Rhinovirus-Induced Exacerbations of Asthma and COPD

Hershenson, Marc B.

Recent studies by the Imperial College London, in which patients with COPD were experimentally infected with rhinovirus [111] , have provided new information about RVinduced exacerbations in these patients. Compared to controls, COPD patients show increased sputum neutrophils in response to experimental RV infection. Other investigators have shown increased neutrophils, eosinophils, macrophages, and lymphocytes in the airways of COPD patients experiencing exacerbations [112] [113] [114] [115] [116] [117] [118] . Unlike asthma patients, COPD patients experimentally infected with RV show increased sputum viral copy number versus controls, and viral load correlates with sputum neutrophils and interleukin-8 levels [111] . BAL cells from patients with COPD show reduced interferon-alpha and -beta responses to rhinovirus infection ex vivo. Together, these results provide ample evidence of altered innate immunity against viruses. These data reinforce in vitro data showing that exposure of lung cells to cigarette smoke extract reduces CXCL10, interferon-beta, and RIG-I expression in response to influenza virus infection [119] .