Lecture 160 Flashcards
(131 cards)
1
Q
What type of bleeding disorder is thrombocytopenia?
A
Platelet deficiency
2
Q
What type of bleeding disorder is immune thrombocytopenic purpura (ITP)?
A
Platelet deficiency
3
Q
What type of bleeding disorder is thrombotic thrombocytopenic purpura (TTP)?
A
Platelet deficiency
4
Q
What type of bleeding disorder is hemolytic uremia syndrome (HUS)?
A
Platelet deficiency
5
Q
What type of bleeding disorder is Bernard-Soulier disease?
A
Platelet dysfunction
6
Q
What type of bleeding disorder is Glanzmann’s thrombasthenia?
A
Platelet dysfunction
7
Q
What type of bleeding disorder is disorders of platelet secretion?
A
Platelet dysfunction
8
Q
What type of bleeding disorder is von Willebrand’s disease?
A
Clotting factor deficiency
9
Q
What type of bleeding disorders are hemophilias?
A
Clotting factor deficiency
10
Q
What type of bleeding disorder is vitamin K deficiency?
A
Clotting factor deficiency
11
Q
What type of bleeding disorder is plasmin overactivity?
A
Disorders of fibrinolysis
12
Q
What type of bleeding disorder is reduced alpha2-antiplasmin?
A
Disorders of fibrinolysis
13
Q
What type of bleeding disorder is Henoch-Schonlein purpura?
A
Vessel wall abnormality
14
Q
What type of bleeding disorder is hereditary hemorrhagic telangiectasia?
A
Vessel wall abnormality
15
Q
What type of bleeding disorder is perivascular amyloidosis?
A
Vessel wall abnormality
16
Q
What coagulation pathway is activated by damage inside the vasculature?
A
Intrinsic pathway
17
Q
What coagulation pathway involves factors XII, XI, IX, and VIII?
A
Intrinsic pathway
18
Q
What lab test measures the effectiveness of the intrinsic pathway?
A
Activated partial thromboplastin time (PTT)
19
Q
What coagulation pathway is activated by trauma that causes blood to leave exposed vasculature?
A
Extrinsic pathway
20
Q
What coagulation pathway is activated by the release of tissue factor (TF)?
A
Extrinsic pathway
21
Q
What coagulation pathway involves factor VII?
A
Extrinsic pathway
22
Q
How is the extrinsic pathway tested?
A
Prothrombin time (PT) or international normalized ratio (INR)
23
Q
What coagulation pathway involves factors X, V, prothrombin (II), and fibrinogen (I)?
A
Common pathway
24
Q
Thrombin converts fibrinogen to ____
A
Fibrin
25
What converts plasminogen to plasmin?
Tissue plasminogen activator (t-PA)
26
What cleaves fibrin and serum fibrinogen, destroys coagulation factors, and blocks platelet aggregation?
Plasmin
27
What inhibits t-PA, thus reducing plasmin formation?
Plasminogen activator inhibitor-1 (PAI-1)
28
What inactivates plasmin?
Alpha-2-antiplasmin
29
What inhibits fibrinolysis?
Thrombin activatable fibrinolysis inhibitor (ATFI)
30
What measures the time to clot in seconds, assessing the extrinsic pathway (factor VII)?
Prothrombin time (PT)
31
What standardizes PT results across different labs?
International normalized ratio (INR)
32
What is INR used to monitor?
Patients on warfarin
33
What measures the time to clot in seconds, assessing the intrinsic pathway?
Activated partial thromboplastin time (PTT)
34
What measures the time to clot dependent on thrombin converting fibrinogen to fibrin?
Thrombin time
35
What is a glycoprotein synthesized by the liver, converted to fibrin by thrombin?
Fibrinogen
36
What is a major product of fibrinolysis?
D-Dimer
37
What does an elevated D-dimer indicate?
Recent intravascular coagulation
38
What is used to differentiate between clotting factor deficiencies and acquired factor inhibitors?
Mixing study
39
If PT or PTT corrects in a mixing study, it indicates ____
A factor deficiency
40
If PT or PTT does not correct in a mixing study, it indicates ____
An acquired inhibitor
41
What are red/purple dots from leaking capillaries called?
Petechiae
42
Petechiae are usually a sign of ____
Primary hemostasis problem
43
What are coalesced petechiae, larger in size called?
