Haematology Flashcards
What are the blood components and products?
Plasma - Clotting or coagulation factors, albumin, antibodies.
Buffy coat - platelets, white cells or leucocytes.
Red Blood Cells
What does blood transport?
RBC - gases - oxygen and carbon dioxide.
Plasma - Nutrients, waste, messages.
How does blood allow maintenance of vascular integrity of the blood?
Prevention of leaks - platelets and clotting factors.
Prevention of blockages - anticoagulation and fibrinolytics.
How does the blood protect from pathogens?
Phagocytosis and killing - granulocytes and monocytes.
Antigen recognition and antibody formation - lymphocytes.
What do haematological abnormalities mean?
High levels:
Increased rate of production, decreased rate of loss.
Low levels:
Decreased rate of production, increases rate of loss.
Altered function.
Describe stem cells
Totipotent
Self-renewal
Home to marrow niche
Binary fission and flux through differentiation pathways amplify numbers.
Flux regulated by hormones/growth factors.
Stem cell properties can now be “induced”
What does a erythroblast become when it is differentiated?
Reticulocyte and then erythrocyte.
What is reticulocyte count?
Measure of red cell production.
When is erythropoietin made?
In kidney in response to hypoxia.
What are the consequences of anaemia?
Poor gas transfer: dyspnoea and fatigue.
Decreased production.
Increased loss.
What red cells are there?
Microcytes, macrocytes
Polychromasia
Burr cells in renal failure.
What is the function of platelets?
Haemostasis (immune)
Production regulated by thrombopoietin - produced in liver.
Lifespan of 7 days.
What is the function of neutrophils?
To ingest and destroy pathogens, especially bacteria and fungi.
Interleukins and CSFs.
Regulation by immune responses.
Lifespan = 1-2 days
Speed of response is few hours.
What are the cells in differentiation of neutrophil?
- Blast
- Promyelocyte
- Myelocyte
- Metamyelocyte
- Neutrophil.
What is neutrophilia?
Elevated neutrophil count.
Production regulated by granulocyte-colony stimulating factor.
Bacterial Infection most common cause - left shift, toxic granulation.
Inflammation.
G-CSF used therapeutically.
What is Neutropenia?
Low neutrophil count.
Decreased production - drugs, marrow failure.
Increased consumption - sepsis, autoimmune.
Altered function
What is the function of monocytes?
To ingest and destroy pathogens, especially bacteria and fungi.
Subset monocytes migrate into tissues and become macrophages.
What are lymphocytes?
Adaptive, versus innate, immune system.
Surface antigens: CD markers.
What is Lymphocytosis?
High level of lymphocytes - acute viral infection.
- Pertussis
- Infectious mononucleosis.
What is Lymphonopenia?
Low levels of lymphocytes
- usually post-viral
- lymphoma
What are the subtypes of lymphocytes?
B cells - make antibodies
T cells - Helper, cytotoxic, regulatory
NK cells
Where are lymphocytes produced?
Bone marrow
B cells mature here
T cells mature in thymus.
What are antibodies?
Antibodies are proteins produced and secreted by B cells. They bind to foreign substances that invade the body, such as pathogens.
What is positive selection?
In the bone marrow if gene rearrangement results in a functional receptor the cell is selected to survive.
What is negative selection?
If the receptor recognises”self”antigens - the cell is triggered to die. Tolerance.
What are the 2 classes of human leucocyte antigen?
Class 1: displays internal antigens on all nucleated cells.
Class 2: Displays antigens eaten by professional antigen presenting cells.
How do the immune cells read HLA on cells?
They read it to help identify self vs non self cells or uninfected vs infected cells.
Immune response triggered if infected cell in identified.
What can happen with
- Too much
- Too little
- Abnormal function of plasma?
- Paraproteins
- Clotting factors: haemophilia
- Clotting factors - haemophilia.
What are the diagnostic tools for blood?
Full Blood count Clotting times for factors and platelets. Chemical assays: Iron (ferritin) B12 Folate Marrow aspirate and trephine biopsy. Lymph node biopsy. Imaging.
What are some of the replacement treatments for Haematology?
Blood
Haematinics
Coagulation factors
Plasma exchange
What are the drug available for Haematology treatment?
Cytotoxics. Monoclonal antibodies. Inhibitors of cellular proliferation. immunosuppressants. Inhibitors of coagulation. Inhibitors of fibrinolysis.
Where do blood groups arise from?
Antigens = something that provokes an immune response.
Red cell antigens are expressed on the cell surface - can provoke antibodies.
What do blood group A have antibodies against?
Blood group B
What do blood group B have antibodies against?
Blood group A
What blood group do O have antibodies against?
A and B
Blood group AB antibodies?
No antibodies against A or B
Group A can receive blood from who?
A and O
Group B can receive blood from who?
B and O
AB can receive blood from who?
A, B, AB and O
O can receive blood from who?
O
A can receive Fresh frozen plasma from who?
A, AB
B can receive fresh frozen plasma from who?
B, AB
AB can receive fresh frozen plasma from who?
AB
O can receive fresh frozen plasma from who?
A, B, AB, O
What are the RhD blood groups?
Either you are RhD positive or RhD negative depending on inheritance from parents.