New perspectives in the treatment of allergic rhinitis and asthma in children

Immune imbalance of regulatory T/type 2 helper cells in the pathogenesis of allergic rhinitis in children

OBJECTIVES

To determine the role of regulatory T/type 2 helper cell-mediated immune imbalance in the pathogenesis of allergic rhinitis and examine the association between clinical severity and regulatory T/type 2 helper cell-mediated immune imbalance.

METHODS

Levels of interleukins 4 and 5 and transforming growth factor β1, and expression of FOXP3 and GATA3 (which are functionally related to regulatory T and type 2 helper cells, respectively), were evaluated in 46 allergic rhinitis patients and 42 healthy subjects.

RESULTS

Compared to controls, allergic rhinitis patients showed significantly higher interleukin 4 and 5 levels, but lower transforming growth factor β1 levels. Furthermore, FOXP3 messenger RNA expression was lower in allergic rhinitis patients, while GATA3 messenger RNA and protein expression was significantly higher. Regulatory T/type 2 helper cell ratio was inversely correlated with clinical symptom scores.

CONCLUSION

Regulatory T/type 2 helper cell immune imbalance may contribute to allergic rhinitis development. These findings provide a new insight into disease pathogenesis and potential therapeutic approaches.

Contribution of interleukin 17A to the development and regulation of allergic inflammation in a murine allergic rhinitis model

BACKGROUND

Interleukin (IL) 17A, a key cytokine of T(H)17 cells, is a well-known proinflammatory cytokine. Despite the important role of T(H)17 cells in acute airway inflammation, the role of IL-17A in allergic rhinitis (AR) remains unclear.

OBJECTIVE

To investigate the role of IL-17A in the allergic response in AR.

METHODS

Wild-type BALB/c and IL-17A-deficient mice were immunized intraperitoneally and were challenged intranasally with ovalbumin. Allergic symptom scores, eosinophil infiltration, serum IgE level, and the levels of several cytokines in nasal lavage fluid and splenocyte supernatants were analyzed.

RESULTS

IL-17A levels increased significantly more in ovalbumin-sensitized wild-type mice than in the negative control group. IL-17A-deficient mice showed a significant decrease in allergic symptoms, serum IgE levels, and eosinophil infiltration into the nasal mucosa compared with wild-type mice. IL-17A-deficient mice also showed decreased histamine and cysteinyl leukotriene release. Bone marrow-derived mast cells from IL-17A-deficient mice showed significantly lower degranulation and secretion of tumor necrosis factor α. Moreover, IL-17A deficiency attenuated the IL-5 level in nasal lavage fluid and its production in response to ovalbumin but did not increase interferon γ production and its level in nasal lavage fluid. In addition, secretion of IL-17A from spleen cells induced the expression of proinflammatory cytokine messenger RNA in macrophages. The mean level of proinflammatory cytokines, including tumor necrosis factor α and IL-17, decreased in IL-17A-deficient mice.

CONCLUSION

These results suggest that IL-17A may partly contribute to the development of nasal allergic inflammation in an AR animal model and regulate AR via the activation of proinflammatory cytokines and modulation of T(H)2 cytokine.

Efficacy and long-term safety of mometasone furoate nasal spray in children with perennial allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) affects up to 40% of children by age 6 years. Perennial AR (PAR) causes sleep disturbance, diminishes concentration in school, impairs psychosocial functioning, and reduces quality of life. This study evaluated efficacy and long-term safety of the intranasal corticosteroid mometasone furoate nasal spray (MFNS) in children with PAR.

METHODS

This study comprised a double-blind, 4-week efficacy and safety period followed by a 6-month, open-label safety period. Primary efficacy variable during the double-blind period was mean change in physician-evaluated total nasal symptom score (TNSS) from baseline to day 15. Other efficacy variables during this phase included subject-evaluated TNSS, individual nasal symptoms, and total symptom score (TSS, nasal and non-nasal symptoms, summed). Physician-evaluated improvement in overall condition of PAR was assessed during the open-label period. Adverse events (AEs) were monitored throughout.

RESULTS

Subjects aged 3-11 years with PAR (n = 381) were randomized to MFNS 100 microg (n = 190) or placebo (n = 191) daily for 4 weeks; 357 subjects continued into the open-label period, receiving MFNS only. Between baseline and day 15, significantly greater mean changes were seen with MFNS-treated patients than placebo in physician-evaluated TNSS (-2.8, -39%, vs. -2.2, -32%; p = 0.02). Statistically significant improvements in MFNS versus placebo were reported for subject-evaluated TNSS, TSS, and individual nasal symptom scores (p < or = 0.03 for all). Improvement continued through the open-label period. Subjects treated with MFNS in both periods experienced a 45% further reduction in TSS in this study phase, while those who switched from placebo to MFNS saw a further 49% decrease. MFNS was well-tolerated in both periods. The most frequently reported treatment-related AEs during the double-blind period for MFNS and placebo, respectively, were epistaxis, seven (4%) and nine (5%); sneezing, five (3%) and seven (4%); headache, six (3%) and five (3%). During the open-label period, the AEs reported most often were epistaxis 37 (10%), headache nine (3%), and rhinitis 12 (3%).

LIMITATIONS

Studies in children present unique challenges because subjects are too young to grasp subjective concepts such as symptom severity, especially as rated on a numbered scale. In addition, the 6-month extension of the placebo-controlled phase used a single agent. It is also possible that subjects' symptoms could have abated independent of mometasone furoate treatment.

CONCLUSION

MFNS 100 microg/day effectively reduces TNSS, TSS (including ocular symptoms), and individual symptoms associated with PAR and is well-tolerated for up to 6 months in children aged 3-11 years with a safety profile similar to placebo.

Prevention of allergic respiratory disease in infants: current aspects and future perspectives

PURPOSE OF REVIEW

Primary and secondary prevention of severe atopic disease exemplified by atopic asthma represents an increasingly prominent focus of research in paediatric allergy. We review below the rationale for this approach and recent progress in development and testing of a range of potential preventive strategies.

RECENT FINDINGS

The principal areas reviewed relate to potential and currently available treatments targeting enhancement of overall immune functions, allergen-specific immunomodulation and respiratory viral infections, particularly during early childhood.

SUMMARY

The scientific rationale for prophylaxis of atopic diseases via early intervention strategies targeting young children is increasingly supported by findings from the experimental and clinical literature and significant progress may be expected in the mid-term future.