Comparison of viral load in individuals with and without asthma during infections with rhinovirus.
BACKGROUND
Most virus-induced attacks of asthma are caused by rhinoviruses (RVs).


OBJECTIVE
To determine whether people with asthma are susceptible to an increased viral load during RV infection.


METHODS
Seventy-four children (4-18 yr old) were enrolled; 28 with wheezing, 32 with acute rhinitis, and 14 without respiratory tract symptoms. Nasal washes were evaluated using quantitative polymerase chain reaction for RV to judge viral load along with gene sequencing to identify strains of RV. Soluble intercellular adhesion molecule-1, IFN-λ1, and eosinophil cationic protein in nasal washes, along with blood eosinophil counts and total and allergen-specific IgE in sera, were also evaluated. Similar assessments were done in 24 young adults (16 with asthma, 8 without) who participated in an experimental challenge with RV (serotype 16).


RESULTS
Fifty-seven percent of wheezing children and 56% with acute rhinitis had nasal washes testing positive for RV. The geometric mean of viral loads by quantitative polymerase chain reaction in washes from wheezing children was 2.8-fold lower, but did not differ significantly from children with rhinitis (7,718 and 21,612 copies of viral RNA per microliter nasal wash, respectively; P = 0.48). The odds for wheezing were increased if children who tested positive for RV were sensitized to one or more allergens (odds ratio, 3.9; P = 0.02). Similarly, neither peak nor cumulative viral loads differed significantly in washes from adults with asthma compared with those without asthma during the experimental RV challenge.


CONCLUSIONS
During acute symptoms, children infected with RV enrolled for wheezing or acute rhinitis had similar viral loads in their nasal washes, as did adults with and without asthma infected with RV-16 experimentally.
1 Pediatric Allergy and Immunology and Respiratory Medicine.
Joshua L
JL
Kennedy
Marcus
M
Shaker
Victoria
V
McMeen
James
J
Gern
Holliday
H
Carper
Deborah
D
Murphy
Wai-Ming
WM
Lee
Yury A
YA
Bochkov
Rose F
RF
Vrtis
Thomas
T
Platts-Mills
James
J
Patrie
Larry
L
Borish
John W
JW
Steinke
William A
WA
Woods
Peter W
PW
Heymann
D000208:Acute Disease; D000293:Adolescent; D001249:Asthma / Q000097:blood / Q000150:complications / Q000821:virology*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D018450:Disease Progression; D047150:Eosinophil Cationic Protein / Q000097:blood; D004804:Eosinophils / Q000378:metabolism; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D007372:Interferons; D007378:Interleukins / Q000097:blood; D007958:Leukocyte Count; D016015:Logistic Models; D008297:Male; D017817:Nasal Lavage Fluid / Q000821:virology; D016017:Odds Ratio; D010850:Picornaviridae Infections / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000821:virology*; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000032:analysis; D012135:Respiratory Sounds / Q000209:etiology* / Q000502:physiology; D012220:Rhinitis / Q000097:blood / Q000821:virology*; D012229:Rhinovirus / Q000235:genetics / Q000302:isolation & purification*; D019562:Viral Load; D055815:Young Adult; D000095022:Interferon Lambda
D015415:Biomarkers; D047150:Eosinophil Cationic Protein; D007073:Immunoglobulin E; D018799:Intercellular Adhesion Molecule-1; D007372:Interferons; D007378:Interleukins; D012367:RNA, Viral; C000624353:interferon-lambda, human; D000095022:Interferon Lambda; C479220:RNASE3 protein, human