"ARIA": global guidelines and new forms of allergen immunotherapy

Allergen immunotherapy: The growing role of observational and randomized trial "Real-World Evidence"

BACKGROUND

Although there is a considerable body of knowledge about allergen immunotherapy (AIT), there is a lack of data on the reliability of real-world evidence (RWE) in AIT, and consequently, a lack of information on how AIT effectively works in real life.

METHODS

To address the current unmet need for an appraisal of the quality of RWE in AIT, the European Academy of Allergy and Clinical Immunology Methodology Committee recently initiated a systematic review of observational studies of AIT, which will use the RELEVANT tool and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) to rate the quality of the evidence base as a whole. The next step will be to develop a broadly applicable, pragmatic "real-world" database using systematic data collection. Based on the current RWE base, and perspectives and recommendations of authorities and scientific societies, a hierarchy of RWE in AIT is proposed, which places pragmatic trials and registry data at the positions of highest level of evidence.

KEY RESULTS

There is a need to establish more AIT registries that collect data in a cohesive way, using standardized protocols.

CONCLUSIONS

This will provide an essential source of real-world data that can be easily shared, promoting evidence-based research and quality improvement in study design and clinical decision-making.

Long-term oral administration of transgenic rice containing cedar pollen T-cell epitopes potentially improves medication- and allergy-related quality-of-life scores

Background: We previously developed a transgenic rice that contains seven linked human predominant T-cell epitopes (7Crp) derived from Japanese cedar (JC) pollen allergens Cry j 1 and Cry j 2. Oral administration of 80 g of transgenic rice for 20 weeks suppressed allergen-specific T-cell proliferation in participants with JC pollinosis, but their clinical symptoms did not improve. Objective: We examined the clinical efficacy of low-dose (5 g and 20 g) intake of the transgenic rice administered for two successive seasons. Methods: In this randomized, double-blind, placebo controlled study, transgenic rice seeds (5 g or 20 g) were orally administered to the participants for 24 weeks in each of two successive JC pollen seasons. We analyzed T-cell proliferation and cytokine expression, and monitored symptom and medication scores during the pollen season. Quality of life (QOL) was evaluated by using the Japanese Allergic Rhinitis Quality of Life Standard Questionnaire (JRQLQ). Results: Specific T-cell proliferation after stimulation with 7Crp, Cry j 1, and Cry j 2 was significantly suppressed in the second JC pollen season. No significant differences were found among the three groups (5 g, 20 g, and placebo) with regard to clinical symptoms or medication scores in the first season. However, the medication scores and face scale for overall condition of JRQLQ improved in the 5-g transgenic rice group in the second season, although careful re-examination with a large sample size is necessary to confirm the results. Conclusion: Low-dose oral administration of transgenic rice that contains 7Crp significantly reduced allergen-specific T-cell responses and improved medication scores during the second season of administration. Thus, oral intake of the transgenic rice has the potential to induce immune tolerance to JC pollen allergens when administered for at least two successive seasons.

Intralymphatic immunotherapy

Gold Standard allergen-specific immunotherapy is associated with low efficacy because it requires either many subcutaneous injections of allergen or even more numerous sublingual allergen administrations to achieve amelioration of symptoms. Intralymphatic vaccination can maximize immunogenicity and hence efficacy. We and others have demonstrated that as few as three low dose intralymphatic allergen administrations are sufficient to effectively alleviate symptoms. Results of recent prospective and controlled trials suggest that this strategy may be an effective form of allergen immunotherapy.

Systemic reactions to inhalant immunotherapy using 1:1 target dosing

BACKGROUND

The 2007 immunotherapy practice parameters advocate maintenance dosing at 1:1 (1:20 maintenance concentrate). There is limited literature exploring the effect of 1:1 dosing on the rate of systemic reactions to subcutaneous immunotherapy (SRITs).

OBJECTIVE

To investigate the effects of 1:1 dosing on SRITs in a large, academic practice.

METHODS

We conducted a retrospective cohort study of all nonvenom and noncluster SRITs that occurred between 2005 and 2011. SRITs that occurred from August 2008 through December 2011, postparameter dosing (post-PD) was initiated, were compared to SRITs that occurred from January 2005 to July 2008 with preparameter dosing (pre-PD) using 1:50 as a maintenance concentrate.

RESULTS

A total of 269 SRITs occurred in a 7-year period. Significantly more post-PD SRITs (131 of 38,548 injections) occurred than pre-PD SRITs (132 of 52,833 injections) (0.34% vs 0.25%, P = .01). However, when excluding 44 SRITs that occurred in established pre-PD patients transitioned to post-PD, there was no significant difference in SRIT rate (0.25% vs 0.22%), World Allergy Organization (WAO) grade, or SRIT time to onset. Nonred (non-1:1) vials accounted for a significantly larger proportion of all post-PD SRITs compared with all pre-PD SRITs (50.7% vs 31.1%, adjusted P = .009). Prior SRITs were reported less frequently among persons with post-PD SRITs (29.2% vs 70.8%, adjusted P = .009). In an adjusted logistic regression model, male sex (odds ratio, 7.9; 95% CI, 2.4-26) and longer time to reaction onset (odds ratio, 0.94; 95% CI, 0.89-0.99) were associated with higher WAO severity grade reactions.

