How Much Plasma is Required for TTP?

First, plasmapheresis is not a top up. This isn't like going to a gas station and filling up the tank. Plasmapheresis is a replacement of the plasma. For Thrombotic Thrombocytopenic Purpura (TTP), this replacement can happen many, many times. In my TTP experience, my plasma has been replaced 39, 10 and 26 times (each of my three TTP episodes). 

The amount of plasma is determined by the weight of the person. Plasma is 55 percent of the blood, so a simple factor is used to determine the amount of plasma. In my case we use 100 kg as the weight. The amount of plasma in my body is 4.2 litres. 

In plasmapheresis, I have had plasma replace at 1.0, 1.5 and 2.0 full volumes. In other words, we needed 4.2, 6.2 or 8.4 litres. So, imagine the amount of plasma required when you multiply by 39, 10 or 18. 

About how donors are required? When blood is donated, they receive about 450 ml. About half is plasma, so a little over 200 ml are received by a donor. In my case I receive solvent detergent plasma provided in 200 ml bags. So, for 1.0, 1.5 or 2.0 full volumes, I would need about the amount from 21, 31 or 42 donors. When the blood clinic RV shows up at work for donations and they get 50 donors, those donations could be all used within two or three days by one TTP patient. 

Bruce Fights TTP encourages blood donation to support all patients in their time of need. Please also note, some donors may be able to provide plasma donation. 

Thanks, Bruce.

@BruceFightsTTP