Two year follow-up of immunological response in mite-allergic children treated with sublingual immunotherapy. Comparison with subcutaneous administration

Experimental observation of the effect of immunotherapy on CD4+ T cells and Th1/Th2 cytokines in mice with allergic rhinitis

The present study aims to investigate the effect of immunotherapy in a mouse model of allergic rhinitis (AR) and to explore the possible molecular mechanisms of action. An animal model of AR was established by sensitization and challenge of BALB/c mice with house dust mite (HDM) extract. The mice were injected subcutaneously with HDM for immunotherapy. AR nasal symptoms were evaluated according to the frequencies of nose rubbing and sneezing and the degree of rhinorrhea. The nasal mucosa and lung tissue architecture and inflammatory status by histological analysis; the infiltration of eosinophils in nasal lavage fluid (NALF) of mice was observed by Diff-Quik stain; ELISA-based quantification of serum HDM-specific IgE and TH1/TH2 cytokine concentration; and flow cytometry detected the number of serum CD4+/CD8+ cells to evaluate the mechanism of immunotherapy. It was found that after immunotherapy, the AR symptom score was reduced, the number of eosinophils in NALF was reduced, and the infiltration of inflammatory cells and tissue damage in the nasal mucosa and lung tissue were alleviated. Immunotherapy can increase the number of CD4+ T cells in the peripheral blood, increase the ratio of CD4+/CD8+ cells, increase the expression of Th1 cytokines such as IL-2 and IFN-γ, reduce the expression of Th2 cytokines such as IL-4 and IL-5. The results showed that repeated intraperitoneal injection of crude extract of HDM for sensitization, followed by nasal drops can effectively construct a mouse model of AR, and subcutaneous injection of immunotherapy in mice can reduce allergic inflammation in model mice and improve the inflammatory infiltration of the nasal cavity in allergic rhinitis. Immunotherapy can reduce the expression of inflammatory factors in AR, improve Th1/Th2 balance, and may play a role in the treatment of AR by improving the function of immune cells.

Immunology of allergen immunotherapy

Allergen immunotherapy (AIT) is the only disease-modifying therapy for allergic disease. Through repeated inoculations of low doses of allergen-either as whole proteins or peptides-patients can achieve a homeostatic balance between inflammatory effectors induced and/or associated with allergen contact, and mediators of immunologic non-responsiveness, potentially leading to sustained clinical improvements. AIT for airborne/respiratory tract allergens and insect venoms have traditionally been supplied subcutaneously, but other routes and modalities of administration can also be effective. Despite differences of allergen administration, there are some similarities of immunologic responses across platforms, with a general theme involving the restructuring and polarization of adaptive and innate immune effector cells. Here we review the immunology of AIT across various delivery platforms, including subcutaneous, sublingual, epicutaneous, intradermal, and intralymphatic approaches, emphasizing shared mechanisms associated with achieving immunologic non-responsiveness to allergen.

Immune mechanisms induced by sublingual immunotherapy in allergic respiratory diseases

Allergic respiratory diseases (ARDs) are still a major burden on global public health. Sublingual immunotherapy (SLIT) is a mode of allergen immunotherapy (AIT) which involves administration of the allergen under the tongue, and benefits from tolerogenic properties of the oral mucosa. Studies revealed reduced levels of eosinophilia and eosinophil-dominated inflammation in airways of both animals and humans after SLIT. SLIT was also suggested to lower basophil responsiveness and innate lymphoid cell-2 function in blood samples collected from patients with ARD. Moreover, apart from shifting pathogenic type 2 (TH2) to a type 1 (TH1) and protective regulatory (Treg) polarization of helper T-cell immune response, antibody isotype switch from IgE to IgG1, IgG2, IgG4 and IgA was also reported in patients with ARD receiving SLIT. Today, the literature on SLIT-mediated activities is still scarce and more studies are required to further enlighten the mechanisms utilized by SLIT for the induction of tolerance. The aim of this review is to summarize the current knowledge about the immune-regulatory mechanisms induced by SLIT against ARDs.

[Effect of sublingual immunotherapy with Dermatophagoides Farinae on the expression of specific IgG4 in patients with allergic rhinitis in Hainan area]

Objective:The aim of this study is to investigate the effect of sublingual immunotherapy with Dermatophagoides Farinae on the expression of specific IgG4（sIgG4） in patients with allergic rhinitis （AR） in Hainan area. Method:Seventy-two patients with dust-mite allergic rhinitis, all three generations of whom were local islanders in Hainan, were randomly divided into control group（36 cases） and SLIT group（36 cases）. sIgG4 and sIgE expression levels were detected before treatment, 6 months after treatment, 12 months after treatment, and 18 months after treatment. The patient's symptom score, medication score, VAS score and adverse reactions was also assessed. Finally, through statistical analysis of the relevant data collected at 4 time points in the two groups of patients, the efficacy, safety and changes of sIgG4 antibody expression level in patients with allergic rhinitis receiving sublingual specific immunotherapy in Hainan were observed. Result:Symptoms scores, medication scores and VAS scores were significantly improved in the SLIT group after treatment compared with before treatment（P<0.05）, and serum sIgG4 increased significantly（P<0.01）, serum sIgE showed no significant change（P>0.05）. In the control group, symptom scores, medication scores and VAS scores were also significantly improved compared with before treatment（P<0.05）, while serum sIgG4 and sIgE showed no significant change（P>0.05）. When comparing the two groups, Symptoms scores, medication scores and VAS scores of the SLIT group were significantly lower than those of the control group at 12 months and 18 months after treatment（P<0.05）. sIgG4 expression levels in the SLIT group were significantly higher than those in the control group after 6, 12 and 18 months of treatment（P<0.01）. There was no significant difference in sIgE expression level between the two groups（P>0.05）. No severe systemic adverse reactions occurred in the two groups, and 3 patients showed mild adverse reactions in the SLIT group. Conclusion:Sublingual immunotherapy of Dermatophagoides Farinae was effective and could increase the expression of sIgG4 in patients with Dermatophagoides farinae AR, sIgG4 is expected to be an immunological marker for the objective evaluation of the clinical efficacy of Hapten.

Changes in CD4+CD25+FoxP3+ Regulatory T Cells and Serum Cytokines in Sublingual and Subcutaneous Immunotherapy in Allergic Rhinitis with or without Asthma

BACKGROUND

Few studies have directly compared the immunologic responses to specific subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT).

OBJECTIVE

We aimed to directly compare clinical efficacy and immunological responses between SLIT and SCIT in allergic rhinitis (AR) sensitized to house dust mites.