CONCLUSION

Pre-PD vs post-PD SRIT rates were not significantly different, adjusting for patients transitioned from established pre-PD to post-PD. This finding suggests that post-PD is as safe as pre-PD. Male sex and faster time to reaction onset were associated with higher WAO grade reactions.

Serum immunologic markers for monitoring allergen-specific immunotherapy

Allergen immunotherapy is an effective treatment option in patients with IgE-mediated allergy, particularly in those who do not respond to usual antiallergic drugs. Successful immunotherapy has been associated with the suppression of allergic inflammation in target organs and increases in allergen-specific IgG antibodies, particularly the IgG(4) subclass. To date there are no biomarkers that are predictive of the clinical response to immunotherapy. This article explores the possibility that functional assays based on the ability of IgG to compete with IgE and inhibit IgE-allergen complex formation may be surrogate or predictive of the clinical response to immunotherapy.

Epicutaneous/transcutaneous allergen-specific immunotherapy: rationale and clinical trials

PURPOSE OF REVIEW

IgE-mediated allergies, such as allergic rhinoconjunctivitis and asthma, have become highly prevalent, today affecting up to 35% of the population in industrialized countries. Allergen immunotherapy (also called hyposensitization therapy, desensitization or allergen-specific immunotherapy), the administration of gradually increasing amounts of an allergen, either subcutaneously or via the sublingual or oral route is effective. However, only few allergy patients (<5%) choose immunotherapy, as treatment duration is over years and because allergen administrations are associated with local and in some cases even systemic allergic side effects due to allergen accidentally reaching the circulation. Therefore, ideally the allergen should be administered to a site that contains high numbers of potent antigen-presenting cells in order to enhance efficacy and shorten treatment duration, and ideally that site should also be nonvascularized in order to prevent both systemic distribution of the allergen and systemic allergic side effects. The epidermis, a nonvascularized multilayer epithelium that contains high numbers of potent antigen-presenting Langerhans cells, could therefore be an interesting administration route.

RECENT FINDINGS

We have recently reintroduced transcutaneous or epicutaneous allergen-specific immunotherapy (EPIT) as treatment option for IgE-mediated allergies. This method was found efficacious and safe. Few applications of allergens using skin patches with a treatment duration of a few weeks were sufficient to achieve lasting relief.

SUMMARY

This review gives an overview on the history, the rationale, and the mechanisms of transcutaneous/epicutaneous immunotherapy.

Intralymphatic immunotherapy: from the rationale to human applications

Allergen specific immunotherapy (SIT) is the only treatment of IgE mediated allergies that is causative and has a long-term effect. Classically, SIT requires numerous subcutaneous injections of the allergen during 3-5 years. Over the last decade sublingual allergen applications have established as an alternative, but treatment duration could not be shortened. This review focuses on direct administration of vaccines in general and of allergens in particular into lymph nodes with the aim to enhance immunotherapy. Several studies have found that direct injection of antigens into lymph nodes enhanced immune responses. Recently we have focused on intralymphatic allergen administration in order to enhance SIT. Data in mouse models and in clinical trials showed that intralymphatic allergen administration strongly enhanced SIT, so that the number of allergen injections could be reduced to three, and the allergen dose could be reduced 10-100 fold. Intralymphatic injections proved easy, practically painless and safe. In mice and men, intralymphatic immunotherapy injecting allergens into a subcutaneous lymph node markedly enhances the protective immune response, so that both the dose and number of allergen injections can be reduced, making SIT safer and faster, which enhances patient convenience and compliance.

Intralymphatic immunotherapy

PURPOSE OF REVIEW

IgE-mediated allergy can be treated by subcutaneous allergen-specific immunotherapy (SCIT). However, the percentage of allergic patients undergoing SCIT is low, mainly due to the long duration of the therapy and the risk of severe systemic allergic reactions associated with the allergen administration. Typically, SCIT requires dozens of subcutaneous allergen injections that stretch over 3-5 years. Over the last decade, sublingual immunotherapy has been established as an alternative to SCIT, but treatment duration and dosing frequencies could not be reduced. Recently, immunotherapy by direct administration of the allergen into lymph nodes [intralymphatic immunotherapy (ILIT)] has proven a promising alternative and this method is the focus of the present review.

RECENT FINDINGS

Several studies on animals and on humans have shown that direct injection into lymph nodes enhanced immune responses to protein, peptide, and naked DNA vaccines. Moreover, ILIT strongly improved allergen immunotherapy, so that the number of allergen administrations as well as the allergen dose could be reduced. As ILIT was also well tolerated, practically painless, and easy to perform, patient compliance was improved as compared with SCIT.

SUMMARY

Direct ILIT into a subcutaneous lymph node markedly enhances protective immune responses, so that both the dose and the number of allergen injections can be reduced, making ILIT safer and faster than other forms of immunotherapy, and most importantly, this enhances patient convenience and compliance.

Sublingual immunotherapy for Japanese cedar pollinosis

The prevalence of pollinosis caused by cedar pollen has increased by 10% these ten years of 26.5% in the investigation of 2008 in Japan. The pharmacotherapy is a main treatment tool for pollinosis, and the surgical treatment is not acknowledged to the treatment of pollinosis internationally. Moreover, allergen immunotherapy enters a special treatment method, and is an important therapeutic procedure. The allergen immunotherapy is unique for having possibility of curing allergen specific allergic diseases. However the side effect of allergen subcutaneous immunotherapy (SCIT), such as anaphylaxis is kept at a distance in a medical situation in Japan. Then, a sublingual immunotherapy (SLIT) that was safer than it, developed in Europe for pollinosis induced by grass or ragweed, but not in Japan. As a result, the effect of SLIT was proven in the cedar pollinosis in Japan as high level evidence. A whole body immunity induction is thought in the appearance of the effect, and, in addition, it is necessary to be going to be cleared the accurate mechanism of the effect in the future. Moreover, the development of a special SLIT and the import of an overseas product are needed in Japan.

