Carbon nanosensor sniffs out kidney disease

The findings, reported in the May 26, 2009 issue of ACS Nano, could lead to a non-invasive and fairly inexpensive way to detect kidney diseases in their earliest - and most treatable - stages.
Such early detection could significantly delay the progression of kidney diseases to end-stage renal disease, and greatly reduce the costs associated with treating it and its resulting complications. According to the National Kidney Foundation, 26 million American adults have chronic kidney disease, and millions of others are at increased risk. Its rising incidence and the subsequent effects on healthcare could make the proposed technology a source of great savings in both private and public health sectors.
"This technology will enable diagnosis even before the disease begins to progress," said lead researcher Dr. Hossam Haick of the Technion's Faculty of Chemical Engineering and the Russell Berrie Nanotechnology Institute at the Technion. "When detected at such an early stage, kidney diseases can be dramatically slowed with medication and diet." He added 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 towards 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% 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 and Profs. Zaid Abassi and 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.
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," said Prof. Abassi.
Large-scale research is already being carried out by Prof. Nakhoul, the director of the Ambulatory Nephrology Unit at Rambam Hospital to test the technology using breath samples from kidney disease patients. The researchers have registered a patent for the modification of the electronic nose for use in kidney research.
The Technion-Israel Institute of Technology is Israel's leading science and technology university. Home to the country's winners of the Nobel Prize in science, it commands a worldwide reputation for its pioneering work in nanotechnology, computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel's high-tech companies are alumni. Based in New York City, the American Technion Society (ATS) is the leading American organization supporting higher education in Israel, with offices around the country.