Preliminary findings may set the stage for development of a breath test to identify patients with renal failure, according to Israeli investigators.
A team at the Technion-Israel Institute of Technology in Haifa developed a gas-analyzing system consisting of a network of single-walled carbon nanotubes coated with organic materials.
They first tested the system on air taken from the tracheas of healthy rats and rats whose kidneys had been removed. The system identified 15 volatile organic compounds common to both healthy and nephrectomized and healthy rats and 27 that were unique to the nephrectomized rats.
The researchers, led by Hossam Haick, PhD, an assistant professor in the institute’s Faculty of Chemical Engineering, then created simulated breath from healthy and nephrectomized rats.
Four compounds present in the highest concentration in the breath of the nephrectomized rats—phenol, 2-ethyl hexanol, acetic acid, and undecane—in addition to water were used to create the simulated breath from these rats. The simulated breath from healthy rats contained lower concentrations of phenol and 3-ethyl hexane in addition to water, carbon dioxide, carbon monoxide, and oxygen.
The gas-analyzing system discriminated between the healthy and unhealthy simulated breath with 100% success, the researchers reported in ACS Nano (2009; published online ahead of print). Dr. Haick said his team is now perfecting the system by developing more specific and sensitive sensors.
“We are currently in the middle of a clinical study being conducted at the Rambam Medical Center, where we are testing the reliability and validity of our ‘electronic nose’ in patients with chronic renal disease at various stages,” Dr. Haick said. “We will conclude the first phase of this study and analyze the data within the next few months.”