Anaemia Flashcards
Definition anaemia
Reduction in red cells or their haemoglobin content
Or increased plasma volume
Example of situation where dilutional anaemia can occur
Pregnancy
Name some substances required for making red cells
Iron
B12
Folic acid
Erythropoietin
3 broad types anaemia
Hypochromic Microcytic anaemia
Normochromic Normocytic
Macroytic
Symptoms in anaemia
Fatigue Dyspnoea Faintness Pallor Oedema Chest pain Palpitations Headache Tinnitus Anorexia
Initial Rx for microcytic anaemia
Serum ferritin
Initial Ix for normochromic normocytic anaemia
Reticulocyte count
Initial Ix for Macrocytic anaemia
Do B12/folate
Which is the commonest type of anaemia
Hypochromic microcytic
What is the main cause of hypochromic microcytic anaemia
Iron deficiency
Hypochromic microcytic anaemia with low ferritin what is the Dx
Iron deficiency anaemia
Hypochromic microcytic anaemia with normal ferritin what are potential Dx
Thalassemia
Sideroblastic anaemia
30% of secondary anaemia
Which is the commonest anaemia worldwide
Iron deficiency
Causes of iron deficiency anaemia
Blood loss:
Menorrhagia
GI bleeding
Poor diet
Malabsorption:
Coeliac disease
Gastrectomy
Signs of iron deficiency
Koilonychia (spoon shaped nails_
Angular cheilitiis (around mouth)
Atrophic tongue
Ix for iron deficiency anaemia
Blood film
Serum ferritin low
Finding cause:
Coeliac serology
Endoscopy
Colonoscopy
Rx for iron deficiency anaemia
Oral iron
IV if intolerable to oral
SE of oral iron
Nausea Abdo. discomfort Diarrhoea Constipation Black stools
What is thalassaemia
Reduced or absent globin chain production
Type of haemoglobinopathy
How many alpha chains are there
4
How many beta chains are there
2
Describe features of (α0/α0 ):
Incompatible with life
Death in utero
Features of (–/-a)
Moderate anaemia Features of haemolysis Hepatosplenomegaly Leg ulcers Jaundice
Features of (–/aa)
Asymptomatic carrier state
Features of (-a/aa)
Clinical state is normal
Describe thalassaemia beta minor
Heterozygous state
Carirer state
Describe Beta thalassaemia intermedia
Intermediate state
Moderate anaemia
but not requiring transfusion
Describe beta thalassaemia major
Homozygous state
Sig. abnormality in both beta globin chains
Transfusion dependent
Which beta thalassaemia is transfusion dependent
Major
Which beta thalassaemia has anaemia not relying on transfusions
Intermedia
Signs of beta minor
Usually asymptomatic
Mild well tolerated anaemia
May worsen during pregnancy
Signs of beta intermedia
Splenomegaly
Moderate anaemia
Signs of beta major
Severe anaemia Failure to thrive Presents early Hepatosplenomegaly Skull bossing ‘Hair on end’ sign Due to marrow activity
Ix for thalassaemia
FBC MCV Iron HbA2 HbF Hb electrophoresis
Describe ferritin level in thalassaemia
Normal or increased
What is iron chelation therapy
Drug to remove excess iron to prevent overloading
Examples of iron chelation drugs
S/C - desferrioxamine infusions
Oral – Deferasirox
Rx for beta major
Chronic transfusion
Iron chelation therapy
Splenectomy
Hormonal replacement or Rx for endocrine complications
Rx beta intermedia
Required treatment for anaemia
NOT transfusions
Rx for beta minor
Relatively asymptomatic
No Rx
May require iron in pregnancy
Normochromic Normocytic anaemia with increased reticulocyte count what are the Ddx
Acute blood loss
Haemolysis
Normochromic Normocytic anaemia with normal/decreased reticulocyte count what are the Ddx
70% secondary anaemia
Hypoplasia
Marrow infiltration
What % of secondary anaemia is normochromic and hypochromic
70% normo
30% hypo
What is haemolytic anaemia
Accelerated red cell destruction before their normal lifespan
What are the effects of increased RBC destruction
Increased bilirubin
Increased faecal and urinary urobilinogen
What is the bone marrow compensation for haemolysis
Reticulocytosis
Hence increased reticulocytes
Is intravascular haemolysis (in the blood vessels) mainly immune or non-immune
Non-immune
Is extravascular haemolysis (elsewhere in the body) usually immune or non immune
Immune
Conditions that can cause congenital haemolysis
Hereditary spherocytosis (HS)
Enzyme deficiency (G6PD deficiency)
Haemoglobinopathy (HbSS)
E.g Thalassaemia, Sickle Cell
Non-immune mediated causes of haemolysis
Underlying malignancy
Result of hypersplenism (e.g portal hypertension)
Lead poisoning
Mechanical e.g artificial valve
Severe infection (DIC, PET, HUS)
Immune mediated cause of haemolytic anaemia
Auto-immune haemolytic anaemia
Tests to Dx haemolysis
FBC Blood film Reticulocyte count Serum bilirubin LDH Serum haptoglobin
Coombs test Urine for haemosiderin/
urobilinogen
Indirect Coombs
Rx for haemolysis
Support marrow function:
Folic acid
Correct cause:
Autoimmune:
Steroids
Treat trigger e.g CLL, lymphoma
Remover site of red cell destruction:
Splenectomy
Consider transfusion
Describe Direct Antiglobulin test
Test to Dx auto-immune anaemia
Detects antibody or complement on red cell membrane
Reagent contains either:
Anti-human IgG
Anti-complement
Reagent binds to Ab (or complement) on red cell surface and causes agglutinatin in vitro
Implies immune basis for haemolysis
DAGT +ve = immune mediated
DAGT –ve = non-immune related
What is autoimmune haemolytic anaemia
Type of anaemia
Mediated by autoantibodies causing mainly extravascular haemolysis and spherocytosis
Secondary causes of warm AIHA
CLL
Lymphoma
Drugs
Autoimmune disease
Secondary causes of cold AIHA
Infection
CHAD
Lymphoma
Cause of AIHA
mainly idiopathic
Compared warm and cold AIHA
Warm AIHA
IgG mediated
Bind at 370 body t.
