Ch. 25 Disorders of Primary Hemostasis
illness or medication
Acquired platelet disorders occur secondary to another
clot retraction
how well a clot forms in an anticoagulated test tube
Paraproteinemia
is a general term that refers to abnormalities of the immunoglobulins.
Glanzmann's thrombasthenia
is a rare autosomal (non sex-linked) platelet function disorder caused by a problem with platelet membrane proteins, there is an absence or deficiency of the membrane GPIIb/IIIa complex.
Ivy bleeding time
is a screen to determine the risk of bleeding and is used to evaluate platelet and vascular disorders
Bernard-Soulier syndrome
is another rare autosomal recessive bleeding disorder and is caused by a deficiency of platelet membrane GPIb/IX complex
Gpb/IX
is important in platelet adhesion, maintaining normal platelet shape, and other important mechanisms in the coagulation process and lack of leads to large and irregularly shaped platelets in patients with this disorder.
Primary purpura
is related to disorders that result in bruising, but not associated with any specific disease.
factor VIII activity, the presence of von Willibrand's antigen (vWF:Ag) and it's activity and platelet aggregation studies.
Which test is used to evaluate for von Willibrand's factor?
light blue and green
Which tubes of collection can be used to correct clumping of platelets?
Thrombocytosis
exists when the platelet count rises above the normal range (greater than 400,000).
Drug-induced Immune Thrombocytopenia
- Many drugs can cause an antibody-drug-platelet complex that leads to a thrombocytopenia. • This is mainly seen in the elderly as a result of increased usage of medication.
Glanzmann's thrombasthenia
- The gene that codes for GPIIb and GPIIIa is located on chromosome 17. - An autosomal-recessive trait with clinical manifestations expressed in homozygotes only are genetic findings of which disease?
Postranfusion Purpura (PTP)
- This order shows a sudden onset of thrombocytopenia one week after transfusion of blood or blood products containing platelets. • This is usually due to an alloantibody made against platelets.
Acquired qualitative platelet disorders
1. renal disease 2. liver disease 3. paraproteinemia 4. Myeloproliferative Disorders 5. Acquire von Willibrand disease 6. cardiopulmonary bypass 7. drug therapy these are all conditions that can lead to
qualitative
A _______ disorder of platelets refers to a problem with how the platelets function with the patient's platelet count may be in the normal range (150-400 X 10(9)/L) yet the patient is still experiencing minor to severe bruising and possibly severe hemorrhages
Thrombotic Thrombocytopenic Purpura (TTP)
A group of disorders that are characterized by fragmentation of RBC's as the cells pass through blood vessels that are blocked by small clots.
150,000 to 400,000 per microliter (ul) of whole blood.
A normal platelet count ranges from
Secondary Immune Thrombocytopenias
A thrombocytopenia can develop along with other disorders such as Hodgkin's disease and non-Hodgkin's lymphoma , CLL and Systemic Lupus Erythematosus (SLE)
various degrees of mucous membrane bleeding
Clinical signs of Bernard-Soulier include
vary and can range from minor bruising to severe hemorrhages
Clinical signs of Glanzmann's include
multiple myeloma and Waldenstrom's macroglobulinemia.
Diseases that fall under the category of paraproteinemia include
reduced vWF, agglutination of platelets in presence of risstocetin and vWF.
Further studies of vonWillebrand's Disease include:
TTP affects adults typically while HUS typically affects children who have experienced in a viral or bacterial infection
How are HUS and TTP different?
30,000 - 50,000/ul range
ITP in adults is most often seen in the 20-50 year old age group and presents as a chronic form of ITP with platelet counts in the
ristocetin
In Bernard-Soulier syndrome there is NO platelet aggregation when platelets are mixed with what?
ADP, epinephrine, and collagen
In Bernard-Soulier syndrome there is normal platelet aggregation when platelets are mixed with what?
thrombin
In Bernard-Soulier syndrome there is reduced platelet aggregation when platelets are mixed with what?
ADP, thrombin, collagen, and epinephrine
In Glanzmann's thrombasthenia there is NO platelet aggregation when platelets are mixed with what?
ristocentin
In Glanzmann's thrombasthenia there is platelet aggregation when platelets are mixed with what?
Quantitative platelet disorders
In these disorders the platelet count is less than normal, are the most common of the platelet abnormalities.
20,000/ul
In this acute form of ITP, the platelet count often falls below
automated platelet count
One of the most important tests to evaluate a patient's bleeding tendency is the
TTP
Patients with ______ will show symptoms of weakness, fever, neurological complications and renal disease along with the thrombocytopenia and microangiopathic hemolytic anemia.
coagulation factor
Patients with a _____________ disorder will demonstrate spontaneous hemarthrosis (bleeding into joints and body cavities) and deep hematomas (blood vessels breaking in tissues and organs).
platelet or vascular
Patients with a _____or _______ disorder will demonstrate bleeding limited to the skin surface and mucous membranes.
larger
Platelets on the blood smear of patients with ITP are _______ than normal due to early release from the bone marrow.
congenital disorders, von Willibrand's, and acquired disorders.
