11- Haemolytic Anaemias: General Basics Flashcards
general symptoms, lab investigations, classifications
what is haemolytic anaemia?
anaemia/ reduced haemoglobin levels due to shortened RBC survival
30–80-day survival before haemolysis as opposed to the normal 120-day lifespan
list and explain the general and chronic clinical findings in haemolytic anaemia
general:
- jaundice = Hb released from ruptured RBCs is broken down into bilirubin - causes yellow discolouration of skin and eye sclera
- pallor = decrease in circulating RBCs decreases oxygen carrying capacity
- fatigue = from reduced oxygen carrying capacity
- splenomegaly = spleen needs to remove more RBCs from increased haemolysis, gets bigger from overactivity
chronic:
- pigment gallstones = excessive RBC haemolysis causes increased bilirubin production - accumulates in liver and forms pigment gallstones
- leg ulcers = reduced oxygen delivery causes hypoxic conditions, affects wound healing
- folate deficiency = chronic haemolysis leads to increased RBC turnover = greater folate demand for RBC production - depletes folate stores
list the general and chronic symptoms of HA
pallor
fatigue
splenomegaly
jaundice of skin and eye sclera
pigment gallstones from bilirubin accumulation
leg ulcers - hypoxia, slow wound healing
folate deficiency - increased RBC haemolysis, turnover and demand for production and depletes folate stores
list and describe different general lab investigations for haemolytic anaemia
reversal of myeloid: erythroid ratio
- normally M:E ratio is 2-5: 1
- in erythroid hyperplasia - ratio is reverse to approx. 1:4
- erythroid cells are RBC precursors
reticulocytosis
- varies between different HAs - e.g. hemoglobinopathies, G6PH deficiency, hereditary spherocytosis
- higher proportion of reticulocytes/ immature RBCs seen in HA as body tries to compensate for high RBC turnover
analysis of peripheral blood film
list and describe potential findings in peripheral blood film for HA
- polychromatophilia
- nucleated/ immature RBCs
- thrombocytosis = increased platelet levels to increase haematopoiesis
- neutrophil with a left shift = increased immature neutrophils as haemolysis triggers an inflammatory response
- morphological RBC abnormalities = potential clue for underlying disorder (e.g. sickle cell, target cell, schistocytes)
- increased lactate dehydrogenase = LDH needed for producing energy in RBCs, deforming and reforming as they go through capillaries
- decreased serum haptoglobin = binds to free Hb
increased urobilinogen and urinary hemosiderin
what conditions are sickle cells associated with?
sickle cell anaemia
what conditions are spherocytes associated with? appearance?
hereditary spherocytosis
autoimmune haemolytic anaemia
appearance - lack central pallor, more spherical than biconcave
appearance of acanthocytes?
irregular spiky projections
what conditions are target cells associated with? appearance?
thalassaemia
haemoglobinopathies
disorders affecting the RBC membrane
appearance - bulls-eye like; central area of Hb, ring of pallor, and outer Hb rim
what are the three main classifications of HA and their subsets?
inherited - hereditary or acquired
origin of RBC damage - intrinsic or extrinsic
= intrinsic = membrane defects, enzyme defects, haemoglobin detects
= extrinsic = immune (autoimmune/ alloimmune) or non-immune mediated
site of RBC destruction - intravascular or extravascular
examples of intrinsic HAs with membrane defects
hereditary spherocytosis
hereditary elliptocytosis
hereditary pyropoikilocytosis
examples of intrinsic HAs with enzyme defects
G6PH deficiency
pyruvate kinase deficiency
examples of intrinsic HAs with haemoglobin defects
thalassaemia - alpha/ beta
sickle cell disease
examples of extrinsic non-immune HA causes
red cell fragmentation from valve replacements
drugs used to treat malaria cause haemolysis
what is polychromatophilia?
RBCs of different colours
