MIDTERM Flashcards
manifests in infancy or childhood with hemorrhage characteristics of defective platelet function: ecchymoses, epistaxis, and gingival bleeding
Bernard-Soulier (Giant Platelet) Syndrome
problem: lack or abnormal GP Ib/IX/V complex in platelet surface
Bernard-Soulier (Giant Platelet) Syndrome
resembles VWD
Bernard-Soulier (Giant Platelet) Syndrome
homozygotes for BSS
50%
heterozygotes for BSS
enlarged platelets, thrombocytopenia, and usually decreased platelet survival
BSS most common form
defect in GP Ib⍺
Bernard-Soulier (Giant Platelet) Syndrome (laboratory profile )
normal platelet aggregation in response to platelet activating agents binding of VWF to platelets
abnormal platelet aggregation: ristocetin-induced
large platelets and thrombocytopenia
Inherited Giant Platelet Syndromes
Inherited Giant Platelet Syndromes platelet ultrastructure:
normal
abnormal microtubule distribution
May-Hegglin anomaly
platelets are spherical and have a prominent surface-connected canalicular system.
Epstein syndrome
Hermansky-Pudlak syndrome
Chédiak-Higashi syndrome problem
problem: platelet dense granule deficiency
tyrosinase- positive oculocutaneous albinism
Hermansky-Pudlak syndrome
defective lysosomal function
Hermansky-Pudlak syndrome
ceroid-like deposition in the cells of the RES
Hermansky-Pudlak syndrome
morphologic abnormality: marked dilation and tortuosity of SCCS
Hermansky-Pudlak syndrome
partal oculocutaneous albinism
Chédiak-Higashi syndrome
frequent pyogenic bacterial infectons
Chédiak-Higashi syndrome
giant lysosomal granules in cells
Chédiak-Higashi syndrome
“accelerated: lymphocytic proliferaton in the liver, spleen, and marrow with macrophage accumulation in tissues>pancytopenia>hemorrhage &
increased susceptibility to infecton”
Chédiak-Higashi syndrome
problem: absence of Wiskott-Aldrich syndrome protein
Wiskott-Aldrich syndrome (WAS)
“problem: absence of Wiskott-Aldrich syndrome protein
>impaired migration>impaired adhesion”
Wiskott-Aldrich syndrome (WAS)
classic form: thrombocytopenia immunodeficiency syndrome
Wiskott-Aldrich syndrome (WAS)
Wiskott-Aldrich syndrome (WAS) classic form:
thrombocytopenia immunodeficiency syndrome
thrombocytopenia immunodeficiency syndrome (WAS classic form) association
susceptibility to infectons
microthrombocytopenia
severe eczema
platelets: abnormal structure and decreased dense granules
Wiskott-Aldrich syndrome (WAS)
presence of microthrombocytes: TORCH
Wiskott-Aldrich syndrome (WAS)
Wiskott-Aldrich syndrome (WAS) (Laboratory profile)
decreased aggregation response (ADP, collagen, and epinephrine)
normal: aggregtion response (thrombin) (Laboratory profile)
problem: radial bones (most pronounced skeletal abnormality)
Thrombocytopenia with absent radii syndrome (TAR)
platelets have structural defects in dense granules
Thrombocytopenia with absent radii syndrome (TAR)
abnormal aggregation responses
Thrombocytopenia with absent radii syndrome (TAR)
megakaryocytes: decreased, immature, or normal
Thrombocytopenia with absent radii syndrome (TAR)
problem: absence of morphologically recognizable ⍺-granules in platelets
Gray platelet syndrome
lifelong mild bleeding tendencies
Gray platelet syndrome
moderate thrombocytopenia
Gray platelet syndrome
fibrosis of the marrow
Gray platelet syndrome
large platelets whose gray appearance
Gray platelet syndrome
large platelets whose gray appearance
Gray platelet syndrome
decreased plasma PF4 and β-thromboglobulin (laboratory profile)
Gray platelet syndrome
problem: deficiency in multimerin
Quebec platelet disorder
protein that is stored complexed with factor V in ⍺-granules
multimerin
inhibition of cyclooxygenase: aspirin & ibuprofen > TXA2
Thromboxane Pathway Disorders: Aspirin-Like Effects
decreased: aggregation response
Thromboxane Pathway Disorders: Aspirin-Like Effects
normal: ultrastructure and granular contents
