1. Types of Apheresis
Blood taken from a healthy donor can be separated into its component parts during blood donation, where the needed component is collected and the "unused" components are returned to the donor.
Fluid replacement is usually not needed in this type of collections. There are large categories of component collections:

2. Plateletpheresis

3. Each year, more than 30,000 units of platelets are transfused at the National Institutes of Health (NIH) Clinical Center (CC) to treat patients undergoing cancer therapy; organ and tissue transplants; and other diseases that require platelet therapy.

4. What are Platelets?
Platelets are small cells that help the blood to clot. Manufactured in the bone marrow and stored in the spleen, their job is to rush to the site of an injury.
Once there,  they form a barrier, help the damaged organ or blood vessel stop bleeding, and give the body a chance to begin healing.

5. What is Plateletpheresis?
Plateletpheresis is the standard procedure by which platelets are separated from whole blood, concentrated, and collected.
To remove platelets, a needle is placed in  each arm. Blood flows through a needle into a machine that contains a sterile, disposable plastic kit specifically designed for this purpose.
The platelets are isolated  and channeled out into a special bag, and red blood cells and other parts of the blood are returned to you through a needle in the opposite arm. There is also a  plateletpheresis procedure that can be performed with a single needle.

6. Is Plateletpheresis Safe?
Absolutely.  The machine and the procedure have been evaluated and approved by the Food and Drug Administration, and all plastics and needles coming into contact  with you are used once and discarded.
At no time during the procedure is the blood being returned to you detached from the needle in your arm, so there is no risk of  returning the wrong blood to you.

7. Who Is Eligible to Give Platelets?
The interval between consecutive platelet donations at NIH is 1 month. However, because the body replaces platelets within a few days, you are allowed to give more frequently (one in 2 weeks) when you are donating for a relative or for a patient who responds particularly well to your platelets. 
In addition to standard donor eligibility requirements, platelet donors should refrain from taking aspirin for 48 hours prior to donation.

8. How Long Does Plateletpheresis Take?
Plateletpheresis procedures take about 90 minutes, but you should allow another 30 minutes for staff to obtain your medical history.
This gives you just enough time to  watch a movie from our extensive video library. Every effort will be made to make the experience relaxing and enjoyable.

9. Plateletpheresis
Platelet transfusion can be a life-saving procedure in preventing or treating serious complications from bleeding and hemorrhage in patients with low platelet count or platelet dysfunction.

10. Platelet transfusion
Platelet transfusions are traditionally given to those undergoing chemotherapy for leukemia, multiple myeloma, those with aplastic anemia, AIDS, hypersplenism, ITP (Idiopathic thrombocytopenic purpura), sepsis, bone marrow transplant, radiation treatment, organ transplant or surgeries.

11. Aplastic anemia
Aplastic anemia is a condition where bone marrow does not produce sufficient new cells to replenish blood cells. The condition, per its name, involves both aplasia (defective development) and anemia.
Typically, anemia refers to low red blood cell counts, but aplastic anemia patients have lower counts of all three blood cell types: red blood cells, white blood cells, and platelets, termed (pancytopenia).

12. AIDS
Acquired immunodeficiency syndrome (AIDS) is a disease of the human immune system caused by the human deficiency virus (HIV). The illness interferes with the immune system, making people with AIDS much more likely to get infections.

13. hypersplenism
Splenomegaly is an enlargement of the spleen. It is one of the four signs of hypersplenism which there is some reduction in the number of circulating blood cells affecting granulocytes, erythrocytes or platelets.

14. Idiopathic thrombocytopenic purpura
Idiopathic thrombocytopenic purpura (ITP) is the condition of having an abnormally low platelet count (thrombocytopenia) of unknown cause (idiopathic).
As most incidents of ITP appear to be related to the production of antibodies against platelets, immune thrombocytopenic purpura or immune thrombocytopenia are terms also used to describe this condition.
Purpura (from latin: purpura, meaning
"purple") is the appearance of red or purple
discolorations on the skin

15. Sepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state (called a systematic inflammatory response syndrome or SIRS) and the presence of a known or suspected infections.
The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues. A lay term for sepsis is blood poisoning.

