Nasal challenge with cold, dry air results in release of inflammatory mediators. Possible mast cell involvement.

Abstract

The purpose of our study was to assess the effect of cold, dry air (CDA) on the nasal mucosa of selected individuals in relation to the release of inflammatory mediators associated with mast cells. 12 subjects with a history of nasal symptoms of rhinorrhea and congestion upon cold or dry environmental exposure were challenged by nasal breathing of CDA and warm, moist air (WMA). Each subject was tested on two occasions with the order of the challenges reversed. Symptom scores were recorded, and the levels of histamine, prostaglandin (PG) D2, kinins, and 1H1-N-a-tosyl-L-arginine methyl ester (TAME)-esterase activity in nasal lavage fluids were measured.CDA caused a significant increase in mediator levels and in symptom scores as compared to baseline or to WMA. No significant increase in symptom scores or mediators was noted after WMA challenge, with the exception of a marginal increase in kinins. The response to CDA was similar, regardless of challenge order. Changes in mediators correlated with one another, and symptom scores correlated significantly with the levels of histamine, kinins, and PGD2. Five subjects without a history of nasal symptoms on cold air exposure had no change in mediators or symptom scores after CDA or WMA challenge. We conclude that CDA causes the release of inflammatory mediators possibly associated with mast cells and speculate that such a mechanism may be involved in the bronchospasm induced by CDA in asthmatics.

Nasal inflammation in sleep apnoea patients using CPAP and effect of heated humidification

“…Previous studies have assessed the role of CPAP on nasal airway of healthy volunteers [8][9][10]16] and in a rodent model [11], and have also evaluated the effect of different forms of humidification on nasal symptoms and adherence in OSA patients [13][14][15]22]. However, the effect of CPAP (with and without humidification) on nasal airway pathophysiology of OSA patients remains unknown.…”

“…Although the pathophysiologic mechanisms by which CPAP causes cytokine release are unknown, some speculations can be made. It is likely that airflow of cold and dry air has a toxic effect on nasal epithelium [26] and mediator containing cells of the nasal mucosa [10]. The addition of heated humidification could eventually prevent this effect, thus avoiding epithelial detachment and shedding and mediator release.…”

“…Among the side effects caused by CPAP, undesirable nasal symptoms such as congestion, dryness or rhinorrhea are particularly prevalent and can significantly compromise compliance [7]. Several mechanisms may be potentially involved in the development of nasal discomfort with CPAP but they have been described only in healthy volunteers [8][9][10] and in a rodent model [11]. Indeed, deliberate mouth leaks while normal subjects were using CPAP can cause high unidirectional nasal airflow with increased nasal airway resistance [8] as well as enhance nasal mucosal blood flux [9].…”

“…Indeed, deliberate mouth leaks while normal subjects were using CPAP can cause high unidirectional nasal airflow with increased nasal airway resistance [8] as well as enhance nasal mucosal blood flux [9]. Similarly, TOGIAS et al [10] documented a release of inflammatory mediators in nasal-wash fluids when compressed cold and dry air was delivered through the nose. More recently, ALMENDROS et al [11] showed that CPAP employed in rats can trigger early nasal inflammation.…”

Evidence for mast cell activation during exercise-induced bronchoconstriction

“…Apart from the methodological problems encountered when sampling plasma histamine [18] and its short half-life in the circulation, approximately 1 min [19], it has been suggested that elevations in plasma histamine mainly reflect the basophilia which normally accompanies exercise [20]. Increases in the levels of tryptase and PGD 2 , both specific mast cell markers, have been detected in nasal lavage following nasal provocation with cold dry air [21], but not after exercise [22,23].…”