04 January 2010

Prion power

I have never been allowed to donate blood in the United States. Having lived in England during the "mad cow years", I'm permanently banned from donating for fear of spreading prion disease. I've never really understood this because in order to get Creutzfeldt-Jacob disease you need to ingest contaminated brain matter (since that's where the prions are located).

A quick aside for those unfamiliar with infectious particles: there are bacteria (alive), viruses (not alive) and prions (also not alive). Bacteria are whole cells, viruses are essentially a little pod of either DNA or RNA and prions are naked proteins. These proteins are misfolded, however, and have a knack for causing normal proteins to also misfold and create aggregates in central nervous system neurons. Since prions live only in neurons, they cannot be transmitted by blood or air or droplets (coughing) like viruses and bacteria.

So basically, the US government is concerned that I am contaminated from prions but haven't shown disease yet and that somehow I will spread this via blood donation. Recent research is now showing - lucky me - that prions may actually be adaptive and develop drug resistance. This is alarming (for the obvious reasons) although currently Creutzfeldt-Jacob is a death sentence (within months) and to my knowledge we didn't think we had effective drugs.

There are several human prion diseases (no, CJD is not the only one) and all are fatal. Worse, standard sterilization procedures do not eliminate prions so it's a good thing they aren't easily transmitted. Adding drug resistance to their virulence is almost superfluous.

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