Transmissible spongiform encephalopathies (TSE): minimizing the risk of transmission by biological/biopharmaceutical products: an industry perspective

R W Kozak, C F Golker, P Stadler
Developments in Biological Standardization 1996, 88: 257-64
Several guidelines and recommendations have been published on assessing the potential risk of a biological product being contaminated with an agent causing a Transmissible Spongiform Encephalopathy (TSE). Basic principles which can be used during the manufacturing of biological products to minimize the risk of transmission of TSE agents include the following: (i) obtaining animals, tissues or animal-derived raw materials from countries in which the relevant TSE agent is reported to be absent; (ii) screening animal-derived material for appropriate animal husbandry, feeding practices, health certification, tissue procurement and processing practices, and human-derived material for appropriate medical history information and, if relevant, plasma donor exclusion criteria; (iii) selection of tissue source of raw material with reference to potential risk for harbouring or amplifying TSE agents; (IV) human tropism of TSE agent of concern; (v) quantity of raw material used to manufacture a dose of product; (vi) number of daily doses required for indication; (vii) route of administration; (viii) indication and age of patient; and (ix) clearance capabilities by the product purification scheme. A risk evaluation will be represented for Trasylol (Aprotinin) which is manufactured from bovine lung tissue. Trasylol is a protease inhibitor used in the control of blood loss during open heart surgery. Bovine Spongiform Encephalopathy (BSE) is a concern when a product is derived from a bovine source. Even though only bovine lung tissue from BSE-free countries is used to manufacture Trasylol, it was decided, based on the primary tissue source selection, to evaluate the potential of the purification process to clear a TSE agent. Duplicate "spiking experiments" were performed using a mouse-adapted strain of scrapie as the model for BSE. Four steps in the purification process were evaluated. Titration of "spiked" loading material and output samples was performed at dilutions of 10(-4) to 10(-7) and undiluted to 10(-7), respectively. The sum of the purification steps evaluated provided a clearance factor in excess of 18 log10 for a TSE agent. An overall safety factor of 30 is obtained using the notification document issued by the Federal Health Office (Germany), dated February 16, 1994, on "Safety Requirements for Medical Products Derived from Body Constituents of Cattle, Sheep, or Goats to Avoid Risk of Transmission of BSE or Scrapie". Based on a six-parameter risk assessment, this document considered a product of low-risk for transmitting TSE agents if obtaining or exceeding a score of 20. Principles for minimizing the risk of transmission of TSE agents in products derived from primary tissues are contrasted to strategies for biotechnology products.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"