H1: Anaemia Flashcards
1/3 of total body cells are?
Red cells (24 trillion)
What is the lifespan of a red blood cell?
4 months (120 days)
Anaemia is low _____?
Haemoglobin
What can cause a decrease in red cell production? (5)
- Iron deficiency
- B12 deficiency
- Folate deficiency
- Marrow infiltration
- Chronic disease
What are 3 mechanisms that cause anaemia?
- Decreased production of red cells
- Increased destruction of red cells
- Loss of red cells (bleeding)
What is Haemolytic anaemia?
A disorder in which red blood cells are destroyed faster than they can be made
Name 2 Microcytic anaemias
- Iron deficiency anaemia
- Thalassaemia
How much iron is there in 1ml of blood?
0.5mg iron
Why does iron deficiency cause anaemia?
Iron is in haem so a deficiency of iron causes defective Hb synthesis. The RBCs produced are small (microcytic) and contain reduced Hb (hypochromic)
What are Hypochromic RBCs?
RBCs which contain reduced amounts of Hb
How much iron does an average adult contain?
3-5 grams of iron
What is the recommended iron consumption per day?
15mg iron/day
What are some factors that enhance iron absorption? (6)
- Haem iron (meat)
- Ferrous salts (Fe2+)
- Acid pH
- Iron deficiency
- Pregnancy
- Hypoxia
What are some factors that impair iron absorption? (5)
- Non-haem iron (veg)
- Ferric salts (Fe3+)
- Alkaline pH
- Iron overload
- Inflammatory disorders
How do you confirm iron deficiency? (5)
- Conduct full blood count
- Blood film check
- Low serum ferritin
- Low serum iron
- Transferrin saturation
If you were to check red cells under a microscope what would an iron deficiency sample look like? (4)
- Red cells vary in size
- Some cells are very small
- Pale cells
- Pencil cells present
What is a common cause for iron deficiency in pre-menopausal females?
Menorrhagia (menstrual periods with abnormally heavy or prolonged bleeding)
What is a common cause for iron deficiency in males and post-menopausal females?
GIT bleeding (ulcer, cancer)
Which cancers can cause anaemias by marrow infiltration? (5)
- Breast
- Prostate
- Lung
- Thyroid
- Renal
What conditions can cause anaemia by marrow infiltration? (4)
- Metastatic cancer
- Myeloma
- Myelofibrosis
- Leukaemia & lymphoma
What occurs during anaemia of a chronic disease? (4)
- Reduced RBC lifespan
- Poor marrow response to EPO
- Depressed erythropoiesis
- Inflammatory cytokines released
What deficiencies cause macrocytic anaemia? (2)
- Vitamin B12
- Folate
What can cause macrocytic anaemias? (7)
- Deficiencies
- Liver disease & alcohol
- Hypothyroidism
- Bone marrow failure
- Aplastic anaemia
- Myelodysplasia
- Drug
How do deficiencies in B12 and Folate cause macrocytic anaemias?
- Vitamin B12 & Folate needed for DNA synthesis
- Deficiency causes impaired DNA synthesis
- Cells fail to divide
- Large cells are formed
What causes megaloblastic anaemia?
- Delayed Maturation of the nucleus of erythroblasts
- Due to defective DNA synthesis
What causes megaloblastic anaemia?
B12/Folate Deficiency
Vitamin B12;
Daily requirement?
Stored for (time)?
Absorption site
Destroyed by cooking?
- 1μg/d
- 3 years (1000μg)
- Binds to IF and then absorbed at Ileum
- Not destroyed by cooking
Folate;
Daily requirement?
Stored for (time)?
Absorption site
Destroyed by cooking?
- 150μg/d
- 4 months only
- Duodenum & jejunum
- Destroyed by cooking
What is Pernicous anaemia?
It is an autoimmune disorder which creates an autoantibody against gastric mucosa and IF
What is Pernicous anaemia?
It is an autoimmune disorder which creates an autoantibody against gastric mucosa and IF
What are some clinical features of Pernicous anaemia? (4)
- Anaemia
- Glossitis
- Mild jaundice
- Neurological problems (ie dementia)
How can anaemias caused by either B12 or Folate be distinguished between by looking at clinical features?
Clinical features present from folate deficiency do not cause neurological problems
What abnormalities of the RBC can cause haemolysis?
- Membrane abnormality
- Hb abnormality
- Enzyme abnormality
Wha are some clinical presentations of haemolytic anaemia? (4)
- Pallor
- Jaundice
- Gallstones
- Splenomegaly
How can you tell from lab investigations that there is Red cell breakdown? (3)
- Increase serum unconjugated bilirubin
- Increased urinary urobilinogen
- Increase serum lactate dehydrogenase
How can you tell from lab investigations that there is Red cell production? (2)
- Increased reticulocytes in blood
- Increased RBCs in marrow
Give an example of a RBC membrane defect
Hereditary Spherocytosis
Give an example of a RBC enzyme defect
G6PD deficiency
What causes sickle cell disease?
Point mutation in Globin gene
Glutamine to Valine at Amino acid 6
What is Autoimmune haemolytic anaemia?
When self-reacting IgG antibodies attaches to RBC and destroy them
