Quantitative imaging of airway liquid absorption in cystic fibrosis

Eur Respir J. 2014 Sep;44(3):675-84. doi: 10.1183/09031936.00220513. Epub 2014 Apr 17.

Abstract

New measures are needed to rapidly assess emerging treatments for cystic fibrosis (CF) lung disease. Using an imaging approach, we evaluated the absorptive clearance of the radiolabeled small molecule probe diethylene triamine penta-acetic acid (DTPA) as an in vivo indicator of changes in airway liquid absorption. DTPA absorption and mucociliary clearance rates were measured in 21 patients with CF (12 adults and nine children) and nine adult controls using nuclear imaging. The effect of hypertonic saline on DTPA absorption was also studied. In addition, in vitro studies were conducted to identify the determinants of transepithelial DTPA absorption. CF patients had significantly increased rates of DTPA absorption compared with control subjects but had similar mucociliary clearance rates. Treatment with hypertonic saline resulted in a decrease in DTPA absorption and an increase in mucociliary clearance in 11 out of 11 adult CF patients compared with treatment with isotonic saline. In vitro studies revealed that ∼ 50% of DTPA absorption can be attributed to transepithelial fluid transport. Apically applied mucus impedes liquid and DTPA absorption. However, mucus effects become negligible in the presence of an osmotic stimulus. Functional imaging of DTPA absorption provides a quantifiable marker of immediate response to treatments that promote airway surface liquid hydration.

Trial registration: ClinicalTrials.gov NCT01223183 NCT01486199.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aerosols
  • Case-Control Studies
  • Cells, Cultured
  • Child
  • Cystic Fibrosis / diagnostic imaging*
  • Cystic Fibrosis / physiopathology
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Middle Aged
  • Mutation
  • Osmosis
  • Pentetic Acid / chemistry
  • Radionuclide Imaging
  • Radiopharmaceuticals
  • Spirometry
  • Technetium Tc 99m Sulfur Colloid / chemistry
  • Treatment Outcome
  • Young Adult

Substances

  • Aerosols
  • Radiopharmaceuticals
  • Technetium Tc 99m Sulfur Colloid
  • Pentetic Acid

Associated data

  • ClinicalTrials.gov/NCT01223183
  • ClinicalTrials.gov/NCT01486199