Canadian researchers identify key immune factors associated with SARS

Montreal, QC – April 29, 2004 – A group of scientists at the Canadian Network for Vaccines and Immunotherapeutics (Canvac) say they have identified key immune factors associated with the early stages of SARS (Severe Acute Respiratory Syndrome). Results of this study, carried out by Canvac scientists and their colleagues, were announced today at the World Vaccine Congress held in Montreal.

Early detection of SARS-infected patients is currently based on symptoms such as high fever, a persistent cough and contact with SARS-infected individuals. Several of these symptoms are also present during the early stages of other illnesses, leading scientists to look for more accurate ways of rapidly identifying SARS-infected patients. A group of scientists, led by Dr David Kelvin of University Health Network at Toronto General Hospital, examined the blood from SARS patients from the 2003 outbreak for the presence of key immune molecules. They found that one immune molecule, known as IP-10, was very high in the blood of all SARS patients at the beginning of their illness. During the early stages of SARS, such high levels of IP-10, a key immune factor, suggest that the body is beginning to fight the battle against SARS.

Moreover, as patients recover from SARS, the amount of IP-10 in the blood drops. However, in the patients who have a very bad case of SARS, IP-10 levels remain high. Sadly, in patients who die, the levels always remain high. Because of these continued levels of IP-10, Dr Kelvin and his team think that the immune system is not working properly in patients who cannot overcome SARS.

“This study was a success because the entire clinical community in Toronto worked as a team in getting us the blood samples we needed to do our work,” said Dr Kelvin. The Canadian SARS Research Network was organized by Dr Mark Loeb of McMaster University during the SARS crisis to get blood and other valuable specimens from SARS patients to immunologists such as Dr Kelvin and his group. Support for this study came from grants from Canvac and the Canadian Institutes for Health Research and from a special investment as part of large-scale project from Genome Canada, in partnership with Genome Quebec and the Ontario Genomics Institute.

“Canvac is a reactive network of scientists who can rapidly respond to new diseases that threaten Canadians,” said Dr Rafick-Pierre Skaly, Canvac’s scientific director and program leader. He added that:” The study of immune responses in SARS-infected patients is likely to pave the way to the discovery of a SARS vaccine.”