Therapeutic Plasma Exchange (TPE)

What it is

Therapeutic plasma exchange uses an apheresis machine to remove plasma and replace it with albumin (and/or fresh frozen plasma in some indications). Established medical uses include certain autoimmune neurological conditions (Guillain-Barré, myasthenia gravis), TTP, and hyperviscosity states.

The longevity hypothesis

Heterochronic parabiosis experiments — surgically joining the circulations of young and old mice — produced apparent rejuvenation of multiple tissues in the older animal. Subsequent “neutral blood exchange” experiments (Conboy lab) suggested that dilution of pro-aging factors in the older animal explained much of the effect, independent of any specific young factor.

This motivated interest in TPE as a way to dilute systemic pro-aging factors in humans.

Human evidence

• Several small pilot studies in Alzheimer’s and aging populations.
• AMBAR trial of TPE in mild-moderate Alzheimer’s reported slower cognitive decline; not yet definitive.
• Direct “young-plasma transfusion” protocols (Ambrosia) were halted by FDA warnings about marketing rejuvenation claims without evidence.

Safety

Allergic reactions, citrate toxicity, hypotension, infection risk from central-line access. Costly and requires apheresis expertise.

Related entries

Altered intercellular communication, Stem cell exhaustion, Alzheimer's disease.