sailor girlAnswers to Common Questions About

Creutzfeldt-Jakob Disease (CJD)
By Bayer

What is CJD?

 Creutzfeldt-Jakob disease is a rare neurological disorder. The symptoms of CJD include severe dementia (mental deterioration), incoordination, and muscle twitching or jerking. The appearance of the disease may be delayed for years. Once symptoms appear, the disease progresses rapidly and is uniformly fatal. Approximately 90% of CJD cases appear spontaneously throughout the world at a current estimated frequency of one per one million people. The remaining 10% of CJD cases occur in families whose members carry an abnormal gene for a cell protein or in persons who acquire CJD through medical procedures or treatments. Creutzfeldt-Jakob disease is not transmitted by air, casual contact, or sexual activity.


What causes CJD?

 The agent which causes CJD has not been clearly identified. Most experts believe it is not a virus. The leading theory is that a prion, an abnormal protein not associated with genetic material, damages brain tissue and leads to CJD.


If CJD can take years to develop, how can I be sure that I will never develop CJD?

 The longest recorded times to onset of CJD (up to 30 years) occurred in people who contracted CJD after receiving human growth hormone derived from pituitary glands. However, CJD was first identified in 1921. In the subsequent 75 years, there have been no proven cases of CJD transmission via plasma or plasma-derived pharmaceutical products.


Is CJD increasing?

 No. The Centers for Disease Control state the number of new cases of CJD occurring each hear has remained stable from 1979 through 1994 at one per one million. Approximately 10 million people donate plasma in the US each year. This means that each year, approximately 10 donors are at risk for developing CJD. Increased awareness of CJD has caused plasma collection centers to increase their screening for CJD risk factors before accepting donors. In addition, because donors are more educated, they are now better able to volunteer information about family members who had CJD.


Why arenít these individuals identified before the product is released?

 Since little is known about the agent that caused CJD and how CJD develops, there is currently no test that can detect the CJD agent in blood, tissue, or drug product. Therefore, screening for CJD in plasma or prior to the release of a plasma-derived product is presently not possible. As mentioned previously, individuals without risk factors who develop CJD following plasma donation or whose risk factors for developing CJD were not identified during pre-donation screening can only be identified by ongoing surveillance of repeat donors by the plasma collection centers. By the time these individuals are identified, the lots of medication which contain their plasma have usually already been in distribution. If plasma-derived medications were held for a longer period of time prior to their release in order to increase the chances of detecting and individual who meets the FDA criteria for withdrawal, the supply of these medications would be compromised.


Is "Mad Cow Disease" the same as CJD?

 The so-called "mad cow disease" is in the same family of diseases as CJD. The cases of CJD allegedly associated with eating beef are a "variant" form of CJD with different characteristics than "classical" CJD. Recent biochemical research has strengthened the possibility that "mad cow disease" is related to "variant" CJD. However, further research must be done to prove a cause and effect relationship. The implication is this information on the possibility of plasma transmission of CJD is unclear.


NOTE: Bayer has prepared this document to facilitate discussions regarding CJD. Bayer feels that the initial discussion regarding CJD should always occur between the consumer and his/her caregiver. These answers to common questions about CJD are intended to increase the publicís understanding of CJD.


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