Using a large data set (n = 811), the relationship between acute respiratory
infection illness severity and inflammatory
biomarkers was investigated to determine whether certain symptoms are correlated more closely than others with the inflammatory
biomarkers,
interleukin-8 (IL-8) and nasal neutrophils. Participants with community acquired acute respiratory
infection underwent nasal lavage for
IL-8 and neutrophil testing, in addition to multiplex polymerase chain reaction (PCR) methods for the detection and identification of respiratory viruses. Information about symptoms was obtained throughout the duration of the illness episode using the well-validated Wisconsin Upper Respiratory Symptom Survey (WURSS-21). Global symptom severity was calculated by the area under the curve (AUC) plotting duration versus WURSS total. Of the specimens tested, 56% were positively identified for one or more of nine different respiratory viruses. During acute respiratory
infection illness, both
IL-8 and neutrophils positively correlate with AUC (r(s) = 0.082, P = 0.022; r(s) = 0.080, P = 0.030).
IL-8 and neutrophils correlate with nasal symptom severity:
runny nose (r = 0.13, P = < 0.00001; r = 0.18, P = < 0.003), plugged nose (r = 0.045, P = 0.003; r = 0.14, P = 0.058), and
sneezing (r = -0.02, P = < 0.0001; r = -0.0055, P = 0.31). Neutrophils correlate with some quality of life measures such as sleeping well (r = 0.15, P = 0.026). Thus, the study demonstrates that
IL-8 and neutrophils are correlated with severity of nasal symptoms during acute respiratory
infection. Further research is necessary to determine if the concentration of these or other
biomarkers can predict the overall duration and severity of acute respiratory
infection illness.