Persistent infection with human rhinovirus of lower airways and clinical state of asthmatic patients
asthma ; PCR in situ ; rhinovirus
Human rhinovirus (HRV), the common cold virus is the most frequent cause of asthma exacerbations in adults. Our objectives were to determine if stable asthmatic patients, who are free of clinical symptoms of a respiratory infection, can harbor HRV in their bronchi, and to compare the frequency of HRV detection between asthmatic and nonasthmatic subjects. We also were concerned whether clinical features of asthma are associated with the presence of HRV. Two methods of HRV detection in bronchial mucosa were used: indirect RTPCR in situ method and indirect immunohistochemistry (IHC). HRV was found by IHC in 64% asthmatic subjects and 33% non-asthmatic controls. Indirect RT-PCR in situ method detected HRV in 73% of asthmatic patients and 22% non-asthmatic controls (p<0,001). Subjects positive for HRV had lower pulmonary function tests, higher numbers of blood eosinophils, leukocytes, granulocytes, and eosinophilic infiltration in bronchial mucosa Asthmatic patients, who are free of clinical symptoms can harbor HRV in the lower airways. The presence of HRV in bronchial tissue is significantly more common in asthmatic than in non-asthmatic subjects. Presence of HRV was associated with clinical features of more severe disease.