human and pigto nvCJD

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EDINBURGH, Scotland, April 20 - Eight cases of Creutzfeldt-Jakob disease (CJD)

caused

by transplanted brain tissue over the past 33 years have been identified in

Britain

-- including what may be the first ever case associated with tissue from a pig.

 

 

Seven transplants of human dura mater resulted in iatrogenic CJD between four

and

15 years after surgery, according to a research team led by Richard Knight,

M.D.,

director of the national CJD Surveillance Unit here.

 

 

Six of the seven transplants involved Lyodura, a product manufactured by the

German

firm B. Braun Melsungen AG, and withdrawn from the market in 1996 after it was

linked

to more than 100 cases of iatrogenic CJD, most of them in Japan. The origin of

the

tissue in the other human tissue case was not known, Dr. Knight and colleagues

reported

online in the Journal of Neurology Neurosurgery and Psychiatry.

 

 

In the eighth case, Dr. Knight and colleagues found, a person undergoing surgery

for a right frontoparietal meningioma in 1988 was given a transplant of porcine

dura. Eleven years later, the recipient presented with headaches, ataxia and

cognitive

decline.

 

 

Investigative features were consistent with sporadic CJD, the researchers said,

and autopsy showed spongiform changes in the frontal and temporal cortex, with

similar

features identified in the basal ganglia, thalamus and cerebellum. The prion

protein

(PrP) was what's called the type 1 isoform, typical of sporadic CJD.

 

 

However, the transplant may not be responsible, the researchers said. The

patient's

age at onset, duration of illness, clinical, and investigative features were

similar

to sporadic CJD, as were the pathological features seen at autopsy.

 

 

It's not possible to exclude transmission of a pathogen, the researchers said,

but

so far no natural transmissible spongiform encephalopathies have been seen in

pigs.

" A chance association seems the most plausible explanation " of the case,

Dr. Knight and colleagues concluded.

 

 

In the cases associated with human dura mater, the latent period between surgery

and onset of CJD ranged from 45-177 (mean 93) months. Autopsy was performed in

five

of the seven cases, the researchers said, and " in general, the neuropathology

was characterized by widespread spongiform change accompanied by variable

neuronal

loss and gliosis. "

 

 

In three cases, the PrP was analyzed; the isoform was type 1. Type 1 differs

from

type 2B, which is found in variant CJD -- the so-called 'mad-cow disease' that

arises

from eating beef from animals with bovine spongiform encephalopathy.

 

 

Although the transplant in the first identified case occurred in 1969, most were

between 1983 and 1987 -- the same period when about 80% of all such cases

occurred

world-wide, Dr. Knight and colleagues reported. (The porcine case occurred in

1988.)

 

 

It was not known whether any of the eight cases in this report originated with

variant

CJD, the so-called mad cow disease.

 

 

All told, 164 cases of CJD associated with human dura mater transplants have

been

reported world-wide, the researchers said.

 

http://www.medpagetoday.com/Neurology/GeneralNeurology/tb/3133

 

 

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