Anaemia Flashcards
What is anaemia?
Describes Hb below normal for age and sex
What are the general symptoms of anaemia?
Pallor
Dyspnoea
Fatigue
Palpitations
Dizziness
Headaches
Ankle swelling
What are the 3 morphological types of anaemia?
Hipochromic Microcytic
Normochromic Normocytic
Macrocytic
What are the causes of hypochromic microcytic anaemia?
Iron deficiency anaemia
Congenital sideroblastic anaemia
Thalassaemia
Lead poisoning
What test is used to distinguish the cause of hypochromic microcytic anaemia?
Ferritin
What is the most common type of anaemia worldwide?
Iron deficiency anaemia
What are the causes of iron deficiency anaemia?
Decreased intake
- Vegetarians
- Infants as breast milk is low in iron
Decreased absorption
- Coeliac
- IBD
- Gastrectomy due to reduced gastric acid
Increased demand
- Adolescence as rapidly growing
- Pregnancy as increased iron requirement for fetal development
Increased loss
- GI blood loss (Gastritis, Gastric ulcer)
- Menorrhagia
- Colon cancer, in elderly assume until proven otherwise
- Hookworms in developing countries
How does iron deficiency anaemia present?
General anaemia signs
Koilonychia
Hair loss
Atrophic glossitis
Angular stomatitis
What investigations are used in iron deficiency anaemia diagnosis?
FBC
- Decreased Hb/MCH
- Decreased MCV
Blood smear
- Microcytic hypochromic
Decreased Ferritin
Decreased serum iron
Increased total Iron Binding Capacity (TIBC), describes the amount of unbound transferrin in the blood
Increased transferrin, as no iron bound to it
Screen for coeliac with Anti-TTG
What blood film sign is seen in iron deficiency anaemia?
Target cells
How is iron deficiency anaemia managed?
Correct the deficiency
- Oral ferrous sulphate for 3 months
- IV iron if intolerant of oral
- Blood transfusion
Correct the Cause
- Diet
- Ulcer therapy
- Surgery
- Gynae interventions
What are side effects of oral iron supplements?
Nausea
Diarrhoea
Constipation
Abdominal pain
What is absorbed iron bound to?
Mucosal ferritin
What transports absorbed iron?
Ferroportin
What binds to transported iron?
Transferrin
What reduces iron absorption?
Hepcidin by blocking ferroportin
What is sideroblastic anaemia?
Condition in which red ells fail to completely form haem, leading to build up of iron, resulting in immature and dysfunctional RBCs
What are the causes of sideroblastic anaemia?
Congenital
Aquired
- Myelodysplasia
- Alcohol
- Lead
- Anti-TB medications
How is sideroblastic anaemia managed?
Supportive
Treat any underlying cause
Pyridoxine may help
What are the Thalassaemias?
Group of congenital anaemias characterised by reduced production rate of alpha or beta chains, and therefore abnormal form or inadequate level of haemoglobin
What is B-Thalassaemia?
Autosomal recessive anaemia characterised by reduced B-globin production of haemoglobin, causing a mild hypochromic, microcytic anaemia
In what age group does B Thalassaemia occur?
Present at 3-6 months of age
What ethnicitys is B Thalassaemia more common?
Mediterranean
Middle East
Asia
What mode of inheritence is B Thalassaemia?
Autosomal recessive
How does B Thalassaemia present?
Severe anaemia
Expansion of ineffective bone marrow
Bony deformities/hypertrophy
Splenomegaly
Growth retardation
How is B Thalassaemia managed?
Chronic transfusion support 4-6 weekly
Iron Chelation Therapy
Bone Marrow Transplantation
Give complications of B Thalassaemia
Secondary hemosiderosis from repeated blood transfusions
What blood film sign is seen in thalassaemia?
Target cells
What are the causes of normochromic normocytic anaemia?
Haemolytic anaemia
Acute blood loss
Chronic kidney disease
Aplastic anaemia
Secondary anaemia/anaemia of chronic disease
- Infection
- Inflammation
- Malignancy
What test is used to distinguish the cause of normochromic normocytic anaemia?
Reticulocyte count
What are the features of aplastic anaemia?
