[Comparison of the detection rate and load of rhinovirus in nasal versus lower airway samples from patients with chronic obstructive pulmonary disease].
OBJECTIVE
To compare the rhinovirus detection rate and the viral load in nasal samples versus lower airway samples from patients with COPD, and therefore to provide evidence for sampling selection for detection of rhinovirus.


METHODS
Nasal swab and induced sputum were collected from patients with COPD during acute exacerbation and the stable period. Rhinovirus was detected by real-time fluorescent quantitative polymerase chain reaction. The difference in detection rates of rhinovirus between acute exacerbation and stable COPD was compared. The detection rates and the viral load from nasal samples versus induced sputum were also compared.


RESULTS
A total of 639 paired nasal swab and induced sputum specimens were collected between September 2009 and January 2013, including 114 paired specimens from COPD patients with acute exacerbations 114 paired specimens from stable COPD (matching with the stable one), and 411 paired specimens from stable COPD patients. For the 114 paired samples from stable and acute COPD patients, there was a higher detection rate in samples [nasal swab 13.2% (15/114) , induced sputum 21.9% (25/114) ] from patients with acute exacerbation, compared those with stable disease [nasal swab 3.5% (4/114), P < 0.05; and induced sputum 5.3% (6/114) P < 0.01, respectively]. Forty-two (6.6%) of the 639 nasal swab specimens were positive for rhinovirus, while 58(9.1%) of the 639 induced sputum specimens were positive for rhinovirus (P < 0.05).For the 27 paired rhinovirus positive specimens, the mean viral load of rhinovirus in induced sputum was (62.1 ± 9.5) × 10⁸ copies/L, significantly higher than that of the nasal swab (3.4 ± 0.5) × 10⁸ copies/L, P < 0.05.


CONCLUSIONS
For patients with COPD, induced sputum specimens may be more suitable for rhinovirus detection compared to nasal swabs, and the load of rhinovirus was higher in the lower airways than in the upper airways.
State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
Hua
H
Liao
Email: chenrc@vip.163.com.
Rongchang
R
Chen
Wenda
W
Guan
Zifeng
Z
Yang
Wenkuan
W
Liu
Rong
R
Zhou
Nanshan
N
Zhong
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000821:virology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000821:virology*; D012367:RNA, Viral / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction; D012229:Rhinovirus / Q000235:genetics / Q000302:isolation & purification*; D013048:Specimen Handling; D013183:Sputum / Q000821:virology*; D019562:Viral Load
D012367:RNA, Viral