Blood Cell Abnormalities Flashcards
What is anaemia?
A reduction in the amount of haemaglobin in a given volume of blood, below what would be expected in comparison with a healthy subject of the same age and gender
What are the four mechanisms of anaemia?
Production - reduced production of RBC
Pooling - RBC may pool in the spleen
Loss - RBCs may be lost due to blood loss
Survival - reduced survival of RBCs
What is meant by microcytic RBCs
Smaller than usual - normally hypochromic and can therefore be identified by their larger area of central pallor
What causes microcytic anaemia?
Occurs either due to a loss of HAEM or GLOBIN
HAEM loss = due to iron deficiency
GLOBIN loss = thalassemia
What causes an iron deficiency?
Heavy menstruation, diet, malabsorption,
What is macrocytic anaemia?
When the red blood cells are larger than normal
What causes megaloblastic anaemia?
Deficiency of folate or B12 - cells are continuing to divide by cannot synthesize the DNA therefore just keep growing
What causes macrocytosis?
Abnormal haematopoiesis - red cell precursors continue to make Hb and other proteins but do not divide properly
How to diagnose megaloblastic anaemia?
Bone marrow examination
Causes of normocytic anaemia?
Recent blood loss - trauma, gastrointestinal bleed
Failure of production
Pooling of RBC in spleen
What is splenic sequestration?
When sickle cells get trapped in the spleen, leading to hyposplenism and the spleen not functioning properly
What is polycythemia?
Too many red cells in circulation
What causes polycythemia?
Blood doping or transfusions
Increased EPO - can be appropriate or inappropriate
What is pseudo polycythemia?
When you have a reduced plasma volume, so it looks like the RBCs take up a larger proportion of the blood colume
What causes a reduced plasma volume?
Dehydration
What is leukemia?
A cancer arising as a result of a mutation in a precursor of myeloid or lymphocyte cells
How is leukemia different to other cancer?
The cells involved circulate in the blood so invasion / metastasis doesn’t apply here
What are the four types of leukemia?
Acute Lymphoblastic Leukemia
Chronic Lymphocytic Leukemia
Acute Myeloid Leukemia
Chronic Myeloid Leukemia