METHODS

Sixty-seven patients (age 5-55 years) with moderate-severe Dermatophagoides pteronyssinus (Der-p) and Dermatophagoides farinae AR with or without asthma were randomized (2:2:1) into SLIT (n = 27), SCIT (n = 26) and placebo (n = 14) groups. Symptom and medication scores, visual analogue score, serum Der-p specific immunoglobulin G4 (Der-p-sIgG4), CD4+CD25+FoxP3+ regulatory T cells (Tregs) and serum cytokines were measured.

RESULTS

After 1-year treatment, a significant improvement of total rhinitis score (TRS), total rhinitis medication score (TRMS) and visual analogue score occurred in both SLIT and SCIT. There were no differences in clinical efficacy except for TRMS (p = 0.026) when SLIT and SCIT were directly compared. CD4+CD25+FoxP3+ Tregs had a trend towards upregulation in the 2 modes and inversely correlated with TRS (p = 0.024) only in SLIT. Der-p-sIgG4 significantly increased in SLIT and SCIT (p < 0.05), and it was 30 times higher in SCIT than SLIT after the treatment (p < 0.05). Serum interferon-γ significantly increased only in SCIT after 1 (p = 0.008), 6 (p = 0.007) and 12 (p = 0.008) months of treatment and inversely correlated with TRS (p = 0.032).

CONCLUSION

While SCIT and SLIT have similar rates of clinical improvement, the 2 modes reveal heterogeneous changes of CD4+CD25+Foxp3+ Tregs, sIgG4 and cytokines.

Mind the gaps: Clinical trial concepts to address unanswered questions in aeroallergen immunotherapy-An NIAID/AHRQ Workshop

The Agency for Healthcare Research and Quality and the National Institute of Allergy and Infectious Diseases organized a workshop to develop trial concepts that could improve the use and effectiveness of aeroallergen immunotherapy (AAIT). Expert groups were formed to accomplish the following tasks: (1) propose a study design to compare the effectiveness and safety of subcutaneous versus sublingual AAIT; (2) propose a study design to compare the effectiveness and safety of AAIT by using 1 or a few allergens versus all or most allergens to which a patient is sensitized; (3) propose a study design to determine whether AAIT can alter the progression of childhood allergic airways disease; and (4) propose a study design to determine the optimal dose and duration of AAIT to achieve maximal effectiveness with acceptable safety. Study designs were presented by the workgroups, extensively discussed at the workshop, and revised for this report. The proposed trials would be of long duration and require large highly characterized patient populations. Scientific caveats and feasibility matters are discussed. These concepts are intended to help the development of clinical trials that can address some of the major questions related to the practice of AAIT for the management and prevention of allergic airways disease.

Biomarkers of immunotherapy response in patients with allergic rhinitis

INTRODUCTION

Allergen immunotherapy represents the only disease-modifying therapy available for immunoglobulin E-mediated diseases such as allergic rhinitis and asthma. Allergen immunotherapy induces allergen tolerance by interfering with the immune-pathogenic mechanisms of the allergic response and is potentially able to provide long-term relief of symptoms of allergic rhinitis and asthma and alter the natural course of allergic diseases. Areas covered: Since allergen immunotherapy (AIT) is actually considered an individualized treatment on patient's clinical and immunological profile, the identification of specific biomarkers, which may guide diagnosis, management, and predict response to AIT treatment in allergic rhinitis (AR) patients, is essential and is currently an active field of research. Expert commentary: The identification and validation of biomarkers of successful AIT for AR is an urgent need to definitively establish the role of AIT as a therapeutic tool of personalized medicine.

Applicability of evidence from previous systematic reviews on immunotherapy in current practice of childhood asthma treatment: a GRADE (Grading of Recommendations Assessment, Development and Evaluation) systematic review

OBJECTIVE

Because most children with asthma now use inhaled corticosteroids (ICS), the added benefit of immunotherapy in asthmatic children needs to be examined. We re-assessed the effectiveness of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) in childhood asthma treatment focusing on studies with patient-relevant outcome measures and children using ICS.

METHODS

We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to systematically search and appraise the evidence using predefined critical patient-relevant outcomes (asthma symptoms, asthma control and exacerbations). We searched to retrieve systematic reviews and randomised controlled trials on immunotherapy for asthma in children (1960-2017). We assessed the quality of the body of evidence with GRADE criteria.

RESULTS

The quality of the evidence for SCIT was very low due to a large risk of bias and indirectness (dated studies in children not using ICS). No effect of SCIT was found for asthma symptoms; no studies reported on asthma control. For asthma exacerbations, studies favoured SCIT. We have little confidence in this effect estimate, due to the very low quality of evidence. For SLIT, quality of the evidence was very low due to a large risk of bias, indirectness and imprecision. The outcome 'asthma symptoms' could not be calculated due to lack of standardisation and large clinical heterogeneity. Other predefined outcomes were not reported.

CONCLUSION

The beneficial effects of immunotherapy in childhood asthma found in earlier reviews are no longer considered applicable, because of indirectness (studies performed in children not being treated according to current asthma guidelines with ICS). There was absence of evidence to properly determine the effectiveness or lack thereof of immunotherapy in asthma treatment in children with ICS.

Sublingual immunotherapy (SLIT) for house dust mites does not prevent new allergen sensitization and bronchial hyper-responsiveness in allergic rhinitis children

Introduction

The aim of this study is to identify the effects of sublingual immunotherapy (SLIT) on immunologic parameters and bronchial-hyper-responsiveness in children with allergic rhinitis to house-dust mite (HDM), through long-term follow-up cohort.

Methods

Among the Allergic Rhinitis Cohort Study for Kids, pediatric patients who visited the hospital for rhinitis symptoms and proven allergy to HDM through skin prick test were studied. In this cohort, 37 patients received SLIT more than 3-years (SLIT group), and 184 patients received only pharmacologic therapy (non-SLIT group) were included in this study. The results of skin prick test, eosinophil percent and count, total immunoglobulin E (IgE), and bronchial provocation test at initial and 3-year followed-up were compared in the two groups.

Results

After 3 year follow-up, only the serum eosinophil percent decreased more significantly in SLIT group than that in the non-SLIT group. New-sensitization rate other than HDM between SLIT and non-SLIT group did not show any significant differences. The distribution of sensitized allergen other than HDM showed increasing tendency after 3 years in both groups. Older age and a small number of sensitized allergen affected the improvement of bronchial hyper-responsiveness regardless of SLIT.

