Haematology Flashcards
Acanthocytes (Spur/spike cells)
RBCs have many spicules. Abetalipoproteinaemia, liver disease, hyposplenism.
Basophilic RBC stippling
Small dots of RNA. Accelerated erythropoiesis or defectve Hb synth. Lead poisoning,
What is anaemia?
Men: Hb
S/S of anaemia
Fatigue, SOB, palpitations; Pallor, ?tachycardia, flow murmurs, CHF.
Microcytic anaemias
Fe definiciency, Anaemia of chronic disease, Sideroblastic, Thalassaemia.
Normocytic anaemias (7)
Blood loss, Haemolysis, Anaemia of chronic disease, Bone marrow failure, Renal failure, Hypothyroidism, Pregnancy.
Macrocytic anaemias
B12 / folate def, Alcohol, Reticulocytosis (eg. in haemolysis), Hypothyroidism, Antifolate (eg. phenytoin), MDS.
TTP pentad
MAHA, Fever, Renal impairment, Neuro signs, Low Plt.
Causes of Iron deficiency anaemia
- Blood loss: GI: - Meckel’s diverticulum in older children, - Peptic ulcers (NSAIDs) - Polyps / colorectal Ca - Menorrhagia - Hookworm - Increased utilisation: pregnancy, growth. - Decreased intake: prematurity, poor diet. - Decreased absorption: Coeliac, post gastric surgery. - Intravascular hamolysis
Management of Iron deficiency anaemia
Thorough GI workup unless clear cause. Treat the cause. Oral iron - SFX: nausea, abdo discomfort, bowel change, black stools)
Mechanism and causes of Anaemia of chronic disease
Cytokines inhibit RBC production. Due to: - Chronic infection (TB, osteomyelitis) - Vasculitis - Rheumatoid arthritis - Malignancy - Renal failure: EPO not made (rather than suppressed).
Mechanism and causes of Sideroblastic anaemia
BM makes ringed sideroblasts rather than healthy RBCs, because it can’t make haem. Causes: - Genetic - Myelodysplastic - Alcohol excess - Lead excess - Chemo - Radiation - TB drugs
Dx and Tx of sideroblastic anaemia
Ring sideroblasts seen in marrow. Tx: - Remove cause. - Pyridoxine (Vit B6 ^RBC production)
Vitamin B12: source and causes of deficiency
= cobalamin From meat and dairy. Deficiency: - Dietary (vegan) - Malabsorption due to stomach: lack of Intrinsic Factor - Malabsorption in terminal ileum: recsection, Crohn’s, bacteria, tropical sprue, tapeworms.
Features of B12 deficiency
Mouth: glossitis, angular cheilosis; Psych: irritability, depression, dementia, psychosis; Neuro: paraesthesia, peripheral neuropathy.
Pernicious anaemia
Autoimm atrophic gastritis: lack of HCl and Intrinsic Factor. Commonest cause of macrocytic anaemia here. Parietal cell Abs, IF Abs (old: Schilling test). Replenish B12 (hydroxocobalamin IM).
Warm autoimmune haemolytic anaemia
IgG (warm hug) binds RBCs at 37deg (+ Coombs DAT). Spherocytes on blood film (IgG bitten off). Mainly idiopathic (can be lymphoma, CLL, lupus, methyldopa). Mx: steroids, splenectomy, immunosuppression.
Cold agglutinin disease
IgM binds RBCs in the cold (often with Reynauds). Mainly idiopathic (can be lyphoma or infections like EBV, mycoplasma). Mx: Treat underlying condition, avoid the cold, chlorambucil.
Paroxysmal cold haemaglobinuria
Viral infection (paroxysmal cold). Donath-Landsteiner Abs bind RBCs in cold; complement lyses on rewarming. Self-limiting.
Paroxysmal nocturnal haemoglobinuria
Non-immune: lose GPI from RBC surface, so complement lysis. Morning haemoglobinuria, thrombosis, Budd-Chiari. Dx: altered GPI on immunophenotype; Ham’s test.
Tx for Haemophilia A
Avoid NSAIDs and IM injections. Desmopressin: more vWF, so less VIII degraded. Factor VIII concentrates.
Tx for Haemophilia B (Christmas disease)
Factor IX concentrates.
Tx for Von Willebrand’s disease
Desmopressin, vWF concentrates, Factor VIII concentrates.
Tx for Vitamin K deficiency
IV Vitamin K, or FFP in acute haemorrage.