I used to donate plasma (plasmapheresis) when I was a student and I had no health problems.
In the wikipedia entry for plasmapheresis (
Plasmapheresis - Wikipedia, the free encyclopedia) there is a sentence “Other complications include: -Potential exposure to blood products, with risk of transfusion reactions or transfusion transmitted diseases -Suppression of the patient's immune system ". While there are risks with the procedure (see the “Complications of plasmapharesis therapy paragraph”) the “other complications” sentence appears to be related to the risk that you get someone else’s blood back instead of yours (this would be a major screw up).
Plasma contains antibodies so I guess one could argue that removing antibodies could affect (suppress / deteriorate) your immune system, but given that your losing only ~10% of your blood protein that is an unreasonable argument.
I looked (
Google Scholar) to see what else I could find about the risks. In summary, the conventional wisdom would be that the risks of plasmapheresis are very low (& not related to any effect on your immune system.)
Don’t forget that plasmapheresis is used as a treatment for some diseases & there is a medical need for plasma to treat (for example) trauma patients.