Meanwhile, this paper has also just come out, which looks at whether such effects are due to factors coming in from the young animals or things being removed from the old ones. The authors, from UC-Berkeley and the California Pacific Medical Center, are looking at what they call a “neutral blood exchange”. They replace half the blood volume in mice (both young and old) with isotonic saline plus added albumin protein. The effect of this on the older animals was also significant, with noticeable improvements in wound-healing ability, neurogenesis, and fibrosis/fatty deposits in the liver. The younger mice were not really changed by the treatment. The authors tried several control experiments to make sure that this wasn’t an effect being driven by added albumin protein, and it apparently isn’t. They conclude that removal and substitution of old plasma “is sufficient for most if not all observed positive effects on muscle, brain and liver” in parabiosis-type experiments. It doesn’t exclude the idea of there being beneficial factors in young plasma, but suggests that this is not the driver of many of the results seen. (It would be very interesting to check the DNA methylation status of various tissues before and after this treatment!)
The paper wastes no time in noting that therapeutic plasma exchange (TPE) is already an FDA-approved process (as witness convalescent plasma treatment in the current coronavirus epidemic), and it says that Phase II and III human trials are being planned on the basis of these results. That will be quite interesting to watch, says the 58-year-old dude writing this blog. Overall, I still find such results hard to believe, but at the same time they seem to be showing up from multiple experiments. This second paper especially seems to be a very testable hypothesis indeed. That’s a good thing, because in the end, it’s going to be reproducible human clinical data that decide whether this is real or not – so I’m glad that feasible experiments will allow such data to be collected. Something to watch. . .
The paper wastes no time in noting that therapeutic plasma exchange (TPE) is already an FDA-approved process (as witness convalescent plasma treatment in the current coronavirus epidemic), and it says that Phase II and III human trials are being planned on the basis of these results. That will be quite interesting to watch, says the 58-year-old dude writing this blog. Overall, I still find such results hard to believe, but at the same time they seem to be showing up from multiple experiments. This second paper especially seems to be a very testable hypothesis indeed. That’s a good thing, because in the end, it’s going to be reproducible human clinical data that decide whether this is real or not – so I’m glad that feasible experiments will allow such data to be collected. Something to watch. . .
https://blogs.sciencemag.org/pipeline/archives/2020/06/12/yo...