Haematology Flashcards
What is serum?
Blood minus clotting factors.
Serum contains:
Glucose
Electrolytes such as sodium and potassium
Proteins such as immunoglobulins and hormones
What is plasma?
The liquid component of blood. Contains RBCs, WBCs, platelets and clotting factors (eg fibrinogen).
What is the bone marrow and what does it do?
Found in pelvis, vertebrae, ribs and sternum. Blood cells develop in the BM.
What can pluripotent haematopoietic stem cells develop into?
Myeloid Stem Cells (–> reticulocytes –> RBCs)
Lymphoid Stem Cells
Dendritic Cells
What are reticulocytes?
Reticulocytes are immature red blood cells
What are platelets? What is their lifespan?
Platelets clump together to cause clots to stop bleeding. They are made by megakaryocytes. Their lifespan is 10 days.
Promyelocytes become:
Monocytes then macrophages Neutrophils Eosinophils Mast Cells Basophils
Lymphoid stem cells become:
B cells or T cells.
B cells mature in the:
Bone marrow
T cells mature in the:
Thymus gland
B cells become
plasma cells and memory B cells
T cells become
CD4 (T helper) cells, CD8 (T killer cells), natural killer cells
What does anisocytosis mean and what does it indicate?
Variation in size of RBCs on blood film. Seen in myelodysplasic syndrome
What do target cells indicate?
Seen on blood film in iron deficiency anaemia and post-splenectomy.
What do Heinz bodies indicate?
Denatured globin on blood film, seen in G6PD and alpha-thalassaemia.
What do Howell-Jolly bodies indicate?
DNA material seen in RBCs on blood film, post-splenectomy and severe anaemia.
What do reticulocytes on blood film indicate?
Immature RBCs, large, contain RNA. High reticulocytes = rapid turnover of RBCs, high BM activity eg haemolytic anaemia.
What do schistocytes on blood film indicate?
Fragments of RBCs. Indicate damage (‘schearing) of RBCs, possibly due to small vessel clots –> HUS, DIC, TTP, or in replacement metallic heart valves, haemolytic anaemias.
What do sideroblasts on blood film indicate?
Immature RBCs that contain blobs of iron. BM unable to incorporate iron into hb molecules eg myelodysplasic syndrome.
What do smudge cells on blood film indicate?
Ruptured WBCs that occur during process of preparing blood film due to aged or fragile WBCs, eg CLL
What do spherocytes on blood film indiate?
Spherical RBCs, eg in autoimmune haemolytic anaemia or hereditary spherocytosis.
Give 2 causes of microcytic anaemia.
Thalassaemia Anaemia of chronic disease Iron deficiency Lead poisoning Sideroblastic
Give 2 causes of normocytic anaemia.
Acute blood loss Anaemia of chronic disease Aplastic Haemolytic Hypothyroidism
Give 2 causes of megaloblastic macrocytic anaemia.
B12 and folate deficiency. Causes impaired DNA synthesis preventing cell from dividing normally, so it keeps growing into a larger, abnormal cell.
Give 3 causes of normoblastic macrocytic anaemia.
Alcohol Reticulocytosis (haemolytic/blood loss) Hypothyroidism Liver disease Drugs eg azathioprine.
How does anaemia present?
Tiredness
Shortness of breath
Headaches
Dizziness
Palpitations
Worsening of other conditions such as angina, heart failure or peripheral vascular disease
Signs: pale, conjuctival pallor, tachycardia, tachypnoea
Give 3 specific features of iron deficiency anaemia.
Pica - dietary cravings for abnormal things such as dirt and can signify iron deficiency
Gradual patchy hair loss/brittle hair and nails
Koilonychia (spoon nails)
Angular chelitis
Atrophic glossitis (smooth tongue due to atrophy of papillae)
What type of anaemia is indicated by jaundice?
Haemolytic.
What type of anaemia can cause bone deformities?
Thalassaemia.
What could cause anaemia with oedema, hypertension and excoriations?
Chronic kidney disease
What investigations would you do for anaemia?
Bloods - Hb, MCV, B12, folate, ferritin, blood film
OGD - bowel cancer (iron deficiency)
BM biopsy if cause is unclear. These are usually taken from the posterior superior iliac rest.
Give 4 causes of iron deficiency.
increased demand eg pregnancy
reduced supply eg malabsorption, diet
loss eg bleed from colon cancer or peptic ulcer, menstruation
How do PPIs interfere with iron absorption?
Raise stomach pH. Lower acid means Fe2+ changes to Fe3+ which is insoluble.
What is TIBC? What are levels like in iron deficiency?
Total iron binding capacity = Total space on transferrin molecules for iron to bind for. Transferrin saturation = serum iron/TIBC.
Levels increase in iron deficiency.