Conclusion

HDM SLIT in allergic rhinitis children for 3 years in Korea does not affect prevention of new sensitization and poly-sensitization rate increment, and improvement of bronchial hyper-responsiveness.

A novel microcrystalline tyrosine-adsorbed, mite-allergoid subcutaneous immunotherapy: 1-year follow-up report

Aim: A 1-year follow-up study comparing the safety and tolerability of the dosing schedules, satisfaction and effectiveness of a novel microcrystalline tyrosine-adsorbed mite (Dermatophagoides pteronyssinus)-allergoid subcutaneous immunotherapy (Acarovac Plus™) in 30 adult patients (18–65 years) with allergic rhinitis and/or asthma. Materials & methods: The effectiveness of the product was assessed by nasal provocation test measuring peak nasal inspiratory flow/symptoms, in vitro immunologic changes (IgE, IgG4 and IL-10) and Treatment Satisfaction Questionnaire for Medication. Results: No adverse events were reported during dosing schedules. Significant decreases in symptom scores and drop of peak nasal inspiratory flow in follow-up visits (4 weeks and 1 year) were recorded. Significant increases in IgG4-specific antibody titers and IL-10 were exhibited. Conclusion: Significant decreases in clinical symptoms and immunological parameters were observed, accompanying a high level of patient satisfaction and tolerance.

Initial immunological changes as predictors for house dust mite immunotherapy response

BACKGROUND

Although specific immunotherapy is the only aetiological treatment for allergic disorders, the underlying mechanisms are not fully understood. Specific immunotherapy induces changes in lymphocyte Th subsets from Th2 to Th1/Treg. Whether differences in immunological patterns underlie patient response to immunotherapy has not yet been established.

OBJECTIVES

We studied the immunological changes occurring during a 1-year period of Dermatophagoides pteronyssinus (DP) immunotherapy and their relation with clinical outcome.

METHODS

We included 34 patients with DP allergy who received subcutaneous specific immunotherapy (SCIT) for 1 year. Following treatment, patients were classified as responders or non-responders. Fourteen allergic subjects who did not receive SCIT were included as controls. Peripheral blood was obtained at 0, 1, 3, 6 and 12 months and cultured with nDer p 1. Phenotypic changes, cytokine production and basophil response were analysed by flow cytometry; transcription factors were measured by mRNA quantification. Serum immunoglobulin levels were also measured.

RESULTS

After 1 year of SCIT, 82% of cases showed improved symptoms (responders). Although increases in sIgG4 were observed, BAT reactivity was not modified in these patients. Increases in T-BET/FOXP3 as well as nDer p 1-specific Th1/Treg frequencies were also observed, along with a decrease in Th2, Th9 and Th17. These changes corresponded to changes in cytokine levels.

CONCLUSION

Patients who respond well to DP-SCIT show immunological differences compared to non-responders. In responders, basal differences include a lower frequency of Th1 and higher frequencies of Th2, Th9 and Th17 cells. After 1 year of treatment, an increased production of sIgG4 was observed in responders, along with a change in Th2 response towards Th1/Treg.

A review of allergoid immunotherapy: is cat allergy a suitable target?

To modify the course of allergy, different types of specific allergen immunotherapy have been developed such as sublingual immunotherapy and subcutaneous immunotherapy with native allergens or subcutaneous immunotherapy with polymerized allergoids. However, the optimal specific immunotherapy, especially for cat allergy, remains undetermined. Few studies investigating immunotherapy in cat allergy have been published, and the risk of serious adverse reactions and systemic reactions has often been an important issue. Monomeric allergoids have lower allergenic potential while their immunogenicity remains constant, resulting in excellent safety with notable efficacy. Specific immunotherapy with monomeric allergoids could, therefore, be of high value, especially in cat allergy as well as other types of allergy, and bring relief to a great community of patients.

Differential Plasma-cell evolution is linked with Dermatophagoides pteronyssinus immunotherapy response

Allergic rhinitis is highly prevalent worldwide. Immunotherapy has been shown to control its symptoms, however, up to 30% of patients may not respond. Previous studies of the immunological mechanisms involved in allergen-immunotherapy (AIT) have focused on the humoral and T-cell response and several studies have evaluated some B-cell subpopulations during AIT and their role in immunological tolerance. However, although B and plasma-cell subpopulations are two of the most important cellular subtypes involved in allergic reactions, their relation with AIT efficacy remains unelucidated. The objective was to analyze the effects of immunotherapy on different B and plasma-cell subpopulations and whether these changes correlate with the clinical response to the treatment. Although no changes are found in B-cell subpopulations, responder patients show increased levels of memory B-cells even before the beginning of treatment. Changes in plasma-cell subpopulations are found, mainly in circulating inflammatory plasma-cells that could affect the response to the allergen. Moreover, an early increase of specific-IgG4 and IgG4 secreting-cells was found. All these suggest that the determination of the memory B-cells before the initiation of the treatment, and the quantification of IgG4 and IgG4-secreting-cells in the first months of immunotherapy, could serve as markers for the clinical response to treatment.

Clinical and cytokine responses to house dust mite sublingual immunotherapy

BACKGROUND

Cytokine responses accompanying sublingual immunotherapy (SLIT) responder phenotypes have not previously been reported.

OBJECTIVE

To investigate clinical and cytokine responses of house dust mite (HDM) sensitive patients with allergic rhinitis receiving HDM SLIT or placebo for 2 years.

METHODS

Sixty adults were randomized to receive SLIT or placebo. Clinical symptoms were measured using the Total 5 Symptom Score (TSS5) and Juniper Rhinitis Quality of Life Questionnaire. HDM specific IgE, IgG, skin prick tests, and HDM-stimulated release of interleukin (IL) 5 and interferon γ (IFN-γ) in peripheral blood mononuclear cells was studied at 0, 6, 12, and 24 months and IL-13, IL-4, and IL-10 at 0 and 24 months.

RESULTS

A total of 32 of 39 SLIT and 16 of 21 placebo patients completed the study. There was significant clinical improvement in both the SLIT and placebo groups. Median T5SS decreased from 14.75 to 5.25 in the SLIT group (P < .001) and 12.7 to 6.0 in the placebo group (P = .003). The median quality-of-life score also decreased in the SLIT group (P < .001) and the placebo group (P < .001). A subgroup analysis of patients found a 60% or greater improvement (on the T5SS and the Juniper Rhinitis Quality of Life Questionnaire) in the good responders group and a 30% to 59% improvement or no improvement in the intermediate responders group. This subgroup analysis also found more good responders in the SLIT group (47%) compared with the placebo group (25%; P = .07). Significant decreases in the IL-5/IFN-γ (P < .001), IL-13/IFN-γ (P < .001), and IL-4/IFN-γ (P = .03) ratios were found in the combined good clinical improvement group at 24 months.

