LONDON -- Microsens, a specialist in the rapid and sensitive detection of Transmissible Spongiform Encephalopathies (TSEs), presented evidence at the NeuroPrion Conference in Paris last month that the company's technology can detect CJD in human blood. Stuart Wilson, chief scientific officer of Microsens, described the company's technology which has demonstrated the ability to detect abnormal prion proteins in the blood of a patient with suspected Creutzfeldt-Jakob disease (CJD). This is the first time such detection has been announced.
"With the recent publication of evidence showing vCJD present in human tissue samples and the ban of certain blood donors to avoid the risk of vCJD transmission, there is an obvious need to accelerate the development of a vCJD screening process in blood," Wilson said. "We believe our Seprion technology is leading the way in the race to find a sensitive, easy to use blood test for both animals and man. However, more resources and development are required before a blood test is a reality."
Microsens has developed a ligand-based technology, called Seprion, into a simple immunoassay. This technology is very selective towards recognising and binding tightly abnormal TSE proteins. Through extensive trialling, it has been demonstrated to have an extremely high selectivity capability, ideal for detecting abnormal TSE proteins which occur at very low concentrations in the blood.
Microsens used its Seprion technology to compare blood samples from a human patient with symptoms associated with CJD to control samples. At the same time, the company also tested and compared blood samples from scrapie-infected sheep to controls. In all cases, the Seprion technology detected the abnormal TSE proteins linked with disease. This is the first time a blood test has successfully demonstrated the detection of these abnormal prion proteins in both humans and animals. The company is currently expanding its studies to include more samples.
The Seprion-based assay has 100 percent sensitivity and specificity compared to current gold standards (1) in post-mortem testing and has received U.S. Department of Agriculture (FDA) approval for use in Bovine Spongiform Encephalopathy (BSE) in cattle and Chronic Wasting Disease in deer. Seprion has already been licensed by Microsens to Idexx Laboratories, Inc. in the U.S. for incorporation into a post-mortem BSE test and to Sanko Junyaku in Japan. A natural extension of the product is for the screening of human blood for vCJD. As a model for the detection of vCJD, the company has data demonstrating the detection of prions in both symptomatic and pre-symptomatic sheep.
At present, the market, primarily in Europe and Japan, for post mortem BSE test kits for cattle exceeds $125 million; the company believes that this market will grow significantly within the next three to five years. In North America, there is increasing concern over BSE, with the first detected case in 2003 which has already caused the level of testing by the U.S. and Canadian governments to rise.
1. Lane, A; Stanley, C; Dealler, S; Wilson, S.M. 2003. Clin. Chem., 49, 1774-1775.