Chapter 17: Immunomodulation of allergic sinonasal disease

Grass pollen sublingual immunotherapy: a double-blind, placebo-controlled study in elderly patients with seasonal allergic rhinitis

BACKGROUND

This study evaluates the safety and efficacy of specific sublingual immunotherapy (SLIT) against grass pollen allergens in patients >60 years of age with seasonal allergic rhinitis (SAR) and/or asthma. This study sought to assess nasal symptoms during the grass pollen season, reduce medication use, and monitor adverse reactions during immunotherapy.

METHODS

Seventy-eight 60- to 70-year-old patients with SAR and a confirmed grass pollen allergy according to skin-prick tests, nasal provocation, and measurement of serum IgE were included in the study. The patients were individually randomized to the active or placebo groups using a double-blind method. A total of 41 subjects in the SLIT group (5 grass pollen mixture) and 37 subjects in the placebo group were monitored for 3 years. The patients were required to record each use of an antiallergy medication on a diary card.

RESULTS

Thirty-eight patients completed 3 years (preseasonal) of SLIT, and 34 subjects finished the placebo treatment in the same time period. The total nasal symptom score decreased by 64% in the active group and 7% in the placebo group after SLIT. This difference was only significant in the active group (p < 0.05). At the end of therapy, the total medication score of the active group decreased significantly by a maximum of 51% (p < 0.05), whereas the total medication score of the placebo group had an insignificant decrease. None of the study participants had systemic adverse reactions during the study period.

CONCLUSIONS

SLIT in elderly patients with a grass pollen allergy generated a significant clinical improvement in the active group compared with the placebo group for grass pollen season. This therapy was well tolerated.

Cytological changes in nasal secretions accompanying delayed nasal response to allergen challenge

BACKGROUND

Patients with allergic rhinitis when challenged with allergen develop various types of nasal response, such as an immediate nasal response (INR), late nasal response (LNR), dual late nasal response (DLNR), or delayed nasal response (DYNR), probably because of different hypersensitivity mechanisms. This study was designed to investigate the cytological changes in the nasal secretions (NSs) during the DYNR, beginning 24-32 hours, reaching maximum at 32-36 hours, and resolving within 56 hours after the nasal provocation tests (NPTs) with allergens.

METHODS

In 45 allergic rhinitis patients developing 45 positive DYNRs (p < 0.01), the NPTs and the phosphate-buffered saline (PBS) controls were repeated and supplemented with cytological examination of the NSs and determination of interferon (IFN) γ and IL-4 in nasal lavage fluid (NLF).

RESULTS

The repeated DYNR (p < 0.001) was accompanied by significant changes (p < 0.05) in the counts of neutrophils, monocytes, lymphocytes, epithelial and goblet cells, and, to a limited extent, of plasma cells and platelets in the NSs and increased concentrations of IFN-γ but not of IL-4, in NLF between 24 and 48 hours after the NPT. No significant cytological changes were found in NSs during the PBS controls (p > 0.1).

CONCLUSION

The DYNR is associated with cytological profiles in the NS different from those observed during the INR or LNR. The significant count changes of neutrophils, monocytes, lymphocytes, epithelial and goblet cells in NSs, and increased IFN-γ but not of IL-4 concentrations in the NLF, suggest a possible involvement of the cell-mediated hypersensitivity in the DYNR. These results also emphasize the diagnostic value of NPTs combined with cytological examination of the NSs in patients with nasal allergy.

Neonatal vaccination with plasmid DNA encoding Cyn d 1 effectively prevents allergic responses in mice

BACKGROUND

Allergic rhinitis is one of the most common atopic disorders in children. There is no available method to prevent airway sensitization in newborns except allergen avoidance. Recombinant DNA plasmids encoding allergens have been proven to activate Th1 but attenuate Th2-deviated allergic responses in adult animal studies. However, their preventive effects are not presumptive in neonates because of their immature immune function. The aim of this study was to examine the potential preventive effect of a DNA vaccine encoding grass pollen allergen Cyn d 1 on allergic reaction to grass pollen in neonatal mice.

METHODS

Recombinant plasmid Cyn d 1 (pCyn d 1) vaccine was constructed by insertion of Cyn d 1 cDNA into the vector pcDNA3. Neonatal BALB/c mice received the vaccine once on the 3rd day of life or a second dose 2 days later. Control mice received PBS only. Mice were sensitized twice with recombinant Cyn d 1 and alum beginning at 7 weeks of age. Serum antibody responses and cytokine profiles of spleen cells were examined.

RESULTS

Neonatal injection with pCyn d 1 vaccine resulted in IgG2a responses and production of interferon gamma in spleen cells. Vaccination with pCyn d 1 also reduced specific IgE responses and spleen cell secretion of IL-4.

CONCLUSION

This study shows the prophylactic effects of DNA vaccine encoding Bermuda grass pollen allergen Cyn d 1 on specific IgE responses in neonatal mice.

Chapter 15: Allergic rhinitis

Allergic rhinitis affects 60 million of the U.S. population, 1.4 billion of the global population, and its prevalence appears to be increasing. The duration and severity of allergic rhinitis symptoms place a substantial burden on patient's quality of life, sleep, work productivity, and activity. The health impact of allergic rhinitis is compounded by associated complications and comorbidities including asthma, otitis media, sinusitis, and nasal polyps. Allergic rhinitis symptoms result from a complex, allergen-driven mucosal inflammatory process, modulated by immunoglobulin E (IgE), and caused by interplay between resident and infiltrating inflammatory cells and a number of vasoactive and proinflammatory mediators, including cytokines. This allergic response may be characterized as three phases: IgE sensitization, allergen challenge, and elicitation of symptoms. A thorough allergic history is the best tool for the diagnosis of allergic rhinitis, the establishment of which is achieved by correlating the patient's history and physical exam with an assessment for the presence of specific IgE antibodies to relevant aeroallergens determined by skin testing or by in vitro assay. Management of allergic rhinitis includes modifying environmental exposures, implementing pharmacotherapy, and, in select cases, administering allergen-specific immunotherapy. Intranasal therapeutic options include antihistamines, anticholinergic agents, corticosteroids (aqueous or aerosol), mast cell stabilizers, saline, and brief courses of decongestants. Selection of pharmacotherapy is based on the severity and chronicity of symptoms with the most effective medications being intranasal corticosteroids and intranasal antihistamines, which can be used in combination (separately or in fixed dose) for more difficult to control allergic rhinitis.

Chapter 16: Determining the role of allergy in sinonasal disease

The contributing role of specific IgE sensitization in the pathophysiology of sinonasal diseases including rhinitis, chronic rhinosinusitis (CRS), and nasal polyps is explored. Although it is estimated that sensitization to environmental allergens is present in 75% of patients with rhinitis, the role of allergy in CRS and nasal polyps is less certain. However, when atopy is present in the setting of nasal polyps, it is associated with worse quality of life and a higher incidence of asthma. Several theories have been put forth whereby inhalant aeroallergen exposure could drive the inflammatory response that occurs both in the nose and in the sinuses. Tools available to determine the presence of allergic sensitization include skin tests for immediate hypersensitivity, in vitro testing for allergen-specific IgE, and nasal allergen provocation testing. Whether by skin testing or in vitro testing, the identification of specific IgE requires clinical correlation with the history and physical exam.