Normochromic, normocytic anaemia
Leukopenia, with lymphocytes relatively spared
Thrombocytopenia
May be the presenting feature acute lymphoblastic or myeloid leukaemia
Minority of patients later develop paroxysmal nocturnal haemoglobinuria or myelodysplasia
What are the causes of aplastic anaemia?
Idiopathic
Congenital
- Fanconi anaemia, dyskeratosis congenita
Drugs
- Cytotoxics
- Chloramphenicol
- Sulphonamides
- Phenytoin
- Gold
- benzene
Infections
- Parvovirus
- Hepatitis
Radiation
What is haemolytic anaemia?
Anaemia characterised by abnormal premature destruction of RBCs
What are the congenital causes of haemolytic anaemia?
Hereditary Spherocytosis
G6PD Deficiency
Sickle Cell Disease
What are the acquired causes of haemolytic anaemia?
Autoimmune haemolytic anaemia (associated with mycoplasma pneumoniae)
Infection
Transfusion reaction
Lymphoma
Drugs
DIC
Artificial valves
What investigations are used in haemolytic anaemia diagnosis?
High unconjugated and total bilirubin
- Produced in red cell breakdown
Increased Reticulocyte
- Trying to make more RBC to compensate for loss
Raised LDH
Blood film
Haptoglobin
- Decreased in autoimmune
Coomb’s test
- Detects antibody or complement on red cell membrane to determine whether haemolytic anaemia is immune
What is warm autoimmune haemolytic anaemia?
Autoimmune haemolytic anaemia in which the antibody (usually IgG) causes haemolysis best at body temperature and occurs in extravascular sites such as the spleen
What are the causes of warm autoimmune haemolytic anaemia?
Autoimmune disease
- SLE
Neoplasia
- Lymphoma
- CLL
Drugs
- Methyldopa
What is cold autoimmue haemolytic anaemia?
Haemolytic anaemia in which the antibody, usually IgM, causes haemolysis best at 4 deg C and occurs mainly intravascularly. Often features symptoms of Raynaud’s and acrocynaosis
What causes cold haemolytic anaemia?
Neoplasia
- Lymphoma
Infections
- Mycoplasma
- EBV
How is autoimmue haemolytic anaemia managed?
Steroids
Immunosuppression
Splenectomy
What is sickle cell disease?
Autodomal recessive anaemia characterised by haemoglobin chain mutation/HbS, resulting in sickle and rigid red blood cells
What mode of inheritence is sickle cell disease?
Autosomal recessive
What group is sickle cell disease more common in?
People of African descent as the heterozygous condition offers some protection against malaria
What crises can occur in sickle cell disease?
Thrombotic/painful/vaso-oclusive crisis
- Clinical diagnosis
- Precipitated by infection, dehydration, deoxygenation, cold
Sequestration crisis
- Sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
- High reticulocyte count
Acute chest syndrome
- Dyspnoea, chest pain, cough, hypoxia and new pulmonary infiltrates
Aplastic
- Sudden fall in haemoglobin and decreased reticulocytes
- Caused by parovirus infection
Haemolytic
- Fall in haemoglobin due an increased rate of haemolysis
- High reticulocyte count
What investigation diagnoses sickle cell disease?
Haemoglobin electrophoresis
What blood film sign is seen in sickle cell disease?
Target cells
What is the acute management of sickle cell crisis?
Morphine sulphate
IV fluids
Oxygen
Consider antibiotics/ceftriaxone
Blood transfusion
Red cell exchange transfusion if stroke, acute chest syndrome, multi-organ failure or rapid drop in haemoglobin
What is the longterm management of sickle cell disease?
Hydroxyurea, prophylactic management of sickle cell crises
Pneumococcal polysaccharide vaccine every 5 years
Give complications of sickle cell disease?
Gallstones
Leg ulcers
Avascular necrosis of femoral head
Chronic renal disease
What is G6PD deficiency?
X linked recessive anaemia characterised by enzyme deficiency that leaves red cells vulnerable to oxidative damage
What is the role of G6PD?