CONCLUSION

A good clinical response (≥60% improvement in both TSS5 and quality of life) is associated with significant decreases in IL-5, IL-13, and IL-4 relative to IFN-γ during 2 years of SLIT therapy for HDMs.

Subcutaneous immunotherapy versus sublingual immunotherapy: which is more effective?

Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are both effective treatments for allergic rhinitis and allergic asthma, both show clinical evidence of disease modification by decreasing new sensitizations in individuals who were monosensitized, by reducing the development of asthma in patients with allergic rhinitis, and by inducing clinical improvement that persists for years after discontinuation of a successful course of treatment. Initiation of SLIT is accompanied by a high incidence of local symptoms, but these are generally mild and do not usually persist beyond the first few weeks. Systemic reactions do occasionally occur with SLIT but much less frequently than with SCIT, and, to date, no fatal or near fatal reactions have been reported. Effective doses have been defined for many allergens for SCIT and are now being defined for SLIT. There remains the unanswered question of the effectiveness of SLIT with multiple allergen extracts. The relative clinical efficacy of SCIT and SLIT remains to be defined. When each is compared with placebo, results of meta-analyses suggest greater efficacy of SCIT. In the limited number of randomized, head-to-head studies, SCIT has more often provided greater clinical and immunologic responses. However, head-to-head studies with well-defined effective doses by the 2 routes are urgently needed.

Characteristics and management of sublingual allergen immunotherapy in children with allergic rhinitis and asthma induced by house dust mite allergens

BACKGROUND

Allergen immunotherapy is a recognised intervention in patients with allergies not responding to standard pharmacotherapy or in whom pharmacotherapy is contraindicated. We describe the sublingual immunotherapy (SLIT) regimens used in children and adolescents with house dust mite (HDM) respiratory allergies in France and assess the efficacy and safety of this treatment.

METHODS

This was a sub-analysis of paediatric patients included in a previous retrospective, observational, multicentre study. Inclusion criteria were: age 5-17 years; respiratory allergy and proven sensitisation to HDM; at least 2 years follow-up after SLIT initiation. The following data were recorded at SLIT initiation: clinical characteristics; sensitisation profile; concomitant symptomatic medications; details of SLIT protocol. During follow-up and at the end of treatment the following data were recorded: any changes to SLIT treatment; any changes to symptomatic medications; symptom progression; adverse events. SLIT efficacy, patient compliance and satisfaction, and safety were assessed.

RESULTS

736 paediatric patients were included in this analysis. Most patients (95.5%) had allergic rhinitis, which was moderate to severe persistent in 62.8%. Allergic asthma was present in 64.0% and was mild to moderate persistent in 52.7% of these patients. The majority of patients had rhinitis with asthma (59.5%). Three-hundred and seventy five (62.3%) patients were polysensitised. Compliance was good in 86.5% of patients and SLIT was effective in 83.8%. Symptoms of rhinitis and asthma were improved in 64.6% and 64.3% of patients, respectively. A decrease in symptomatic medication was observed following SLIT initiation in patients with rhinitis and/or asthma. SLIT was well tolerated with mainly local reactions reported.

CONCLUSIONS

HDM SLIT appears to be effective in children and adolescents with rhinitis and/or asthma due to HDM allergens, with no tolerability issues and similar benefits as in adults.

Sublingual immunotherapy: World Allergy Organization position paper 2013 update

We have prepared this document, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update", according to the evidence-based criteria, revising and updating chapters of the originally published paper, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2009", available at http://www.waojournal.org. Namely, these comprise: "Mechanisms of sublingual immunotherapy;" "Clinical efficacy of sublingual immunotherapy" - reporting all the data of all controlled trials published after 2009; "Safety of sublingual immunotherapy" - with the recently published Grading System for adverse reactions; "Impact of sublingual immunotherapy on the natural history of respiratory allergy" - with the relevant evidences published since 2009; "Efficacy of SLIT in children" - with detailed analysis of all the studies; "Definition of SLIT patient selection" - reporting the criteria for eligibility to sublingual immunotherapy; "The future of immunotherapy in the community care setting"; "Methodology of clinical trials according to the current scientific and regulatory standards"; and "Guideline development: from evidence-based medicine to patients' views" - including the evolution of the methods to make clinical recommendations.Additionally, we have added new chapters to cover a few emerging crucial topics: "Practical aspects of schedules and dosages and counseling for adherence" - which is crucial in clinical practice for all treatments; "Perspectives and new approaches" - including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, "Raising public awareness about sublingual immunotherapy", as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Grass tablet sublingual immunotherapy downregulates the TH2 cytokine response followed by regulatory T-cell generation

BACKGROUND

Sublingual administration of Phleum pratense allergen immunotherapy (SLIT) tablets is a clinically efficient treatment for grass pollen-induced rhinoconjunctivitis. This immunotherapy downregulates TH2 immune responses, induces tolerogenic pathways, and increases regulatory T cells. However, associated immune response markers of allergen desensitization remain undefined.

OBJECTIVE

We sought to characterize the kinetics of individual changes in the immunologic response to grass tablet SLIT.

METHODS

We evaluated the systemic effects of SLIT in a longitudinal analysis of humoral and cellular immune parameters in peripheral blood samples.

RESULTS

Grass tablet SLIT administration induced a 2-phase systemic humoral and cellular response. The TH2 response was initially exacerbated and detected as increased allergen-specific IgE (sIgE) and IgG4 (sIgG4) levels and an increase in IL-4-producing cells, followed by downregulation of the TH2 response with a shift toward a TH1 cytokine profile. T cells with a regulatory phenotype were also elicited. Statistical correlations between immunologic measurements for each patient throughout therapy indicated that TH2 response downregulation and reduction of the immediate SLIT-induced IgE response were associated with increased allergen-specific IgG4 synthesis early in therapy. TH2 response downregulation by month 4 correlated with increased frequency of CD4(+) T cells with a regulatory phenotype by 12 months.

CONCLUSION

Changes in sIgE levels after therapy were linked to a specific IgG4 response, and production of blocking antibodies correlated with TH2 response downregulation. Reduced IL-4(+) cell frequency was linked to an increase in the frequency of CD4(+) T cells with a regulatory phenotype. Changes in sIgE levels and reduced IL-4 and blocking antibody levels could thus be used as indicators of a patient's immune response to therapy.