Thromboxane Pathway Disorders: Aspirin-Like Effects
deficiency of ⍺2β1 (GP Ia/IIa) integrin
Collagen Receptors
deficiency of GP VI
Collagen Receptors
abnormal aggregation response to collagen
deficiency of ⍺2β1 (GP Ia/IIa) integrin
abnormal aggregation response to collagen
deficiency of ⍺2β1 (GP Ia/IIa) integrin
platelets did not adhere to collagen
deficiency of ⍺2β1 (GP Ia/IIa) integrin
lifelong mild bleeding disorder
deficiency of ⍺2β1 (GP Ia/IIa) integrin
mild bleeding
deficiency of GP VI
abnormal aggregation and adhesion response to collagen
deficiency of GP VI
associated with gray platelet syndrome
deficiency of GP VI
“mediate calcium mobilizaton and shape change in response
to ADP”
P2X1
“macroscopic platelet aggrega;on and is coupled to adenylate
cyclase through a G-inhibitory (Gi) protein complex”
P2Y12
decreased platelet aggrega;on in response to ADP
P2Y12
normal platelet shape change and calcium mobiliza;on
P2Y12
disorder of calcium-induced membrane phospholipid scrambling
Scott Syndrome
platelets are always in an “activated”
Stormorken Syndrome
phosphatidylserine on the outer leaflet of the membrane without prior activation
Stormorken Syndrome
“associated with abnormal in vitro clot retraction and a
normal platelet count”
Glanzmann Thrombasthenia (GT)
“petechiae, purpura, menorrhagia, gastrointestinal
bleeding, and hematuria”
Glanzmann Thrombasthenia (GT)
problem: deficiency or abnormality of the platelet membrane GP IIb/IIIa (⍺IIbβ3)
Glanzmann Thrombasthenia (GT)
homozygotes: deficient > serious bleeding manifestations
Glanzmann Thrombasthenia (GT)
“principle: pro-⍺Iib>⍺IIb (megakaryocytes) complexed with β3 (ER) > ⍺IIbβ3 complex (Golgi body)”
Glanzmann Thrombasthenia (GT)
acquired (thrombasthenia-like state)
Glanzmann Thrombasthenia (GT)
development of autoan;bodies against GP IIb/IIIa
acquired (thrombasthenia-like state) (GT)
multiple myeloma in which the paraprotein is directed against GP IIIa
acquired (thrombasthenia-like state) (GT)
afibrinogenemia
acquired (thrombasthenia-like state) (GT)
Glanzmann Thrombasthenia (GT) (laboratory profile)
normal platelet count
normal platelet morphology
lack platelet aggregation in response to all platelet activating agents
Glanzmann Thrombasthenia (GT) (laboratory profile)
induced release/secretion reaction by stimulation with strong agonists
Glanzmann Thrombasthenia (GT) (laboratory profile)
normal platelet aggregation: ristocetin-induced binding of VWF to platelets
Glanzmann Thrombasthenia (GT) (laboratory profile)
normal platelet aggregation: ristocetin-induced binding of VWF to platelets
Glanzmann Thrombasthenia (GT) (laboratory profile)
markedly fewer microvesicles are produced
Decreased platelet procoagulant activity (PF 3 test)
prothrombin binds directly to GP IIb/IIIa
Decreased platelet procoagulant activity (PF 3 test)
Collagen Receptors
Decreased platelet procoagulant activity (PF 3 test)
normal laboratory profile of platelets and blood coagulation
Vascular Disorders
diagnosis is based on medical history and is made by ruling out other sources of bleeding disorders
Vascular Disorders
clinical sign: tendency to bruise easily or to bleed spontaneously (mucosal surfaces)
Vascular Disorders
thin-walled blood vessels with a discontinuous endothelium
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
inadequate smooth muscle
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
inadequate or missing elastin in the surrounding stroma
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
occur throughout the body (face, lips, tongue, conjunc;va, nasal mucosa, fingers, toes, and trunk and under the tongue)
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
lesions blanch when pressure is applied
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
usually manifests by puberty and progresses throughout life.
