Haematology Flashcards
What are causes of anaemia in infancy?
- Physiologic anaemia of infancy MC
- Anaemia of prematurity
- Blood loss
- Haemolysis (caused by things like haemolytic disease of newborn, hereditary spherocytosis, G6PD deficiency)
- Twin-twin transfusion
What test can be used to check for immune hameolytic anaemia?
Direct Coombs test (DCT)
Causes of microcytic anaemia?
- T – Thalassaemia
- A – Anaemia of chronic disease
- I – Iron deficiency anaemia
- L – Lead poisoning
- S – Sideroblastic anaemia
What is fanconi anaemia?
Rare, inherited genetic disorder that primarily affects bone marrow resulting in pancytopenia.
What inheritance pattern is fanconi anaemia?
Autosomal recessive
Complications of fanconi anaemia?
- Acute myeloid leukemia (AML)
- Squamous cell carcinomas
Sx of fanconi anaemia?
Congenital abnormalities:
* Short stature
* Skeletal abnormalities - in thumb/radius (forearms)
* Cafe-au-lait spots
* Microcephaly (small head size)
* Eye abnormalities - small eyes or strabismus (crossed eyes)
* GU abnormalities
Ix for fanconi anaemia?
- Bloods - pancytopenia (due to bone marrow failure)
- Chromosome breakage tests
- Genetic testing
What is haemophilia A and B?
Inherited bleeding disorders caused by deficiencies in clotting factors 8 (A) and 9 (B) both which are imp. components of intrinsic pathway of coagulation cascade.
What kind of genetic inheritance are haemophilia A and B?
X-linked recessive
Sx of haemophilia A and B?
- Spontaneous deep and severe bleeding into soft tissues, muscles and joints (resulting in a deforming arthropathy)
- Excessive bleeding following trauma or surgical intervention
- Cerebral haemorrhage
Ix for haemophilia?
- Coagulation factors 8/9 assay
- Bloods: clotting profile (APTT elevated), vWF antigen, defective platelet
- Genetic testing
Mx of haemophilia?
- For minor bleeds for haemophilia A pts: desmopressin (DDAVP)
- For major bleeds: IV infusion - recombinant factor VIII or IX
- Supportive mx for bleeding wounds - Antifibrinolytics (eg. tranexamic acid)
What is Von Willebrand disease (VWD)?
Inherited bleeding disorder characterised by reduced quantity or function of von Willebrand factor which is a protein that normally links platelets to the exposed endothelium and stabilises clotting factor 8. Therefore it’s deficiency leads to inc. risk of bleeding.
Describe the following subtypes of VWD:
* Type 1 VWD
* Type 2 VWD
* Type 3 VWD
- Type 1 VWD: Partial quantitative deficiency in VWF
- Type 2 VWD: Qualitative defects in VWF (e.g. decreased adhesion to platelets or factor VIII)
- Type 3 VWD: Almost complete deficiency of VWF
Pts w/ type 2 or 3 VWD have more severe sx + at earlier stage than pts w/type 1.
Sx of VWD?
- Excess/prolonged bleeding from minor wounds
- Excess/prolonged bleeding post-operatively
- Easy bruising
- Menorrhagia
- Epistaxis (nose bleed)
- GI bleeding
Ix for VWD?
- Clotting tests - Prolonged APTT
- Normal platelet count
- GS - Von Willebrand factor level and activity assay
Mx of VWD?
- 1st line - Desmopressin (inc. factor 8 and VWF levels)
- Can increase VWF through blood transfusions
- Give tranexamic acid for minor bleeds/prior to surgery
What is immune thrombocytopenia purpura?
Autoimmune cdtn characterised by reduction in number of circulating platelets - T2 hypersensitivity reaction.
Primary causes of ITP?
viral infection or following immunisation
Sx of ITP?
- Easy or excessive bruising (purpura)
- Superficial bleeding into skin that appears as rash of pinpoint-sized reddish-purple spots (petechiae) (usually on the lower legs)
- Prolonged bleeding from cuts
- Spontaneous bleeding from the gums or nose
- Blood in urine or stools
- heavy menstrual flow
ITP presents with mucocutaneous bleeding (rather than e.g. haemarthrosis which is often associated with defects in the coagulation cascade like in haemophilia)
Ix for ITP?
- FBC - platelet count
- Blood film
- Infl. markers
- Bone marrow biopsy
Tx of ITP
- Usually no tx require as pts return to normal spontaneously
- If severe (platelets<10):
* Prednisolone
* IVIG
* Blood transfusions
* Platelet transfusions - only works temporarily
What medications should someone with ITP avoid?
NSAIDs, aspirin and blood thinning medications
