I recently heard that donating plasma will almost deteriorate your immune system, is that true? Also biomats around the us are letting people donate no more than two times a week , is this harmful to our bodies?
Thank you kristie:)

No it does not hurt your immune syste. The two times a week sounds very wrong,


American Red Cross
GENERAL GUIDELINES
To give blood for transfusion to another person, you must be healthy, be at least 17 years old or 16 years old if allowed by state law, weigh at least 110 pounds, and not have donated blood in the last 8 weeks (56 days) or a donation of double red cells in the last 16 weeks (111 days). "Healthy" means that you feel well and can perform normal activities. If you have a chronic condition such as diabetes or high blood pressure, "healthy" also means that you are being treated and the condition is under control.

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.

You can donate PLASMA twice a week since they return your red blood cells. You can only donate WHOLE blood once every 8 weeks.

I have been donating plasma for several moths and in a period of two weeks had 3 infections bronchitis and sinusitis, I have never been this sickly before in my life and when I asked others about it, turns out they also experienced very weakened immune systems. I still donate maybe 2 times a moth as opposed to three and take more vitamins. Haven't had anymore trouble as yet except I still have not been able to shake this ear infection I have had for a couple of weeks now :/ hope this was informative I guess it also depends on how quickly your individual body builds plasma back up.