Intralymphatic allergen administration renders specific immunotherapy faster and safer: a randomized controlled trial

The only causative treatment for IgE-mediated allergies is allergen-specific immunotherapy. However, fewer than 5% of allergy patients receive immunotherapy because of its long duration and risk of allergic side effects. We aimed at enhancing s.c. immunotherapy by direct administration of allergen into s.c. lymph nodes. The objective was to evaluate safety and efficacy compared with conventional s.c. immunotherapy. In a monocentric open-label trial, 165 patients with grass pollen-induced rhinoconjunctivitis were randomized to receive either 54 s.c. injections with pollen extract over 3 years [cumulative allergen dose 4,031,540 standardized quality units (SQ-U)] or 3 intralymphatic injections over 2 months (cumulative allergen dose 3,000 SQ-U). Patients were evaluated after 4 months, 1 year, and 3 years by nasal provocation, skin prick testing, IgE measurements, and symptom scores. Three low-dose intralymphatic allergen administrations increased tolerance to nasal provocation with pollen already within 4 months (P < 0.001). Tolerance was long lasting and equivalent to that achievable after standard s.c. immunotherapy (P = 0.291 after 3 years). Intralymphatic immunotherapy ameliorated hay fever symptoms (P < 0.001), reduced skin prick test reactivity (P < 0.001), decreased specific serum IgE (P < 0.001), caused fewer adverse events than s.c. immunotherapy (P = 0.001), enhanced compliance (P < 0.001), and was less painful than venous puncture (P = 0.018). In conclusion, intralymphatic allergen administration enhanced safety and efficacy of immunotherapy and reduced treatment time from 3 years to 8 weeks.

A randomized double-blind comparative study of sublingual immunotherapy for cedar pollinosis

BACKGROUND

Seasonal allergic rhinitis (SAR) induced by Japanese cedar pollen is a substantial problem in Japan. Sublingual immuno-therapy (SLIT) is safer than conventional antigen-specific immunotherapy, the only treatment modality by which complete cure of the disease can be expected. We investigated the safety and efficacy of SLIT in the treatment of cedar pollinosis patients compared to placebo.

METHODS

A randomized, placebo-controlled, double-blind study was conducted in 61 cedar pollinosis patients. Increasing doses of standardized Japanese cedar extract or placebo were administered sublingually in intervals ranging from daily to once a week after six weeks. The primary efficacy variable was the mean of the daily total symptom scores (TSS) during the pollen dispersing period. Secondary efficacy variables included the QOL scores and related variables.

RESULTS

Primary efficacy variable scores were significantly lower for some days in the SLIT group than in the placebo group (P < .01 or P < .05). Secondary efficacy for the QOL score in SLIT group was almost of half of placebo group. There was no significant difference in the overall incidence of side effects between the SLIT group and the placebo group.

CONCLUSIONS

SLIT was effective and safe in the treatment of cedar pollinosis.

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

Although the efficacy of allergen-specific sublingual immunotherapy (SLIT) is now accepted, the underlying mechanisms remain elusive. Such mechanisms are better documented in the case of subcutaneous immunotherapy (SCIT). In order to understand the T-lymphocyte response in patients receiving SLIT, we compared children with respiratory disease monosensitized to Dermatophagoides pteronyssinus receiving SLIT or SCIT over a 2-yr period. Peripheral blood was obtained before beginning immunotherapy, and after 3 months, 1 yr and 2 yr. Total IgE, specific IgE and IgG4 to D. pteronyssinus were determined in serum. T-cell markers (CD3, CD4, CD8, CD25) and intracellular cytokine production (TNF-alpha, IL-2, IL-4 and IFN-gamma) were determined in peripheral blood mononuclear cells (PBMC) by flow cytometry. No differences between SCIT and SLIT were detected in the clinical variables or in the subjective evaluation. Although an increase in specific IgE and IgG4 was only detected in SCIT, a significant decrease in the specific IgE/IgG4 ratio was found in both groups. SCIT and SLIT experienced an increase in the CD4/CD8 ratio over time, but an increase in the CD4(+)CD25(+) and a decrease in the CD8(+)CD25(+) subsets were only found with SCIT. A slight shift from a Th2 to a Th1 pattern, measured by the IFN-gamma/IL-4 ratio, was only detected in the CD4 T cells with SCIT. A decrease in both groups was found in TNF-alpha and IL-2 production over time. Children with respiratory allergic diseases receiving SCIT or SLIT had a different immunologic response in peripheral blood during treatment, though the clinical improvement was similar. Whether SLIT induces a mucosal protective response should be studied.

Grass pollen immunotherapy: IL-10 induction and suppression of late responses precedes IgG4 inhibitory antibody activity

BACKGROUND

Grass pollen immunotherapy is an effective treatment for seasonal allergic rhinitis that provides the opportunity to study the induction and maintenance of allergen-specific immune tolerance.

OBJECTIVES

We investigated the relationship between clinical responsiveness, regulatory cytokine production, and antibody responses to allergen during 1 year of immunotherapy.

