RESEARCH: Eyes of Creutzfeldt-Jakob disease( CJD) patients show evidence of prions.

RESEARCH: Eyes of Creutzfeldt-Jakob disease patients show evidence of prions. Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, fatal brain disorder. It affects about one person in every one million per year worldwide; in the United States there are about 350 cases per year. CJD belongs to a family of human and animal diseases known as the transmissible spongiform encephalopathies (TSEs) or prion diseases. A prion—derived from “protein” and “infectious”—causes CJD in people and TSEs in animals. Spongiform refers to the characteristic appearance of infected brains, which become filled with holes until they resemble sponges when examined under a microscope. CJD is the most common of the known human TSEs. CJD usually appears in later life and runs a rapid course. The typical onset of symptoms occurs at about age 60, and about 70 percent of individuals die within one year. In the early stages of the disease, people may have failing memory, behavioral changes, lack of coordination, and visual disturbances. As the illness progresses, mental deterioration becomes pronounced and involuntary movements, blindness, weakness of extremities, and coma may occur. There are three major categories of CJD. 1)In sporadic (sCJD), the disease appears even though the person has no known risk factors for the disease. This is by far the most common type of CJD and accounts for at least 85 percent of cases. 2)In hereditary CJD, the person may have a family history of the disease and test positive for a genetic mutation associated with CJD. About 10 to 15 percent of cases of CJD in the United States are hereditary. 3) in acquired CJD, the disease is transmitted by exposure to brain or nervous system tissue, usually through certain medical procedures. There is no evidence that CJD is contagious through casual contact with someone who has CJD. Since CJD was first described in 1920, fewer than one percent of cases have been acquired CJD. A type of CJD called variant CJD (or vCJD) can be acquired by eating meat from cattle affected by a disease similar to CJD called bovine spongiform encephalopathy (BSE) or, commonly, “mad cow” disease. A new study, researchers at University of California San Diego School of Medicine with colleagues at the National Institutes of Health and UC San Francisco, report finding tell-tale evidence of the condition's infectious agent in the eyes of deceased sCJD patients, making the eye a potential source for both early CJD detection and prevention of disease transmission. In the November 20 issue of the journal mBio, co-corresponding author Christina J. Sigurdson, DVM, PhD, professor of pathology at UC San Diego and UC Davis, and colleagues discovered high levels of prions in the eyes of 11 deceased patients, all with confirmed sCJD. Almost half of sCJD patients develop visual disturbances, and its a known fact that the disease can be unknowingly transmitted through corneal graft transplantation.