Haemolytic Anaemia Flashcards
What is anaemia
Reduction of one or more of the major red blood cell measurement: haemoglobin concentration, haematocrit, RBC count
Do men or wmen have higher ranges of blood count parameters
Men
What are the causes of microcytic anaemia
Iron deficiency
Thalassemia
What are the cuases of normocytic anaemia
Anaemia of chronic disease- sickle cell disease
Blood loss
What are the causes of macrocytic anaemia
Alcohol
Nutrient deficiency- vitamin b12 and folate deficiency
What is haemolytic anaemia
Anaemia due to shortened survival of circulating red blood cells due to the premature destruction
Where can the destruction of red blood cells occur
Inside the cell
Outside the cell
Where does extravascular haemolysis (outside the cell occur)
Liver
Spleen
Bone marrow
What are the features of haemolytic anaemia
- Increased RBC destruction which can give:
- high LDH
- low haptoglobin
- high bilirubin
- positive DAT
- high MCV
- spherocytes (not biconcave shape) - Increased RBC production which can give:
- reticulocytes
- erythyorid hyperplasia in the bone marrow
What are the types of coombs test
Direct
Indirect
What is the direct anti globulin test (DAT/Coombs test)
You put anti human globulin to the patients blood which will bind to the anti RBC in the blood
What is the indirect anti-globulin test (coombs test)
- Take the patients plasma with the antibody
2. Add test RBC and the anti human globulin
What does a positive coombs test mean
There are antibodies that destroy your own red blood cells i.e autoimmune haemolytic anaemia
What is the classification of haemolytic anaemia
- Hereditary:
- RBC interior abnormality : enzymes defects, haemoglobinopathies
- RBC membrane abnormality: hereditary spherocytosis, hereditary elliptocytosis - Acquired:
Extrinsic factors: hyersplenism, antibody: immune haemolysis, mechanical trauma, infections, toxins and drug induced
Name a enzyme defect that leads to haemolytic anaemia
G6PD deficiency
What type of condition is enzyme G6DP deficiency
X-linked inherited condition
What is the normal role of G6PD
It protects the RBC from harmful effects of reactive oxygen radicals
What happens to the RBC when there is deficient g6dp
Becomes destroyed by the radicals
Which factors is g6pd deficiency precipitated by
Infection
Drugs
Food: fava beans
What would the blood film for g6pd show for diagnsosis
Blister cells
Bite cells
Heinz bodies
What is the treatment for g6pd deficiency
Prevention of precipitating factors
Blood transfusion
Folic acid
Splenoctomy if the spleen is destroying the RBC
Give another example of a enzyme deficiency that can affects the RBC
Pyruvate kinase deficiency
What type of a disorder is pyruvate kinase deficiency
Autosomal recessive disorder
What is the clinical presentation of pyruvate kinase deficiency
Gallstones
Jaundice
Anaemia
What is the diagnosis of pyruvate deficiency by
Enzyme assay
What is the treatment for pyruvate kinase deficiency anaemia
If symptomatic: folic acid
Splenectomy in some cases
What type of abnormality does sickle cell disease show
Qualitative abnormality due to mutation of globin genes
What type of abnormality does thalassemia show
Quantitative abnormality
How is sickle cell disease diagnoses
HPLC PLOTS
Haemoglobin gel electrophoresis
What is the treatment of sickle cell disease
Folic acid Prophylactic antibiotics Transfusion ACEI- nephropathy Hydroxycarbamide Bone marrow transplant in children
What is the presentation of beta thalaessemia major
Early in life Failure to thrive Poor weight gain Growth delay Haemolytic anaemia Jaundice Extramedullar haemopoiesis- hepatosplenomegaly
What is the clinical presenation of beta thalassemia intermedia
Mild or severe anaemia
What is the clinical presentation of beta thalaessemia trait
Mild asymptomatic anaemia
What is the treatment of thalassemia