Comparing subcutaneous and sublingual ımmunotherapy: what do we know?

PURPOSE OF REVIEW

Although allergen-specific sublingual (SLIT) and subcutaneous immunotherapy (SCIT) have been demonstrated to be clinically effective with similar immunological responses, head-to-head studies comparing those two modes of allergen administration in terms of onset of clinical improvement along with simultaneous immunological responses and underlying mechanisms of preventive effect are scarce. The present review will update current data on this issue.

RECENT FINDINGS

Compared with SLIT, SCIT provides a rapid onset of clinical improvement by eliciting a simultaneous surge in production of T helper 1 (Th1) and T regulatory cell (Treg) cytokines and blocking antibodies. Similar immunological and clinical responses are evoked quite later, with no effect on Immunoglobulin G (IgG)4 levels during SLIT. Increases in TGFβ secretion due to nonrelevant allergens during SLIT may explain the preventive effect on new sensitizations.

SUMMARY

SLIT and SCIT are both clinically effective in the treatment of respiratory allergic diseases with slight differences in the early phase in terms of onset of clinical efficacy and simultaneous immunological responses. Both SLIT and SCIT induce similar T-cell responses in time, but specific IgG4-blocking antibody responses are more prevalent following SCIT. Further head-to-head studies addressing the preventive effect of monotherapy and the efficacy and immunological responses of nonrelated multiallergen immunotherapy in polysensitized patients are warranted.

Birch pollen immunotherapy results in long-term loss of Bet v 1-specific TH2 responses, transient TR1 activation, and synthesis of IgE-blocking antibodies

BACKGROUND

Early events of specific immunotherapy (SIT) are induction of allergen-specific IL-10-producing T(R)1 cells and production of IgG antibodies, but there is little knowledge about the long-term immune mechanisms responsible for sustained allergen tolerance.

OBJECTIVE

Bet v 1-specific immune responses of 16 patients with birch pollen allergy were characterized up to 54 months at defined time points before, during, and after a 3-year period of SIT.

METHODS

We sought to analyze allergen-specific T- and B-cell responses. Bet v 1-specific IL-5-, IFN-γ-, and IL-10-secreting T cells were quantified in peripheral blood, and birch pollen-specific IgE and IgG antibody levels were determined in serum. Furthermore, the inhibitory capacity of SIT-induced IgG was evaluated by blocking allergen binding to IgE and inhibition of facilitated allergen presentation.

RESULTS

Seasonal increases in Bet v 1-specific T(H)2 cell numbers ceased to appear after the first year of SIT without deviation to a T(H)1-dominated immune response. Furthermore, the frequency of IL-10-producing T(R)1 cells, which had increased during the first year of SIT, returned to pretreatment levels in the second year. In contrast, allergen-specific IgG antibody concentrations continuously increased during SIT but started to decrease after cessation of treatment. Functional analysis confirmed the ability of the IgG antibodies to inhibit IgE-allergen interactions, which peaked at the end of SIT but then slowly started to decrease.

CONCLUSION

Long-term allergen tolerance achieved by SIT is associated with the development of peripheral T-cell tolerance characterized by decreased reactivity of Bet v 1-specific T(H)2 cells and enriched allergen-specific IgG competing with IgE antibodies for allergen binding.

Synthesized OVA323-339MAP octamers mitigate OVA-induced airway inflammation by regulating Foxp3 T regulatory cells

Background

Antigen-specific immunotherapy (SIT) has been widely practiced in treating allergic diseases such as asthma. However, this therapy may induce a series of allergic adverse events during treatment. Peptide immunotherapy (PIT) was explored to overcome these disadvantages. We confirmed that multiple antigen peptides (MAPs) do not cause autoimmune responses, which led to the presumption that MAPs intervention could alleviate allergic airway inflammation without inducing adverse effects.

Results

In this study, synthesized OVA_323-339MAP octamers were subcutaneously injected into ovalbumin (OVA)-sensitized and -challenged Balb/c mice to observe its effect on allergic airway inflammation, Th2 immune response, and immune regulating function. It was confirmed that OVA sensitization and challenge led to significant peritracheal inflammatory, cell infiltration, and intensive Th2 response. Treatment of OVA_323-339MAP octomers in the airway inflammation mice model increased CD4⁺CD25⁺Foxp3⁺ T regulatory (Treg) cells and their regulatory function in peripheral blood, mediastinal draining lymph nodes, and the spleen. Furthermore, OVA_323-339MAP increased IL-10 levels in bronchial alveolar lavage fluid (BALF); up-regulated the expression of IL-10, membrane-bound TGF-β1, as well as Foxp3 in lung tissues; and up-regulated programmed death-1 (PD-1) and cytotoxic T lymphocyte associated antigen 4 (CTLA-4) on the surface of Treg cells. These results were further correlated with the decreased OVA specific immunoglobulin E (sIgE) level and the infiltration of inflammatory cells such as eosinophils and lymphocytes in BALF. However, OVA_323-339 peptide monomers did not show any of the mentioned effects in the same animal model.

Conclusions

Our study indicates that OVA_323-339MAP had significant therapeutic effects on mice allergic airway inflammation by regulating the balance of Th1/Th2 response through Treg cells in vivo.

House dust mite-specific immunotherapy alters the basal expression of T regulatory and FcεRI pathway genes

BACKGROUND

Regulatory T (Treg) cells and IgE-mediated signaling pathways could play important roles in the induction of allergen tolerance during house dust mite-specific subcutaneous immunotherapy (HDM-SCIT). Our aim was to compare the basal expression levels of Treg, T helper 1 (Th1) and Th2 transcription factors and components involved in IgE-mediated signaling in healthy subjects with those in HDM-allergic patients both untreated and successfully treated with HDM-SCIT.

METHODS

Thirty-nine HDM-allergic patients who completed a 3- to 5-year course of mite extract SCIT, 20 mite-allergic controls and 25 healthy controls participated in this study. The efficacy of SCIT was monitored using skin-prick tests (SPTs), total immunoglobulin E (tIgE), specific IgE (sIgE), sIgG(4), nasal challenge and visual analog scale (VAS) scores at several time points. The mRNA levels of forkhead box protein 3 (FOXP3), T-BET, GATA-3, FcεRI, spleen tyrosine kinase (Syk), phosphatidylinositol 3 kinase (PI3K) and SH2 domain-containing inositol phosphatase (SHIP) were quantified by real-time RT-PCR using nonstimulated whole blood samples.

