Lab investigation of the FBC Flashcards
What happens during normal haematopoeisis?
- Blood is made in the long bones from the bone marrow
- We start off making immature cells, which will gradually mature in the bone marrow
- When they are mature, they are pushed into the peripheral blood
What results do we get from an FBC?
Red cell
- Hb - conc of Hb
- haematocrit - percentage of blood volume that is RBCs
- Mean cell volume
- Mean cell haemoglobin
- Red cell distribution width - range of deviation around RBC size
- Reticulocyte count
- Blood film
White cell
- Total WBC and differential neutrophils, lymphocyes, monocytes, basophils and eosinophils
Platelets
- count and size
What does a blood film show?
red
- Size (big or small)
- Colour (Hb content)
- Shape
- Polychromasia
- Inculsions
White
- Numbers
- Normal morphology
- Immature cells (myelocytes, precursors)
- Abnormal cells - blasts
- Inclusions
Why would we do a blood film?
- If specifically asked, or if something abnormal comes up
- Smears are made and labelled
- Stained in a machine after conveyor belt process
What would a normal blood film look like?
- Most RBCs are round with an area of central pallor
- Little tiny spots = platelets
- Neutrophils have lobed nucleus - not too many
- Lymphocytes present (spotty cytoplasm) - not too many
What would an iron deficient anaemic blood film look like?
- Area of central pallor is much bigger
- Pale cells because less Hb
- Less platelets
What would a macroblastic megaloblastic anaemic blood film look like?
- arent round and regular
- Little tiny scrappy Hb bits
- Lots of ovalocytes
- Big cells with not enough RBCs
What would an acquired haemolytic anaemia blood film look like?
- Loss of central pallor
- spherocytes - round ball
- Polychromasia
- Some look more purple - take up more stain
What would a sickle-cell blood film look like?
- Sickle shaped RBCs
When would you see tear drop poikilocytosis?
Myelofibrosis
Bone marrow infiltration with malignant disease
What would a leucocytosis blood film look like?
Lots of WBCs in general
What would an AML blood film look like?
- Lots of blast cells present
- Very large nuclei, cant distinguish what they are
What would a chronic granulocytic leukaemia blood film look like?
- all stages of cell maturation represented
