Introduction to Haematology Flashcards
label the components of blood
how is anaemia classified?
anaemia = low Hb
what are some causes for microcytic anaemia?
MCV < 78fL
- iron deficiency anaemia
- haemoglobinopathies e.g. thalassaemia
what are some causes for normocytic anaemia?
MCV 78-98 fL
- anaemia of chronic disease
- bone marrow failure
what are some causes of macrocytic anaemia?
MCV > 98fL
- haematinic deficiency
- haemolysis
- other non-megaloblastic causes
what is leukopenia?
Low total WBC count. Can occur because of a reduction in number of all WBCs or specific cells e.g. neutrophils (neutropenia), lymphocytes (lymphopenia).
what is leucocytosis?
High total WBC count. Either from increase in all WBCs or specific cells e.g. neutrophils (neutrophilia), eosinophils (eosinophilia), lymphocytes (lymphocytosis).
what is thrombocytopenia?
A reduced platelet count.
Caused by decreased production or increased consumption of platelets.
what is thrombocytosis?
A high platelet count. Caused by increased production (e.g. response to inflammation) or decreased consumption (hyposplenism).
What is pancytopenia?
Combination of:
- anaemia (low red blood cells)
- thrombocytopenia (low platelets)
- leucopenia (low white blood cells)
Happens when abnormal myeloid stem cells in the bone marrow do not develop into normal blood cells.
Pancytopenia symptoms
Often vague at first:
- anaemia: tiredness, breathlessness
- more frequent infections: fever, cough, headache
- abnormal bleeding: nose bleeds, bleeding gums, bruising, blood clots.
- bone pain in your back or hips.
- other: weight loss, loss of appetite, swollen glands and headaches.
what are some causes of bone marrow failure?
- malignancy/clonal: blood and others
- drugs: chemotherapy, other cytotoxics, antibiotics
- infection (HIV)
- nutritional
- radiation, poisons
- congenital
define acute leukaemia
- A cancer of ‘blast’ cells in bone marrow.
- Blasts crowd out normal haematopoiesis and cause marrow failure.
- They circulate in blood and can cause enlarged spleen or liver.
define chronic leukaemia
- Cancers of marrow where lymphocytes (CLL) or granulocytes (CML) spill into blood and infiltrate the liver, spleen (and lymph nodes in CLL).
- Marrow failure can occur late in disease.
what is a lymphoma?
- A cancer of lymphocytes in lymph nodes and extra-nodal areas (spleen, liver, bone marrow etc).
- If lymphoma is in the bone marrow you may find lymphoma cells in the blood.
Since Non-Hodgkin’s lymphomas (NHLs) are such a diverse group of diseases, clinicians often subdivide them:
Low grade:
- Indolent: grow over months-years.
- may not require treatment until symptoms develop.
- treat to induce remission but not cure.
High grade:
- aggressive
- life-threatening and need urgent treatment
- often more curable
Describe the Prothrombin Time test.
A coagulation screen test
- The PT is the time taken for the sample of blood to clot after tissue facter and calcium are added.
- normal range: 10-13.5 seconds
- test of: extrinsic (and common) pathways (PeT)
what causes a prolonged Prothrombin time?
- problems with factors II, V, VII, X or fibrinogen (either a deficiency or inhibitor)
- warfarin use/vitamin K deficiency
- liver disease +++
- disseminated intravascular coagulation (DIC)
Describe a APTT.
a coagulation screen test
- aPTT is the time taken for the sample of blood to clot after a contact activator and Ca2+ are added.
- normal range: 25-35 seconds
- test of: intrinsic (and common) pathway (A PinTT)
what causes a prolonged aPTT?
- problems with factors II, V, VIII, IX, X, XII or fibrinogen
- heparin therapy
- ‘lupus anticoagulant’/antiphosphilipid antibodies
- liver disease +
- disseminated intravascular coagulation
what are anticoagulant drugs?
Anticoagulant drugs interfere with secondary haemostasis (i.e. coagulation factors). We tend to distinguish them from antiplatelet drugs or thrombolytic therapies.
how is the severity of haemophilia determines?
describe the main functions of plasma
- Transporting blood cells
- Transporting nutrients and waste: Plasma carries nutrients, hormones, and proteins to the body’s cells, and waste products away from the cells.
- Maintaining blood pressure and volume
- Maintaining pH balance
- Regulating body temperature
- Clotting blood
- Supporting immunity
- Maintaining fluid balance
- Supporting blood vessels
what is the function of the spleen?
- filtering blood: removes old and damaged red blood cells, as well as germs and other abnormal cells.
- controlling blood cell levels
- producing immune system components: lymphocytes and antibodies
- storing blood and iron for body to use later
- regulating blood flow
what are some causes of splenomegaly?
- infections: HIV, tuberculosis, endocarditis, malaria, toxoplasmosis.
- liver disease: chronic hepatitis or chirrhosis
- cancer: leukemia, myeloproliferative neoplasms (MPNs) aand lymphomas.
- focal lesions
- autoimmune disease: lupus, sarcoidosis, RA.
- inherited metabolic disorders e.g. sickle cell
- thrombosis
