Table 5– A comparison of time to decline in DL,CO in relation to technetium-99m-labelled DTPA clearance in ILD of SSc and IPF patients
DTPA clearance variableTime to decline in DL,CO
SSc-ILDIPF
HR (95% CI)p-valueHR (95% CI)p-value
Increasing rapid total clearance# min1.01 (1.00–1.02)0.071.00 (0.99–1.02)0.62
Patients with an abnormal clearance# min1.45 (0.90–2.34)0.121.52 (0.65–3.56)0.34
Increasing rapid fast clearance min1.04 (0.96–1.14)0.331.00 (0.93–1.06)0.90
Increasing %FC1.02 (1.00–1.03)0.091.00 (0.99–1.02)0.72
Increasing delayed slow clearance min1.00 (1.00–1.01)0.321.01 (1.00–1.02)0.12
  • DL,CO: diffusing capacity of the lung for carbon monoxide; DTPA: diethylene triamine pentacetate; ILD: interstitial lung disease; SSc: systemic sclerosis; IPF: idiopathic pulmonary fibrosis; HR: hazard ratio; %FC: % DTPA cleared by the fast component. #: 168 SSc-ILD patients and 97 IPF patients; : 126 SSc-ILD patients and 81 IPF patients.