ANAEMIA Flashcards
What is Indirect Antiglobulin Coomb’s test?
Test looking for antibody to patient’s own serum. Used to cross match blood for suitability for transfusion.
How to make diagnosis of hereditary spherocytosis?
- Strong family history
- Blood film
- Macrocytic anaemia
- High bilirubin
- High reticulocyte count
For Beta Thalassaemia Major patients; how often are the 12 hour subcutaneous desferrioxamine infusions required?
3 to 5 times per week
What does a positive indirect antiglobulin Coomb’s test mean?
That the tested donor red blood cells are incompatible and should not be given as a transfusion.
When does Beta Thalassaemia major usually present? and why?
Usually presents after first 6 months of life. Because during the first 6 months the neonate has HbF (fetal haemoglobin) which gradually reduces. HbF does not contain beta globin chains (instead has gamma globin chains).
HbH disease/Thalassaemia is most often caused by what inheritance?
Inherited deletion of 3 of the 4 alpha globin genes.
What does EMA binding test for? and when would you request it?
Used to detect hereditary spherocytosis. Request when baby has signs of anaemia and neonatal jaundice.
What inheritance pattern is Hereditary spherocytosis?
Autosomal dominant
What is Coomb’s test?
there are 2 types; both of which look for antibodies to red blood cells.
What is DAT Coomb’s test?
Direct antiglobulin test; less often done, detects antibody to patient’s own serum causing an AIHA.
How often are blood transfusions performed in Beta Thalassaemia major patients?
every 4 weeks of life
How is the Beta Thalassaemia trait diagnosed?
Raised level of HbA2
What is the main cause of death in Beta Thalassaemia Major disease?
Cardiac iron overload.
what 2 medications are given in thalassaemia to prevent iron overload?
DEFERIPRONE + DESFERRIOXAMINE
twice weekly
what is the treatment for beta thalassaemia?
blood transfusions every 2-4 weeks
to maintain Hb > 90 g/dL + to suppress extramedullary haematopoiesis
what is SIDEROBLASTIC ANAEMIA?
Microcytic anaemia caused by the bone marrow producing ringed sideroblasts (instead of healthy red blood cells)
what is the genetics behind SICKLE CELL ANAEMIA?
autosomal recessive genetic conditons;
resulting in synthesis of abnormal haemoglobin chain (HbS)
why is sickle cell anaemia more common in the Africo-caribbean population?
Heterozygous (carriers) have the HbSHb which offers them protection against Plasmodium Falciparum malaria and they are only affected by the anaemia when severely hypoxic.
In individuals with SICKLE CELL ANAEMIA; what do the HaemoglobinS do in the deoxygenated state?
HbS molecules polymerise causing the RBC to sickle and haemolyse –> blockage of small vessels –> infarction.
List 5 symptoms of SICLE CELL ANAEMIA.
- headache
- pale/yellowish skin
- malaise
- SoB + chest pain
- cold hands/feet
what are the 4 types of sickle cell crisis?
- THROMBOTIC “PAINFUL” “
- APLASTIC
- SEQUESTRATION
- HAEMOLYTIC
what is the management of a thrombotic sick cell crisis?
- Analgesia
- Fluid rehydration
- Antibiotics
- Blood transfusion
- Oxygen
Name 3 precipitants of a thrombotic sickle cell crisis.
- Dehydration
- Infection
- Deoxygenation
What is the pathology of a sequestration sickle cell crisis?
HbS sickle within organs (e.g. lungs, spleen) causing a pooling of blood w/ worsening of anaemia.
what is ACUTE CHEST SYNDROME, and what is it caused by?
Caused by a sequestration sickle cell crisis, where the HbS sickle within in the lungs causing;
- dyspnoea
- chest pain
- low PO2
- pulmonary infiltrates
What is the commonest anaemia in hospital patients?
Anaemia of chronic disease
What is the treatment of Anaemic of chronic disease?
EPO
what are the side effects of giving EPO?
