Analysis of Sequential Aliquots of Hypertonic Saline Solution-Induced Sputum: Inflammatory Mediators
There was a mean half-log decrease in both nonmucoid P aeruginosa and S aureus with time (p = 0.05 and p < 0.01, respectively). The mean changes in nonmucoid P aeruginosa density and S aureus were 0.0.54 log10 cfu/mL (95% CI, — 1.60 to 0.52) and — 0.55 log10 cfu/mL (95% CI, — 1.42 to 0.32), respectively. There was no change in bacterial density of mucoid P aeruginosa (p = 0.12). R pickettii was seen in 60% of subjects but at low colony counts up to 7,600 colonies per milliliter.
IL-8 was detected in all subjects and in all samples. The mean ± SD concentration (log10) was 1.8 ± 1.4 ng/mL, 1.8 ± 1.5 ng/mL, 1.9 ± 1.6 ng/mL, 1.8 ± 1.6 ng/mL, and 1.8 ± 1.5 ng/mL at the five time points, respectively. The mean change in IL-8 (log10) was — 0.026 ng/mL (95% CI, — 0.103 to 0.051). There was no linear time trend in IL-8 concentrations (p = 0.99; Fig 3).
SP-D was not found in any sample. SP-A was detected in all subjects and in all samples. The mean ± SD concentration (log10) was 1.62 ± 0.29 ng/mL, 1.95 ± 0.62 ng/mL, 2.23 ± 0.58 ng/mL, 2.30 ± 0.59 ng/mL, and 2.40 ± 0.44 ng/mL at the five time points, respectively. The mean change in SP-A (log10) was 0.79 ng/mL (95% CI, 0.46 to 1.11). There was a linear time trend in SP-A concentrations (p < 0.001; Fig 4). canadian health&care mall
Interpretation of Results in Light of Multiple Comparisons
As 10 different statistical outcome measures were performed, a value of p < 0.005 is required to maintain the overall risk of a type I error equal to 0.05. We can reasonably conclude that only SP-A is statistically remarkable (p < 0.001).
Serial aliquots of induced sputum in clinically stable adult CF patients with mild-to-moderate obstructive lung disease show significant changes over time in SP-A concentration and a 3% increase in alveolar macrophages. This provides evidence for increased distal airway sampling over time with the SI procedure in patients with CF. In addition, there was a 3% decreased in polymorphonuclear leukocytes (PMNs), and a half-log decrease in P aeruginosa and S aureus density between the 0- to 4-min and 16- to 20-min collections.
Figure 3. Concentrations of IL-8 from induced-sputum aliquots. IL-8 was detected in all subjects and in all samples. There was no linear time trend in IL-8 concentrations (p = 0.99).
Figure 4. Concentrations of SP-A from induced-sputum aliquots. SP-A was detected in all subjects and in all samples. There was a linear time trend in SP-A concentrations (p < 0.001). HSPA = human surfactant protein-A.