Haematology Flashcards
What are the four groups of causes of iron deficiency anaemia?
- Excessive blood loss
- Dietary inadequacy
- Iron malabsorption
- Excessive requirements
What condition can typically cause iron malabsorption?
Coeliac disease
What is the most common cause of iron deficiency anaemia in tropical countries?
Hookworm causing blood loss from the GI tract
What are some signs you see when examining an iron deficient patient?
- Pallor
- Pale palmar creases
- Koilonychia (spooning of the nails)
- Angular stomatitis
- Atrophic glossitis
- Dysphagia = Plummer-Vinson syndrome
What would a blood film look like in iron deficiency anaemia?
Hypochromic microcytic anaemia +/- anisocytosis and poikilocytosis
Hypochromia = low mean corpuscular Hb (MCH) Microcytosis = low MCV Anisocytosis = variation in size between RBCs Poikilocytosis = abnormally shaped RBCs
Why is serum ferritin not always a very useful marker of iron levels?
It is an acute phase reactant
i.e. although it correlates with total body iron stores, it can be raised in infection/inflammation
What further investigations would you do in a patient with iron deficiency anaemia?
Coeliac serology. If negative (and male or post-menopausal woman), refer for gastroscopy + colonoscopy to rule out GI bleed
What is the treatment for iron deficiency anaemia and how long do you treat for?
Ferrous sulphate 200-300mg 1-2 times a day
Once Hb levels are normal, continue treatment for a minimum of 3 months
What are the main side effects of iron replacement therapy?
Constipation or diarrhoea
Black stools
Nausea
Abdominal pain
What is the main reason that Hb levels do not rise despite iron replacement therapy?
Non-compliance due to GI upset side effects of iron. So always check compliance first and adjust dose if necessary.
Microcytic anaemia does not always mean iron deficiency. What are other causes of microcytic anaemia?
- Thalassaemia
- Sideroblastic anaemia (would see basophilic granules)
- Anaemia of chronic disease
- Lead poisoning
What is sideroblastic anaemia due to?
Impaired ability of bone marrow to produce normal RBC (ineffective erythropoiesis)
Iron levels are normal or high but not used properly
Can be caused by TB medications
What is a complication of sideroblastic anaemia?
Organ damage due to excess iron deposition
What MCV is macrocytosis defined by?
MCV > 96 fL
What is a megaloblast?
A cell in which the nuclear maturation is delayed compared with the cytoplasm due to defective DNA synthesis
What are the main causes of megaloblastic macrocytic anaemia and why?
Vitamin B12 and folate deficiency - they are required for normal DNA synthesis
What drugs can cause folate deficiency?
Methotrexate
Anti-epileptics
Trimethoprim
What surgical procedure commonly causes vitamin B12 deficiency?
Gastrectomy
What causes non-megaloblastic macrocytic anaemia?
- Excess alcohol
- Liver disease
- Hypothyroidism
- Reticulocytosis in haemolysis
Describe the difference between macrocytosis and microcytosis
Macrocytosis occurs when there is a problem with the synthesis of blood cells
Microcytosis occurs when there is a problem with haemoglobin production
What might a high MCV without anaemia suggest?
Myeloma
Hyperglycaemia
What vitamin is folate?
Vitamin B9
What do neutrophils look like in B12 and folate deficiency?
Hypersegmented. Normally there should be less than 5 segments.
When testing for folate levels, why is serum folate not always very reliable and what is a more reliable indicator?
Serum folate only indicates recent intake
Red cell folate is a more reliable indicator
What is pernicious anaemia?
Autoimmune condition where atrophic gastritis leads to lack of intrinsic factor secretion from parietal cells of stomach, therefore vitamin B12 cannot be absorbed in the terminal ileum.
What cells are characteristic of Hodgkin’s lymphoma?
Reed-Sternberg cells = multi-nucleated giant cells
Previous infection with what virus can cause Hodgkin’s lymphoma?
Epstein-Barr virus
What do the lymph nodes feel like in lymphomas?
Enlarged, non-tender, rubbery, superficial lymph nodes
Mostly cervical
What staging system is used for lymphomas?
Ann Arbor staging
- Single lymph node region
- Involvement of 2+ nodal areas on same side of diaphragm
- Involvement of nodes on both sides of diaphragm
- Spread beyond lymph nodes
Each stage has A (no systemic symptoms except pruritis) or B (systemic symptoms present)
What blood test results indicate a worse prognosis in Hodgkin’s lymphoma?
High ESR
Low Hb
What lymphomas does Non-Hodgkin’s lymphoma include?
All lymphomas without Reed-Sternberg cells
What is the most common Non-Hodgkin’s lymphoma?
Diffuse large B-cell lymphoma
What is the most common area for extranodal disease in Non-Hodgkin’s lymphoma?
GI tract
What are the 3 types of GI tract Non-Hodgkin’s lymphomas?
- Gastric MALT
- Non-MALT gastric lymphoma
- Small bowel lymphomas
What is Gastric MALT caused by?
H. Pylori
In LFTs, what indicates a poorer prognosis in Non-Hodgkin’s lymphoma?
Raised LDH because it indicates increased cell turnover
In terms of treatment/prognosis, what is the difference between low and high grade lymphomas?
Low-grade - slow-moving but incurable and widely disseminated
High-grade - aggressive but often curable
What symptom is uncommon but specific to Hodgkin’s lymphoma?
Alcohol induced pain
If there is major bleeding when a patient is on warfarin, what is your management? When can you restart warfarin?
Give prothrombin and vitamin K
Restart warfarin when INR < 5.0