EAACI Guidelines on Allergen Immunotherapy: Allergic rhinoconjunctivitis

Allergic rhinoconjunctivitis (AR) is an allergic disorder of the nose and eyes affecting about a fifth of the general population. Symptoms of AR can be controlled with allergen avoidance measures and pharmacotherapy. However, many patients continue to have ongoing symptoms and an impaired quality of life; pharmacotherapy may also induce some side-effects. Allergen immunotherapy (AIT) represents the only currently available treatment that targets the underlying pathophysiology, and it may have a disease-modifying effect. Either the subcutaneous (SCIT) or sublingual (SLIT) routes may be used. This Guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on AIT for AR and is part of the EAACI presidential project "EAACI Guidelines on Allergen Immunotherapy." It aims to provide evidence-based clinical recommendations and has been informed by a formal systematic review and meta-analysis. Its generation has followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included involvement of the full range of stakeholders. In general, broad evidence for the clinical efficacy of AIT for AR exists but a product-specific evaluation of evidence is recommended. In general, SCIT and SLIT are recommended for both seasonal and perennial AR for its short-term benefit. The strongest evidence for long-term benefit is documented for grass AIT (especially for the grass tablets) where long-term benefit is seen. To achieve long-term efficacy, it is recommended that a minimum of 3 years of therapy is used. Many gaps in the evidence base exist, particularly around long-term benefit and use in children.

Allergen immunotherapy for allergic rhinoconjunctivitis: A systematic review and meta-analysis

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost-effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis.

METHODS

We searched nine international biomedical databases for published, in-progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost-effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random-effects meta-analyses.

RESULTS

We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD -0.53, 95% CI -0.63, -0.42), medication (SMD -0.37, 95% CI -0.49, -0.26), and combined symptom and medication (SMD -0.49, 95% CI -0.69, -0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post-discontinuation of AIT, suggesting a benefit in relation to symptom scores.

CONCLUSIONS

AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy.

Local and systemic effects of cat allergen nasal provocation

Background

Cat allergen is widely distributed in homes and schools; allergic sensitization is common.

Objective

To develop a model of cat allergen nasal challenge to establish dose–response and time–course characteristics and investigate local and systemic biomarkers of allergic inflammation.

Methods

Nineteen cat‐allergic individuals underwent titrated nasal challenge, range 0.243 to 14.6 μg/mL Fel d1, and matched diluent‐only provocation. Clinical response to 8 h was assessed by symptom scores and peak nasal inspiratory flow (PNIF). Nasal fluid was collected using polyurethane sponges and analysed by ImmunoCAP and multiplex assays. Whole blood flow cytometry for basophil surface CD63, CD107a, and CD203c was carried out at baseline and 6 h post‐challenge.

Results

A dose–response to allergen was seen in symptom scores and PNIF, maximal at 10 000 BU/mL (4.87 μg/mL Fel d1), P < 0.0001 vs. diluent. Nasal fluid tryptase was elevated at 5 min after challenge (P < 0.05 vs. diluent); eotaxin, IL‐4, ‐5, ‐9, and ‐13 were increased at 8 h (P < 0.05 to P < 0.0001 vs. diluent); TSLP was undetectable; IL‐10, IL‐17A, and IL‐33 were unchanged compared to diluent challenge. Nasal fluid IL‐5 and IL‐13 correlated inversely with PNIF after challenge (IL‐5, r = −0.79, P < 0.0001; IL‐13, r = −0.60, P = 0.006). Surface expression of CD63 and CD107a was greater at 6 h than at baseline, both in the presence (both P < 0.05) and absence (CD63, P < 0.01; CD107a, P < 0.05) of in vitro allergen stimulation; no changes were seen on diluent challenge day.

Conclusions

Cat allergen nasal challenge produces local and systemic Th2‐driven inflammatory responses and has potential as a surrogate outcome measure in clinical trials.

Effect of grass pollen immunotherapy on clinical and local immune response to nasal allergen challenge

Rationale

Nasal allergen provocations may be useful in investigating the pathophysiology of allergic rhinitis and effects of treatments.

Objective

To use grass pollen nasal allergen challenge (NAC) to investigate the effects of allergen immunotherapy in a cross‐sectional study.

Methods

We studied nasal and cutaneous responses in untreated subjects with seasonal grass‐pollen allergic rhinitis (n = 14) compared with immunotherapy‐treated allergics (n = 14), plus a nonatopic control group (n = 14). Volunteers underwent a standardized NAC with 2000 biological units of timothy grass allergen (equivalent to 1.3 μg major allergen, Phl p5). Nasal fluid was collected and analysed by ImmunoCAP and multiplex assays. Clinical response was assessed by symptom scores and peak nasal inspiratory flow (PNIF). Cutaneous response was measured by intradermal allergen injection. Retrospective seasonal symptom questionnaires were also completed.

