Combined fluticasone propionate and salmeterol reduces RSV infection more effectively than either of them alone in allergen-sensitized mice.
BACKGROUND
Respiratory syncytial virus (RSV) infection is the major cause of bronchiolitis in infants and is a risk factor for the development of asthma. Allergic asthmatics are more susceptible to RSV infection and viral exacerbation.


METHODS
Since the effectiveness of corticosteroids in treating RSV infection has been controversial, we tested fluticasone propionate (FP) and salmeterol (Sal) alone versus FP plus Sal (FPS) on RSV-induced airway inflammation. Mice were sensitized and challenged with ovalbumin (OVA) and infected with RSV. Following infection they were treated with FP, Sal, or FPS intranasally and airway hyperreactivity (AHR), inflammation and RSV titers were examined.


RESULTS
The group treated with FPS showed significantly lower AHR compared to the group treated with FP or Sal alone. The group treated with FP alone showed slightly decreased (non-significant) AHR compared to controls. Treatment with FPS resulted in significant decreases in the percentage of eosinophils and neutrophils in bronchoalveolar lavage fluid and in lung pathology compared to FP or Sal. FP alone decreased eosinophils but not neutrophils or lymphocytes, while Sal alone decreased eosinophils and neutrophils but not lymphocytes. FPS treatment of mice infected with RSV in the absence of allergen sensitization resulted in a 50% decrease of RSV titer in the lung and a reduction in neutrophils compared to FP or Sal.


CONCLUSIONS
Together, these results indicate that fluticasone in combination with salmeterol is a more effective treatment for decreasing airway hyperreactivity and inflammation than either of them alone in allergen-sensitized, RSV-infected mice.
Singam
Rajeswari
R
Division of Allergy and Immunology, Joy McCann Culverhouse Airway Disease Research Center, University of South Florida College of Medicine and James A, Haley VA Hospital, Tampa, FL, USA. rsingam@hsc.usf.edu
Jena
Prasanna K
PK
Behera
Sumita
S
Hellermann
Gary R
GR
Lockey
Richard F
RF
Ledford
Dennis
D
Mohapatra
Shyam S
SS
D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000485:Allergens / Q000276:immunology*; D000730:Androstadienes / Q000008:administration & dosage* / Q000627:therapeutic use*; D000818:Animals; D018926:Anti-Allergic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy; D018893:Bronchoalveolar Lavage; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use; D004338:Drug Combinations; D005260:Female; D000068298:Fluticasone; D000068297:Fluticasone-Salmeterol Drug Combination; D008168:Lung / Q000187:drug effects / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology*; D018357:Respiratory Syncytial Virus Infections / Q000188:drug therapy* / Q000276:immunology; D000068299:Salmeterol Xinafoate
D000485:Allergens; D000730:Androstadienes; D018926:Anti-Allergic Agents; D001993:Bronchodilator Agents; D004338:Drug Combinations; D000068297:Fluticasone-Salmeterol Drug Combination; D000068299:Salmeterol Xinafoate; D010047:Ovalbumin; D000068298:Fluticasone; D000420:Albuterol