Qualitative Platelet Defects

Question 1

Inheritance and defect in Glanzmann Thrombasthenia

Answer 1

AR defect in GPIIb/IIIa (the functional aggregation receptor)

Question 2

Platelet aggregation studies:
ADP: Reduced
Epinephrine: reduced
Collagen: Reduced
Ristocetin: Normal
Diagnosis?

Answer 2

Glanzmann Thrombasthenia

Question 3

Management of Glanzmann Thrombasthenia?

Answer 3

Platelet transfusions
If refractory to transfusions, recombinant FVII

Question 4

Inheritance and defect seen in Bernard Soulier Disease

Answer 4

AR defect in GP1b/IX

Question 5

Platelet aggregation studies:
ADP: normal
Epinephrine: Normal
Collagen: Normal
RIstocetin: Markedly reduced
Diagnosis?

Answer 5

Bernard Soulier

Question 6

30 year old with mild mucocutaneous bleeding presents with mild thrombocytopenia, normal coags, increased platelet size on smear and platelet aggregation studies that show normal aggregation to ADP, epinephrine, and collagen. There is markedly reduced aggregation to ristocetin. Diagnosis?

Answer 6

Bernard Soulier

Question 7

Patient presents with moderate thrombocytopenia, large platelets seen on smear that seem to lack granules. B12 levels are elevated. Platelet aggregation studies show ADT reduced, epinephrine shows normal primary wave but absent secondary wave, normal ristocetin. Diagnosis?

Answer 7

Grey platelet syndrome

Question 8

What is a potential complication of grey platelet syndrome?

Answer 8

Myelofibrosis

Question 9

Patient with oculocutaneous albinism and pulmonary fibrosis presents with GI bleeding. Platelet count and peripheral smear are normal. Coags are normal. Platelet studies show normal ristocetin, sligtly reduced to collagen and epinephrine. There is a lack of a secondary wave to ADP. Diagnosis?

Answer 9

Hemansky-Pudlak Syndrome

Question 10

What is the defect seen in Quebec Platelet Syndrome? And what is the inheritance?

Answer 10

AD of increased expression of urokinase plasminogen activator within alpha granules of platelets. Causes intraplatelet generation of plasmin, and degradation of proteins within alpha granules, causing premature lysis of thrombi

Question 11

How does Quebec platelet syndrome typically present?

Answer 11

Delayed onset severe bleeding after surgery or trauma

Question 12

Management of uremia platelet dysfunction? (6)

Answer 12

HD
Platelet transfusion (not ideal, very transient)
DDAVP
Cryo
RBC transfusions
Conjugated estrogens

Question 13

Treatment for Bernard Soulier disease

Answer 13

DDAVP