Cold AIHA: IgM mediated Bind at temp (<4C0) Activating cell-surface complement Often made worse by cold e.g Raynauds
How is AIHA classified
Warm and cold
According to optimal binding to temperature to RBC
Rx for warm AIHA
Steroids
Immunosuppression
+/- splenectomy
Rx for cold AIHA
Keep warm
What is the 2nd most common anaemia
Secondary
Describe 2ndry anaemia
When there is an identifiable underlying disease
Describe ferritin in secondary anaemia
Usually elevated
What is hereditary spherocytosis
Type of congenital anaemia
Caused by defective RBC membrane
Inheritance of hereditary spherocytosis
Most common form
Autosomal dominant
Which proteins are defective in hereditary spherocytosis
5 structural proteins: Ankyrin Alpha spectrin Beta spectrin Band 3 Protein 4.2
Mechanism of haemolysis in hereditary spherocytosis
RBC are defective in shape
Recognised defective and removed from the circulation by the RE system in the spleen
Shape of RBC in hereditary spherocytosis
Spherical
Rx for hereditary spherocytosis
As congenital usually compensation occurs
Folic acid
Transfusion
Splenectomy
Name 3 other rare RBC membrane disorders
Hereditary Elliptocytosis
Hereditary Pyropoilkilocytosis
South East Asian Ocalocytosis
What is the chief RBC enzyme disorder
G6PD deficiency
Hereditary pattern of G6PD deficiency
X linked
Blood film appearance in G6PD deficiency
Bite cells
Clinical presentation of G6PD deficiency
Neonatal jaundice
Drug, broad bean or infection precipitated jaundice and anaemia
Splenomegaly
Pigment gallstones
Haemolysis triggers in G6PD deficiency
Infection
Drugs
Which drugs can trigger haemolysis in G6PD deficiency
Anti-malarials e.g Primaquine
Anti-bacterials e.g Nitrafurantoin
Analgesics e.g Aspirin
Sulphonamides and Sulphones
Ix for G6PD deficiency
Enzme assay
Rx for G6PD deficiency
Avoid precipitants
Transfuse if severe
Name another rare RBC enzyme deficiency
Pyruvate Kinase Deficiency
Cause of megaloblastic anaemia
B12 deficiency
Folate deficiency
Cause of non-megaloblastic anaemia
Myelodysplasia
Marrow infiltration
Drugs
Initial Rx for macrocytic anaemia
B12/Folate assay
What does vitamin B12 bind to in the stomach
Intrinsic factor
Which cells produce intrinsic factor
Parietal cells
Where does final absorption of B12 take place
Terminal ileum
Causes of Vitamin B12 deficiency
Pernicious anaemia (autoimmune)
Gastrectomy (removal of stomach hence removal of B12 producing parietal cells)
Poor dietary intake
Gastric/ileal disease
Signs of Vitamin B12 deficiency
Anaemia
Neurological symptoms:
Paraesthesia
Peripheral neuropathy
Lemon tinge skin
Glossitis
Which system can Vit B12 deficiency have serious consequences on
Neurological
Describe pernicious anaemia
Autoimmune disease Atrophic gastritis leads to lack of intrinsic factor secretion from parietal cells in the stomach
Dietary B12 therefore remains unbound
And not absorbed at the terminal ileum
Associations of pernicious aneamia
Other autoimmune disease
Thyroid
Addison’s
Hypoparathyroidism
Ix for pernicious anaemia
Antibodies against
Intrinsic factor (Dx)
Gastric parietal cells (less specific)
Serum B12
Hb
WCC
MCV
Rx for pernicious anaemia
IM B12 injections
Initial loading dose
Then every 3/12
What is 3x more common in pernicious anaemia
Stomach carcinoma
Another name for Folate acid
Vitamin B9
Causes of folate deficiency
Dietary Increased requirement (haemolysis, pregnancy) GI pathology (e.g Coeliac)
Rx for folate deficiency
Oral folate replacement
