Laboratory Investigation of the Full Blood Count and WBC disorders Flashcards
Draw a diagram of stem cell development pathways.
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What do you get out of red blood cell count?
Red Blood Cells Results:
- Hb: concentration of Haemoglobin - Hct: Percentage of blood volume as RBC - MCV: Mean Cell volume, average size of RBC - MCH: Mean corpuscular/cell haemoglobin, average haemoglobin content of RBC - RDW: Range of deviation around RBC size - Reticulocyte count - Blood film
What white blood cell information is included in a full blood count?
White Blood Cells Results - Total WBC and then differential WBSs - Neutrophils, lymphocytes, monocytes, - basophils, eosinophils Platelets results - Platelet count and size Others: Warning Flags
What do you look for in a blood film
Red cells: - Size- big or small- anisocytosis - Colour- Hb content - Shape- round, TDP, irregular, elliptocytes- poikilocytosis - Polychromasia - Inclusions White blood cells: - Numbers- too few or many - Normal morphology- dysplastic features - Immature cells- Myelocytes, precursors - Abnormal cells- blasts, atypical lymphoid cells - Inclusions
How could you identify an abnormal white blood cell profile?
FBC processed using optical scatter methods and presented in cytogram where population of cells are displayed in distinct cluster. (remember flow cytometry)
If the differentials are not displayed correctly, this alerts operator to refer the sample for a blood smear to be examined; as shown on left cytogram with immature granulocytes in the neutrophil region
What are the advantages and disadvantages of using an automated haematology analyzer?
Advantages:
Efficient and cost effective:
- processing of large number of samples.
Accuracy and precision of quantitative blood test
Ability to perform multiple test on single platform
Reduced labour requirements
Invaluable for accurate determination of red cell indices; e.g. MCV
Disadvantages:
Flagging of laboratory test results demand labour intensive manual examination of blood smear.
Comments on red cell morphology cannot be generated.
Platelet clumps are counted at single, so low count.
Expensive with high running cost
What does iron deficiency anaemia look like on a blood film?
In the iron deficiency anaemia blood film the cells are generally much smaller and also of different sizes
We also see some central pallor
So this is microcytic hypochromic anaemia
What is anisopoikilocytosis?
Red cells are much larger and of different shapes such as oval so these are referred to as macro ovalocytes
Haemoglobin content is higher in some of the cells so there’s a lack of central pallor
So this patient is suffering from B12 deficiency (from a gastrectomy) so there’s a delayed nuclear maturation so are much bigger
Macrocytic megaloblastic anaemia
What does acquired haemolytic anaemia look like on a blood film?
This patient has jaundice and splenomegaly
This blood film shows spherocytosis, small round red blood cells with no central pallor so they have lost their biconcave shape
Polychromasia can also be seen, cells with a more bluish hue, as they are reticulocytes which have more RNA within the cytoplasm
- Due to an increase in haemolysis
Also a lot of neutrophils
What is tear drop poikilocytosis?
Tear drop poikilocytosis – seen in myelofibrosis or bone marrow infiltration with malignant disease; large platelets
What does neutrophil leucocytosis look like on a blood film?
This patient is plethoric and has splenomegaly
There are microcytes, hypo chromatic, and tear-drop poikilocytes
Very high number of neutrophils
A couple of the red cells have prickles and the central pallor is much bigger
SO the red cells are microcytic hypochromic
There are also a lot of platelets
What does acute myeloblastic leukaemia look like on a blood film?
This patients has had a recent infection
The neutrophil count in low but the white blood cell count is high
A patient with leukaemia will have a much larger amount of WBCs
There is a huge number of blast cells
So this is called acute myeloblastic leukaemia
There are also very few platelets
What does chronic granulocytic leukaemia look like on a blood film?
This is a 48M with L-sided abdominal discomfort and a painful foot
Very very high neutrophil count
So he suffers from chronic granulocytic leukaemia so there are all stages of granulocyte maturation here
So we see some blast cells, some myelocytes and meta-myelocytes, band-neutrophils (pre-neutrophils)
The red cells are hypochromic and there are a few platelets
What does malarial parasitization of red cells look like on a blood film?
26M has a fever, is confused and has been to Kenya recently
Low white cells count and platelet count
Blood film shows malarial parasites in the RBCs
What is the malarial antigen test?
Currently, the only available RDT for malaria in the United States is the BinaxNOW® Malaria Test.
The Binax assay contains both the HRP II (for P. falciparum) and aldolase which is a pan-malarial antigen.
It cannot separate non-falciparum species.
The Binax assay should always be accompanied by thick and thin film microscopy.
HRT – Histidine-rich protein
pLDH – plasmodium lactate dehydrogenase