METHODS

Eighteen subjects with severe seasonal allergic rhinitis were randomized double-blind to receive active or placebo injections of an alum-adsorbed grass pollen vaccine (Alutard SQ). Subjects underwent repeated testing of early- and late-phase skin responses to intradermal allergen, and cellular responses to grass pollen allergen were tested. Sera were tested for allergen-specific IgG4, IgA, and inhibitory activity in biologic assays of IgE responses.

RESULTS

Grass pollen immunotherapy was effective in reducing overall symptom scores (P < .05) and conjunctival reactivity (P < .05). In the active group significant IL-10 production occurred early at low allergen doses and at a similar time as inhibition of late skin responses at 2 to 4 weeks. Serum allergen-specific IgG4, IgA, and inhibitory antibody activity for basophil histamine release and IgE-facilitated allergen binding to B cells occurred later, at 6 to 12 weeks, at higher allergen doses and preceded inhibition of early skin responses.

CONCLUSION

IL-10 responses occur early but at immunotherapy doses that are not clinically effective. Later induction of inhibitory antibodies, including IgG4 and IgA, might be required for efficacy through modulation of IgE-mediated events.

Allergic rhinitis--current approaches to skin and in vitro testing

This article discusses the currently available techniques used for the diagnosis of IgE-mediated upper respiratory allergy. These methods are necessary to confirm the presence and the intensity of allergy in an effort to select patients for immunotherapy and to dose immunotherapy properly. Specific techniques discussed include epicutaneous and intradermal skin tests and in vitro tests designed to measure antigen-specific IgE antibody.

Exhaled nitric oxide in persistent rhinitis with or without lower airway involvement: a review of the literature

The link between upper and lower respiratory airways has been investigated in the past decade leading to the concept of united airways disease. This hypothesis was suggested by several epidemiological observations, which had shown the high prevalence of rhinitis and sinusitis in patients with asthma, and indirectly, by observing the effects of drugs used for rhinitis on asthma symptoms. A broad spectrum of airway involvement severity can be associated with rhinitis or rhinosinusitis: from a subclinical/asymptomatic inflammatory involvement with an increase in eosinophils in induced sputum cell count, to asthma-like symptoms without functional features of asthma with or without extrathoracic airway hyperresponsiveness, to respiratory symptoms with clinical and functional criteria of asthma. The aim of this paper is to review the literature about the role of breath analysis in the relationship between nose and lung, focusing on exhaled nitric oxide (FE(NO)) measurement, a non-invasive marker of inflammation, in rhinitis and in chronic rhinosinusitis in patients complaining or not of asthma symptoms.

New reagents on the horizon for immune tolerance

Recent advances in immunology and a growing arsenal of new drugs are bringing the focus of tolerance research from animal models into the clinical setting. The conceptual framework for therapeutic tolerance induction has shifted from a "sledgehammer" approach that relies solely on cellular depletion and cytokine targeting, to a strategy directed toward restoring a functional balance across the immune system, namely the different populations of naive cells, effector and memory cells, and regulatory cells. Unlocking the key to tolerance induction in the future will likely depend on our ability to harness the functions of T regulatory cells. Also, dendritic cells are strategically positioned at the interface between innate and adaptive immunity and may be subject to deliberate medical intervention in a way that can control a chronic inflammatory response. Many reagents with tolerance-inducing potential are currently undergoing clinical testing in transplantation, autoimmune diseases, and allergic diseases, and even more that are on the horizon promise to offer enormous benefits to human health.

Visual analog scales can assess the severity of rhinitis graded according to ARIA guidelines

BACKGROUND

The allergic rhinitis and its impact on asthma (ARIA) guidelines provide a new classification of allergic rhinitis, but a quantitative analysis for severity assessment is lacking.

OBJECTIVE

To study whether a visual analog scale (VAS) for global rhinitis symptoms could be used to assess the disease severity according to ARIA.

METHODS

Three thousand fifty-two allergic rhinitis patients seen in primary care were tested. Fifty three per cent had an objective diagnosis of allergy and 58% of the patients were treated. Patients were categorized according to ARIA guidelines. The severity of nasal symptoms was assessed using a VAS. Quality of life was measured using the rhinoconjunctivitis quality of life questionnaire (RQLQ).

RESULTS

Severity had more impact on VAS levels than duration: mild intermittent rhinitis (3.5, 2.4-5.0 cm), mild persistent rhinitis (4.5, 3.2-5.6 cm), moderate/severe intermittent rhinitis (6.7, 5.3-7.7 cm) and moderate/severe persistent rhinitis (7.2, 6.1-8.2 cm). The receiver operating characteristic curve results showed that patients with a VAS of under 5 cm could be classified as 'mild' rhinitis (negative predictive value: 93.5%) and those with a VAS of over 6 cm as 'moderate/severe' rhinitis (positive predictive value: 73.6%). Receiver operating characteristic curves and a logistic regression showed that current treatment and allergy diagnosis have no effect on the assessment of rhinitis severity using VAS. Visual analog scale and the RQLQ global score were significantly correlated (rho = 0.46; P < 0.0001).

CONCLUSION

A simple and quantitative method (VAS) can be used for the quantitative evaluation of severity of allergic rhinitis.

