PT  - JOURNAL ARTICLE
AU  - Harada, Tatsuhiko
AU  - Ishimatsu, Yuji
AU  - Hara, Atsuko
AU  - Morita, Towako
AU  - Nakashima, Shota
AU  - Kakugawa, Tomoyuki
AU  - Sakamoto, Noriho
AU  - Kosai, Kosuke
AU  - Izumikawa, Koichi
AU  - Yanagihara, Katsunori
AU  - Mukae, Hiroshi
AU  - Kohno, Shigeru
TI  - Premedication with Clarithromycin Is Effective against Secondary Bacterial Pneumonia during Influenza Virus Infection in a Pulmonary Emphysema Mouse Model
AID  - 10.1124/jpet.116.233932
DP  - 2016 Sep 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 457--463
VI  - 358
IP  - 3
4099  - http://jpet.aspetjournals.org/content/358/3/457.short
4100  - http://jpet.aspetjournals.org/content/358/3/457.full
SO  - J Pharmacol Exp Ther2016 Sep 01; 358
AB  - Secondary bacterial pneumonia (SBP) during influenza increases the severity of chronic obstructive pulmonary disease (COPD) and its associated mortality. Macrolide antibiotics, including clarithromycin (CAM), are potential treatments for a variety of chronic respiratory diseases owing to their pharmacological activities, in addition to antimicrobial action. We examined the efficacy of CAM for the treatment of SBP after influenza infection in COPD. Specifically, we evaluated the effect of CAM in elastase-induced emphysema mice that were inoculated with influenza virus (strain A/PR8/34) and subsequently infected with macrolide-resistant Streptococcus pneumoniae. CAM was administered to the emphysema mice 4 days prior to influenza virus inoculation. Premedication with CAM improved pathologic responses and bacterial load 2 days after S. pneumoniae inoculation. Survival rates were higher in emphysema mice than control mice. While CAM premedication did not affect viral titers or exert antibacterial activity against S. pneumoniae in the lungs, it enhanced host defense and reduced inflammation, as evidenced by the significant reductions in total cell and neutrophil counts and interferon (IFN)-γ levels in bronchoalveolar lavage fluid and lung homogenates. These results suggest that CAM protects against SBP during influenza in elastase-induced emphysema mice by reducing IFN-γ production, thus enhancing immunity to SBP, and by decreasing neutrophil infiltration into the lung to prevent injury. Accordingly, CAM may be an effective strategy to prevent secondary bacterial pneumonia in COPD patients in areas in which vaccines are inaccessible or limited.