Full Blood Count Interpretation Flashcards
What do you use in the red cell count to classify anaemia?
Main method is by using the mean cell volume
If the reticulocyte count is raised in a patient with anaemia what is the likely cause?
blood loss
haemolytic anaemia
what is sideroblastic anaemia?
when the body has enough iron but is unable to use it to make haemoglobin
What does Hb show on a red cell count?
conc. of Hb within the blood.
What does MCV mean?
Mean cell volume of the red blood cells.
What is the reticulocyte count?
conc. of immature red blood cells
what is the haematocrit?
volume percentage of red blood cells in the blood
What is mean corpuscular haemoglobin
mean haemoglobin quantity within the blood cells - affects the colour of the cells.
Most normocytic and macrocytic anaemias are normochromic
Most microcytic anaemias are hypo chromic
If patient has anaemia and an abnormal WCC and platelets, what does this suggest?
Bone marrow cause is likely
Name three causes of Microcytic anaemia?
SIT Sideroblastic Iron deficiency Thalassaemia Chronic disease
Name three causes of normocytic anaemia
Acute blood loss Haemolytic anaemia Sickle cell Chronic disease Hypothyroidism Bone marrow failure
Name two causes of megaloblastic macrocytic anaemia?
Decreased B12
Decreased Folate
Name 4 causes of non-megaloblastic macrocytic anaemia?
Alcohol
Reticulocytosis
Liver disease
Pregnancy
What tests could you do to find specific causes of anaemia?
- Haematinics : B12, folate, ferritin
- Iron studies
- TFTs
- Blood film +/- bone marrow biopsy
- Hb electrophoresis (if sickle cell or thalassaemia suspected)
- Billirubin (raised in haemolysis)
Causes of iron deficient anaemia
- Chronic blood loss
- Menstrual bleeding
- GI tract loss (malignancy, ulcers, varices
- Urinary tract loss - Increased demand
- Pregnancy
- Growth - Decreased absorption
- Coeliacs
- gastrectomy - Poor intake
Investigations for iron deficient anaemia if there is no clear cause?
Upper GI endoscopy + colonoscopy
Coeliac screen
Urine dipstick
Treatment for iron deficient anaemia
Treat the cause
Ferrous sulfate tablets
Transfusion if Hb < 70
What is a common side effect of ferrous sulphate tablets
Constipation
what is the physiology of B12
vitamin B12 is found in meat and dairy products. The stomach produces intrinsic factor which binds to B12, allowing it to be absorbed in the terminal ileum.
Causes of B12 deficient anaemia?
Pernicious anaemia
Malabsorption (e.g after gastrectomy or terminal ileum disease/resection)
Investigations for pernicious anaemia
parietal cell antibodies
intrinsic factor antibodies
Schilling’s test (purpose of the test is to determine how well the patient is able to absorb B12 from their intestinal tract.)
What is the treatment for B12 deficient anaemia?
treat the cause
hydroxocobalamin injections 3 monthly
Causes of folate deficient anaemia
Dietary (alcoholism, neglect)
Increased requirements (pregnancy, haematopoiesis)
Malabsorption (coeliacs, pancreatic insufficiency, gastrectomy, Crohn’s)
Drugs that interfere with metabolism (phenytoin, methotrexate, trimethoprim)
What is classically shown on a FBC of someone with anaemia of chronic disease?
Low iron
Low TIBC (total iron binding capacity)
normal ferritin
Name three inherited causes of haemolytic anaemia
- Haemoglobinopathies
- sickle cell
- thalassaemia - Membrane defects
- hereditary spherocytosis, elliptocytosis - Enzyme defects
- G6PD deficiency, pyruvate kinase deficiency
Name three acquired causes of haemolytic anaemia
- Immune mediated
- autoimmune haemolytic anaemia
- drug-induced haemolytic anaemia - Non-immune
- DIC
- TTP
- physical damage (heart valves, toxins e.g lead, malaria)
Investigations to confirm haemolytic anaemia
- Increased Hb breakdown
- increased unconjugated bilirubin
- increased LDH
- increased urinary urobilinogen (on urine dipstick) - Increased Hb production
- increased reticulocytes - Intravascular haemolysis
- decreased free haptoglobin
- haemoglobinuria
Investigations to find cause of haemolytic anaemia
- Blood film
- sickle cells
- schistocytes
- inclusion bodies (malaria)
- spherocytes/elliptocytes (hereditary spherocytosis/elliptocytosis)
- Heinz bodies, bite / blister cells (G6PD)
- prickle cells (pyruvate kinase deficiency) - Coombs’ test
- autoimmune haemolytic anaemia - Hb electrophoresis
- Enzyme assays
what is polycythaemia
increased concentration of red blood cells within the blood
what are the causes of polycythaemia
Relative polycythaemia (i.e decreased plasma volume)
- acute dehydration
- chronic (obesity, HTN, alcohol excess, smoking associated)
Absolute (i.e increased RBC mass)
- Primary : polycythaemia ruba vera
- Secondary : due to increased EPO (renal cell carcinoma) or chronic hypoxia (COPD, high altitudes, congenital cyanotic heart disease)
What mutation is associated with polycythaemia ruba vera?
