Platelet disorders

Question 1

What are the 2 types of haemophilia’s? What’s their genetic inheritance? What’s their symptoms? Important findings on clotting profile? How do you treat them?

Answer 1

• A (8 deficiency) & B (9 deficiency)
• x-linked recessive
• haemoarthoses, haemotomas of muscles, prolonged bleeding after surgery or trauma
• prolonged APTT (everything else normal)
• replace factors missing

Question 2

4 causes of severe thrombocytopaenia?

Answer 2

• Immune (idiopathic) thrombocytopaenia purpura
• Thrombotic thrombocytopaenia purpura
• Disseminated intravascular coagulation
• bone marrow failure

Question 3

Tell me about ITP please.

Answer 3

• immune-mediated reduction in platelets
• can be acute or chronic
• anti-bodies against platelet surface antigens
• signs = isolated thrombocytopaenia, non-blanching purpuric rash, easily bruising, mucosal bleeding (periods, gums, noses)
• acute - self-limiting last 1-2 weeks
• chronic - autoimmune Hx, relapsing remitting course, female more likely

Question 4

How is ITP treated?

Answer 4

• stop NSAIDS/aspirin/anti-coagulation
• observe platelet count
• Prednisolone
• IVIG
• 2nd line - rituximab

Question 5

Tell me more about TTP.

Answer 5

• thrombotic thrombocytopaenia purpura
• The Terrible Pentad
• pentad = thrombocytopaenia, anaemia, fever, altered mental state, renal dysfunction
• something about increased vWF and that causing platelets to aggregate
• Tx - supportive, steroids immune suppress, Vincristine

Question 6

Tell me about DIC.

Answer 6

• Disseminated intravascular coagulation
• inappropriate activation of coagulation cascade caused by trauma, infection and obstetric complications, transplant rejection, pancreatitis
• microthrombi EVERYWHERE w/ concurrent consumption of clotting factors + platelets
• Ix - APTT/PT/INR increased, D-Dimer increased, fibrinogen low (doesn’t happen in other thrombocytopaenias)
• evidence of end organ damage

Question 7

How do you treat DIC?

Answer 7

• Treat underlying cause

- supportive - transfuse platelets, FFP and cryoprecipitates

Question 8

Tell me about HUS.

Answer 8

• Haemolytic uraemic syndomre (HUS = Haemolysis, Uraemia, Stomach virus)
• toxin mediated haemolysis with platelet aggregation in the kidney
• E.Coli H157:H7 causes bloody diarrhoea
• anaemia (schistiocytes), thrombocytopaenia, increased creatine therefore acute renal failure
• Supportive Tx - fluids, dialysis - NO abx