Haem Onc Flashcards
Define anaemia
WHO definition - Number of RBCs and O2 carrying capacity is insufficient to meet the body’s physiological needs
Categorise the causes of anaemia
Reduced red cell production
Increased red cell loss
Increased red cell destruction
3 phases of iron deficiency
Depletion
- Normal Hb, low ferritin, low t sats
Deficient erythropoeisis
- low ferritin, t sats and serum iron
Anaemia
- Low Hb, t sats and serum iron
What is serum ferritin a marker of?
Measure of iron stores in liver and bone marrow.
Also an acute phase protein so increased in inflammatory states.
Risk factors for iron deficiency
<37 weeks + / - LBWT
Multiple pregnancy
Breast fed babies
Early weaning to Cow’s milk
Adolescent girls - menstruation
Restrictive diets - vegetarians
Pica
Chronic disease
Malabsorption - coeliac disease, h. pylori, IBD
Hookworm
Blood film findings in IDA
Hypochromic, microcytic anaemia
What form does iron mostly exist in in the body?
Haeme
Non-haematological effects of iron deficiency
Reduced CNS higher functions
Diminished T cell function and cell-mediated immunity
Diminished muscle performance
What foods is B12 found in?
Present in animal products (eggs, meat, fish, dairy)
Blood film findings in B12 deficiency?
Oval macrocytes, hyper segmented neutrophils
What else can be checked if b12 indeterminate but high clinical suspicion?
Check MMA (methylmalonic acid)
What else can be checked if b12 indeterminate but high clinical suspicion?
check MMA (methylmalonic acid)
Foods containing folate
Fortified cereals and foods
Green leafy vegetables
Fruit
Yeast
Note - folate is destroyed by prolonged cooking
Causes of folate deficiency
Dietary deficiency
Chronic infections - HIV, malaria
Drugs
Blood film findings in folate deficiency
Hyper segmented neutrophils, oval macrocytes, can develop pancytopenia
Presentation of copper deficiency
Ataxia
Proprioception difficulties
What type of anaemia can pyridoxine (Vit B6) deficiency cause?
Sideroblastic anaemia (rare)
What condition is basophilic stripping seen in?
Lead toxicity
Bone marrow changes seen in Anorexia Nervosa?
Gelatinous changes (due to fat cell atrophy)
Mechanisms of neutropenia
Inadequate production (Ineffective granulopoiesis, bone marrow repalcement)
Destruction at source (haemophagocytic syndromes)
Defective release (myelokathexis)
Splenic pooling (Felty’s syndrome)
Shortened intravascular lifespan (immune mediated destruction)
Rapid egress from tissues (sepsis in neonates)
What is NAIT
NeoNatal Allo Immune Neutropenia
Inheritance pattern of hereditary spherocytosis
Autosomal dominant (75%)
Autosomal recessive (25%)
Most common non-haematological complication in patients with hereditary spherocytosis
Gallstones
5 genes which can be affected in hereditary spherocytosis
ANK1
SLC4A1
SPTA1
SPTB
EPB42
All the above genes code for proteins that are part of the red blood cell membrane
Red cell membrane proteins affected in hereditary spherocytosis
Spectrin
Anykrin
Protein 4.2
These are the major components of the cytoskeleton responsible for red blood cell shape
Pathophysiology of why spherocytic red blood cells are destroyed prematurely in the spleen in hereditary spherocytosis
The decrease in the deformability of the spherocytic red blood cells causes impaired cell passage from the splenic cords to the splenic sinuses
Mx of hereditary spherocytosis
Steroids
Folate supplementation
Red cell transfusions
Splenectomy (>6 yrs, mod-severe disease only, will then also need Abx prophylaxis and additional vaccines)
Which infection can cause sudden anaemia in hereditary spherocytosis
Parvovirus
What is Shwachman-Diamond syndrome
Genetic condition (autosomal recessive) causing bone marrow failure and neutropenia
Associated with exocrine pancreas dysfunction