Qualitative platelet disorders can be categorized as
secondary purpura
Scurvy (due to a lack of vitamin C), Cushing's syndrome ( caused by an excess of corticosteroids), Diabetes mellitus, Protein C deficiency, Amyloidosis these can all cause what?
20,000
Spontaneous hemorrhage is not usually seen until the platelet count falls to less than
100,000.
Symptoms of thrombocytopenia are usually not seen until the platelet count falls below
1. Idiopathic Thrombocytopenic Purpura (ITP) 2. Postranfusion Purpura (PTP) 3. Drug-induced Immune Thrombocytopenia 4. d) Heparin Therapy
What are the 4 types of immunological thrombocytopenias?
1. Deficient platelet production 2. Sequestration of platelets by the spleen (spleen removes platelets from the circulation) 3. Destruction of the platelets in the peripheral blood
The 3 main reasons for a quantitative platelet disorder include
vonWillebrand's Disease
These are all lab results of which disease? o -normal PT o -prolonged APTT o -normal platelet count o -abnormal bleeding time
Bernard-Soulier syndrome
These are other lab findings of which disease? - normal to moderately reduced platelet count -large, irregularly shaper platelets on the blood smear (platelets may be as large as lymphocytes) -prolonged bleeding time
Glanzmann's thrombasthenia
These are other lab finds of which disease? o Normal platelet count and normal platelet morphology - bleeding time is prolonged (>9.5 minutes) o -abnormal clot retraction
Desseminated Intravascular Coagulation (DIC)
This condition involves increased platelet destruction in combination with the consumption of coagulation factors and is stimulated by trauma such as crush injuries, childbirth, and sepsis.
Hemolytic Uremic Syndrome (HUS)
This condition is characterized by a microangiopathic hemolytic anemia, thrombocytopenia, and renal failure and closely resembles TTP
1. Thrombotic Thrombocytopenic Purpura (TTP) 2. Hemolytic Uremic Syndrome (HUS) 3. Desseminated Intravascular Coagulation (DIC) 4. Pregnancy-Associated Thrombocytopenia
What are the 4 types of microangiopathic thrombocytopenia?
Idiopathic Thrombocytopenic Purpura (ITP)
This disorder is one of the most common of the thrombocytopenias and is seen in children and adults.
reactive thrombocytosis
This thrombocytosis usually occurs in response to another condition. these conditions include: hemorrage, IDA, malignancy, infections, inflammatory disease, epihepherine or growth factors such as interleukin
Primary thrombocytosis
This type of thrombocytosis can occur as a result of a myeloproliferative disorder (MPD) and can result of a platelet as high as 1 million.
150,000/ul
Thrombocytopenia is defined as a platelet count below
acquired quantitative platelet disorders
What are the most common disorders of primary hemostasis?
platelet aggregation
What assesses platelet function by measuring the response of the platelet to various stimuli such as epinephrine, ADP, collagen, thrombin and ristocetin.
schistocytes and poikilocytosis
What two types of cells are present on blood smears of patients with Thrombotic Thrombocytopenic Purpura (TTP)
splenectomy and corticosteroids
Treatment for ITP includes
Viral Infections
Viral infections such as HIV and Hepatitis may lead to a decease in the cellularity of the bone marrow and resulting in a thrombocytopenia
congenital
Von Willebrand's disease is a __________ bleeding disorder due to a deficiency of Von Willebrand's factor (vWF).
Idiopathic Thrombocytopenic Purpura (ITP)
Young children may develop _____ within 1-3 weeks following a viral illness
Plasmapheresis
a procedure of cleansing the patient's plasma and returning it to their body) and gamma globulin treatments are used for patients with PTP
Thrombotic Thrombocytopenic Purpura (TTP)
a rare and often fatal disorder involving thrombocytopenia and microangiopathic hemolytic anemia
purpura
are recognized on a patient by red discolorations (blotches) on the surface of the skin due to hemorrhages into the skin and can also occur in mucous membranes, internal organs and tissues
Cardiopulmonary Bypass
platelet activation and platelet dysfunction are the primary cause of bleeding complications found in this procedure
satellitism
platelets surrounding red cells is referred to as
secondary purpura
results from other diseases such as infections, allergies, hormonal or biochemical abnormalities.
d) Heparin Therapy
some patients develop a thrombocytopentia 4 to 7 days after taking heparin, which is administered intravenously to prevent clot formation. The platelet count usually returns to normal 4 to 6 days after the heparin is discontinued
absence or deficiency of GPIIb/IIIA surface protein
what do the flow cytometry results reveal in the instance of Glanzmann's thrombasthenia
Idiopathic Thrombocytopenic Purpura (ITP)
• Patients may experience mucous membrane bleeding in the form of nose bleeds and easy bruising. • Women may experience heavy menstrual periods. In which disease??