Purpura
44
What are larger bruises occurring deeper in the dermal layer called?
Ecchymosis
45
Ecchymosis is usually a sign of a ____
Secondary hemostasis problem
46
What is the platelet count threshold for thrombocytopenia?
<150,000/microliter
47
What platelet level typically involves bleeding with minor trauma and increased surgical bleeding risk?
Platelets <50,000/uL
48
What platelet level typically involves spontaneous bleeding and risk of intracranial bleeding?
Platelets <20,000/uL
49
What is caused by autoantibody-mediated destruction of platelets?
Immune thrombocytopenic purpura (ITP)
50
Autoantibodies in ITP are usually directed against ____
Platelet membrane glycoproteins
51
What are clinical features of ITP?
Bleeding into skin and mucosal surfaces
52
What suggests ITP with low platelet count, normal or increased megakaryocytes in BM, large platelets in peripheral blood, and normal PT/PTT?
ITP
53
How is ITP treated?
Glucocorticoids, sometimes splenectomy
54
What is a disease of childhood, symptoms appear abruptly, often 1-2 weeks after a self-limited viral illness?
Acute ITP
55
What is the course of acute ITP?
Self-limited, resolves within 6 months
56
What is characterized by excessive platelet activation, leading to thrombi in small blood vessels?
Thrombotic microangiopathies
57
What bleeding disorder group causes microangiopathic hemolytic anemia (MAHA) due to RBC fragmentation?
Thrombotic microangiopathies
58
What is TTP?
Thrombotic thrombocytopenic purpura
59
What is the classic pentad of TTP?
Fever, thrombocytopenia, MAHA, transient neurological deficits, and renal failure
60
What is characterized by deficiency or inhibition of ADAMTS13 leading to accumulation of large vWF multimers?
Thrombotic thrombocytopenic purpura (TTP)
61
What metalloprotease degrades vWF multimers?
ADAMTS13
62
What suggests thrombotic thrombocytopenia purpura (TTP) with low platelets, normal PT/PTT, low hemoglobin, and schistocytes on smear?
Thrombotic thrombocytopenia purpura (TTP)
63
How is TTP treated?
Plasma exchange
64
What is HUS?
Hemolytic uremic syndrome
65
What bleeding disorder is associated with MAHA, but typically presents with prominent acute renal failure?
Hemolytic uremic syndrome (HUS)
66
What is typical HUS strongly associated with?
Infectious gastroenteritis caused by shiga-like toxin-producing E. coli (STEC)
67
What toxin causes endothelial injury, provoking platelet activation and aggregation in HUS?
STEC
68
What is the clinical triad of HUS?
Renal failure, MAHA, thrombocytopenia
69
How is HUS treated?
Supportive care
70
What is atypical HUS associated with?
Defects in alternative complement pathway inhibitors
71
What suggests HUS with low platelets, normal PT/PTT, low hemoglobin, schistocytes, and renal dysfunction?
HUS
72
What is HIT?
Heparin-induced thrombocytopenia
73
What type of HIT is clinically silent?
HIT-1
74
What type of HIT is often life-threatening?
HIT-2
75
When does type 2 HIT typically occur?
5-14 days after the beginning of heparin therapy
76
What forms against the complex of heparin bound to platelet factor 4 (PF4)?
IgG antibodies
77
What symptoms should prompt consideration of heparin-induced thrombocytopenia?
Petechial rash, thrombocytopenia, and high risk of thrombosis
78
What is the inheritance pattern of Bernard-Soulier syndrome?
Autosomal recessive
79
What is the defect in Bernard-Soulier syndrome?
Platelet adhesion to the subendothelial matrix
80
What is the receptor of vWF?
Platelet membrane glycoprotein complex Ib (GpIb)
81
What causes decreased adhesion of platelets to vWF in Bernard-Soulier syndrome?
Inherited deficiency in GpIb
82
What is the result of the Ristocetin Agglutination Test in Bernard-Soulier syndrome?
No agglutination with ristocetin
83
What is the inheritance pattern of Glanzmann's thrombasthenia?
Autosomal recessive
84
What is the defect in Glanzmann's thrombasthenia?
Platelet aggregation caused by decreased expression or dysfunction of GpIIb-IIIa
85
What is the function of GpIIb-IIIa?
Forms bridges between platelets by binding fibrinogen
86
What is the result of the Ristocetin Agglutination Test in Glanzmann's thrombasthenia?
