatment for the right patient and should be seen as one aspect of the promising trend towards precision medicine. This review provides a comprehensive overview of the current state of endotypes, biomarkers and targeted treatments in chronic inflammatory conditions of the nose and paranasal sinuses.

Mechanisms, safety and efficacy of a B cell epitope-based vaccine for immunotherapy of grass pollen allergy

BACKGROUND

We have developed a recombinant B cell epitope-based vaccine (BM32) for allergen-specific immunotherapy (AIT) of grass pollen allergy. The vaccine contains recombinant fusion proteins consisting of allergen-derived peptides and the hepatitis B surface protein domain preS as immunological carrier.

METHODS

We conducted a randomized, double-blind, placebo-controlled AIT study to determine safety, clinical efficacy and immunological mechanism of three subcutaneous injections of three BM32 doses adsorbed to aluminum hydroxide versus aluminum hydroxide (placebo) applied monthly to grass pollen allergic patients (n=70). Primary efficacy endpoint was the difference in total nasal symptom score (TNSS) through grass pollen chamber exposure before treatment and 4weeks after the last injection. Secondary clinical endpoints were total ocular symptom score (TOSS) and allergen-specific skin response evaluated by titrated skin prick testing (SPT) at the same time points. Treatment-related side effects were evaluated as safety endpoints. Changes in allergen-specific antibody, cellular and cytokine responses were measured in patients before and after treatment.

RESULTS

Sixty-eight patients completed the trial. TNSS significantly decreased with mean changes of -1.41 (BM32/20μg) (P=0.03) and -1.34 (BM32/40μg) (P=0.003) whereas mean changes in the BM32/10μg and placebo group were not significant. TOSS and SPT reactions showed a dose-dependent decrease. No systemic immediate type side effects were observed. Only few grade 1 systemic late phase reactions occurred in BM32 treated patients. The number of local injection site reactions was similar in actively and placebo-treated patients. BM32 induced highly significant allergen-specific IgG responses (P<0.0001) but no allergen-specific IgE. Allergen-induced basophil activation was reduced in BM32 treated patients and addition of therapy-induced IgG significantly suppressed T cell activation (P=0.0063).

CONCLUSION

The B cell epitope-based recombinant grass pollen allergy vaccine BM32 is well tolerated and few doses are sufficient to suppress immediate allergic reactions as well as allergen-specific T cell responses via a selective induction of allergen-specific IgG antibodies. (ClinicalTrials.gov number, NCT01445002.).

Multiplex component-based allergen microarray in recent clinical studies

During the last decades component-resolved diagnostics either as singleplex or multiplex measurements has been introduced into the field of clinical allergology, providing important information that cannot be obtained from extract-based tests. Here we review recent studies that demonstrate clinical applications of the multiplex microarray technique in the diagnosis and risk assessment of allergic patients, and its usefulness in studies of allergic diseases. The usefulness of ImmunoCAP ISAC has been validated in a wide spectrum of allergic diseases like asthma, allergic rhinoconjunctivitis, atopic dermatitis, eosinophilic esophagitis, food allergy and anaphylaxis. ISAC provides a broad picture of a patient's sensitization profile from a single test, and provides information on specific and cross-reactive sensitizations that facilitate diagnosis, risk assessment, and disease management. Furthermore, it can reveal unexpected sensitizations which may explain anaphylaxis previously categorized as idiopathic and also display for the moment clinically non-relevant sensitizations. ISAC can facilitate a better selection of relevant allergens for immunotherapy compared with extract testing. Microarray technique can visualize the allergic march and molecular spreading in the preclinical stages of allergic diseases, and may indicate that the likelihood of developing symptomatic allergy is associated with specific profiles of sensitization to allergen components. ISAC is shown to be a useful tool in routine allergy diagnostics due to its ability to improve risk assessment, to better select relevant allergens for immunotherapy as well as detecting unknown sensitization. Multiplex component testing is especially suitable for patients with complex symptomatology.

Intralymphatic immunotherapy induces allergen specific plasmablasts and increases tolerance to skin prick testing in a pilot study

Background

Allergen Immunotherapy is a promising treatment of allergy. Seven patients with rhinoconjunctivitis to grass allergen were treated with intralymphatic immunotherapy (ILIT) to explore whether this treatment could be performed. Effect of treatment was assessed as change in symptom medication score, response in skin prick test and nasal allergen provocation. ILIT deposits allergen in an inguinal lymph node to elicit a strong immune stimulus. This allowed us to monitor appearance of allergen specific plasmablasts 7 days after allergen injection.

Findings

In an open trial of seven patients with a history of symptomatic allergic rhinoconjunctivitis due to grass pollen, three injections of allergen into inguinal lymph nodes were performed with monthly intervals. Allergen injections induced grass allergen specific plasmablasts expressing other isotypes than IgE after 7 days, induced a trend toward improvement in symptom and medication score and rhinoconjunctivitis-related quality of life during the grass pollen season 2013 and significantly raised the threshold in nasal allergen challenge and titrated skin prick testing. Mild side-effects were recorded after 3 of the 21 of injections (14 %).

Conclusions

This pilot study shows that ILIT may induce allergen specific plasmablasts, and confirms an effect on provocation of mast cells in skin and nasal mucosa during the ensuing winter.