Fig. 2.

Intranare, day-to-day, and interindividual variability of IL-8 production in epithelial lining fluid (ELF). A: flowchart describing methods for determining variability in ELF samples within nares, from day to day, and between individuals using Leukosorb paper and IL-8 ELISA. B: intranare variability in IL-8 production using the average of the right nare over 3 days of sampling and left nare over 3 days of sampling (biological replicates = 3). There was no significant difference in IL-8 concentration intranare. Means are graphed for each individual. C: day-to-day variability in IL-8 production. The left and right nare were averaged for each day for a biological replicate of two. There was no significant variability in IL-8 concentration over the 3 days. Means are graphed for each individual at each day. D: interindividual variability in IL-8 production. Right and left nare measurements for each of the 3 days is graphed for each individual. There is significant interindividual variability. There is also a significant sex difference, IL-8 production is greater in men than it is in women. Values are presented as means ± SE. In B–D, n = 5; open squares indicate men, closed circles indicate women. ***P ≤ 0.001.