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
cherry-red hemangiomas: (common in older men and women
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
ataxia-telangiectasia: Louis-Bar syndrome
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
chronic liver disease
pregnancy
“Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)”
giant cavernous hemangioma
“Hemangioma-Thrombocytopenia Syndrome (Kasabach- Merritt
Syndrome)
thrombocytopenia
bleeding diathesis
“Hemangioma-Thrombocytopenia Syndrome (Kasabach- Merritt
Syndrome)
complications:
acute or chronic disseminated intravascular coagulation
sequestration of platelets in the hemangiomas
microangiopathic hemolytic anemia
“Hemangioma-Thrombocytopenia Syndrome (Kasabach- Merritt
Syndrome)
defects in collagen production, structure, or crosslinking, with resulting inadequacy of the connective tissues
Ehlers-Danlos Syndrome
hyperextensible skin
Ehlers-Danlos Syndrome
hypermobile joints
joint laxity
fragile tissues
bleeding tendency (subcutaneous hematoma formation)
Ehlers-Danlos Syndrome
allergic/ anaphylactoid purpura
allergic manifesta;ons (skin rash and edema)
associated with foods and drugs, cold, insect bites, and vaccinations
Henoch-Schönlein Purpura Allergic Purpura
acute IgA-mediated disorder with widespread generalized vasculitis involving the skin, joints, kidneys, gastrointestinal tract, and, less commonly, the lungs.
Henoch-Schönlein Purpura Allergic Purpura
purpuric skin lesions are frequently confused with the hemorrhagic rash of immune thrombocytopenic purpura
disease of children (3-7 years of age); more common in males
“palpable purpura’, itchy purpuric lesions
Henoch-Schönlein Purpura Allergic Purpura
(+) proteinuria and hematuria
Henoch-Schönlein Purpura Allergic Purpura
normal: platelet count & blood coagulation tests
Henoch-Schönlein Purpura Allergic Purpura
increased: WBC & ESR
Henoch-Schönlein Purpura Allergic Purpura
platelet func;on can be inhibited by myeloma proteins
Paraproteinemia
coating of the platelet membrane with the paraprotein >abnormalities in platelet aggregation, secretion, and procoagulant activity
Paraproteinemia
exhibit platelet function abnormalities
IgA myeloma, Waldenström macroglobulinemia & IgG3 myeloma
inhibiting fibrin polymerization
“poor correlation between abnormal results on laboratory tests and evidence of clinical bleeding.”
deposition of abnormal quantities of amyloid protein in tissues
Amyloidosis
fibrous protein with rigid, linear, non- branching, aggregated fibrils
amyloid:
primary or secondary, and localized or systemic
Amyloidosis
characterized by: purpura, hemorrhage, and thrombosis
Amyloidosis
abnormal platelet function
Amyloidosis
occurs more commonly in elderly men than in women
Senile Purpura
“due to a lack of collagen support for small blood vessels and loss of subcutaneous fat and elastic fibers”
Senile Purpura
“dark blotches are flattened, do not blanch with pressure, and resolve slowly,
often leaving a brown stain in the skin.”
Senile Purpura
laboratory results: normal
increased: capillary fragility
no other bleeding manifesta;ons
Senile Purpura
aspirin, warfarin, barbiturates, diuretics, digoxin, methyldopa, sulfonamides and iodides
Drug induced