Regular blood transfusion Iron chelation therpay- due to risk of iron overload as they have a lot of blood Folic acid and prophylactic antibiotics Gene therapy Allogenic stem cell transplant
What is hereditary spherocytosis
Autosomal dominant condition
Abnormality of the red blood cells caused by defects in the structural membrane proteins
What shape does the RBC become in hereditary spherocytosis instead of biconcave shape
Spherical
What happens to spherocytes
Phagocytosed by macrophages and destructred in the spleen
What can hereditary spherocytosis present with in childhood
Anaemia
Jaundice
What is hereditary elleptocytosis
Autosomal dominant condition
Functional abnormality in one+ anchor proteins in RBC membrane (alpha spectrin protein 4.1)
What shape does the RBC have in hereditary elleptocytosis
Elliptical
What is the treatment for hereditary spherocytosis
Folic acid
Blood transfusion
Splenectomy for tx dependent
What are the causes of acquired haemolytic anaemia , immune causes
Autoimmune: cold and warm AIHA
Alloimmune: red cell destruction by antibodies that are foreign antibodies eg transfusion reaction
Drug induced
What are acquired non immune haemolytic anaemia causes
Infection Mechanical PNH TMA Hypersplenism Oxidant substance DIC Severe burns Renal failure
What is autoimmune haemolytic anaemia
Decompensated acquired haemolysis caused by the hosts immune system reacting to its own red cell anitgens
What is DAT in autoimmune haemolytic anaemia
Positive
What are the 2 types of autoimmune haemolytic anaemia
Cold
Warm
What is warm AIHA
Caused by autoantibodies of igG which binds to the red blood cells at body temp
What does the blood film in warm AIHA show
Spherocytes
Macrocytes
What are the causes of warm AIHA
Idiopathic
Secondary to: maligannt, infection, immune (sle), drugs
What is the treatment of warm AIHA
Treat underyling cause Prenisolone (steroid) Rituximab Immunosupressive Splenectomy Transfusion
What is cold AIHA
Caused by autoantibodies usually igM that bind to the rbc at cooler temperature
What will the blood film show in cold AIHA
Red cell agglutination
What will the DAT be positive for in cold AIHA
C3d
What is the cause for cold AIHA
Primary
Seconday to malignancy, infection, autoimmune disorders
What is the treatment for cold AIHA
Keeping the paitent warm Transfuse the blood by a blood warmer Folic acid Treat the underlying casue Rituximab
What is an alloimmune haemolytic anaemia
When the red cells are destroyed by antibodies that are foreign
Name an example of alloimmune haemolytic anaemia
Haemolytic disese of the new born
Why does haemolytic disease of the newborn happen
- Mum is RHD negative
- Mum has first child that is rhd+ there is no problem
- The mum will develop sensitisation and anti rh antibody
- When there is a second baby with rhd+ blod the mums antibody will develop antibodies to destory the babies blood
Give an example of a non immune acquired haemolytic anaemia
Microangiopathic haemolytic anaemia (MAHA)
What is MAHA
When there is intravascular haemolysis 2nd to mechanical injury of the RBC whilst passing through the fibrin strands deposited in the small blood vessels
What are the causes of MAHA
Haemolytic uraemic syndrome Thrombotic thrombocytopenia Pre eclampsia in pregenancy Disseminated carcinoma Collagen vascular disease Medication Malignant hypertension
What is thrombotic thrombocytopenia
- A molecule called ADAMTS13 is in the circulation
- There is VWF that interact with platelets to hold the platelet plug
- ADAMTS13 cleaves VWF so the platelets aggreagte
- Deficiency in ADAMTS14 mean VWF will get together and consume all the platelets so the platelets levels are low and there is high risk of thrombosis
What will the blood film in thrombotic thrombocytopenia show
RBC fragments
What is the treatment of thrombotic thrombocytopenia
Plasma exchange that has ADAMTS13 Steroids e.g prednisolone Folic acid Rituximab Low molecular heparin and aspirin