RESULTS

Decreased wheal sizes and VAS scores, negative challenges and increased sIgG(4) levels indicated that SCIT was effective in the treated patients. Basal expression levels of FOXP3 and GATA-3 decreased and T-BET levels increased in both treated patients and in healthy controls compared to untreated patients. The IgE-mediated pathway kinases Syk and PI3K exhibited reduced expression, whereas SHIP phosphatase levels were elevated in both treated patients and healthy controls relative to untreated patients. The expression levels of FcεRI were not significantly altered.

CONCLUSIONS

Immunotherapy using HDM extracts results in a modification of the basal expression levels of several IgE-related signaling factors and induces a highly significant upregulation of Th1-response and downregulation of Th2-response transcription factors. Interestingly, this therapy also appears to reduce the basal expression of FOXP3.

Efficacy of sublingual immunotherapy versus subcutaneous injection immunotherapy in allergic patients

While it is generally accepted that Subcutaneous Injection Immunotherapy (SCIT) and Sublingual Immunotherapy (SLIT) are both efficacious, there is not yet a significant amount of information regarding their comparative efficacy. In this paper, we performed a retrospective chart review and compared treatment results in two groups of patients (both with nasal allergies with or without asthma) that were treated either with SCIT or SLIT. Both treatment modalities were found to be of similar efficacy.

Significance of ovomucoid- and ovalbumin-specific IgE/IgG(4) ratios in egg allergy

BACKGROUND

The role of specific IgG(4) antibodies in natural tolerance acquisition remains a matter of debate; the specific IgE/IgG(4) ratio might add value to the measurement of absolute amounts of IgE for assessing the ongoing status of egg reactivity.

OBJECTIVE

We sought to determine the significance of IgG(4) antibodies to ovalbumin (OVA) and ovomucoid (OVM) in egg-allergic children.

METHODS

One hundred seven egg-allergic children (mean age 6.9 years; range 1.6-18.6 years) were challenged to baked egg. The outcomes of the challenges were related to the level of specific IgE and IgG(4) to OVM and OVA, component IgE/IgG(4) ratios, and mediator release in a functional assay based on the rat basophil leukemia cell line.

RESULTS

Baked egg-reactive children had significantly higher OVA and OVM ratios of IgE/IgG(4) and mediator release in the rat basophil leukemia-based assay than did tolerant children (P < .05 for both). The OVA- and OVM-specific IgE/IgG(4) ratios and mediator release were correlated. In the receiver operating characteristic analysis, the areas under the curve for a logistic regression model including specific IgE and IgG(4) to OVA and OVM were significantly greater compared with the areas under the curve for egg white-specific IgE and OVM-specific IgE.

CONCLUSIONS

The balance between IgE and IgG(4) to OVA and OVM has functional consequences. A model that includes the interactions between IgE and IgG(4) to OVA and OVM accurately predicts reactivity to baked egg and warrants further investigation.

Sublingual immunotherapy in asthma does not influence lymphocyte sensitivity to Fas stimulation

BACKGROUND

The resistance of T lymphocytes to Fas-mediated apoptosis is an important feature of atopic asthma. The only effective causative treatment of atopic diseases is immunotherapy. Clinical efficacy of sublingual immunotherapy (SLIT) has been already proven, but there is still limited number of studies on its influence on lymphocytes function.

OBJECTIVES

The aim of the study was to evaluate whether SLIT could restore the sensitivity of asthmatic T cells to undergo Fas-mediated apoptosis.

MATERIAL AND METHODS

Peripheral blood was collected from 12 patients aged 8 ±2 years suffering from atopic asthma and undergoing sublingual specific immunotherapy. To evaluate sensitivity to Fas-mediated apoptosis, the blood was transmitted to sterile tubes and mixed with purified monoclonal antibody anti-CD95. After incubation, leukocytes were stained with Annexin V, propidium iodide, and monoclonal antibody against CD2 conjugated with phycoerythrin-cyanin 5.1, and then analyzed with flow cytometry. The procedure was repeated for each patient after 12 months of SLIT. -

RESULTS

Stimulation with anti-CD95 of T lymphocytes from patients with atopic asthma before treatment increased the number of early apoptotic cells (from 19.5 ±16.7% before stimulation to 26.6 ±16.7% Annexin V positive cells after stimulation). After one year of SLIT anti-CD95 still caused an increase of the early apoptotic cells ratio in the lymphocyte population (from 12.4 ±7.4% before stimulation to 24.7 ±15.4% Annexin V positive T cells after CD95 stimulation). Although an increasing trend could be observed, differences between the analyzed groups were not statistically significant.

CONCLUSIONS

A year of SLIT does not change the sensitivity of T lymphocytes from peripheral blood of children suffering from atopic asthma to Fas-mediated apoptosis.

House dust mite sublingual immunotherapy: results of a US trial

BACKGROUND

Few trials of sublingual immunotherapy (SLIT) in the United States have been reported.

OBJECTIVE

This randomized, placebo-controlled feasibility SLIT study compared the safety and physiologic effects of high- versus low-dose Dermatophagoides farinae vaccine.

METHODS

Thirty-one D farinae-sensitive adults with allergic rhinitis with or without mild intermittent asthma were eligible for randomization to high-dose maintenance vaccine (n = 10, 4200 allergen units [approximately 70 μg of Der f 1/d]), low-dose maintenance vaccine (n = 10; 60 allergen units [approximately 1 μg of Der f 1/d]), or placebo (n = 11) over 12 to 18 months. Medication-symptom scores and adverse events were monitored, serum D farinae-specific IgE and IgG4 levels were measured, and bronchial reactivity to D farinae was determined at baseline and 6-month intervals.

RESULTS

Of the 31 randomized subjects, 6 withdrew because of non-treatment-ascribed events. Four withdrew because of treatment-ascribed effects: high-dose group, 1 of 10 (gastrointestinal symptoms); low-dose group, 1 of 10 (gastrointestinal symptoms); and placebo group, 2 of 11 (headache and increased nasal symptoms). Thus 21 subjects completed the study: high-dose group, 9; low-dose group, 7; and placebo group, 5. Eleven of the 21 subjects experienced mild-to-moderate gastrointestinal symptoms, throat irritation, or both (high-dose group, 5/9; low-dose group, 4/7; and placebo group, 2/5). No severe systemic reactions were noted. No differences in symptom-medication scores were found. High-dose SLIT increased the bronchial threshold to allergen challenge and increased serum D farinae-specific IgG4 levels, whereas low-dose SLIT and placebo had no significant effect.