Targeting dendritic cells in allergen immunotherapy

Allergen immunotherapy is a well-established strategy for treating allergic diseases with the goal of inducing allergen-specific tolerance. Identified mechanisms contributing to the therapeutic effect of immunotherapy include a shift of T helper 2 (Th2)-type immune responses to a modified Th2 immune response, a change of the balance of IgE-producing B cells to the production of IgG subtypes, in addition to increased IL-10 and TGF-beta secretion and activation of the suppressive functions of regulatory T-cells. Dendritic cells (DCs), which as outposts of the immune system are capable of T-cell priming through efficient allergen uptake by IgE receptors expressed on their cell surface. Most of the hypotheses concerning the function of DCs as facilitators of allergen-specific tolerance in allergen immunotherapy remain speculative. Therefore, studies must focus on the functional changes of DCs under immunotherapy to close the gap of knowledge about their exact role. These experimental data should help confirm the hypothesis of DCs as efficient silencers and potential target cells and take advantage of the bivalent character and tolerogenic properties of DCs.

Molecular approaches for new vaccines against allergy

Type I allergy represents an important health problem that is currently affecting approximately 25% of the population in Western countries. Immunotherapy, the only causative treatment of Type I allergy, is currently performed with crude allergen extracts, which contain unpredictable amounts of allergenic, as well as nonallergenic, components. The application of molecular biology for allergen characterization has revealed the molecular nature of the most common allergens and allowed the production of recombinant allergens that equal natural allergens. Based on this knowledge, several different strategies to improve immunotherapy have become available. Until now, T-cell peptides, selected wild-type-like recombinant allergens and genetically modified hypoallergenic allergen derivatives have been evaluated in clinical trials in patients. Immunotherapy based on T-cell peptides has focused on allergen-specific T-cell responses, whereas genetically modified recombinant allergen molecules offer the advantage of combining T-cell and B-cell epitopes. Genetically modified recombinant birch pollen derivatives (Bet v 1-fragments, Bet v 1-trimer) have been evaluated in a double-blind, placebo-controlled, multicenter study. Vaccination with the Bet v 1-derivatives improved symptoms of birch pollen allergy, induced a healthy allergen-specific immunoglobulin G response and led to a significant reduction of seasonally induced boosts of immunoglobulin E.

Exhaled nitric oxide as a diagnostic test for asthma in rhinitic patients with asthmatic symptoms

BACKGROUND

Rhinitis is a major risk factor for asthma, so that evaluation of the lower airways is recommended in patients with rhinitis. Exhaled nitric oxide (FE(NO)) is considered a marker of airway inflammation and it has been found to be useful for the screening of patients with suspected diagnosis of asthma. Our aim was to assess the validity and accuracy of FE(NO) to identify patients with asthma in 48 non-smoking patients with persistent rhinitis and asthma-like symptoms.

METHODS

Asthma was diagnosed on the basis of 12% improvement in FEV1 after salbutamol or a methocholine PD(20)FEV1<800 microg. Prior to lung function FE(NO) was measured with the single exhalation method at 50 ml/s.

RESULTS

The geometric mean (95% confidence interval) FE(NO) was significantly higher in the 18/48 asthmatics than in the non-asthmatic patients (60 ppb, CI 95%: 50-89, versus 30 ppb, CI 95%: 28-45, P=0.001). Receiver operating characteristic (ROC) curve for the diagnosis of asthma indicated that FE(NO) is an acceptable discriminator between patients with and without asthma (area under the ROC curve=0.78). None of the asthmatic patients had FE(NO) values<25 ppb and all the patients with FE(NO)>100 ppb (n=5) were asthmatics. The sensitivity and specificity of FE(NO) for detecting asthma, using 36 ppb as cut-off point, were 78% and 60% and the positive and negative predictive values were 54% and 82%, respectively.

CONCLUSIONS

Measuring FE(NO) may be useful for the screening of rhinitic patients with asthma-like symptoms.

Determinants of bronchial hyperresponsiveness in subjects with rhinitis

Subjects with rhinitis but without asthma may have coexisting bronchial hyperresponsiveness, although the reasons for this are uncertain. To evaluate the factors that determine BHR in rhinitis we examined 410 patients with symptomatic rhinitis with forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC)>or=80% of the predicted value. In all subjects a skin prick test (SPT) was performed, a determination of total serum IgE and an eosinophils count in the blood. Of the 410 subjects we found that 161 (39.3%) exhibited a methacholine PD20 of 800 mg or less (Group A), whereas 249 (60.7%) had a methacholine PD20 more of 800 mg (Group B). Despite the matched mean values for FEV1 and FVC, compared with Group B, Group A had a lower predicted forced expiratory flow between 25% and 75%(FEF25%-75%) (86.7 +/- 12.0 vs. 93.7 +/- 7.3, P < 0.0001). A great portion of the subjects of the Group Ain respect to subjects of the Group B were exposed to passive smoke (37.8% vs. 22.0%, P = 0.0008), reported having mothers with asthma (34.1% vs. 6.0%, P < 0.0001), presented a positive skin prick test (93.7% vs. 67.0%, P < 0.0001), had higher levels of total serum IgE (geometric mean of Log10 2.46 +/- 0.27 kU/L vs. 2.06 +/- 0.38 kU/L, P < 0.0001) and higher blood eosinophil counts (geometric mean of Log10 2.67 +/- 0.07 x 10(-3) mL vs. 2.57 +/- 0.09 x 10(-3) mL, P < 0.0001), and reported increased nasal obstruction (2.0 (95% CI 1.8 to 2.2) vs. 0.6 (95% CI 0.5 to 0.7), P < 0.0001). Logistic regression demonstrates that nasal obstruction (OR 2.19, 95% CI 1.72 to 2.80) and the presence of positive SPT (OR 6.15, 95% CI 2.42 to 15.61) were the most available predictors to discriminate between subjects with BHR and subjects without BHR. In addition, BHR was positively related to blood eosinophil counts (OR= 2.80, 95% CI 1.54 to 5.07), FEF25%-75% values (OR= 2.72, 95% CI 1.23 to 5.99) and familiarity (mother) for asthma (OR = 2.45, 95% CI 1.10 to 5.46). Whereas passive smoke and total serum IgE were not positively related to BHR. Increased nasal obstruction and the presence of positive SPT were the most available predictors to discriminate between subjects with and without BHR. Finally, BHR was positively related to blood eosinophil counts, FEF25%-75% values and to familiarity (mother) for asthma.

