The study followed 31 patients with chronic Hepatitis C who were treated at Toronto Western Hospital from October 2001 until May 2004. Hepatitis C is a disease of the liver caused by the hepatitis C virus (HCV). About 230,000 Canadians are infected with it, and about 170 million people worldwide. Over time the viral infection leads to liver damage, cirrhosis and/or liver cancer. It is currently the leading indication for liver transplants.
Liver biopsies were performed on the 31 chronic HCV patients before treatment, and were compared to 20 biopsies from healthy, uninfected livers. 16 patients did not respond to subsequent treatment, while 15 did; both groups were well matched with respect to age, HCV viral load (number of viral particles circulating in the blood), and liver disease activity.
In order to define which genes discriminate between those patients who respond to therapy to those who do not, microarray technology, based in a Banting and Best Department of Medical Research laboratory at University of Toronto, was used to analyze the pattern of genes in all participants. This technology allows scientists to compare levels of expression for tens of thousands of genes on a glass slide ?these "gene chips" are the size of a postage stamp. The technology is able to quickly scan the expression of those genes and differentiate between genes which are "turned on" or "turned off". Comparing "genetic fingerprints" allows researchers to rapidly and effectively identify sensitive genetic changes associated with various stages of disease, and hopefully identify the most suitable candidates for specific therapies.
"We went into this experiment without any hypot
Source:University of Toronto