Thrombocytopenia

Question 1

what is thrombocytopenia?

Answer 1

low platelet count
normal is 150-450 x 10 9 /L
productoin or destruction

Question 2

problems with platelet production

Answer 2

(not enough production)

Sepsis
B12 or folic acid deficiency
Liver failure causing reduced thrombopoietin production in the liver
Leukaemia
Myelodysplastic syndrome

Question 3

problems with platelet destruction

Answer 3

(too much destruction)

Medications (sodium valproate, methotrexate, isotretinoin, antihistamines, proton pump inhibitors)
Alcohol
Immune thrombocytopenic purpura
Thrombotic thrombocytopenic purpura
Heparin-induced thrombocytopenia
Haemolytic-uraemic syndrome

Question 4

presentation of thrombocytopenia

Answer 4

mild can be asymptomatic and incidental finding

<50 x 10.9/L results in easy or spontaenous bleeding and prolonged bleeding times

nose bleed, bleeding gums, heavy periods, easy bruising or blood in urine or stools

platelt count <10x10 high risk of spontaenous bleeding. intracranial haemorrhage, GI bleeds

Question 5

differential diagnosis for abnormal or prolonged bleeding

Answer 5

Thrombocytopenia (low platelets)

Haemophilia A and haemophilia B

Von Willebrand Disease

Disseminated intravascular coagulation (usually secondary to sepsis)

Question 6

ITP

immune thrombocytopenia purpura

Answer 6

autoimmune thrombocytopenic purpura

antibodies are created againt platelets

mx:
Prednisolone (steroids)
IV immunoglobulins
Rituximab (a monoclonal antibody against B cells)
Splenectomy

monitor and educate
concerning signs - persistent headache, malena etc

monitor BP and supress menstural periods

Question 7

TTP

thrombotic thrombocytopenic purpura

Answer 7

tiny blood clots develop through the small vessels of the body (+ microangiopathy)
uses up platelets

protein ADAMTS13 normally inactivates VWF and reduces platelt adhesion to vessels. if there is a shortage then VWF willl be overactive= formatin of clots in small vessels. lots of platelts ued up leading to thromboyctpenia

small vessels break up RBC= haemolytic anaemia

treat: plasma exchange, steroids, rituximab

Question 8

heparin induced thrombocytopenia

Answer 8

HIT
development of antibodies against platelts in response to exposure to heparin

heparin induced antibodies target platelt factor 4 (anti PF4/heparin antibodies)

HIT bind to platelt and active clotting mechniams. cause a hypercoagulable state and lead to thrombosis.

break down platelt and cause thrombocytopenia

diagnose = test ofr HIT antibodies.