Cytokine levels during symptomatic viral upper respiratory tract infection.
BACKGROUND
Previous studies suggest a role for locally produced proinflammatory cytokines in the development and expression of illness during experimental infection with a variety of respiratory viruses. However, most of these studies fail to make comparisons between symptomatic and asymptomatic infected subjects.


OBJECTIVE
To compare the pattern of nasal cytokine elaboration in asymptomatic and symptomatic subjects experimentally infected with rhinovirus-39 (RV-39).


METHODS
Healthy adults underwent experimental intranasal inoculation with a safety-tested clinical isolate of RV-39. Nasal lavages were collected, nasal symptoms were recorded, and expelled nasal secretions were weighed before and then daily for 6 days after challenge. Nasal lavages were submitted for viral culture and assayed for cytokine protein levels by enzyme-linked immunosorbent assay.


RESULTS
Twenty-nine subjects were enrolled in the study. All subjects were infected as evidenced by viral shedding and/or seroconversion. Sixteen subjects were symptomatic and 13 were asymptomatic as evaluated by subject self-report. During infection, significant increases in mean levels of nasal interleukin 6 (IL-6) (P = .01) and IL-1 (P = .02) were observed in symptomatic but not asymptomatic subjects. In symptomatic subjects, these increases were temporally related to the development of nasal symptoms and production of secretions. Mean levels of IL-8, IL-10, and tumor necrosis factor a were not increased in either group during infection.


CONCLUSIONS
The results of this study demonstrate elevations in certain locally produced cytokines during symptomatic but not asymptomatic respiratory infection with RV-39. Future studies using selected anticytokine therapies may help elucidate the precise role of cytokines in mediating disease expression.
Department of Pediatrics, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15212, USA. gentiledebann@aol.com
Deborah A
DA
Gentile
Eliseo
E
Villalobos
Betty
B
Angelini
David
D
Skoner
D000293:Adolescent; D000328:Adult; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D017817:Nasal Lavage Fluid / Q000276:immunology; D010850:Picornaviridae Infections / Q000276:immunology / Q000821:virology; D012141:Respiratory Tract Infections / Q000276:immunology / Q000821:virology; D012229:Rhinovirus / Q000276:immunology*
D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6