Safety and tolerability of ultra-rush induction, less than one hour, of sublingual immunotherapy in children

BACKGROUND

The safety and tolerability of sublingual immunotherapy (SLIT) has been documented in allergic patients both in the build-up phase as well as during maintenance, but only two studies have evaluated the occurrence of adverse reactions with an ultra-rush regimen of SLIT induction in a mixed paediatric/adult population. Moreover one of these two studies used a chemically modified extract (allergoid). The aim of the present study was to evaluate the occurrence of immediate or late adverse reactions in allergic children after a very fast (40 min) ultra-rush SLIT induction with two different allergen extract solutions.

METHODS

We studied 100 children (64 boys, mean age of 9.6 years, range 3.5-16.8), with a history of intermittent/persistent rhinitis and/or intermittent/mild persistent asthma due to inhalant allergens. The ultra-rush build-up phase involved the administration, every 10 min, of increasing doses of the highest-concentration vial of SLIT of two different manufacturers (Anallergo and Stallergènes).

RESULTS

All patients completed the treatment, side-effects have been recorded in 19% of the cases: 10% within 1 h after the build-up phase, 7% within 48 h and 2% mixed. A major difference (p = 0.0001) was recorded between Anallergo (6 patients, 8.7%) and Staloral (13 patients, 41.9%), but all the reactions were mild: principally oral symptoms, in 1 case rhinorrhoea and cough, and delayed abdominal pain and diarrhoea in another patient.

CONCLUSIONS

No severe adverse reactions were observed with this ultra-rush SLIT induction also in the paediatric age; statistical differences have been documented between the two different extracts.

Update on allergy immunotherapy

This article summarizes and provides commentary regarding guidelines on the administration of immunotherapy (IT) for allergic airway disease. Recent investigations have provided important insights into the immunologic mechanism of IT and the prominent role of interleukin-10-producing regulatory T lymphocytes. The most important aspect of successful IT is the administration of an appropriate dose of an extract containing a sufficient concentration of the relevant allergen. This is largely possible now only with standardized extracts. When the major allergen content of successful IT extracts was quantified, efficacy was demonstrated across a surprisingly narrow concentration range (approximately 5-24 μg per injection), irrespective of the extract. This presumably reflects the concentration of an antigen that drives an immune response toward tolerance. It may be predicted that as major allergen content is quantified in currently nonstandardized extracts, effective IT will also be achieved by administering a dose in this range, in contrast to current practices involving fairly arbitrary dosing decisions. With the availability of nonsedating antihistamines, intranasal corticosteroids, and the leukotriene modifiers, inadequate pharmacologic response or intolerable side effects are less commonly the major indications for starting IT for allergic rhinitis (AR). However, with the recognition that a relatively short course (3-5 years) of IT can provide long-term immunomodulation and clinical benefit, a desire to avoid long-term pharmacotherapy and the associated high costs may be the primary indication for IT in AR cases. While evidence overwhelmingly supports the beneficial influences of IT in asthma cases, the positioning of IT for this disorder is not established. The observed prevention of asthma in children who have AR is intriguing, but further studies are required to assess the extent to which the prevalence and severity of chronic asthma will be reduced when these children reach adulthood. Similarly, safety issues overwhelmingly suggest that uncontrolled asthma is the greatest risk factor for mortality associated with IT and that IT therefore may be contraindicated for most patients who have inadequate pharmacologic responses or are unable to tolerate useful pharmacologic agents. Paradoxically, these are the patients for whom a response to IT may be most desirable.

Peptide-based vaccination: where do we stand?

PURPOSE OF REVIEW

Allergen-specific immunotherapy represents the only causative approach towards allergy treatment. Specific immunotherapy can, however, include allergic reactions and occasionally life-threatening anaphylaxis. Peptides have been evaluated as a potential therapeutic approach in atopic allergic disease because they have the potential to inhibit T-cell function but not induce anaphylaxis.

RECENT FINDINGS

Data from early clinical trials of peptide vaccination revealed that therapy was associated with a modest improvement in allergic disease, and was accompanied by a high frequency of adverse reactions. More recent studies have demonstrated improved clinical outcomes, improved safety, and have defined the mechanisms of adverse events observed in earlier studies. Mechanisms of peptide vaccination include the hyporesponsiveness of allergen-specific responses and the induction of regulatory T cells and cytokines. Novel peptide design has allowed the generation of fragments that contain T-cell stimulatory epitopes, lack B cell epitopes, and can induce protective IgG responses in both mice and humans. Other approaches have focused on hypoallergenic B-cell epitopes that induce inhibitory IgG antibodies. Peptides that specifically induce regulatory cytokine production would also enhance peptide vaccines. Several recent studies have described immunodominant epitopes from major allergens that may form candidate peptides for use in peptide vaccination.

