Dear Steve & Harold,
I agree with all of your comments and logic and that plasma exchange seems the way forward. Just playing “Devil’s Advocate” to try to hear all positives and negatives.
On Saturday, March 14, 2015, steve hill wrote:
Far better to test the theory using HPE then work out factors at later once proof of concept is made IMO, there are plenty of people doing that already including big pharma but that does not hold back the ground work using full plasma now. Blood contains potentially hundreds of factors as Harold says including good things like GDF-11, Oxytocin, Klotho, FOXN1 plus bad things like pro-inflammatory cytokines.
The key with Harold’s proposal is we do not need to know all the factors in order to test the theory and it is something that we can do right now with very little lead time. Plasma is safe and approved medically so we could begin testing right now, we don’t need to wait decades.
From: Dr. Harold Katcher To: Gerontology Research Group Sent: Friday, 13 March 2015, 17:45Subject: Re: [GRG] Plasma Factors and aging
I agree that in principle you could filter out the ‘bad’ elements and add the ‘good’ ones, in reality we don’t know either the bad ones (except perhaps CCL11 and some pro-inflammatory cytokines) or the good ones (apart from GDF-11 and oxytocin). There may be molecules such as miRNAs contained in exosomes that are vital for age-determination – and yet others that we have no idea about.
I would check my math however – while the formula you use for the replacement of plasma is correct the number you get is wrong. About 1.5 plasma volumes would get you down to around 20% old plasma remaining after a single exchange. One and a half plasma volumes is fairly normal for a plasma exchange. So after two exchanges you are left with ~ 4% old plasma remaining. And that’s not a lot. Imagine that we knew all the factors needed to be changed- my guess is there would be hundreds and the costs would be tremendous.- you’d sill need plasmapheresis to accomplish that – so aside from allergic reactions what would be the advantage – I can easily see the disadvantages? And plasma is used under life-threatening conditions on the battlefield to save lives – without overmuch worry about allergic reactions.