Correlation of pulmonary function tests with SP-D and KL-6.
| Kendall Tau b Correlation Coefficients | |||
|---|---|---|---|
| KL-6 | SP-D | ||
| All SSc “alveolitis” + non-alveolitis | FVC, n = 61 | −0.17 | −0.15 |
| p = 0.0602 | p = 0.0782 | ||
| DLCO, n = 60 | −0.29 | −0.21 | |
| p = 0.0012 | p = 0.0198 | ||
| SSc with “alveolitis” | FVC, n = 44 | −0.03 | −0.03 |
| p = 0.7462 | p = 0.7926 | ||
| DLCO, n = 44 | −0.25 | −0.13 | |
| p = 0.0188 | p = 0.2321 | ||
| SSc without “alveolitis” | FVC, n = 17 | −0.22 | −0.31 |
| p = 0.2165 | p = 0.0836 | ||
| DLCO, n = 16 | −0.27 | −0.34 | |
| p = 0.1488 | p = 0.0711 | ||
SP-D: surfactant protein D; SSc: systemic sclerosis; FVC: forced vital capacity; DLCO: diffusing capacity of carbon monoxide.