The Diagnostic Value of the Interstitial Biomarkers KL-6 and SP-D for the Degree of Fibrosis in Combined Pulmonary Fibrosis and Emphysema

Table 4

Correlation of pulmonary function tests with KL-6 and SP-D.

	Spearman rank correlation coefficient
	KL-6	SP-D	KL-6xSP-D
%VC	−0.34	−0.33	−0.43
	𝑃=0.028	𝑃=0.03	𝑃=0.005
FEV1.0/FVC (%)	0.21	0.34	0.40
	𝑃=0.17	𝑃=0.03	𝑃=0.01
%FRC	−0.40	−0.16	−0.41
	𝑃=0.03	𝑃=0.36	𝑃=0.01
%RV	−0.56	−0.09	−0.48
	𝑃=0.001	𝑃=0.58	𝑃=0.004
%TLC	−0.53	−0.29	−0.60
	𝑃=0.002	𝑃=0.09	𝑃=0.0004
%RV/TLC	−0.36	−0.04	−0.32
	𝑃=0.03	𝑃=0.83	𝑃=0.06
%DLco	−0.33	−0.09	−0.32
	𝑃=0.036	𝑃=0.57	𝑃=0.046

KL-6xSP-D: the combined product of KL-6 and SP-D.