DISORDERS OF PRIMARY HEMOSTASIS – PLATELET DISORDERS Flashcards
a term wherein there’s a CHANGES IN
PLATELET FUNCTION
THROMBOCYTOPATHY
conditions associated with platelet aggregation
- glanzmann thrombasthenia
- hereditary afibrinogenemia
- acquired defects of aggregation
✓acquired von willebrand disease
✓ acquired uremia
conditions associated with platelet adhesion
− Bernard-Soulier Syndrome
− Von Willebrand Disease
− Acquired Defects of Platelet Adhesion
✓ Myeloproliferative/ Lymphoproliferative
Disorders, Dysproteinemias
✓ Antiplatelet Antibodies
✓ Cardiopulmonary Bypass Surgery
✓ Chronic Liver Disease
✓ Drug-Induced Membrane Modification
congenital disorders of platelet function based on platelet membrane defects
Glanzmann’s Thrombasthenia
Bernard-Soulier Syndrome
Storage Pool Deficiency (Granule Defect)
congenital disorders of platelet function based on platelet release
primary secretion defects (Enzymatic Pathway Defects)
In quantitative, we have two ___
thrombocytosis and thrombocytopenia
what causes the decrease in plt or thrombocytopenia
increase PLT destruction
Decrease platelet production
abnormal platelet distribution
what causes the decrease in plt or thrombocytosis
PRIMARY/ ESSENTIAL
THROMBOCYTOSIS
REACTIVE/ SECONDARY
THROMBOCYTOSI
clinical manifestation of bleeding disorders
superficial bleeding
deep tissue bleeding
in clinical manifestation of bleeding, superficial bleeding includes
petechiae
epistaxis (nose bleeding)
gingival bleeding
in clinical manifestation of bleeding, deep tissue bleeding includes
hematomas
hemarthrosis (joint bleeding)
hemarthrosis means bleeding in __
joints
In bernard soulier syndrome, ____complex is missing from the platelet surface or exhibits abnormal function
GP Ib/IX/V
BERNARD-SOULIER SYNDROME is also known as
giant platelet disorder
why BSS is called as giant platelet disorder
because it can grow from 5-8 um up to 20 um
BSS is characterized by ___
giant platelets and thrombocytopenia
who first studied bernard-soulier syndrome,, where they described two children from a consanguineous family who had a sever bleeding disorder characterized by mucocutaneous hemorrhage
1948, bernard and soulier
They identified an abnormality in platelet GPIb as the cause of the functional defect
1975, Nurden and Caen
Six different feature features may contribute to the hemorrhagic diathesis in BSS
thrombocytopenia
von willebrand’s factor is deficient (carrier of factor VIII and for adhesion)
abnormal platelet interaction with thrombin
abnormal plt coagulant activity
abnormal plt interactions with P selectin - P selection functions in adhesion
abnormal plt concentrations with leukocyte integrin a MB2
Laboratory features of BSS
normal responses to ADP, epinephrine, collagen and arachidonic acid
do not respond to ristocetin and thrombin
treatment for BSS
no tx as it is congenital
platelet transfusion - therapy of choice - however causes production ALLOANTIBODIES; thus PLATELETPHERESIS is better
management : desmopressin for enhancement of plt function
DDAVP or desmopressin means
1-deamino-8-D-arginine vasopressin
this 1-deamino-8-D-arginine vasopressin functions as
increases the function of PLT
what is missing in glanzmann thrombasthenia
GbIIb- IIIa responsible for aggregation
mode of inheritance of glanzmann thrombasthenia
rare autosomal recessive disease
who studied glanzmann thrombastenia
1918, eduard glanzmann
which deep tissue bleeding manifestation is not present in glanzmann’s thrombasthenia
deep hematoma
and recurrent hemarthrosis are not present
Manifests in the neonatal period or infancy, with bleeding after circumcision and frequent epistaxis and gingival
bleeding
GLANZMANN’S THROMBASTHENIA
Originally a bleeding disorder associated with abnormal in vitro clot retraction and normal platelet count
GLANZMANN’S THROMBASTHENIA
Hemorrhagic manifestation of glanzmann thrombasthenia
petechiae
purpura
menorrhage
GIT bleeding and hematuria
Bleeding is most common from mucosal surfaces (easy bruisability, epistaxis, gingival bleeding, prolonged
bleeding for minor cuts and menorrhagia)
glanzmann thrombasthenia
in glanzmann thrombasthenia, __ and ___ are seen in infants associated with crying
facial petechiae and subconjunctiva hemorrhages
Laboratory features of GLANZMANN THROMBASTHENIA
normal platelet count and platelet morphology
lack of plt aggregation in response to all plt activating agent (ADP, collagen, thrombin, epinephrine)
ristocetin-induced binding of VWF to plts and the resulting plt agglutination are normal
cbc is normal
