Can CJD be transmitted through the blood supply?

• Published in: Canadian Medical Association journal (CMAJ) 1998-03, Vol.158 (6), p.714; author reply 715-714; author reply 717
• Main Author: Giulivi, A
• Format: Article
• Language: English
• Subjects: Blood Banks; Blood donation & transfusion; Blood Transfusion; Canada; Creutzfeld-Jakob disease; Creutzfeldt-Jakob Syndrome - prevention & control; Creutzfeldt-Jakob Syndrome - transmission; Humans; Letters; Risk Factors
• ISSN: 0820-3946; 1488-2329

There has been conjecture based on tentative evidence that a staining procedure for tonsillar tissues may demonstrate vCJD, as well as a report from Switzerland that the receptor for vCJD may occur on B cells. In addition, studies from the National Institutes of Health have shown that only under certain controlled conditions can the vCJD prion occur in the blood of mice and furthermore that the prion can be transmitted and cause CJD only if the blood is injected into the brain of the mouse; transmission does not occur through the blood-brain barrier. The inaccurate statement in the editorial is disturbing to physicians charged with counselling patients who may have received blood components from donors in whom CJD was subsequently diagnosed. It also stands in stark contrast to the article "Is Creutzfeldt-Jakob disease transmitted in blood? Is the absence of evidence of risk evidence of the absence of risk?" (CMAJ 1997;157[10]:1367-70), by Dr. Maura N. Ricketts, who concludes, "Evidence indicates that the risk of transmission of CJD through blood and blood products is not simply rare or even exceedingly rare. It is theoretical." Although I am unaware of any direct evidence that new variant CJD "can be spread through the blood supply," there is nevertheless increasing concern over our complete lack of knowledge on this point. It is now generally accepted among investigators in this field that the strain of transmissible spongiform encephalopathy (TSE) responsible for the bovine spongiform encephalopathy (BSE) epidemic in the UK and the strain causing vCJD are identical and distinct from all other TSE strains characterized to date. Moreover, several factors have aroused concern that vCJD may lie outside the spectrum of even our limited knowledge of classic CJD and scrapie: the apparent ease with which BSE is transmitted orally, the readiness with which it has jumped species barriers (first to cattle from whatever species it originated in and then to domestic and wild cats, antelopes and finally humans), its unique clinical and histopathological presentation in humans, and recent reports that the protease-resistant protein amyloid (PrP[Symbol Not Transcribed]) is recoverable from the highly hematogenous tonsillar tissue of patients with vCJD but not those with classic CJD. Is the tonsillar PrP[Symbol Not Transcribed] transported there from the blood stream? Is there some essential hematogenous involvement in the pathogenesis that facilitates oral transmission