SUMMARY

The manipulation of peptide epitopes may provide a strategy for the rational design of peptide allergy vaccines further improving safety and efficacy.

A pilot study of feasibility of ultra-rush (20-25 minutes) sublingual-swallow immunotherapy in 679 patients (699 sessions) with allergic rhinitis and/or asthma

Few studies have evaluated the occurrence of immediate adverse reactions in allergic patients after an ultra-rush regimen of different commercial allergen extracts for sublingual immunotherapy (SLIT) Methods: 679 patients took part in trials of specific ultra-rush SLIT for the treatment of IgE-mediated rhinitis and/or IgE-mediated asthma. 14 patients received two different sublingual allergen vaccines during two distinct SLIT sessions. On the whole, 699 SLIT sessions were performed. The build up ultrarush phase involved the administration every five minutes of increasing doses of either different allergen extracts. The cumulative allergen extract solution after half an hour was several times the dose administered at the start of subcutaneous immunotherapy (range 4.7-525 microg of major allergens). All patients tolerated the treatment very well. 122 (17.96%) had mild local symptoms (pruritus of the buccal cavity) that spontaneously disappeared with increasing dose. Two patients allergic to Parietaria had urticaria about three hours after the last sublingual Parietaria-extract intake. A subject allergic to Artemisia vulgaris pollen had urticaria and rhinitis two hours later than the last dose of vaccine. As reported in our previous study, no immediate severe adverse reactions were observed after that rapidly increasing doses of allergen extract were administered in a very short period to a large number of patients, showing the excellent safety profile of ultra-rush SLIT.

Safety and tolerability of ultra-rush (20 minutes) sublingual immunotherapy in patients with allergic rhinitis and/or asthma

BACKGROUND

The safety and good tolerability of sublingual immunotherapy (SLIT) has already been proved in allergic patients, but only one study has investigated the occurrence of immediate adverse reactions in allergic patients after a 2-hour ultra-rush regimen of SLIT performed with a chemically modified extract (sublingual monomeric allergoid, Lais, Lofarma S.p.A., Milan). The objective of the present study was to evaluate the occurrence of immediate adverse reactions in allergic patients after a very fast (20 minutes) ultra-rush regimen of sublingual allergoid SLIT.

METHODS AND RESULTS

We studied 105 patients: 28 children (20 male, mean age 13.3 +/- 2.1 yr) and 77 adults (29 male, mean age 34.7 +/- 9.9 years) with a history of intermittent/persistent rhinitis or intermittent/mild persistent asthma due to House Dust Mite (n = 56), Parietaria (n = 34) and Timothy-grass (n = 15) The build-up ultra-rush phase involved the administration, every five minutes, of increasing doses of the sublingual allergoid SLIT. All patients tolerated the treatment very well. Only one patient out of 105 (0.9%) had a mild local symptoms (gastric pirosis) that occurred 30 minutes after the last initial dose and spontaneously disappeared as the treatment was continued.

CONCLUSIONS

These data show the excellent safety and tolerability profile of an ultra-rush SLIT regimen performed with a chemically modified extract, even when high doses were administered through an extremely short induction phase (20 minutes), thus confirming the previously reported results.

Characteristics of intermittent and persistent allergic rhinitis: DREAMS study group

BACKGROUND

In the Allergic Rhinitis and its Impact on Asthma (ARIA) classification, intermittent and persistent rhinitis were proposed to replace seasonal and perennial allergic rhinitis (AR).

AIM

To better understand the ARIA classification of rhinitis.

METHODS

A cross-sectional study was carried out in 591 patients consulting ENT or allergy specialists for AR and 502 control subjects. The diagnosis of AR was based on a score for allergic rhinitis (SFAR) > or =7. Patients were classified according to the four ARIA classes (mild intermittent, mild persistent, moderate/severe intermittent and moderate/severe persistent). Allergen sensitization (skin prick tests (SPTs) or specific IgE) and co-morbidities were examined according to the ARIA classes.

RESULTS

Ten percent of patients had mild intermittent rhinitis, 14% mild persistent rhinitis, 17% moderate/severe intermittent rhinitis and 59% moderate/severe persistent rhinitis. Most patients with intermittent rhinitis had a pollen sensitivity, but 5% had a single house dust mite (HDM) sensitization. Over 50% of patients with persistent rhinitis were allergic to pollens or HDM. Asthma was present in 24% of rhinitis patients and in only 2% of the control population (P<0.0001). Patients with moderate/severe persistent rhinitis had the highest asthma prevalence (33%).

DISCUSSION

Intermittent and persistent rhinitis are not synonymous of seasonal and perennial rhinitis. Most patients consulting specialists have severe rhinitis. Asthma prevalence increases with duration and severity of rhinitis supporting the ARIA major recommendation that patients with persistent rhinitis should be evaluated for asthma.

