17. Haemolytic Anaemia Flashcards
What are the causes of anaemia?
Failure to make RBCs
Lack haematinics
Increased loss of RBCs
Chronic disease
What is haemolytic anaemia?
Increased breakdown in RBCs
Bone marrow compensates, so increased reticulocyte count
How can haemolytic anaemia be determined by blood tests?
High lactate dehydrogenase and bilirubin
What happens in autoimmune haemolytic anaemia?
Self-antigens cause destruction of the RBCs
Warm= IgG
Cold= IgM
Why are autoimmune anaemias classified as warm and cold?
Correlates to the temperature the antigen binds at
What cases might an alloimmune reaction occur in?
Haemolytic transfusion
Disease of the newborn
Post bone marrow transplant
What drug can induce haemolytic anaemia?
Dapsone
What diseases can haemolytic anaemia be related to?
Lymphoma
Mycoplasma infection
Lupus
Paraneoplastic syndrome
What test is used to detect IgG and IgM antibodies?
Coombe’s test
Give some reasons for non-immune acquired haemolytic anaemia?
Fragmentation syndromes (eclampsia, sepsis, DIC) Prosthetic heart valves
What congenital defects can cause non-immune haemolytic anaemia?
Membrane abnormalities
Enzyme defects
Haemoglobin defects
What membrane abnormality can cause haemolytic anaemia?
Structural protein of RBC membrane defect causes spherocytes
Which enzyme defect causes haemolytic anaemia?
G6PD
What haemoglobin defects cause haemolytic anaemia?
Sickle cell
Thalassaemia
What mutation causes sickle cell anaemia?
Glutamic acid to valine
What sort of inheritance is present in sickle cell anaemia?
AR
What situations cause an increase in sickling?
Hypoxia Acidosis Hypotension Infection Dehydration Hypothermia
Why are gram - infections common in sickle cell anaemia?
People with sickle cell anaemia tend to be hyposplenic
What complications are associated with sickle cell anaemia?
Osteomyelitis Gall stones Renal failure Cardiac failure Chronic leg ulcers
What causes osteomyelitis, renal failure and chronic leg ulcers in sickle cell anaemia?
Infarction
In osteomyelitis this leads to infection
What causes gall stones in sickle cell anaemia?
High bilirubin
What causes cardiac failure in sickle cell anaemia?
Increased stress on the heart to oxygenate
What is marrow fibrosis?
Response to cell death or tumour infiltration in the marrow
Results in scarring
What are the causes of marrow fibrosis?
Metastases Chemo Radio Drugs Primary myelofibrosis
What is the issue with haemoglobin in thalassaemia?
One globin chain is underproduced and the other is overproduced
The overproduced chains stick together and damage RBCs
Why is there variation in severity with thalassaemia?
4 genes encode globin chains
1-2 genes deleted= mild anaemia
3= splenomegaly and severe anaemia
4= hydrops fetalis
What are the lab results for thalassaemia?
Severe anaemia
Immature cells
Hypochromic microcytic cells
DNA test needed to confirm
How are haemolytic anaemias managed?
Regular transfusion Iron chelation Splenectomy Immunisation Bone marrow transplant
What are the potential effects of haemolysis?
Anaemia
Hyperbilirubinaemia
Effects of blood transfusions
Extra medullary haemopoiesis (splenomegaly)