Produces NADPH which is vital for maintaining a healthy Hb, allowing it to withstand the stresses caused by drugs and sepsis
Deficiency means Hb breaks down under stress, resulting in haemolytic anaemia
What is the mode of inheritence of G6PD deficiency?
X linked recessive
How does G6PD deficiency present?
Neonatal Jaundice
Vomiting and diarrhoea
Intravascular haemolysis
Splenomegaly
Pigment gallstones
What can trigger G6PD deficiency haemolysis?
Drugs
- Antimalarials
- Ciprofloxacin
- Sulphasalazine
- Sulfonylurea
Infection
Broad/fava beans
What investigations are used in G6PD deficiency diagnosis?
Blood film
- Heinz bodies
- Bite and blister cells
- Schistocytes and spherocytes
G6PD enzyme assay
- Levels should be checked at time of presentation and around 3 months after an acute episode of hemolysis to avoid false negatives
How is G6PD deficiency managed?
Avoidance of drugs known to precipitate haemolysis
Folic acid in acute episode
Consideration for splenectomy
What is Hereditary Spherocytosis?
Autosomal dominant anaemia characterised by mutations in membrane proteins/defect of cell cytoskeleton, causing spherical fragile red cells
What is the mode of inheritence of hereditary spherocytosis?
Autosomal dominant
How does hereditary spherocytosis present?
Neonatal jaundice
Splenomegaly
Pigment gallstones
Failure to thrive
Aplastic crisis precipitated by parvovirus infection
What investigations are used in hereditary spherocytosis diagnosis?
EMA binding test
Blood film
- ONLY spherocytes present
How is hereditary spherocytosis managed?
Acute haemolytic crisis
- Treatment is generally supportive
- Transfusion if necessary
Longer term treatment
- Folate replacement
- Splenectomy
What are the causes of macrocytic anaemia?
F: Folate deficiency
A: Alcohol, liver disease
T: Hypothyroidism
R: Reticulocytosis
B: B12 deficiency, baby/pregnancy
C: Cytotoxic drugs: Methotrexate
What test is used to distinguish the cause of macrocytic anaemia?
B12/folate assay
- Megaloblastic is B12/folate deficiency, normoblastic is anything else
Blood film
- Hypersegmented neutrophils
What is pernicious anaemia?
Autoimmune disease resulting in malabsorption of dietary B12 due to lack of intrinsic factor
How does pernicious anaemia present?
Typical anaemia features
Neurological and neuropsychiatric features
Lemon tinge
Glossitis
What can cause B12 deficiency?
Pernicious anaemia, associated with hypothyroidism and DM1
Post gastrectomy
Vegan/poor diet
Disorders or surgery of terminal ileum, as this is site of absorption
- Chrons
Rarely, metformin
What investigations are used in pernicious anaemia diagnosis?
Antibodies against
- Intrinsic factor
- gastric parietal cells (less specific)
FBC
- Pancytopenia
Blood film
- Cabot rings
How does B12 deficiency/pernicious anaemia present?
Macrocytic anaemia
Sore tongue and mouth
Neurological symptoms
- Dorsal column is usually affected first (joint position and vibration)
Neuropsychiatric symptoms/mood disturbances
Why do symptoms of B12 deficiency take 3 years to occur?
B12 stores up to 3 years
How is B12 deficiency/pernicious anaemia managed?
If no neurological involvement, 1 mg of IM hydroxocobalamin/B12 3 times each week for 2 weeks as loading dose, then once every 3 months for maintenance
If a patient is also deficient in folic acid then it is important to treat the B12 deficiency first to avoid precipitating subacute combined degeneration of the cord
What causes folate deficiency?
Dietary
- Lack of green vegetables
Increased requirements
- Haemolysis
GI Pathology
- Coeliac
What blood film sign is seen in folate deficiency anaemia?
Hyper-segmented neutrophil polymorphs
How is folate deficiency managed?
Oral replacement
Ensure B12 is normal if neuropathic symptoms
Give causes of polycythaemia
Relative
- Dehydration
- Stress
Primary
- Polycythaemia vera
Secondary
- COPD
- Altitude
- Obstructive sleep apnoea
- Uterine fibroids, hepatoma and cerebellar haemangioma all cause excessive erythropoietin