Safety and tolerability of ultra-Rush (20 minutes) sublingual immunotherapy in patients with allergic rhinitis and/or asthma

BACKGROUND

The safety and good tolerability of sublingual immunotherapy (SLIT) has already been proved in allergic patients, but only one study has investigated the occurrence of immediate adverse reactions in allergic patients after a 2-hour ultra-rush regimen of SLIT performed with a chemically modified extract (sublingual monomeric allergoid, Lais, Lofarma S.p.A., Milan). The objective of the present study was to evaluate the occurrence of immediate adverse reactions in allergic patients after a very fast (20 minutes) ultra-rush regimen of sublingual allergoid SLIT.

METHODS AND RESULTS

We studied 105 patients: 28 children (20 male, mean age 13.3 +/- 2.1 yr) and 77 adults (29 male, mean age 34.7 +/- 9.9 years) with a history of intermittent/persistent rhinitis or intermittent/mild persistent asthma due to House Dust Mite (n = 56), Parietaria (n = 34) and Timothy-grass (n = 15) The build-up ultra-rush phase involved the administration, every five minutes, of increasing doses of the sublingual allergoid SLIT. All patients tolerated the treatment very well. Only one patient out of 105 (0.9%) had a mild local symptom (gastric pirosis) that occurred 30 minutes after the last initial dose and spontaneously disappeared as the treatment was continued.

CONCLUSIONS

These data show the excellent safety and tolerability profile of an ultra-rush SLIT regimen performed with a chemically modified extract, even when high doses were administered through an extremely short induction phase (20 minutes), thus confirming the previously reported results.

New strategies in the treatment and prevention of allergic diseases

Allergic diseases (AD) are more prevalent today than 30 years ago but over the same period, few novel efficacious drugs have been discovered to treat, control or even cure these disorders. Topical or systemic glucocorticosteroids combined with symptom-relieving medications, such as beta 2 -adrenoceptor agonists, leukotriene inhibitors or antihistamines, are still the mainstay of antiallergic treatment. Modified glucocorticosteroids with less adverse effects, better bronchodilators and new selective mediator inhibitors may improve symptom control in the future. Only specific immunotherapy has shown potential for long-lasting disease-modifying effects. Immunomodulation is a therapeutic goal, aiming to modify the dominant helper T cell Type 2 inflammation to a helper T cell Type 1 response using modified allergens, mycobacteria or CpG oligodeoxynucleotides. Humanised monoclonal anti-IgE antibodies are an exciting new immunomodulatory medication that are expected to reach the clinical practice and have recently been licensed in Australia and the US. Advances in molecular, cellular and genetic research of the immunopathophysiology of AD have led to the development of new antagonists for cytokines, chemokines, receptors, second messengers and transcription factors that may become available for clinical use in the next 10 years. Specific diets supplemented with antioxidants or probiotics need further study but offer promise as safe and cheap preventative medicine. The strong genetic component of AD and the Human Genome Project have opened a new field of research, and modification or replacement of target genes has a curative potential with exciting new therapeutic developments in the years ahead.

Adjuvants for allergen immunotherapy: experimental results and clinical perspectives

PURPOSE OF REVIEW

Inclusion of adjuvants in immunotherapy vaccines are important to enhance immune responses to allergens. This article will cover the recent advances in adjuvant formulations described in published articles primarily over the past 2 years.

RECENT FINDINGS

Traditionally, allergen immunotherapy preparations utilize aluminium hydroxide as an adjuvant. These have generally proved efficacious and have a good safety profile. However, recent advances in the understanding of immunological mechanisms underlying immunotherapy and in the design of new adjuvants may allow a more rational approach to adjuvant use. One approach is to use adjuvants such as immunostimulatory sequences or monophosphoryl lipid A, which can deviate allergy-associated Th2 immune responses towards a Th1 phenotype. Both of these adjuvants have been used in pilot controlled clinical trials which have demonstrated clinical efficacy and the induction of protective IgG antibodies. Other approaches to improve immunotherapy vaccines include microencapsulation of allergen to allow delivery of the allergen directly to the gut in order to induce immunological tolerance and vaccination with heat-killed mycobacteria.

SUMMARY

There is great interest in newly designed adjuvants to improve the efficacy and safety of allergen immunotherapy. A better understanding of immunological mechanisms and further clinical trials utilizing new adjuvants are needed.

Long-term and preventive effects of sublingual allergen-specific immunotherapy: a retrospective, multicentric study

There is now an increasing body of evidence to support the practice of allergen-specific sublingual-swallow immunotherapy (SLIT) in the treatment of IgE-mediated respiratory allergies. Recent studies on traditional injection therapy have pointed out that this form of treatment is not only capable to decrease actual allergic symptoms, but may also have long-term clinical and preventive effects and may influence atopy natural history. In the year 2000, our group published a retrospective, multicenter study showing the efficacy and safety of SLIT in a survey of 302 patients. We now carried out a second study on the same patients, with the aim of investigating long-term and preventive effects of SLIT. Beside the well-known safety and efficacy of this treatment (80.8% of patients reported clinical benefits), SLIT proved also to elicit long term clinical effects: over a mean follow-up of 11.6 months after the end of treatment, 80.8% of patients still maintained the previously achieved benefits. During the follow-up period, only 1% of non-asthma patients reported an onset of respiratory symptoms, and only 9.6% of patients undergoing new skin tests showed new sensitizations. All the clinical benefits were strongly linked to the length of treatment: patients with long-lasting benefits were treated for a mean length of 29.1 months, while patients showing a return to pre-SLIT condition were treated for a mean 13.3 months. SLIT can obtain long-term and preventive effects so far attributed to injection immunotherapy.