JAK2 mutation
what causes polycythaemia ruba vera
malignant proliferation of a clone derived from 1 pluripotent stem cell
what is a complication of polycythaemia ruba vera
increased risk of thrombosis/bleeding
what is the presentation of polycythaemia ruba vera
may be asymptomatic and picked up on routine blood count
May present with vague symptoms related to hyper viscosity e.g headache, dizziness, tinnitus, erythromelalgia)
Investigations for polycythaemia
- WCC and platelets
- both raised in primary absolute polycythaemia (polycythaemia ruba vera), but not in secondary absolute polycythaemia - 51Cr Red Cell Mass study
- normal red cell mass in relative polycythaemia
- raised red cell mass in absolute polycythaemia - EPO level
- If polycythaemia ruba vera suspected : bone marrow biopsy
Treatment options for polycythaemia ruba vera
Venesection
Hydroxycarbamide (don’t take if pregnant or planning pregnancy)
Interferon
Aspirin daily to reduce blood clots
Why may neutrophils be high?
- Bacterial infection
- Inflammation
- Necrosis
- Corticosteroids
- Malignancy / myeloproliferative disorder
- Stress (trauma, surgery, burns)
Why may neutrophils be low?
- Post-chemotherapy
- Agranulocytosis causing drugs (carbamazepine, clozapine, colchicine, carjimazole)
- viral infection
- hypersplenism
- bone marrow failure (e.g leukaemia)
Why may lymphocytes be high?
- Viral infection
- chronic infections
- CLL/lymphoma
Why may lymphocytes be low?
- viral infection
- HIV
- post-chemotherapy
- bone marrow failure (e.g in leukaemia)
- whole body radiation
Why may monocytes be high?
- bacterial infection
- autoimmune disease
- leukaemia/Hodgkin’s
Why may monocyte count be low
acute infections
corticosteroids
leukaemia
why may eosinophils be high?
allergy (eczema) parasite infection drug reaction skin diseases malignancy e.g Hodgkin's
Why may basophils be high?
Some leukaemia/lymphomas IgE mediated hypersensitivity Inflammatory disorders Myeloproliferative disorders Viral infection
on what is thrombocytopenia?
decreased platelets
causes of thrombocytopenia (decreased production) ?
bone marrow failure
aplastic anaemia
megaloblastic anaemia
myelosuppresion
what is aplastic anaemia
Aplastic anaemia causes a deficiency of all blood cell types: red blood cells, white blood cells, and platelets.
what is megaloblastic anaemia
Megaloblastic anemia is a condition in which the bone marrow produces unusually large, structurally abnormal, immature red blood cells
Causes of thrombocytopenia (increased destruction/consumption)
Non immune
- DIC
- TTP
- HUS
- sequestration in hypersplensim
Primary immune
- ITP
Secondary immune
- SLE
- CLL
- viruses
- drugs
- alloimmune
possible Ix for thrombocytopenia
- Blood film +/- bone marrow biopsy
- Infection screen (e.g HIV)
- LFTs
- LDH
- Serum B12 and folate
- Coagulation screen - fibrinogen and D-dimer
- Acute phase reactants
Treatment of thrombocytopenia
Treat the cause
- immunosuppressants if autoimmune e.g prednisolone, azathioprine
- plasmapheresis for TTP / HUS
Platelet concentrate transfusion
Splenectomy
What is HUS?
Hemolytic–uremic syndrome (HUS) is a group of blood disorders characterized by low red blood cells, acute kidney failure, and low platelets
What is thrombocythemia
increased platelets
Causes of thrombocythemia
Primary : essential thrombocythemia
Secondary : bleeding, inflammation, infection, malignancy, post-splenectomy
Investigations for thrombocythemia
- Blood film +/- bone marrow biopsy
- Acute phase reactants
- JAK2 mutation
Treatment of essential thrombocythemia
aspirin
hydroxycarbamide
Presentation of essential thrombocythemia
bleeding
arterial and venous thrombosis
microvascular occlusion (headache, atypical chest pain, light-headedness)
what happens to the urea in a GI bleed?
increased in upper GI bleeding
