Effects of leukotriene D4 nasal challenge on bronchial responsiveness and inflammation in asthmatic patients with allergic rhinitis

Montelukast, an Antagonist of Cysteinyl Leukotriene Signaling, Impairs Burn Wound Healing

BACKGROUND

Burns are severe injuries often associated with impaired wound healing. Impaired healing is caused by multiple factors, including dysregulated inflammatory responses at the wound site. Interestingly, montelukast, an antagonist for cysteinyl leukotrienes and U.S. Food and Drug Administration approved for treatment of asthma and allergy, was previously shown to enhance healing in excision wounds and to modulate local inflammation.

METHODS

In this study, the authors examined the effect of montelukast on wound healing in a mouse model of scald burn injury. Burn wound tissues isolated from montelukast- and vehicle-treated mice at various times after burn injury were analyzed for wound areas ( n = 34 to 36), reepithelialization ( n = 14), inflammation ( n = 8 to 9), and immune cell infiltration ( n = 3 to 6) and proliferation ( n = 7 to 8).

RESULTS

In contrast to previously described beneficial effects in excision wounds, this study shows that montelukast delays burn wound healing by impairing the proliferation of keratinocytes and endothelial cells. This occurs largely independently of inflammatory responses at the wound site, suggesting that montelukast impairs specifically the proliferative phase of wound healing in burns. Wound healing rates in mice in which leukotrienes are not produced were not affected by montelukast.

CONCLUSION

Montelukast delays wound healing mainly by reducing the proliferation of local cells after burn injury.

CLINICAL RELEVANCE STATEMENT

Although additional and clinical studies are necessary, our study suggests that burn patients who are on montelukast may exhibit delayed healing, necessitating extra observation.

Response of upper and lower airway inflammation to bronchial challenge with house dust mite in Chinese asthmatics: a pilot study

Background

Allergen nasal challenge can induce increase of eosinophils in sputum, but report about eosinophilic inflammation in upper airway after allergen bronchial challenge in Chinese asthmatics was rare. The article aims to evaluate response of upper and lower airways to house dust mite (HDM) allergen bronchial challenge.

Methods

HDM allergen bronchial challenge was carried out in asthmatic patients with allergic rhinitis (AR). Bronchial methacholine challenge and blood test were performed before and at 24 hours after allergen challenge. Nasal lavage and induced sputum for differential cells count and fractional exhaled nitric oxide (FeNO) measurement were performed before, 7 and 24 hours after allergen challenge.

Results

Eighteen asthmatic patients with AR underwent HDM allergen bronchial challenge with no serious adverse events reported. Fifteen patients showed dual asthmatic response (DAR), while 2 patients showed early (EAR) and 1 late asthmatic response (LAR) only. At 24 hours after allergen bronchial challenge testing, average PC₂₀FEV₁ to methacholine significantly decreased (1.58 to 0.81 mg/mL, P=0.03), while both FeNO and the percentage of eosinophils in blood and sputum were significantly increased [52.0 (54.0) to 69.0 (56.0) ppb, P=0.01; 4.82% to 6.91%, P<0.001; 20.70% to 27.86%, P=0.03, respectively], but with no significant differences found in the percentage of eosinophils in nasal lavage (39.36% to 38.58%, P=0.89). However, at 7 hours after allergen challenge, the eosinophils in sputum were significant increased to 40.45% (P<0.001), but there was an increase (39.36% to 48.07%) with no statistical difference (P=0.167) found in nasal lavage.

Conclusions

HDM allergen bronchial challenge induced different response of airway inflammation in upper and lower airways.