Normal agglutination with ristocetin
87
What is defective in storage pool diseases?
Release of certain mediators of platelet activation from platelet granules
88
What is the result of storage pool diseases?
Impaired platelet aggregation and plug formation
89
What does aspirin block the production of?
TXA2
90
What is a common condition associated with acquired defects in platelet function?
Uremia (renal dysfunction)
91
What is the inheritance pattern of hemophilia A?
X-linked recessive
92
What is the deficiency in hemophilia A?
Factor VIII
93
What coagulation pathway is FVIII a crucial cofactor in?
Intrinsic
94
What suggests hemophilia A with prolonged PTT and normal PT?
Hemophilia A
95
What complication associated with hemophilia A is a major concern?
Hemarthroses (bleeding into joints)
96
How is hemophilia A treated?
Infusions of recombinant Factor VIII
97
What medication can be used to treat mild cases of hemophilia A?
Desmopressin (DDVAP)
98
What is the inheritance pattern of hemophilia B?
X-linked recessive
99
What is the deficiency in hemophilia B?
Factor IX (FIX)
100
What suggests hemophilia B & C with prolonged PTT and normal PT?
Hemophilia B & C
101
How is hemophilia B & C treated?
Infusions of recombinant Factor IX
102
What is the inheritance pattern of hemophilia C?
Autosomal recessive
103
What is the deficiency in hemophilia C?
Factor XI (FXI)
104
What is synthesized in endothelial cells and megakaryocytes?
vWF
105
What does vWF form a complex with in the blood?
Factor VIII
106
What impact does vWF binding have on Factor VIII?
Increases its half-life significantly
107
What vWD type displays mild to moderate quantitative deficiency of vWF?
Type 1 vWD
108
What vWD type displays little to no vWF synthesis and severe bleeding?
Type 3 vWD
109
What vWD type expresses vWF in normal amounts but has defective multimer assembly?
Type 2 vWD
110
What is the most common inheritance pattern of vWD?
Autosomal dominant
111
What vWD types may have prolonged PTT due to secondary deficiency of Factor VIII?
Type 1 & 3
112
What vitamin serves as a coenzyme for gamma-glutamyl carboxylase?
Vitamin K
113
What coenzyme is essential for the carboxylation of clotting Factors II, VII, IX, and X?
Vitamin K
114
What suggests vitamin K deficiency with prolonged PT, prolonged PTT, and normal platelet count?
Vitamin K
115
What is characterized by excessive systemic activation of coagulation, leading to thrombi in the microvasculature?
Disseminated intravascular coagulation (DIC)
116
What are the two categories of triggers for DIC?
Release of tissue factor and widespread injury
117
Why are obstetric complications, malignant neoplasms, and sepsis all triggers of DIC?
They release Tissue Factor
118
Why are deposition of antigen-antibody complexes, temperature extremes, and microorganisms all triggers of DIC?
They all cause widespread injury of endothelial cells
119
What is acute DIC normally dominated by?
Bleeding
120
What does insidious DIC often present more with?
Thrombotic issues
121
What suggests DIC with low platelet count, prolonged PT and PTT, schistocytes on blood smear, and elevated D-dimer?
DIC
122
What can cause disorders of fibrinolysis?
Plasmin overactivity
123
What can radical prostatectomy and cirrhosis of the liver cause?
Disorders of fibrinolysis
124
What suggests disorders of fibrinolysis with increased PT/PTT, normal platelet count, and negative D-dimer?
Disorders of fibrinolysis
125
How are disorders of fibrinolysis treated?
Aminocaproic acid
126
What is a systemic immune disorder characterized by deposition of IgA-containing immune complexes?
Henoch-Schonlein purpura (IgA vasculitis)
127
What is the clinical tetrad of Henoch-Schonlein purpura?
Palpable purpura, colicky abdominal pain, polyarthralgia, acute glomerulonephritis
128
What is the inheritance pattern of hereditary hemorrhagic telangiectasia (HHT)?
Autosomal dominant
129
What gene mutations are involved in hereditary hemorrhagic telangiectasia?
TGF-beta signaling
130
What is characterized by dilated, tortuous blood vessels that bleed easily?
Hereditary hemorrhagic telangiectasia (HHT)
131
What causes vascular fragility and bleeding in perivascular amyloidosis?
Deposition of misfolded amyloid proteins
