Anaemia Flashcards
What are the general causes of anaemia?
Not enough red blood cells
Not enough haemaglobin within red blood cells
What are the causes of anaemia to do with erythropoiesis in the bone marrow?
Reduced erythropoiesis
Dyserythropoiesis
Haemaglobin synthesis
What are the causes of reduced erythropoiesis?
Chronic kidney disease
Empty bone marrow
Infiltration of bone marrow
Why does chronic kidney disease lead to reduced erythropoiesis?
Kidneys don’t produce erythropoietin
Why does empty bone marrow lead to reduced erythropoiesis?
Lack of cells in bone marrow
lack of precursors of red blood cells
What can cause bone marrow to be empty?
Chemotherapy
Parvovirus infection
Aplastic anaemia
Why does infiltration of bone marrow lead to reduced erythropoiesis?
Lack of normal haematopoietic cells
lack of precursors of red blood cells
What can bone marrow be infiltrated with?
Cancer cells
Fibrous tissue
What is the term for bone marrow infiltrated by fibrous tissue?
Myelofibrosis
How is reduced erythropoiesis by chronic kidney disease treated?
Give patient erythropoietin hormone
What are the causes of dyserythropoiesis?
Anaemia of chronic disease
Myelodysplastic syndromes
Which chronic conditions might anaemia be a symptom of?
Chronic inflammatory conditions
- inflammatory bowel disease e.g. crohn’s, ulcerative colitis
- rheumatoid arthritis
Chronic infection
-TB
How do some chronic conditions cause anaemia?
Bone marrow doesn’t respond to erythropoietin
Increased activity of macrophages
-circulating red cells have reduced lifespan
Inflammatory cytokines increase production of hepcidin
- less iron absorption in gut
- less iron release from macrophages
How does anaemia of chronic disease appear on a blood film?
Anaemia can be
- microcytic
- normocytic
- macrocytic
What are the levels of inflammatory markers in anaemia of chronic disease? Give examples
E.g. ferritin
CRP
both raised
How is anaemia of chronic disease treated?
Treat the underlying cause of the anaemia
What is the pathophysiology of myelodysplastic syndromes?
Mutations in cells of bone marrow
As a result
- do not mature
- produce clones of themselves
How do myelodysplastic syndromes cause anaemia?
Proper red blood cells not produced
Red blood cells prematurely destroyed by reticuloendothelial system
How does anaemia caused by myelodysplastic syndromes appear on a blood film?
Macrocytic - red blood cells are large
How is myelodysplastic syndrome diagnosed?
Look at chromosomal changes in bone marrow cells
Look at bone marrow cells and blood film under microscope
How is anaemia caused by myelodysplastic syndromes treated?
Chronic transfusions of red blood cells
Chemotherapy followed by stem cell transplantation in younger patients
What can myelodysplastic syndromes develop into?
Acute leukaemia
What are the causes of anaemia to do with haemaglobin synthesis in the bone marrow?
Lack of iron
Lack of vitamin B12, folate
Genetic disorders
What are vitamin B12 and folate required for?
Nuclear maturation
nuclear division
Cell division
What is seen on a blood film with vitamin B12 and folate deficiency?
Macrocytic - red blood cells are large
What causes macrocytic anaemia with vitamin B12 and folate deficiency?
Cytoplasm develops faster than nuclear maturation, nuclear division and cell division
red blood cell precursors have large nuclei, are large themselves
What do neutrophils look like with vitamin B12 and folate deficiency?
Hypersegmented nuclei
What can prolonged vitamin B12 and folate deficiency lead to?
Pancytopenia - low neutrophils and platelets as well as low red blood cells
What is the term for anaemia caused by vitamin B12 and folate deficiency?
Megaloblastic anaemia
What are the genetic disorders of haemaglobin synthesis?
Sickle cell
Thalassaemia
What is the inhertiance pattern of sickle cell anaemia?
Autosomal recessive
What is the genotype of sickle cell anaemia?
HbS HbS
What is the cause of sickle cell anaemia?
Point mutation in B-globin gene
Valine replaced by glutamate
What are the symptoms of sickle cell anaemia?
Anaemia
Haemolytic crises
Vaso-occlusive crises
Aplastic crises
How severe is the anaemia in sickle cell anaemia? Why?
Mild
because HbS gives up oxygen more readily than HbA
What happens to HbS with oxygen gas exchange?
Deoxygenated HbS
forms polymers of HbS