There are many people who need regular medication to survive. Some of these medicines can only be made from blood plasma. There are also many people who want to help – in Germany, more than 7,000 healthy people donate blood fluid every day. Nevertheless, the amount is not enough to meet demand. And producing plasma artificially is still not possible.
Why is blood plasma important?
Plasma is a clear, yellowish fluid – the portion of blood that remains when red and white blood cells are separated. Blood plasma is more than 90% water. Dissolved in it are smaller molecules such as sugar, vitamins, hormones, urea and uric acid, as well as – at up to 8 %, the largest proportion – more than 120 proteins with important, sometimes vital, functions. They play a role in the coagulation and immune systems in particular, but also as transport vehicles for various substances.
If these proteins are missing or are only produced to a reduced or defective extent by the body, diseases such as blood clotting disorders and immune deficiencies can result. If proteins obtained from donor plasma are not regularly supplied, this can have life-threatening consequences. But patients with major blood loss, for example after an accident or burns, also benefit from transfusions with blood plasma.
What is the procedure for a plasma donation?
About a quarter of the proteins contained in blood plasma can be used to treat disease. The blood fluid is obtained by plasmapheresis. In this process, blood is taken from a vein in the arm after skin disinfection, as in “normal” blood donation. This flows in a closed circuit into a special device that separates the solid blood components, i.e. the blood cells, from the blood plasma. The plasma – about 650 to 850 ml per “donation session” depending on body weight – is collected in a special bag; the blood cells are returned directly to the donor in a body-compatible liquid via the same cannula.
The blood in the tubing system is made non-coagulable with a special additive. The entire procedure takes about half to three quarters of an hour. Afterward, the donor is monitored for about another half hour.
How often can plasma be donated?
Advantage of plasma donation in contrast to whole blood donation is that hardly any red blood pigment is removed from the donor and that the removed components are newly formed in the body within 1 to 2 days. A new donation can be made after 2and days, but an interval of 7 days is recommended. By law, there is a maximum annual limit of 60 donations.