CONCLUSIONS

High-dose D farinae SLIT was generally tolerable, increased serum D farinae-specific IgG4 levels, and improved the bronchial threshold to allergen challenge. Larger US trials are warranted.

Certainties and doubts about sublingual and oral immunotherapy in children

PURPOSE OF REVIEW

Sublingual (SLIT) and oral immunotherapy (OIT) are two variants of immunotherapy that might be especially of interest for children. After adult studies, lately many trials in children are published. However, the quality of published material varies. In the present review we analyze paediatric SLIT publications from the past 2 years in the light of a new system of evaluation of quality of evidence, the grading of recommendations assessment, development and evaluation system.

RECENT FINDINGS

High quality evidence in children: high-dose daily grass SLIT reduces symptoms and medication use; low-dose pollen SLIT reduces the development of new sensitizations. Low-dose SLIT reduces symptoms and medication in mild-moderate atopic dermatitis. Latex SLIT for 3 years results in a negative glove test. The evidence for the effectiveness of SLIT for seasonal and perennial asthma is still of moderate-low quality, as is the evidence for asthma prevention. Too high dose of mite SLIT seems ineffective for asthma. Oral allergen immunotherapy is promising for some food allergies. Some definite immunological changes are seen with SLIT; facilitated antibody presentation and IL-17 might correlate with efficacy.

SUMMARY

Even after a hundred years of immunotherapy, it is still an ever changing field with SLIT and OIT making fast progress.

T-cell responses induced by allergen-specific immunotherapy

Allergen-specific immunotherapy is recognized as a highly effective practice in the treatment of patients with severe allergic rhinitis and/or asthma and is recommended by World Health Organization as an integrated part of allergy management strategy. Several studies have shown that allergen-specific immunotherapy, based on the administration of increasing doses of allergen, achieves a hyposensitization and reduces both early and late responses occurring during the natural exposure to the allergen itself. This is the unique antigen-specific immunomodulatory treatment in current use for human diseases. Successful immunotherapy is associated with reductions in symptoms and medication scores and improved quality of life. After interruption it usually confers long-term remission of symptoms and prevents the onset of new sensitizations in children up to a number of years. Subcutaneous immunotherapy usually suppresses the allergen-induced late response in target organs, likely due to the reduction of the infiltration of T cells, eosinophils, basophils, mast cells and neutrophils. In addition to the reduction of cells of allergic inflammation, immunotherapy also decreases inflammatory mediators at the site of allergen exposure. This review provides an update on the immunological T cell responses induced by conventional subcutaneous and sublingual immunotherapy, and gives a unifying view to reconciling the old dualism between immunoredirecting and immunoregulating mechanisms.

Clinical outcome and IL-17, IL-23, IL-27 and FOXP3 expression in peripheral blood mononuclear cells of pollen-allergic children during sublingual immunotherapy

Induction of allergen-specific, tolerogenic, IL-10 and/or TGF-β-producing T-regulatory (Treg) cells that express transcription factor FOXP3 is considered as one of the key mechanisms of allergen-specific immunotherapy. However, little is known of the induction of FOXP3 expression in children during sublingual immunotherapy (SLIT). Recently, also, a novel subgroup of T-helper (Th) cells, the Th17 cells, secreting predominantly IL-17 (IL-17A), was identified. The expressions of IL-17 or the Th17-regulating cytokines IL-23 and IL-27 during SLIT are currently completely unexplored. This randomized, placebo-controlled dose-response study was performed to analyze the effects of SLIT on FOXP3, IL-17, IL-23, and IL-27 expressions in peripheral blood mononuclear cells (PBMC) of children with allergic rhinitis and their associations with clinical outcome. Thirty children were included: ten received SLIT with a glycerinated mixture of birch, hazel and alder with a cumulative weekly dose of 24,000 SQ-U, 10 with dose 200,000 SQ-U/wk, and ten received placebo. Cytokine and FOXP3 mRNA expressions in allergen-, purified protein derivative-stimulated and non-stimulated PBMC were determined at 0, 1 and 2 yr of SLIT by real-time RT-PCR (TaqMan). Symptoms and medications were recorded using diary cards. Allergen-induced IL-17 mRNA expression was significantly increased in the study subjects with elevated combined Symptom Medication Score (SMS) after 2 yr. There was also a significant positive correlation between the allergen-induced IL-17 and SMS in whole study group (r = 0.38, p = 0.039) and especially the 200,000 SQ-U dose-treated group (r = 0.74, p = 0.027) at 2 yr. Allergen-induced FOXP3 mRNA expression was significantly increased in the 200,000 SQ-U dose-treated children after two study years as compared with baseline (p = 0.016) and placebo-treated children (p = 0.028). The changes in FOXP3 mRNA expression positively correlated with IL-10 and TGF-β mRNAs during SLIT in whole study population. Increased allergen-induced IL-17 responses during SLIT are associated with elevated SMS. Increased tolerogenic, allergen-specific Treg responses are also observed in children during SLIT.

Clinical efficacy and immunological mechanisms of sublingual and subcutaneous immunotherapy in asthmatic/rhinitis children sensitized to house dust mite: an open randomized controlled trial

BACKGROUND

In children, the clinical efficacy and immunological mechanisms of sublingual immunotherapy (SLIT) compared with subcutaneous immunotherapy (SCIT) is still to be elucidated.

OBJECTIVES

To compare SLIT, SCIT and pharmacotherapy in relation to clinical efficacy and immunological mechanisms that govern its effect in asthmatic/rhinitis children who were sensitized to house dust mite (HDM).

METHODS

In this single centre, prospective, randomized, controlled, open labelled, three parallel group trial, 48 patients mono-sensitized to HDM were randomized to receive either SLIT (n=16), SCIT (n=16) or pharmacotherapy alone (n=16). Symptom, medication and visual analogue score (VAS) were collected and bronchial-nasal hyper-reactivity, skin prick tests, total-specific IgE were performed at baseline and 12 months after treatment. In addition, peripheral blood mononuclear cells were cultured with recombinant Der p 1 and Bet v 1 extracts and allergen-specific IL-4, IL-5, IL-13, IFN-gamma, IL-10, and TGF-beta secretions were measured.

