Our laboratory recently had to handle samples from a patient suspected of
having CJD. The recommendations from the World Health Organization (WHO)
are to handle blood samples using universal precautions, just the same as
samples from any other patient. However, the WHO classifies cerebrospinal
fluid (CSF) as a fluid of low infectivity and therefore requiring more
stringent handling. The recommendations go on to say that analysis of CSF
should not be performed in automated equipment. Materials, presumably
including automated equipment pipets, etc., coming in contact with the CSF
"must either be incinerated or decontaminated by..." autoclaving at 134 °C
for 18 minutes, immersion in 1 N NaOH for 1 hour at room temperature, or
immersion in 0.5% sodium hypochlorite for 2 hours at room temperature.
Clearly, these decontamination procedures would be either extremely
difficult or impossible to complete on most automated analyzers. The two
most commonly requested biochemical tests for CSF are glucose and protein.
If, and it is a big if, the samples could be labeled as having come from a
patient suspected of having CJD, then automated analysis could be avoided.
Has anyone addressed this issue? I suspect that our colleagues in the UK
may have some ideas to offer as a result of the mad cow scare in the recent
past. How have specimens, or patients, been identified? How have you
handled the specimens? Have you notified any referral laboratories of the
possible infectivity of CSF specimens sent for analysis? Have you developed
manual methods for measuring glucose and protein for CJD CSF specimens? I
don't know if i-Stat glucose cartridges have been approved for CSF use, but
they should work. However, I don't know of any POC test for quantitative
protein analysis at CSF levels of concentration.
Can anyone offer me any advice?
Thanks.
Robert C. Elser, Ph.D.
Technical Director of Clinical Chemistry and Immunochemistry
York Hospital Department of Laboratory Services
[log in to unmask]
Phone: 717-851-2549
Fax: 717-851-2707
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