Haematology Flashcards
A reduction in RBCs due to lack of production is described as
Bone marrow aplasia
Polychromatophils are seen using Wrights stain, and indicate immature red blood cells (and a regenerative anaemia). What are these cells called when using a methylene blue stain?
Reticulocytes
Why might a patient with a regenerative anaemia have a high mean corpuscular volume (MCV) and a low mean corpuscular haemaglobin (MCGV) concentration?
In a regenerative anaemia the Bone marrow is releasing immature RBCs. These polychromatophils/reticulocytes have a larger mass and smaller haemoglobin concentration compared to mature RBCs.
Feline have two types of immature red blood cell, what are they called?
Punctate and aggregate reticulocytes
Compare the appearance of a punctate reticulocyte to an aggregate reticulocyte in the feline patient
Aggregate contain granules in the cytoplasm and look similar to WBCs with new methylene blue stain. Punctate have small dots of concentrated stain around the outside of the cell.
Patients with suspected pyruvate kinase deficiency will have anaemia on presentation. Would this be a regenerative or non regenerative anaemia ?
Strongly regenerative
Describe the pathophysiology of pyruvate kinase deficiency
Genetic defect that means RBC have inefficient metabolism. The RBCs have a shortened half life (5-6 days). Patients will have lifelong exercise intolerance and weakness.
How is pyruvate kinase deficiency diagnosed?
MCV will be high due to increased reticulocytes/polychromatophils. Radiographs of the long bones will show signs of osteosclerosis. Bone marrow biopsies will have low cellularity due to progressive myelofibrosis and osteosclerosis.
Which infectious agent in cats is responsible for generating a secondary aplastic anaemia
FeLV
Which infectious agent in dogs causes an immune mediated destruction of progenitor cells in the erythronium line within the bone marrow, resulting in a non-regenerative anaemia ?
Ehrlichia canis
Describe how polycythemia is different to erythrocytosis?
Polycythemia is related to an increase in the numbers of multiple myeloid cell lines. Erythrocytosis relates to red blood cells specifically.
How is absolute polycythemia different to relative polycythemia?
Relative polycythaemia is a term that describes an increase in RBCs that is due to a shift in fluid (typically due to dehydration). It can also be caused from splenic contraction and redistribution of RBCs.
Absolute polycythaemia relates to the actual increase in the mass of red blood cells. It can be primary or secondary
Which disease is characterised as a primary myeloproliferative disorder of the bone marrow that results in increased RBC production, regardless of erythropoietin levels?
Polycythaemia Vera (or primary polycythaemia). The erythrocytes will often appear without morphological abnormalities
How could you distinguish an absolute primary polycythemia from relative polycythaemia or secondary polycythaemia?
- Assess hydration status
- Assess PaO2 and EPO levels
If relative, then when rehydrated PCV would fall within range. If PaO2 is low, and EPO high, it is secondary to a chronic hypoxia (heart/lung dz, BOAS). If PaO2 and EPO are within normal limits, likely a polycythaemia Vera (primary, absolute).
What haematological changes would you see in a patient with iron deficient anaemia?
Microcytic, hypochromic
