Blood Transfusion May Transmit Variant CJD

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http://www.medscape.com/viewarticle/468432

 

Blood Transfusion May Transmit Variant CJD

 

Laurie Barclay, MD

Medscape Medical News 2004. © 2004 Medscape

 

 

 

 

 

Feb. 5, 2004 — Blood transfusion may be a mode of transmitting variant

Creutzfeldt-Jakob disease (vCJD), according to a case report and public health

study and an animal study published in the Feb. 7 issue of The Lancet.

 

On Dec. 17, 2003, the U.K. announced the death from vCJD of an individual who

had previously received a red cell transfusion from a donor who subsequently

developed vCJD. Symptoms of vCJD developed in the recipient 6.5 years after the

transfusion, and in the donor 3.5 years after the transfusion.

 

Using the national blood-donor database and the U.K. CJD register, a team from

the National CJD Surveillance Unit of Western General Hospital in Edinburgh,

U.K., identified 48 individuals, including the subject of the case report, who

received a blood component from 15 donors who later developed vCJD.

 

" Our findings raise the possibility that this infection was transfusion

transmitted, " senior author Robert G. Will says in a news release. " Infection in

the recipient could have been due to past dietary exposure to the BSE [bovine

spongiform encephalopathy] agent. However, the age of the patient was well

beyond that of most vCJD cases, and the chance of observing a case of vCJD in a

recipient in the absence of transfusion-transmitted infection is about 1 in

15,000 to 1 in 30,000. "

 

The clinical presentation and preliminary examination of neuropathology of this

patient were typical of vCJD. Although magnetic resonance imaging did not show

the classical pulvinar sign seen in most cases of vCJD, fluid attenuated

inversion recovery sequences with the highest sensitivity were not obtained. The

red blood cells transfused in this patient were not leucodepleted, but the

authors note that the efficiency of leucodepletion in reducing infectivity is

uncertain.

 

The surviving recipients of blood transfusions from donors who later developed

vCJD are being informed of their possible increased risk of developing vCJD and

warned not to donate organs or blood.

 

" To date, no case of vCJD has been identified with a history of exposure to

fractionated blood products, " the authors write. " The most direct action to

reduce risk is a careful case-by-case evaluation of the need for blood

transfusion. "

 

The National Blood Service supported this study.

 

In an animal study in the same issue of The Lancet, Corinne Lasmézas and

colleagues, from the French Atomic Energy Commission, compared the degree of

tissue infectivity among macaques with oral or intravenous exposure to tissue

containing the BSE agent.

 

Using the misfolded prion protein as a marker, they found that the degree of

organ infectivity was similar regardless of the route of entry, and that tonsil

tissue was the most strongly infected. In addition to expected concentrations of

prion protein in the brain and spinal cord, it was also present in the autonomic

nervous system, in peripheral nerves, and in Peyer's patches in the gut,

suggesting possible risk of transmission from endoscopic procedures.

 

" In view of the high efficiency of transmission of the BSE agent to primates by

the intravenous route, the latter should be regarded as a likely route of

contamination for vCJD patients with a medical history involving a transfusion

during the period at risk, " the authors write. " To avoid further contamination

to human beings from peripheral tissues, the same precautionary measures taken

for primary vCJD cases should apply to possible transfusion cases of the

disease. "

 

In an accompanying commentary, Adriano Aguzzi and Markus Glatzel, from the

University Hospital of Zurich in Switzerland, note that transmission of vCJD via

blood transfusion is shocking but not surprising. Sheep models support possible

transmission of prion diseases via blood, even if blood is collected before

symptoms appear. By December 2003, 153 cases of vCJD had been reported

worldwide.

 

" The probable existence of subclinical vCJD carriers raises concerns of an

iatrogenic human-to-human wave of vCJD transmission, " they write. " Public-health

authorities are faced with considerable insecurity about the prevalence of

subclinical prion carriers, and any human-to-human transmission will complicate

estimation of the size of the vCJD epidemic. Although cross-sectional studies to

assess the prevalence of prion carriers pose organisational and ethical

problems, there is no alternative for assessing the future of the vCJD

epidemic. "

 

The authors of both studies and of the commentary report no financial conflicts

of interest.

 

Lancet. 2004;363:411-412, 417-421, 422-428

 

Reviewed by Gary D. Vogin, MD

 

 

 

 

 

 

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