- flu like symptoms
- hypertension
- mild rise in platelet count
Name the medication that increases gamma-globin; thus increasing fetal haemoglobin
HYDROXYUREA
Name common side effects of HYDROXYUREA;
- bone marrow suppression
- fever
- loss of apetite
- SoB
- headaches
3 Megaloblastic Macrocytic anaemias;
- Vitamin B12 deficiency
- Folate deficiency
- Cytotoxic drugs
Name 5 non-megaloblastic macrocytic anaemias;
- pregnancy
- liver disease
- alcohol
- reticulocytosis
- hypothyroidism
What is megaloblastic anaemia?
Anaemia due to inhibition of DNA synthesis during red blood cell production.
Causes of malabsorption causing vitamin B12 deficiency anaemia?
- ilieal resection
- lack of IF in the stomach
- chron’s disease
- bacterial overgrowth
what are the dietary requirements of Vitamin B12
1 ug / day
name some sources of dietary Vitamin B12;
- milk
- red meat
- salmon
- fortified cereals
- sardines
Neuropsychiatric features of Vitamin B12 deficiency;
- depression
- irritability
- psychosis
Neurological features of Vitamin B12 deficiency;
- paraesthesia
- peripheral neuropathy
Ataxia + decreased vision; progressing to stiffness and weakness; can develop in Vitamin B12 deficiency; caused by ?
subacute degeneration of spinal cord
What is PERNICIOUS ANAEMIA?
Autoimmune disease; antibodies to gastric parietal cells leading to lack of IF –> vit. B12 malabsorption
2 specific tests for PERNICIOUS ANAEMIA?
- Parietal cell antibodies
- IF antibodies
Treatment to replenish Vit.B12 stores in pernicious anaemia?
Hydroxocobalamin 1 mg IM
- alternate days for 2 weeks
Treatment to maintain Vit B12 stores in pernicious anaemia?
Hydroxocobalamin 1 mg IM
- every 3 months for life
IMENSLUND-GRASPECK SYNDROME?
Rare autosomal recessive familial form of vitamin B12 deficiency –> malfunction of cuban receptor in terminal ileum
what are the daily requirements of folate?
100-200 ug
name 4 dietary sources of folate;
- liver
- leafy vegetables
- nuts
- yeast
name 2 drugs that can cause folate deficiency anaemia
methotrexate
anticonvulsants
when awaiting a diagnosis for megaloblastic macrocytic anaemia; treatment ?
HYDROXOCOBALAMIN 1mg/48hrs IM
+
FOLIC ACID 5mg/24hrs PO
Treatment for folate deficiency anaemia?
Folic acid 5mg daily PO
for 4 months
Chronic blood loss causes ____ anaemia
macrocytic
Acute blood loss causes ____ anaemia
normocytic
Why does acute blood loss cause normocytic anaemia?
Blood loss occurs –> it takes several hours for plasma to expand –> therefore rapid blood loss will only happen when the loss of blood volume is replaced either by natural plasma expansion or replacement with non-RBC containing blood products.
Name 3 RBC membrane defects;
- HEREDITARY SPHEROCYTOSIS
- ELLIPTOCYTOSIS
- HEREDITARY STOMATOCYTOSIS
A RBC enzyme defect;
G-6-PD deficiency
2 Haemoglobin disorders;
- SICKLE CELL DISEASE
2. THALASSAEMIA
____ ___ anaemia has a positive direct coomb’s test?
autoimmune haemolytic anaemia
Increased; unconjugated bilirubin + urinary urobilinogen
is a sign of _____?
increased RBC destruction
which AIHI is IgG antibody medicated?
WARM AIHI
1st line treatment for warm AIHI?
corticosteroids
Treatment for cold AIHI?
- avoid cold
- RITUXIMAB
due to progressive destruction of the spleen in sickle cell anaemia; patients are at an increased risk of infection with encapsulated bacteria; give examples of these;
- HAEMOPHILIUS INFLUENZAE
- STREPTOCOCCUS PNEUMONIAE
- NEISSERIA MENINGITIS
- SALMONELLA
what prophylactic treatment is given to children with sickle cell disease; to prevent infection with encapsulated bacteria ?
PENICILLIN
+
POLYSACCHARIDE VACCINE
15% women with heavy periods have ___
vWD
what is HbH most often caused by?
inherited deletion of 3 of the 4 alpha globin genes
what is SUBCUTANEOUS DESFERRIOXAMINE used for?
iron chelation
12 hour infusions required 3 to 5 times per week