RESULTS

SLIT and SCIT demonstrated a significant reduction of total rhinitis and asthma symptom score, total medication score, VAS and skin reactivity to HDM (P<0.05) when compared with pharmacotherapy. A significant reduction of serum-specific HDM-IgE in SCIT and SLIT were observed. Moreover, titrated nasal provocative dose significantly increased in both immunotherapy groups when compared with the pharmacotherapy group. No adverse effects were reported in SLIT, while two patients demonstrated serious adverse events in SCIT. After 1 year of treatment, Der p 1-driven IL-10 significantly increased in SLIT compared with pharmacotherapy, whereas Bet v 1-driven TGF-beta (negative control) increased significantly in SLIT only. No changes were observed for Th1-Th2 cytokines.

CONCLUSION

Both SLIT and SCIT demonstrated clinical improvement compared with pharmacotherapy in asthma/rhinitis children sensitized to HDM.

Birch pollen immunotherapy leads to differential induction of regulatory T cells and delayed helper T cell immune deviation

Correction of an imbalance between allergen-specific T cell subsets is considered a critical event in establishing allergen tolerance by specific immunotherapy (SIT). In a comprehensive, longitudinal study, distinct T cell populations and Ig subtypes were analyzed in subjects allergic to birch pollen during decisive time points of SIT (i.e., induction and maintenance phase), as well as in and out of birch pollen season. An increase in Bet v 1-specific, IL-10-secreting T cells, fulfilling the criteria of inducible type 1 regulatory T (Tr1) cells, was observed by the end of the induction phase; this resulted in a decreased ratio of allergen-specific IL-5(+) Th2/Tr1 cells. In contrast, CD4(+)CD25(+)CD127(low) regulatory T cell numbers did not change. Furthermore, enhanced concentrations of allergen-specific IgG Abs were observed, whereas allergen-specific IgE and IgA levels remained unchanged. After 1 y of SIT, a reduced ratio of allergen-specific Th2/IFN-gamma(+) Th1 cells was apparent. Although untreated and SIT-treated allergic subjects developed enhanced Th2 cell responses during birch pollen season, only SIT-treated patients experienced elevated numbers of allergen-specific Tr1 cells, which were associated with reduced skin prick test reactivity and diminished clinical symptoms. In coculture assays, allergen-specific Tr1 cells showed an IL-10- and dose-dependent inhibition of CD4(+)CD25(-) T effector cells. Thus, SIT has differential effects on regulatory T cell subsets, resulting in an early induction of allergen-specific Tr1 cells associated with an increase in allergen-specific IgG, and it leads to a delayed shift from an allergen-specific Th2- to a Th1-dominated immune response.

Sublingual immunotherapy for children: Are we there yet? Defining its role in clinical practice

Immunotherapy in various forms has been used to treat allergic disorders since the early 19th century. Subcutaneous immunotherapy is now well established for the treatment of insect anaphylaxis and allergic rhinitis. The route of administration and possibility of severe adverse reactions to subcutaneous immunotherapy make sublingual immunotherapy an appealing alternative, especially for the paediatric patient. This form of immunotherapy has been increasingly used in Europe, and over the past decade several meta analyses have attempted to provide evidence for its efficacy in the treatment of seasonal and perennial allergic rhinitis and in asthma, both in the adult and paediatric population. Several trials have also shown a potential immunomodulatory effect of sublingual immunotherapy, with evidence of a reduction in the progression from allergic rhinitis to asthma and reduced new aeroallergen sensitisation. This review will give an overview of the current evidence for sublingual immunotherapy in the paediatric population.

Sublingual immunotherapy in children: complete and updated review supporting evidence of effect

PURPOSE OF REVIEW

The interest in sublingual immunotherapy (SLIT) is still growing worldwide and especially for the pediatric age group, this modality is appealing. Lately, some negative systematic review articles have been published on SLIT in children. However, high quality articles published from 2007 onward had not been included.

RECENT FINDINGS

Explanations are sought for the negative outcomes in these reviews and shortcomings are discussed. New pediatric studies - not included in the previous reviews -designed taking into account the golden rules for SLIT (high daily dose, starting at least 4 months before pollen season) do show statistically significant improvement in symptom and medication scores for rhinitis and asthma in pollen allergy. New house dust mite studies still show inconsistent data.

SUMMARY

Evidence of effect is confirmed for SLIT in children with allergic rhinitis or asthma caused by pollen exposure. For house dust mite asthma, evidence is still nonconcordant. New techniques to improve SLIT efficacy are under investigation.

Current immunological approaches for management of allergic rhinitis and bronchial asthma

A large population world over is affected with allergic diseases and asthma. Pharmacotherapy for allergic diseases and asthma is effective in controlling symptoms but on discontinuation of medication, symptoms reoccur. In contrast, immunotherapy modifies and corrects the underlying pathological immune responses in an antigen-specific manner. Immunotherapy shows an increase in IgG (blocking antibody) that competes with IgE for allergen, inhibiting the release of inflammatory mediators. Recent studies suggest that immunotherapy acts by modifying CD4+ T-cell responses either by immune deviation, T-cell anergy and/or both. Current immunological approaches for management of allergies and asthma involve immunization with native allergen, modified allergen, peptides/cDNA of allergen, anti-IgE, adjuvants coupled allergen, including immunostimulatory DNA sequences, cytokines, and bacterial products. These approaches modulate the immune response and are intended to give long-term benefit.

Subcutaneous and sublingual immunotherapy in children: complete update on controversies, dosing, and efficacy

For this review, articles on immunotherapy dosing in pediatric respiratory allergy were identified via PubMed, through congressional abstracts for 2008, in reference lists of recent review articles, and via personal communication with experts. In pediatric subcutaneous immunotherapy (SCIT), doses shown to be effective, mostly in aluminium-adsorbed preparations administered every 6 weeks, contain 20 microg of group 5 major allergen, 12 microg Bet v 1, 15 microg Fel d 1, and 5 to 20 microg Der p 1. Evidence indicates that SCIT prevents new sensitizations and asthma onset 7 years after discontinuation and reduces symptoms 12 years after a 5-year SCIT course, even though skin reactivity returns. Consistent evidence of effect exists for sublingual immunotherapy in pediatric respiratory allergy with daily 15- to 25-microg grass group 5 major allergen and 6 microg Bet v 1. Der p/f doses of 0.8/0.4 microg three times weekly (up to 27/57 microg daily) demonstrate inconsistent findings. Evidence of effect exists for SCIT in pediatric allergic rhinitis and asthma as treatment and preventive management. Evidence of effect exists for sublingual immunotherapy in pediatric allergic rhinoconjunctivitis and seasonal asthma. Similar results are doubtful for perennial asthma.