He. Fleming et al., Rhinovirus-16 colds in healthy and in asthmatic subjects - Similar changesin upper and lower airways, AM J R CRIT, 160(1), 1999, pp. 100-108
Rhinovirus (RV) infections appear to precipitate most asthma exacerbations.
To investigate whether RV-16 induces different inflammatory changes in upp
er and lower airways of asthmatic and healthy subjects, we inoculated 10 no
natopic healthy and 11 atopic asthmatic adults with 2,000 TCID50 RV-16. Sub
jects recorded symptoms and peak flow daily; and they underwent spirometry,
methacholine challenge (PC20), nasal lavage, and sputum induction at basel
ine and on Days 2, 4, 15, and 29 d after inoculation. One asthmatic subject
developed an exacerbation requiring prednisone treatment 5 d after inocula
tion. The cold symptom severity (Jackson score) did not differ between grou
ps. During the cold, asthma symptoms increased slightly from baseline in th
e asthmatic group; and PC20 decreased in the healthy group. However, peak f
low, bronchodilator use, and spirometry did not change in either group. At
baseline, asthmatics had higher neutrophils, eosinophils, and interleukin (
IL)-6 in nasal lavage. After inoculation, both groups developed significant
increases in nasal neutrophils, IL-6 and IL-8, and modest increases in spu
tum neutrophils and IL-6, but not IL-8. However, these changes did not diff
er between groups. IL-5, interferon-gamma, and RANTES were detected only in
nasal lavages from two asthmatic subjects, who had the most severe colds.
IL-11 was not detected in any sample. We conclude that inflammatory respons
es of upper and lower airways during RV-16 colds are similar in asthmatic a
nd healthy subjects, and that RV-16 infection is not by itself sufficient t
o provoke clinical worsening of asthma.