Haem1 Flashcards
Anaemia
What are the two causes of raised Hb?
True polycythaemia
Pseudopolycythaemia
What is the normal pathway for erythrocytosis?
Tissue hypoxia
Raised EPO production from kidney
RBC production in bone marrow
What are the two types of true polycythaemia?
Primary (polycythaemia vera)
Secondary (high EPO)
What are the types of secondary polycythaemia?
COPD
Renal cell carcinoma
High altitude
Smoker
What is polycythaemia vera?
Clonal haematopoietic disorder of bone marrow resulting in erythrocytosis
May be associated with thrombocytosis, leukocytosis, and splenomegaly
What is the genetic link with PCV?
85% are related to a JAK2 V617F mutation
What are the symptoms of PCV?
Asymptomatic Headache Aquagenic pruritus Blurred vision Tinnitus Thrombosis Gangrene
What are the signs of PCV?
Choreiform movements
Hepatosplenomegaly
Red face, fingers, palms, toes, heels
What are the investigations for PCV?
FBC- raised Hb, Hct, WCC, platelets
Gene mutation screen for JAK2 V617F
What is anaemia?
Reduction in Hb, red cell count, and packed cell volume below reference age and sex
What are the symptoms of anaemia?
Asymptomatic Fatigue Faintness Dyspnoea Angina pectoris Intermittent claudication
What are the signs of anaemia?
Pale skin Pale mucous membranes Tachycardia Koilonychia Cardiac failure
What are the three types of anaemia and what are the MCV levels that distinguishes them?
Microcytic (<80)
Normocytic (80-96)
Macrocytic (>96)
What are the causes of microcytic anaemia?
Iron deficiency anaemia (IDA)
Thalassaemia
Anaemia of chronic disease
Sideroblastic anaemia
What are the causes of IDA?
Blood loss (commonly uterus, GI tract) Increased demand (pregnancy/growth) Decreased absorption (SI disease, post-gastrectomy) Poor intake (vegans)
What are the investigations for IDA?
FBC- low Hb, MCv Iron studies: -low serum iron -low ferritin -high transferrin -low transferrin saturation Blood film: -microcytic, hypochromic RBCs with anisocytosis and poikilocytosis Upper GI endoscopy + colonoscopy Coeliac serology (IgA TTG antibodies)
What is the management for IDA?
Treat underlying cause
Oral Fe
IV/IM Fe if poor tolerance/uptake
What can cause ACD?
Chronic inflammation (RhA)
Chronic infection (TB)
Chronic malignancy
No other obvious cause of anaemia
What is the cause of ACD?
Cytokine release Blocks EPO production Blocks Fe flow out of cells Increased intracellular Fe storage Increased RBC turnover
What are the investigations for ACD?
Raised ESR/CRP FBC- low Hb, low/normal MCV Iron studies: -low serum iron -high/normal ferritin (acute phase protein) -low/normal transferrin -normal transferrin sat
What is normal haemoglobin made of?
2 alpha chains
2 beta chains
What are the two main types of thalassaemia?
Alpha thalassaemia
Beta thalassaemia
How many genes code the alpha Hb chain?
4 genes, 2 from each parent
What are the types of alpha thalassaemia?
Alpha thalassaemia silent (1 absent gene)
Alpha thalassaemia trait (2 absent genes)
Haemoglobin H (3 absent genes)
Haemoglobin Barts (4 absent genes)
What are the characteristics of alpha thalassaemia silent?
No clinical symptoms
What are the characteristics of alpha thalassaemia trait?
Low MCv + MCH
Can be confused with IDA
Hb electrophoresis shows low/normal HbA2
What are the characteristics of haemoglobin H?
Microcytic hypochromic anaemia Target cells and Heinz bodies Hepatosplenomegaly Presents in childhood/early adulthood Needs lifelong transfusions
What are the characteristics of haemoglobin Barts?
Often fatal in utero unless intrauterine transfusions
What are the types of beta thalassaemia?
Beta thalassaemia minor
Beta thalassaemia trait
Beta thalassaemia major
What are the characteristics of beta thalassaemia minor?
Asymptomatic heterozygous carrier
Mild/absent anaemia
Normal ferritin
Electrophoresis shows increased HbA2
What are the characteristics of beta thalassaemia trait?
Combination of homozygous beta and alpha thalassaemias
Moderate anaemia that doesn’t require transfusions
Splenomegaly, gallstones, bone deformities, recurrent leg ulcers
What are the characteristics of beta thalassaemia major?
Presents at 2-3 months with profound anaemia, failure to thrive, recurrent infections
Bony abnormalities due to bone marrow hypertrophy
Extramedullary haematopoiesis
Electrophoresis shows HbF and reduced/absent HbA
What are the investigations for thalassaemia trait?
FBC- low Hb, MCV Iron studies: -normal serum iron -normal ferritin -normal transferrin -normal transferrin saturation Hb electophoresis -alpha trait: low/normal HbA2 -beta trait: high HbA2
What is the management for severe thalassaemia?
Blood transfusions Iron chelators Bone marrow transplant: -only curative treatment -causes infertility
What are the types of macrocytic anaemia?
Megaloblastic
Normoblastic