Haematology 1: Haemolytic Anaemias Flashcards
What is the difference between intravascular and extravascular haemolysis ?
Intravascular- occurs inside the circulation
Extravascular- Occurs in the reticuloendothelial system
Which one of these is an example of a disease in which you get extravascular haemolysis ?
A) Malaria
B) Hereditary spherocytosis
C) G6PD
D) Microangiopathic haemolytic anaemia
B- hereditary spherocytosis
Occurs in the spleen.
The others are all intravascular
Name one drug that causes intravascular haemolysis ?
Dapsone
What is the inheritance pattern of Hereditary spherocytosis ?
Autosomal dominant
What happens in haemolytic anaemia patients if they become infected with Parvovirus b19 ?
Transient aplastic crisis
Massive reduction in Hb and circulating RBCs. Low reticulocytes shows RBC production has stopped
What is the Name of the disease caused by Parvovirus b19 infection in children ?
Fifth’s disease
“Slapped cheeks” rash is characteristic of which infection in children ?
Parvovirus B19 (fifth’s disease)
What disease can immunocompromised patients get if they become infected with Parvovirus B19 ?
Pure red cell aplasia
Which stain can detect hepatic siderosis (iron overload)?
Perl’s stain (Prussian blue)
What are haptoglobins ?
A Protein in the blood that binds to and removes free haemoglobin
What causes Paroxysmal nocturnal haemoglobinuria ?
Acquired genetic defect in GPI anchor
What does a low level or absent haptoglobin suggest ?
Intravascular haemolysis
All the haptoglobins have been used up and there is lots of free haemoglobin
Which of these proteins is not part of the red cell membrane ?
A)Spectrin B)Ankyrin-1 C)Band 3 D) GPI E) Myosin
E) Myosin
What is the diagnostic test for Hereditary spherocytosis ?
Osmotic Fragility test
Which autosomal recessive disease similar to hereditary eliptocytosis has abnormal sensitivity to heat?
Hereditary Pyropoikilocytosis
More severe
How is G6PD inherited ?
X-linked
List 6 triggers of acute haemolysis in patients with G6PD
Antimalarials Dapsone Favs beans Napthalene moth balls Infections Antibiotics (Sulphonamides)
Normally G6PD patients are asymptomatic but these agents are oxidative and cause acute haemolysis
Name 2 characteristic cells seen in G6PD ?
Bite cells
Hemighosts
Oxidative haemolysis causes characteristic Blue inclusions of denatured haemoglobin in RBCs. These are also known as ………………………
Heinz bodies
Name one type of cell that is characteristically seen in PKD (pyruvate kinase deficiency) ?
Burr cells (echinocytes)
They are spikey cells that look like sea urchins
List 4 causes of basophilic stippling ?
Pyrimidine 5 nucleotidase deficiency
Lead poisoning
Megaloblastic anaemia (alcoholics)
Thalassaemia
Which test is used to diagnose Paroxysmal nocturnal haemoglobinuria (PNH) ?
HAM’s test
Which test is used to diagnose Malaria ?
Thick and thin blood films
Which test is used to diagnose Autoimmune haemolytic anaemia ?
DAT test
Which type of immunoglobulin causes warm autoimmune haemolytic anaemia ?
IgG
Which type of immunoglobulin causes cold auto immune haemolytic anaemia ?
IgM
Child recovering from measles suddenly presents with haemoglobinuria after going into an ice bath. Complement levels are low. Donath-Landsteiner test is positive.
Most likely diagnosis ?
PCH (paroxysmal cold haemoglobinuria)
Preceding viral infection
Cold exposure
IgG antibodies bind to P-antigen on red cells
Causes complement mediated haemolysis on warming up again
Which test can be used to diagnose Paroxysmal nocturnal haemoglobinuria ?
Ham’s test
Or immunophenotyping
Which drug can be used to treat PNH?
Eculizumab
Which antibodies cause TTP ?
Antibodies against ADAMTS13
(ADAMTS13 is an enzyme which normally cuts vWF into smaller strands of protein. In TTP, very long strands of vWF cause shearing of RBCs in vessels leading to haemolysis and schistocytes)
What is the Pentad for TTP ?
MAHA Thrombocytopenia Renal impairment fever Neurological symptoms
Which infection is commonly responsible for causing HUS ?
E.Coli
Which conditions are associated with cold AIHA ?
Think cold LID
Lymphoproliferative - CLL, Lympomas
Infections - Mycoplasma, EBV
Do not know - Idiopathic
List 2 conditions associated with Spherocytes ?
Hereditary spherocytosis
Warm AIHA
List 2 conditions and 1 drug that are associated with warm AIHA ?
CLL
SLE
Penicillin
Name a congenital cause of aplastic anaemia ?
Fanconi anaemia
List 4 drugs can cause aplastic anaemia ?
Carbamazepine
Chloramphenicol
Cytotoxic drugs
Phenytoin
Name 1 drug used in the treatment of Sickle cell anaemia ?
Hydroxycarbamide
Which drug acts to replenish vitamin b12 stores in pernicious anaemia ?
IV Hydroxocobalamine
List 2 drugs that can cause Folate deficiency ?
Methotrexate
Phenytoin
List causes of MAHA ?
TTP HUS DIC SLE Malignant hypertension Pre-eclampsia
