HAEM; Lecture 11 and Tutorial 12, 13 - Abnormal White Cell count Flashcards
What is haemopoiesis?
Production of blood cells in Marrow
What is normal haemopoiesis?
Polyclonal healthy/reactive -> normal/reactive marrow
What is malignant haemopoiesis?
Abnormal/clonal -> leukaemia (lymphoid, myeloid), myelodysplasia, myeloproliferative
How does normal haematopoiesis work?
Self-renewing cells (haemopoietic cells)
How does a myeloblast differentiate into a neutrophil?
NB: In peripheral blood the precursors are not seen in normal conditions -> BUT in CML you will see all precursors in peripheral blood or in chemotherapy with GCSF; in septic blood you can also find some myeloid precursors
What factors control differentiation and proliferation?
Cytokines -> Erythroid part = erythropoietin, lymphoid = IL2, myeloid = G-CSF and M-CSF
What happens if DNA is damaged during differentiation and proliferation of white cells?
Cancer -> leukaemia, lymphoma, myeloma
What are the different lymphoblasts in the bone marrow?
Myeloblasts, promyelocytes, myelocytes, metamyelocytes
What are the immunocytes and phagocytes present in peripheral blood?
Immunocytes: T/B and NK cells. Phagocytes: Granulocytes - neutrophils, eosinophils, basophils; monocytes
What are the different reasons why abnormal WBC occur?
Increased or decreased number of WBC -> either increase/decrease cell production, decreased/increase cell survival
When do WBC pass from the bone marrow to the peripheral blood and how does that differ in Haemopoietic cancers?
What are the 2 types of eosinophilia infections causing increased cell numbers?
Reactive and Primary (malignant)
How does reactive eosinophilia affect haemopoiesis and what are the causes?
Keeps it normal, stimulating by inflammation, infection, increased cytokine production (distant tumour, haemopoietic or non haemopoietic)
How does primary eosinophilia affect haemopoiesis and what are the causes?
Causes abnormal haemopoiesis (autonomous cell growth) -> cancers of haemopoietic cells, leukaemia (myeloid/lymphoid, chronic/acute), myeloproliferative disorders
How does malignant haematopoiesis affect differentiation?
Haemopoietic stem cells have had DNA damage which means that when it differentiates can lead to an increased number of megakaryocytes, granulocytes and monocytes
How do you investigate a raised WCC?
History and examination (if recent infection, enlarged spleen), Hb and platelet count, Automated differential (machine can’t recognise immature cells), examine blood film (most important to make a diagnosis), abnormality in white cells only or all 3 (red/platelets/white), 1 white cell type only or all (common in reactive conditions to see more than one), mature cells only or mature and immature?
If mature white cells ONLY are elevated, what could the diagnosis be?
No underlying leukaemia as no immature cells