Links between allergic rhinitis and asthma:

Variance of melatonin and cortisol rhythm in patients with allergic rhinitis

OBJECTIVE

Allergic rhinitis is an IgE-mediated inflammatory disease which effects 10%-50% of the normal population. The mechanism of its formation and the circadian rhythm of cortisol and melatonin in allergic rhinitis have not been investigated.

STUDY DESIGN

Salivary levels of melatonin and cortisol were measured by radioimmunoassay in 35 newly diagnosed allergic rhinitis patients and in 23 control subjects matched for age and gender.

RESULTS

In the study group; amplitude, baseline and peak levels of salivary melatonin were significantly decreased compared with healty controls (p<0.001). No differences were found in the acrophase and the peak duration of salivary melatonin between the study and control groups (p>0.05). In the study subjects, the circadian rhythm of cortisol was flattened when compared with the control group. The amplitude and the 24h mean levels of salivary cortisol in the study group were significantly lower than in the control group and the acrophase was delayed in patients compared with control subjects (p<0.001).

CONCLUSION

The circadian rhythms of salivary melatonin and cortisol were found to be disrupted in patients with allergic rhinitis. These results may also be contributive data to explain the pathogenesis of allergic rhinitis and also they can be applicable as adjunctive therapeutic tools in the future and melatonin drugs might be an alternative in the therapy of resistant allergic rhinitis patients or allergic rhinitis patients who cannot use cortisol drugs.

Role of airway epithelial cells in development of asthma and allergic rhinitis

Asthma and allergic rhinitis frequently coexist in the same patient. There is a similarity and variation as well as potential relationship between asthma and allergic rhinitis. There is an increasing evidence to suggest a major involvement of airway epithelial cells in the pathogenesis of asthma and allergic rhinitis. The present review describes the importance of the airway epithelial cell in the development of allergic airway diseases, its role as the primary airway defense against exposure of the airway and lung to inflammatory stimuli and antigens and as an important player through activation of epithelial Toll-like receptors (TLRs) to provide an important link between innate immunity and allergic disease. Additionally, airway epithelial cells can act as inflammatory promoters capable of directing dendritic cells (DCs) towards a T helper 2 (Th2) response, and as active producers of several inflammatory/anti-inflammatory mediators. It is hypothesized that airway epithelial cells may play as both inflammatory initiator and immuno-pathological feedback regulation between allergic rhinitis and asthma via release of systemic inflammatory mediators. Thus, airway epithelial cells may be valuable therapeutic targets for discovery and development of new drugs and/or new therapeutic strategies to treat asthma and allergic rhinitis.