What are Platelets
Blood is composed of a mixture of cells, suspended in a fluid called plasma. Red Cells carry oxygen around the body to the organs and tissue. White Cells fight ‘invaders’ such as harmful bacteria and help prevent infection. Plasma is the liquid part of blood. It contains proteins, salts and ‘clotting factors’ that help to prevent or stop bleeding. Platelets are very small fragments of cells. Platelets work with the clotting factors in plasma to form a mesh or ‘plug’ to stop or prevent bleeding.

Why do we need Platelets?
When a patient undergoes chemotherapy or radiotherapy to treat cancer or leukaemia, that treatment can destroy the patient’s bone marrow. Bone marrow is the ‘orchard’ within the bones where blood cells form. Until the bone marrow recovers, the patient will be at risk of severe bleeding due to a lack of platelets in his or her bloodstream. During this recovery period, which may take several weeks the patient may need to receive platelet transfusions to maintain satisfactory numbers of platelets in circulation, or to stop actual bleeding.As treatments develop, more patients are being successfully treated. This has led to a large increase in the numbers of platelet transfusions required. Platelet transfusions can also be lifesaving to babies in whom bleeding due to a lack of platelets can leave serious long term consequences.

How do we collect Platelets?
Platelets can either be processed from donations of whole blood or can be obtained from a PLATELETPHERESIS donation. In Plateletpheresis the donor is connected to a machine called a cell separator. This machine automatically separates the donor's blood components and collects the platelets with a small amount of plasma in a special type of bag. All the other blood components such as red cells and white cells and most of the plasma are returned to the donor during the donation.

Why collect by Plateletpheresis?
If platelets are processed from whole blood donations, it takes four of these donations to make enough platelets for a single adult transfusion. By contrast, one plateletpheresis donation will provide enough platelets for one or two adults for a transfusion, since more platelets can be collected from a donor this way. Plateletpheresis ensures that patients receive blood components from as few donors as possible whilst enabling us to meet ever increasing demands for platelet transfusions.

What is involved?
As a platelet donor you will be connected to the collection system by means of a needle in your arm as in a Whole Blood donation. The donation will typically last for about 60 to90 minutes, during which time you can read, watch TV or simply relax! Since all donations are collected with new and sterile equipment for each donor which is never re-used there is no possibility of catching any infectious disease as a result of the donation.

Who can donate Platelets?
In general, first time platelet donors should be aged between 18 and 60 years. You should have given at least one previous blood donation and you need to weigh more than 9 stone. The number of circulating platelets will vary from person to person and we test a sample of blood from prospective donors to determine those who are particularly well suited for platelet donation. Platelets from Group O and Group A donors are likely to be in greatest demand and it is always our aim to ask donors to donate by the method which will provide most benefit to most patients. Because of this we may ask some people to remain as one of our whole blood donors at the present time.

(Informations in this page have been derived from www.welsh-blood.org.uk)