Table 2

Correlations between lung function measurements at 12 years of age and CC16, IL-1β and TNF-α (and ratios) in tracheal aspirate at birth

CC16 in tracheal aspirateIL-1β in tracheal aspirateTNFα in tracheal aspirateIL-1β/CC16 ratio in tracheal aspirateTNF-α/CC16 ratio in tracheal aspirate
Spirometry(n=20)(n=18)(n=18)(n=18)(n=18)
FEV1, Lr=0.03, p=0.90r=−0.47, p=0.048r=−0.55, p=0.019r=−0.52, p=0.028r=−0.51, p=0.029
FEV1, z-scorer=0.27, p=0.26r=−0.13, p=0.60r=−0.21, p=0.41r=−0.21, p=0.41r=−0.37, p=0.13
FEV1/FVCr=0.51, p=0.021r=−0.17, p=0.49r=−0.09, p=0.74r=−0.63, p=0.005r=−0.68, p=0.002
FEV1/FVC, z-scorer=0.50, p=0.025r=−0.22, p=0.39r=−0.18, p=0.47r=−0.62, p=0.006r=−0.71, p=0.001
FEF25–75, L/sr=0.33, p=0.16r=−0.39, p=0.11r=−0.36, p=0.15r=−0.73, p<0.001r=−0.73, p<0.001
FEF25–75, z-scorer=0.39, p=0.094r=−0.25, p=0.32r=−0.21, p=0.40r=−0.51, p=0.031r=−0.58, p=0.011
Impulse oscillometry(n=20)(n=18)(n=18)(n=18)(n=18)
R5, kPa×s/Lr=−0.19, p=0.43r=0.09, p=0.71r=−0.23, p=0.36r=0.18, p=0.47r=0.001, p=1.00
R20, kPa×s/Lr=−0.02, p=0.93r=0.18, p=0.49r=−0.12, p=0.64r=−0.01, p=0.97r=−0.16, p=0.53
R5–R20, kPa×s/Lr=−0.49, p=0.028r=0.14, p=0.58r=0.09, p=0.72r=0.57, p=0.013r=0.62, p=0.006
X5, kPa×s/Lr=0.37, p=0.11r=−0.29, p=0.24r=−0.18, p=0.48r=−0.61, p=0.008r=−0.53, p=0.023
Fres, 1 /sr=−0.65, p=0.002r=0.02, p=0.95r=0.02, p=0.95r=0.54, p=0.022r=0.69, p=0.002
AX, kPa/Lr=−0.57, p=0.008r=0.26, p=0.31r=0.16, p=0.53r=0.72, p<0.001r=0.73, p<0.001
Body plethysmography(n=18)(n=17)(n=17)(n=17)(n=17)
Rinsp, kPa×s/Lr=−0.27, p=0.27r=0.17, p=0.52r=0.19, p=0.47r=0.36, p=0.15r=0.53, p=0.029
Rexp, kPa×s/Lr=−0.26, p=0.30r=0.30, p=0.25r=0.25, p=0.34r=0.60, p=0.012r=0.60, p=0.011
Rtot, kPa×s/Lr=−0.31, p=0.21r=0.27. p=0.30r=0.22, p=0.39r=0.55, p=0.023r=0.61, p=0.010
Diffusion capacity(n=18)(n=17)(n=17)(n=17)(n=17)
DLCO, mmol/(min×kPa)r=0.24, p=0.33r=−0.07, p=0.80r=−0.03, p=0.91r=−0.12, p=0.65r=−0.13, p=0.61
DLCO, z-scorer=0.46, p=0.056r=0.36, p=0.16r=0.35, p=0.18r=0.15, p=0.57r=0.081, p=0.76
Alveolar volume, Lr=−0.24, p=0.34r=−0.28, p=0.28r=-041, p=0.10r=−0.29, p=0.26r=−0.15, p=0.58
Alveolar volume, z-scorer=0.09, p=0.72r=0.06, p=0.82r=0.17, p=0.52r=0.13, p=0.62r=0.26, p=0.31
KCO, mmol/(min×kPa×L)r=0.60, p=0.008r=0.27, p=0.30r=0.39, p=0.12r=0.028, p=0.91r=−0.083, p=0.75
KCO, z-scorer=0.42, p=0.086r=0.28, p=0.27r=0.22, p=0.39r=0.020, p=0.94r=−0.15, p=0.58
Multiple breath washout(n=19)(n=17)(n=17)(n=17)(n=17)
LCI2.5r=−0.30, p=0.22r=−0.09, p=0.74r=−0.40, p=0.12r=0.21, p=0.43r=−0.037, p=0.89
LCI5.0r=−0.33, p=0.17r=−0.31, p=0.23r=−0.53, p=0.030r=0.022, p=0.93r=−0.15, p=0.58
Scond×VTr=−0.21, p=0.39r=−0.08, p=0.76r=0.07, p=0.79r=0.18, p=0.48r=0.26, p=0.31
Sacin×VTr=−0.09, p=0.72r=−0.53, p=0.030r=−0.54, p=0.027r=−0.25, p=0.33r=−0.25, p=0.33
  • The table shows correlations (regression coefficients and p values) by Spearman's r between CC16, IL-1β, TNF-α, IL1-β/CC16 and TNFα/CC16 in tracheal aspirate and the various lung function measurements. The actual number (n) is given for the respective test, except for FEF25–75 where data from one child are missing. P values <0.05 were considered significant and are marked as bold.

  • AX, area under the reactance curve between 5 Hz and Fres; CC16, club cell secretory protein; FEF25-75, mean forced expiratory flow between 25% and 75% ; FEV1, forced expiratory volume in 1 s; Fres, resonant frequency; FVC, forced vital capacity; IL-1β, interleukin-1β; LCI5.0 and LCI2.5, lung clearance index, defined as the number of lung volume turnovers required to reach 5% and 2.5%; Rexp, expiratory flow resistance of the airways; Rinsp, inspiratory flow resistance of the airways; R5, R20, respiratory resistance at 5 and 20 Hz, respectively; R5-R20, frequency dependence of resistance; Rtot, total flow resistance of the airways; Scond x VT, an index of ventilation inhomogeneity in conductive airways; TNFα, tumour necrosis factor-α; X5, respiratory reactance at 5 Hz.