Expression of interferon-{gamma} and its effect on cough hypersensitivity in chronic refractory cough patients

Chronic refractory cough (CRC) is characterised by cough hypersensitivity. Interferon- (IFN-) has been reported to induce calcium influx, action potentials of vagal neurons in vitro and cough response in guinea pigs. While the effect of IFN- in CRC patients remains unknown. Here, via flow-cytometry and inhalation cough challenge, we found CRC patients had significantly increased levels of sputum IFN-+CD4+ T cells, IFN-+CD8+ T cells as well as supernatant of IFN-. The average number of coughs in CRC patients increased as the concentration of inhaled IFN- went up in IFN- cough challenge. Two or more coughs and five or more coughs elicited by inhaled IFN- in CRC patients occurred in 7 of 10 and 2 of 10, respectively. Preinhaled IFN- (100 µg/mL) increased the capsaicin cough sensitivity in CRC patients but not healthy volunteers. Targeting IFN- may be a potential effective anti-tussive strategy in CRC patients.
Source: Thorax - Category: Respiratory Medicine Authors: Tags: Thorax Brief communication Source Type: research