**7. Therapeutic developments in the treatment of allergic rhinitis (AR)**

Due to the increased prevalence of AR, its impact on quality of life, its societal costs and the fact that it is a predisposing factor for asthma, new therapeutic options are being sought. Studies are being performed with anti-leukotrienes, anti-immunoglobulin E antibodies, phosphodiesterase inhibitors, and others, which seem to confirm promising results.

Schultz et al state that, in addition to the well established therapeutic guidelines in the treatment of rhinitis with antihistamines, corticosteroids, nasal decongestants, etc., there are an increasingly number of new therapeutic alternatives, such as anti-leukotrienes, antiimmunoglobulin E antibodies, phosphodiesterase inhibitors and intranasal heparin, as well as new specific immunotherapies (recombinant). There are promising results, but more studies are needed to confirm these initial data (Schultz et al, 2003).

Bjermer and Diamant observed that, although inhaled corticosteroids are currently considered first-line drugs in the anti-inflammatory control of asthma and rhinitis, there are studies with anti-leukotrienes and anti-immunoglobulin E that are highly promising. Clinical trials are being performed with modified cytokines (Bjermer & Diamant, 2004).

Koreck et al reported on *low intensity UVB, UVA and visible light phototherapy* as treatment for AR (3 times per week for three weeks). The authors reported that there was a significant reduction in the number of eosinophils, ECP and IL-5 in the nasal lavage. They also found inhibition in the RBL-2H3 mediator release of basophils. Phototherapy is a new option in the treatment of immunologically mediated mucosal diseases, including allergic rhinitis (Koreck et al, 2005).

Kirchhoff et al used the *H1-receptor antagonist dimethindene maleate* topically on patients with seasonal allergic rhinitis for 2 weeks and compared it with placebo. With this antagonist, they achieved statistically significantly better results in the quality of life questionnaires for rhinitis than with placebo (Kirchhoff et al, 2003).

Unal et al investigated the potential benefits of the *toxin botulinum type A* on nasal symptoms of allergic rhinitis, and compared it to an isotonic saline solution as placebo. The results were significantly better in patients treated with botulinum toxin, especially in rhinorrhoea, nasal obstruction and sneezing. In selected cases, the injection of intranasal toxin botulinum may help control allergic rhinitis symptoms (Unal et al, 2003).

*Monoclonal antibodies anti-IL-5* seem to be an effective treatment that reduces the number of eosinophils locally in the airway and in peripheral blood in asthmatic patients. Two monoclonal antibodies have been designed to neutralize IL-5 (mepolizumab and reslizumab). Mepolizumab is a fully humanized anti-IL-5 monoclonal IgG1 antibody that binds to free IL-5 with high affinity and specificity to prevent IL-5 from associating with the IL-5 receptor complex alpha-chain on the surface of eosinophils (Leckie et al, 2000).

There are clinical trials with recombinant soluble IL-4 receptor, and recombinant IL-12. Immunomodulatory treatments for IL-9, IL-l0, IL-12 and IL-13 are being studied, as well as immunostimulatory DNA sequences, with encouraging results.