16. Leukemia
Leukemia (American English) or leukaemia (British English) is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called “blasts".
As a consequences for the chemotherapy treatment of leukemia you need to have platelet transfusion as the disease itself has led to significant anemia or thrombocytopenia (low platelet count).

17. Multiple myeloma
Multiple myeloma (from Greek myelo-, bone marrow), also known as plasma cell myeloma or Kahler's disease (after Otto Kahler ), is a cancer of plasma cells.
Plasma cells, also called plasma B cells, plasmocytes, and effector B cells, are white blood cells which produce large volumes of antibodies. They are transported by the blood plasma and the lymphatic system. Like all blood cells, plasma cells ultimately originate in the bone marrow; however, these cells leave the bone marrow as B cells, before terminal differentiation into plasma cells, normally in lymph nodes.
Myeloma patients can also develop bleeding
complications (need platelet transfusion)

18. Platelet transfusion
Platelet transfusions should be avoided in those with TTP (Thrombotic thrombocytopenic purpura) because it can worsen neurologic symptoms and acute renal failure.
It should also be avoided in those with heparin-induced thrombocytopenia (HIT) or disseminated intravascular coagulation (DIC).

19. Thrombotic thrombocytopenic purpura
Thrombotic thrombocytopenic purpura (TTP or Moschcowitz syndrome) is a rare disorder of the blood coagulation system, causing extensive microscopic clots to form in the small blood vessels throughout the body. These small blood clots, called thromboses, can damage many organs including the kidneys, heart and brain.
(Platelet transfusions are generally not recommended for this group of patients due to creation of new thrombi as the platelets are consumed).

20. Heparin-induced thrombocytopenia
Heparin-induced thrombocytopenia (HIT) is the development of thrombocytopenia (a low platelet count), due to the administration of various forms of heparin, an anticoagulant.
HIT predisposes to thrombosis, the abnormal formation of blood clots inside a blood vessel, and when thrombosis is identified the condition is called heparin-induced thrombocytopenia and thrombosis (HITT). HIT is caused by the formation of abnormal antibodies that activate platelets.

21. Disseminated intravascular coagulation
Disseminated intravascular coagulation (DIC), also known as disseminated intravascular coagulopathy or consumptive coagulopathy, is a pathological activation of coagulation (blood clotting) mechanisms that happens in response to a variety of diseases. DIC leads to the formation of small blood clots inside the blood vessels throughout the body.

22. the whole-blood platelets, sometimes called "random" platelets, from a single donation are not numerous enough for a dose to give to an adult patient. They must be pooled from several donors to create a single transfusion, and this complicates processing and increases the risk of diseases that can be spread in transfused blood, such as human immunodeficiency virus.
but Collecting the platelets from a single donor simplifies human leukocyte antigen (HLA) matching, which improves the chance of a successful transfusion. Since it is time-consuming to find even a single compatible donor for HLA-matched transfusions, being able to collect a full dose from a single donor is much more practical than finding multiple compatible donors.

23. Dosage
The number of platelet units to be administered depends on the clinical situation of each patient.
Each unit of platelets separated from donated whole blood is called a "platelet concentrate".
transfusions should be given until recovery of platelet function, generally approximately twice weekly.

24. Dosage
A post-donation platelet count should be performed after each collection.
A donor should undergo no more than 24 PlateletPheresis collections in a 12-month period.
It may be given appropriately when the platelet count is <50 x 109 /L .
Normal Plts: * 10^9/L

25. Dosage
One unit (one standard adult dose) of Platelets Apheresis would be expected to increase the platelet count of a 70 kg adult by 20–40 x 109 /L. The usual dose in an adult patient is 1 unit (apheresis).
One unit of Platelets Paediatric Apheresis would be expected to increase the platelet count of an 18 kg child by 20 x 109 /L.
Because platelets have a life-span of just 5 days, more platelet donors are always needed.