Results

Immunotherapy‐treated patients had lower symptom scores (P = 0.04) and higher PNIF (P = 0.02) after challenge than untreated allergics. They had reduced early (P = 0.0007) and late (P < 0.0001) skin responses, and lower retrospective seasonal symptom scores (P < 0.0001). Compared to untreated allergics, immunotherapy‐treated patients had reduced nasal fluid concentrations of IL‐4, IL‐9 and eotaxin (all P < 0.05, 8 h level and/or area under the curve comparison), and trends for reduced IL‐13 (P = 0.07, area under the curve) and early‐phase tryptase levels (P = 0.06).

Conclusions

Nasal allergen challenge is sensitive in the detection of clinical and biological effects of allergen immunotherapy and may be a useful surrogate marker of treatment efficacy in future studies.

Efficacy of mometasone furoate nasal spray in the treatment of allergic rhinitis. Meta-analysis of randomized, double-blind, placebo-controlled, clinical trials

RATIONALE

Several randomized, double-blind, placebo-controlled clinical trials have demonstrated the efficacy of mometasone furoate nasal spray (MFNS) in the treatment of allergic rhinitis (AR) thus allowing for a meta-analysis to determine the overall treatment effect.

METHODS

A comprehensive search of the MEDLINE, LILACS, SCOPUS, and the Cochrane Library databases up to 31 October, 2007 was carried out. Randomized, double-blind, placebo-controlled, clinical trials evaluating the efficacy of MFNS in patients with AR compared to placebo were included. Total nasal symptom scores (TNSS), individual nasal symptoms, total non-nasal symptom scores (TNNSS) and nasal airflow were analysed as the standardized mean difference (SMD). Meta-analysis was performed with the random or the fixed effect models depending on heterogeneity, by using revman 5 software.

DATA SYNTHESIS

Sixteen of the 113 identified articles met the inclusion criteria. For MFNS efficacy on TNSS, 2998 participants were analysed: 1534 received MFNS and 1464 placebo. Mometasone furoate nasal spray was associated with a significant reduction in TNSS (SMD -0.49, 95% CI: -0.60 to -0.38; P < 0.00001; I(2) = 50.1%). A significant effect on SMD for nasal stuffiness/congestion (-0.41; 95% CI: -0.56 to -0.27), rhinorrhoea (-0.44; 95% CI: -0.66 to -0.21), sneezing (-0.40; 95% CI: -0.57 to -0.23) and nasal itching (-0.39; 95% CI: -0.53 to -0.25) was also demonstrated. Mometasone furoate nasal spray treated subjects also showed a significant reduction in TNNSS (-0.30; 95% CI: -0.43 to -0.18). The proportion of patients with adverse events was similar for MFNS and placebo (0.99; 95% CI: 0.81-1.20; P = 0.91).

CONCLUSIONS

This meta-analysis provides a level Ia evidence for the efficacy of MFSN in the treatment of AR vs placebo. Adverse events frequency was similar in both groups.

Efficacy of desloratadine in the treatment of allergic rhinitis: a meta-analysis of randomized, double-blind, controlled trials

The objective of the study is to assess the efficacy of the nonsedating antihistamine, desloratadine, in the treatment of allergic rhinitis (AR). A search of MEDLINE, EMBASE, LILACS, and CINAHL databases was undertaken from January, 1966 to May, 2006. Double-blind, randomized, controlled studies of desloratadine in the treatment of AR in adult patients were carried out. The measured outcomes included the total symptoms score, the total nasal symptoms score, nasal airflow, and inflammatory markers (nasal eosinophils, nasal interleukin-4). The analysis included the calculation of standardized mean difference (SMD). A total of 57 studies were analyzed, and 13 randomized, double-blind, controlled trials were included in the meta-analysis. The trials included 3108 subjects who had completed studies involving desloratadine. There was significant heterogeneity among the study results, because of differing study methodologies. Desloratadine was associated with significant reductions in total symptoms scores (SMD -1.63; 95% CI -2.75 to -0.51; P = 0.004) and total nasal symptoms score (SMD -0.66; 95% CI -0.91 to -0.42; P < 0.001), when compared with placebo. Analysis of objective data on nasal blockage demonstrated a significant improvement in nasal airflow with desloratadine, when compared with placebo (SMD 0.32; 95% CI 0.10 to 0.55; P = 0.005). A benefit favoring desloratadine over placebo in terms of nasal eosinophil levels was also noted in the analysis. This meta-analysis confirms the reduction of AR symptoms and improvement in nasal airflow seen in individual studies of desloratadine. Objective improvements in nasal airflow, total symptoms, and total nasal symptoms seen with desloratadine are supported by Ia evidence.