July 13, 2006

 

US team to develop blood test for prion diseases

 

 

The difficulty in detecting prion diseases such as mad cow disease and chronic wasting disease (CWD) lies in obtaining infected but live brain tissue samples for studies, a challenge which has so far impeded surveillance programmes.

 

Now, a team of South Dakota State University researchers are exploring the possibility of developing a test for detecting the disease in live animals.

 

The university's Center for Infectious Disease Research and Vaccinology (CIDRV) is working on a live animal test for CWD.

 

Alan Young, associate professor of veterinary science and a CIDRV faculty member, is lead investigator for SDSU in a partnership between CIDRV and Rural Technologies Inc. (RTI), a South Dakota-based contract-research company.

 

Although CWD mainly affects elk, deer and moose, like mad cow disease, it is caused by abnormal prion proteins.

 

Since the test is based on the presence of these proteins, it holds promise for detecting mad cow disease as well.

 

Young's preliminary research suggests it is possible to perform a test on a blood sample from a living animal.

 

The popular view is that CWD and mad cow disease are neurological diseases that affect the brain and neurological tissues.

 

Since it is hard to get live neuronal cells for diagnosis, all existing licensed tests for these diseases are post-mortems.

 

However, infectious prions are found in other places as well. One of them being lymphoid tissue, such as lymph nodes or tonsils. They are also found in immune cells in the blood.

 

The team basically hopes to develop a blood test to detect the presence of the infectious prion in the blood, Young said.

 

Preliminary tests indicate low levels of the infectious prion molecules can be detected, Young said.

 

A commercial test should be available within the next few years, Christopher Mateo, RTI manager of operations, said.