Detection of respiratory viruses and the associated chemokine responses in serious acute respiratory illness.
BACKGROUND
A specific diagnosis of a lower respiratory viral infection is often difficult despite frequent clinical suspicion. This low diagnostic yield may be improved by use of sensitive detection methods and biomarkers.


METHODS
The prevalence, clinical predictors and inflammatory mediator profile of respiratory viral infection in serious acute respiratory illness were investigated. Sequential bronchoalveolar lavage (BAL) fluids from all patients hospitalised with acute respiratory illness over 12 months (n=283) were tested for the presence of 17 respiratory viruses by multiplex PCR assay and for newly discovered respiratory viruses (bocavirus, WU and KI polyomaviruses) by single-target PCR. BAL samples also underwent conventional testing (direct immunoflorescence and viral culture) for respiratory virus at the clinician's discretion. 27 inflammatory mediators were measured in a subset of the patients (n=64) using a multiplex immunoassay.


RESULTS
39 respiratory viruses were detected in 37 (13.1% of total) patients by molecular testing, including rhinovirus (n=13), influenza virus (n=8), respiratory syncytial virus (n=6), human metapneumovirus (n=3), coronavirus NL63 (n=2), parainfluenza virus (n=2), adenovirus (n=1) and newly discovered viruses (n=4). Molecular methods were 3.8-fold more sensitive than conventional methods. Clinical characteristics alone were insufficient to separate patients with and without respiratory virus. The presence of respiratory virus was associated with increased levels of interferon gamma-inducible protein 10 (IP-10) (p<0.001) and eotaxin-1 (p=0.017) in BAL.


CONCLUSIONS
Respiratory viruses can be found in patients with serious acute respiratory illness by use of PCR assays more frequently than previously appreciated. IP-10 may be a useful biomarker for respiratory viral infection.
Sumino
Kaharu C
KC
Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA. ksumino@dom.wustl.edu
Walter
Michael J
MJ
Mikols
Cassandra L
CL
Thompson
Samantha A
SA
Gaudreault-Keener
Monique
M
Arens
Max Q
MQ
Agapov
Eugene
E
Hormozdi
David
D
Gaynor
Anne M
AM
Holtzman
Michael J
MJ
Storch
Gregory A
GA
D000208:Acute Disease; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology; D054413:Chemokine CCL11 / Q000032:analysis; D054357:Chemokine CXCL10 / Q000032:analysis; D018925:Chemokines / Q000096:biosynthesis*; D006760:Hospitalization; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D012367:RNA, Viral / Q000032:analysis; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000821:virology; D014773:Virology / Q000379:methods; D014777:Virus Diseases / Q000175:diagnosis* / Q000821:virology
D015415:Biomarkers; C515456:CCL11 protein, human; C114753:CXCL10 protein, human; D054413:Chemokine CCL11; D054357:Chemokine CXCL10; D018925:Chemokines; D018836:Inflammation Mediators; D012367:RNA, Viral