Transcript What are Platelets?

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:
Plateletpheresis
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
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.
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.
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).
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.
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.
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
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.
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).
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)
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 heparininduced thrombocytopenia (HIT) or disseminated
intravascular coagulation (DIC).
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).
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 heparininduced thrombocytopenia and thrombosis (HITT). HIT
is caused by the formation of abnormal antibodies that
activate platelets.
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.
• 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 timeconsuming to find even a single compatible donor for HLAmatched transfusions, being able to collect a full dose
from a single donor is much more practical than finding
multiple compatible donors.
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.
Dosage
• A post-donation platelet count should be performed
after each collection.
• A donor should undergo no more than
PlateletPheresis collections in a 12-month period.
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• It may be given appropriately when the platelet count is
<50 x 109 /L .
Normal Plts: 150-450 * 10^9/L
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.