Disorders of Platelets and vessel wall

Question 1

How is the production of TPO regulated?

Answer 1

Synthesis is increased with inflammation and specifically by interleukin 6. TPO binds to its receptor on platelets and megakaryocytes, by which it is removed from the circulation.

Question 2

heparin differs from that seen with other drugs in two major ways. Enumerate

Answer 2

counts rarely less than 20,000/μL. (2) Heparin-induced

thrombocytopenia (HIT) is not associated with bleeding and, in fact, markedly increases the risk of thrombosis.

Question 3

4T’s” have been recommended to be used in a diagnostic algorithm for HIT. Enumerate

Answer 3

thrombocytopenia, timing of platelet count drop, thrombosis and other sequelae such as localized skin reactions, and other causes of thrombocytopenia not evident

Question 4

% dos doentes que fazem bypass cardiopulmonar desenvolvem anticorpos anti-heparina/PF4

Answer 4

50%

Question 5

anticoagulants used in HIT?

Answer 5

direct thrombin inhibitors (DTIs) argatroban and lepirudin; Danaparoid, a mixture of glycosaminoglycans with anti-Xa activity

Question 6

Causes of secondary ITP

Answer 6

autoimmune disorders, particularly systemic lupus erythematosus (SLE), and infections, such as HIV and hepatitis C, are common causes. The association of ITP with Helicobacter pylori infection is unclear.

Question 7

TPO receptor agonists

Answer 7

Two agents, one administered subcutaneously (romiplostim) and another orally (eltrombopag)

Question 8

autosomal dominant thrombocytopenia

Answer 8

May-Hegglin anomaly, and Sebastian, Epstein’s, and Fechtner syndromes

Question 9

Autosomal recessive thrombocytopenia

Answer 9

congenital amegakaryocytic thrombocytopenia, thrombocytopenia with absent radii, and Bernard-Soulier syndrome

Question 10

X-linked thrombocytopenia

Answer 10

Wiskott-Aldrich syndrome and a dyshematopoietic syndrome

Question 11

introduction of treatment with plasma exchange markedly improved the prognosis in patients. How much?

Answer 11

decrease in mortality from 85–100% to 10–30%

Question 12

% of relapse in PTT?

Answer 12

25– 45% of patients relapse within 30 days of initial “remission,” and 12–40% of patients have late relapses

Question 13

mortality in SHU?

Answer 13

overall mortality is 5%. 26% atypical

Question 14

Inherited platelet function disorders

Answer 14

autosomal recessive disorders Glanzmann’s thrombasthenia and Bernard-Soulier syndrome; Platelet storage pool disorder (SPD) is the classic autosomal dominant; secretion defects

Question 15

prevalence of VWD?

Answer 15

prevalence of approximately 1%

Question 16

most common type of VWD?

Answer 16

type 1– 80%

Question 17

Genes involved in the pathogenesis of the arteriovenous malformation (AVM) in the lung in Osler-WeberRendu disease

Answer 17

eng (endoglin) associated with pulmonary AVM in 40% of cases, and alk1, associated with a much lower risk of pulmonary AVM