procoagulant activity is diminised
GT platelets are not as activated as are normal plts
treatment of glanzmann thrombasthenia
transfusion of normal plt
to reduce alloabtibodies, single donor plts apheresis
recombinant factor VIIa
hormonal therapy to control menorrhagia
antifibrinolytic therapy to control gingival hemorrhage or excessive bleeding after tooth extraction
glanzmann thrombasthenia and bernard-soulier syndrome
plt count
normal in GT
decrease in BSS
glanzmann thrombasthenia and bernard-soulier syndrome
morphology
normal in GT
giant in BSS
glanzmann thrombasthenia and bernard-soulier syndrome
bleeding time
both prolonged - parehong plt function and problem eh
glanzmann thrombasthenia and bernard-soulier syndrome
plt aggregation - ADP
abnormal in GT
normal in BSS
glanzmann thrombasthenia and bernard-soulier syndrome
PLT AGGREGATION THROMBIN
both abnormal
glanzmann thrombasthenia and bernard-soulier syndrome
plt aggregation - collagen
both abnormal
glanzmann thrombasthenia and bernard-soulier syndrome
plt aggregation - epinephrine
abnormal GT
normal BSS
glanzmann thrombasthenia and bernard-soulier syndrome
plt aggregation - ristocetin
normal GT
abnormal BSS
what are the aggregating agent
ADP
THROMBIN
COLLAGEN
EPINEPHRINE
RISTOCETIN
QUEBEC plt disorder is originally described as
Platelet Factor 5 quebec
problem in quebec platelet disorder
platelet factor 5
problem in quebec platelet disorder
inability to form clot all together as it lacks PF5
Quebec platelet disorder
characterized by
bleeding - specific defect in plt function
this plt disorder resembles BSS
MEDITERRANEAN MACROTHROMBOCYTOPENIA
mode of inheritance of Mediterranean macrothrombocytopenia
autosomal dominant thrombocytopenia
in relation with BSS, it’s autosomal recessive
Mediterranean macrothrombocytopenia has a gene mutation to the short arm of chromosome ___
17 (GP Ia)
genotype and phenotype are equivalent to that of carrier of bernard soulier syndrome
Mediterranean macrothrombocytopenia
PLATELET STORAGE POOL DISEASE
hermansky-pudlak syndrome
chediak higashi syndrome
wiskott-aldrich syndrome
gray plt syndrome
mode of inheritance of hermansky-pudlak syndrome
rare autosomal recessive disorder
patient shows albinism (oculocutaneous) and may have hemorrhagic events
hermansky-pudlak syndrome
characterized by tyrosinase-positive oculocutaneous albinism, defective lysosomal function in a variety of cell types, ceroid-like deposition in the cells of the RES and profound platelet dense granule deficiency
hermansky-pudlak synrome
HERMANSKY-PUDLAK
SYNDROME (HPS)
which chromosome is affected
chromosome 19
Marked dilation and tortuosity of the surface connective tubular system (Swiss cheese
platelet)
HERMANSKY-PUDLAK
SYNDROME (HPS)
is bleeding in hermansky pudlak syndrome severe?
,most bleeding is not severe
An autosomal-recessive disorder, in which patients show albinism and giant lysosomal
granules in neutrophils
chediak higashi syndrome
Storage pool defect on dense granules
chediak higashi syndrome
Patients show frequent infections because of impaired phagocytic ability and death
usually occurs in childhood
chediak higashi syndrome
lab findings in chediak higashi syndrome
Neutropenia is present
thrombocytopenia
Partial oculocutaneous albinism
CHEDIAK-HIGASHI
SYNDROME
Platelet dense granule deficiency and hemorrhages
CHEDIAK-HIGASHI
SYNDROME
An X-linked recessive disorder in which patients show severe eczema, recurrent
infections, immune defects, thrombocytopenia and small platelets
WISKOTT-ALDRICH
SYNDROME
WISKOTT-ALDRICH
SYNDROME triad
thrombocytopenia
eczema
recurrent infection
diseases or conditions that patients with hermansky pudlak syndrome can acquire
albinism
lung disease (pulmonary fibrosis)
bleeding problem
vision loss
defect in plt granules
Alpha granules are absent or greatly reduced
GRAY PLATELET
SYNDROME
Gray platelet syndrome will result into leakage of
growth factor and cytokines in the marrow causing myelofibrosis
mode of inheritance of Gray plt syndrome
autosomal recessive
GRAY PLATELET
SYNDROM characteristics
thrombocytopenia
fibrosis of the marrow
large platelet
plt satellitism cause
anticoagulant - ply surrounds the neutrophil
ACQUIRED DEFECTS OF PLATELET FUNCTION
myeloproliferative disorders
cardiopulmonary bypass
paraproteinemia
liver disease
uremia
MYELOPROLIFERATIVE
DISORDERS (MPD) is characterized by
polycythemia vera
idiopathic myelofibrosis
cmk
essential thrombocythemia
Hemorrhagic manifestations of myeloproliferative disorders
epistaxis
ecchymosis
mucocutaneous bleeding from GUT and GIT