PDE4A and chronic obstructive pulmonary disease: Because PDE4 inhibitors do not modulate RV-induced inflammation or replication this study suggests PDE4 inhibitors may be safe to supplement bronchodilating medication during RV-induced exacerbations of COPD and asthma as well as having other beneficial effects of reducing inflammatory neutrophils during exacerbations of COPD caused by bacteria or viruses other than RV.