Comparison of nasal immunohistology in patients with seasonal rhinoconjunctivitis treated with topical steroids or specific allergen immunotherapy

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

A rhinitis primer for family medicine

Rhinitis and related problems such as facial pressure and nasal congestion are a very common reason people seek medical care. There are four, often overlapping, syndromes or conditions that account for most of what patients perceive as "nose" problems or rhinitis. These conditions are irritant rhinitis, the anterior nasal valve effect, migraine with vasomotor symptoms, and allergic rhinitis. Virtually all patients with allergic rhinitis have some concomitant irritant or nonallergic rhinitis. Many migraine sufferers with vasomotor nasal symptoms will have their nasal congestion, headaches, and runny noses exacerbated by irritant rhinitis, allergic rhinitis, and/or a preexisting nasal valve effect. Failure to consider all of the causes for the symptoms will result in poor clinical outcomes. The work-up and management of these common conditions is discussed in this article.

Subcutaneous injection immunotherapy for optimal effectiveness

Immunotherapy by the subcutaneous injection of increasing doses and then maintenance doses of extracts of inhalant allergens has been practiced for 100 years. Controlled clinical trials have established its efficacy in treating allergic rhinitis, asthma, and stinging insect sensitivity, and there are preliminary data to suggest a favorable response in some patients with atopic dermatitis. The response to subcutaneous injection immunotherapy is dose dependent. Disease-modifying actions include blocking development of new sensitivities in monosensitized patients, blocking progression to asthma in patients with allergic rhinitis, and persistence of treatment effects for up to 7 to 10 years after an initial course.

Clinical and Immunological Correlates of Pre-Co-Seasonal Sublingual Immunotherapy with Birch Monomeric Allergoid in Patients with Allergic Rhinoconjunctivitis

Sublingual immunotherapy is safe and efficacious in the treatment of patients with allergic rhinitis. The clinical and biological efficacy of modified allergens (allergoids) has not been fully clarified. We investigated in birch allergic patients the effect of a pre-co-seasonal sublingual immunotherapy regimen with a modified allergen extract on clinical parameters and on T cell proliferation and regulatory cytokine production (IL-10, TGF-beta). We found that during the birch pollen season symptoms and drug usage scores were 30 and 40% improved, respectively, in treated versus control subjects (p<0.0001 for both comparisons) whereas well days were 23.5 (33%) versus 16.9 (23%) (p=0.0024), respectively. Bet v 1 allergen specific proliferation decreased (p = 0.0010), whereas IL-10 transcription increased (p = 0.0010) in treated, but not in control patients. Moreover, TGF-beta transcription was increased, although not significantly (p=0.066), following immunotherapy. Thus, sublingual immunotherapy with modified allergen in birch-allergic subjects was safe, clinically efficacious and associated with the reduction of allergen-specific proliferation and with the increased production of the IL-10 regulatory cytokine.

Allergic rhinitis and its impact on asthma update: allergen immunotherapy

The Allergic Rhinitis and its Impact on Asthma document was first published in 2001. Since then, new data on specific immunotherapy have appeared. This review is intended as an update to the original document. MedLine (2001 to June 2006) was searched with appropriate key words, and panelists were asked to identify further relevant articles. Randomized controlled trials were considered for the evaluation of efficacy. For the evaluation of safety and additional effects, studies with lower grades of evidence were included. The clinical efficacy of injection immunotherapy in rhinitis and asthma was confirmed, as well as the safety, provided that recommendations are followed. Studies have demonstrated the long-term efficacy and the preventive effect of immunotherapy in reducing the onset of new sensitizations. One randomized open trial demonstrated that in children with allergic rhinitis, injection immunotherapy may reduce the risk of developing asthma. There is strong evidence that sublingual immunotherapy is effective in allergic rhinitis in adults. Recent meta-analyses demonstrated its efficacy in allergic rhinitis in children and in asthma, although more definitive trials are required. Current data indicate that sublingual immunotherapy is safe and the rate of adverse reactions is not greater below 5 years of age. One randomized open trial showed that in children with allergic rhinitis, sublingual immunotherapy reduced the onset of asthma. Further studies are needed to identify the optimal maintenance dose and to elucidate the mechanism of action. Novel approaches for immunotherapy are currently under evaluation, including the use of adjuvants, peptides, and DNA-conjugated and recombinant allergens.

Allergen immunotherapy: where is it now?

The scientific basis and the proof of clinical effectiveness of allergen immunotherapy administered by subcutaneous injection (SCIT) are well established. It is effective treatment for sensitivity to Hymenoptera venom and for allergic rhinitis and allergic asthma. SCIT administered in the proper setting reduces the development of new sensitivities and progression from rhinitis to asthma. Further, the beneficial effects persist long after completion of a course of treatment. Although many people enjoy the benefits of SCIT, extension of its use to the many others who might be candidates for this treatment is limited by its drawbacks of safety concerns and the inconvenience of repeated clinic visits over several years to receive the injections. There are many attempts underway to improve on the safety and convenience while still retaining the benefits of SCIT. These include approaches using current allergen extracts, especially by administering them sublingually. Alternatively, through recombinant technology, extracts are being modified to reduce their allergenicity without reducing their immunogenicity. They are being linked to immunostimulatory DNA sequences that will modify their in vivo processing resulting in an enhanced nonallergic response or they are being incorporated into fusion proteins with inhibitory properties for mast cells and basophils.