Intro to Haem Flashcards
Haematopoiesis (from bone marrow to circulation) outline the process then the products…
uncommited stem cell > committed stem cell > following below: erythroblast –> erythrocyte, megakaryocyte –> platelets, other cells formed: neutrophils, monocytes, basophils, eosinophils, lymphocytes
name the myeloid cells
erythrocytes, mast cells, platelets, neutrophils, monocytes, basophils, eosinophils,
name the lymphoid cells
NK CELLS, T cells AND B cells
stem cells are…
totipotent and can self renew
outline the process of erythroid differentiation
eryhtroblast –> reticulocyte –> erythrocyte
where is epo (erythropoietin) made?
in the kidneys in response to hypoxia
what is reticulocyte count?
a measure of rbc production
whata er the ocnsequences of anaemia?
poor gas transfer, dyspnoea, fatigue. (may be casued by increased loss - bleeding, haemolysis) (may also be caused by decreased rpoduction - haemantics deficiency e.g. iron, folate, vitB12 or congenitally - thalassaemias)
what is the function of platelets
haemostasis (clotting)
what regulates platelet production?
thrombopoietin (produced in the liver, Regulation by platelet mass feedback Agonists (romiplostim, eltrombopag) used therapeutically, Lifespan =7 days)
funciton of neutrophils
Function: to ingest and destroy pathogens, especially bacteria and fungi, Interleukins (‘between white cells’) and CSFs (colony stimulating factors) granulocyte colony stimulating factor (G-CSF), regulation by immune responses , Macrophages, IL-17, Lifespan =1-2 days, Speed of response=few hours
neutrophlia…
Production regulated by granulocyte-colony stimulating factor (G-CSF) - Infection, Left shift, toxic granulation, Inflammation eg MI, postoperative, rheumatoid arthritis. G-CSF used therapeutically. Neutropenia, Mobilisation of stem cells.
neutropenia…
Decreased production - Drugs, Marrow failure
Increased consumption - Sepsis, Autoimmune
Altered function - eg chronic granulomatous disease
what are monocytes?
Function: to ingest and destroy pathogens, especially bacteria and fungi, Subset of monocytes migrate into tissues and become macrophages or dendritic cells, Some populations of macrophages self-maintaining.
what do eosinophils do?
fight parasites and become active in allergies
what are Lymphocytes?
Adaptive, versus innate, immune system, Immunological memory, Surface antigens: CD markers. Lymphocytosis - Infectious mononucleosis, Pertussis. Lymphopenia - Usually post-viral, lymphoma
Produced in bone marrow
B cells mature in bone marrow, T cells in thymus
Circulate in blood, lymph and lymph nodes
Differentiate into effector cells in secondary lymphoid organs (lymph nodes or mucosal associated lymphoid tissue)
list the subtyoes of lmyphocytes and their functions
B cells – make antibodies
T cells – Helper, cytotoxic, regulatory
NK cells
what is positive selction?
if gene rearrangement results in a functional receptor the cell is selected to survive – positive selection
what is negative selection?
If the receptor recognises ‘self’ antigens - the cell is triggered to die – negative selection: tolerance
HLA TYPE 1 AND 2
Human Leukocyte antigen - immune cells read HLA-barcode on cells to help identify self vs non-self cells or infected vs noninfected cells (an immune response is triggered if a infected cell is identified).
Class I: displays internal antigens on all nucleated cells
Class II: displays antigens eaten by professional antigen presenting cells
what systemic dieseases effect the blood?
rheumatoid arthritis, Anaemia of chronic disease, Iron deficiency, Folate deficiency, Immune haemolysis, Neutrophilia, Immune thrombocytopenia, Cytopenias, secondary to medication, Felty syndrome (triad of RA, splenomegaly and neutropenia, resulting in susceptibility to bacterial infections)
what are formed if there is too much plasma?
Paraproteins
name some disgnostic tools
FBC, clotting times, INR, chemical assays (Fe (ferritin), B12, Folate), marrow aspirate and trephine biopsy, lymph node biopsy, imaging (plain film, CT),
Haematology Tx
Replacement, Blood, Haematinics, Coagulation factors, Plasma exchange, Transplantation, Drugs: Cytotoxics, Monoclonal antibodies, inhibitors of cellular proliferation, Immunosuppressants, Inhibitors of coagulation, Inhibitors of fibrinolysis
