por Lynn Shapiro
, Writer | August 11, 2009
A carbon nanosensor "electronic nose", first developed by Technion-Israel Institute of Technology enabling researchers to detect cancer from breath samples, has been modified to identify chronic renal failure (CRF).
The findings, reported in ACS Nano, could lead to a non-invasive and fairly inexpensive way to detect kidney diseases in their earliest and most treatable stages.
This technology will enable diagnosis even before the disease begins to progress," Dr. Hossam Haick and Prof. Zaid Abassi told DOTmed News in an email interview from Israel.
"When detected at an early stage, kidney diseases can be dramatically slowed with medication and diet," the scientists say. They add that even in cases where chronic renal failure is discovered in its advanced stages, appropriate medication can slow its progress and spare the patient's deterioration toward end-stage renal disease, and the need for dialysis.
Current methods for testing for kidney diseases can be inaccurate and invasive. According to the researchers, blood and urine tests now used to diagnose CRF can come out "normal" even when patients have already lost 65-75 percent of their kidney function. The most reliable test, a kidney biopsy, may result in infections and bleeding.
So far, the researchers have tested the "electronic nose" on the exhaled breath of laboratory rats with no kidney function and normal kidney function. The device identified 27 volatile organic compounds that appear only in the breath of rats with no kidney function. Of these, the team identified the five most important compounds that signal the development of kidney disease.
The idea to use the electronic nose to test for kidney diseases came about during a conversation between Dr. Haick, Prof. Abassi and Prof. Farid Nakhoul of the Technion Faculty of Medicine and Rambam Medical Center, who were aware that one characteristic of patients with diseased kidneys is an ammonia-like odor in the breath," Dr. Haick and Prof. Abassi tells DOTmed.
They say the team's next challenge is to distinguish between the various types of kidney disease and identify their stages.
"Developing sensors that are sensitive enough to differentiate between the various stages of different kidney diseases will enable not just the diagnosis, but also the ability to monitor with great accuracy a patient's response to medication and lifestyle changes," the scientists say.
Dr. Haick and Prof. Abassi say they are now in the midst of a clinical study in Rambam Medical Center in Israel, where they are testing the reliability of Dr. Haick's electronic nose in patients with chronic renal disease at various stages of disease, including very early stage disease, which requires highly sensitive sensors.