Plasma
What is plasma?
Plasma is the largest single component of blood, and makes up about 55% of total blood volume. It is a clear, straw-coloured liquid, which carries platelets, red and white blood cells.
It contains over 700 proteins and other substances. Once separated from blood cells, plasma can be used in transfusions.
Donating plasma for coronavirus trials
We are collecting COVID-19 convalescent plasma from people who have recovered from this illness for use in COVID-19 clinical trials.
The trials will investigate whether convalescent plasma transfusions could improve a COVID-19 patient’s speed of recovery and chances of survival.
If you have had a positive test result for coronavirus or the symptoms, you may be able to help by donating plasma at one of our main donor centres.
Find out who we’re looking for and how to register your interest in taking part.
Collecting plasma from blood and platelet donors
There are two ways we normally collect plasma:
- by separating it out from regular blood donations
- from our male A and AB type platelet donors, while they’re donating platelets
Plasma from female donors is not currently used (except for in coronavirus trials) because it is more likely to contain antibodies that could cause a serious reaction when given to a patient.
Some people do not develop antibodies while others do. It is not clearly understood why this happens, but antibodies are more likely to develop after pregnancy.
For this reason, it is safest for patients if we only produce plasma products from male donors.
How plasma is used to save lives
Donated plasma is frozen to preserve its quality and function. This component is known as fresh frozen plasma, or FFP.
FFP can be issued to hospitals or further processed into a more concentrated component that is rich in certain clotting factors called cryoprecipitate.
Plasma transfusions can help the blood to clot and also replace dangerous substances in the patient’s own plasma.
FFP and cryoprecipitate can be used to help many types of patients – for example people with massive blood loss, liver failure, or rare diseases.
Keri Anglin (pictured) received 22 units of blood, 16 units of fresh frozen plasma, two units of cryoprecipitate and two units of platelets, after a massive bleed while giving birth.
Plasma for immunoglobulins
Plasma can also be used for medicines called immunoglobulins. We do not work with these products.
