Concepts in haematology Flashcards
What can cause a low cell count?
Increased destruction; haemolysis, HIV, acute blood loss
Reduced production; chemo, parovirus infection
Redistribution; splenomegaly, chronic liver disease, portal hypertx, glandular fever
What can cause a high cell count?
Increased production in response to stimulus; infection, chronic hypoxia (high altitude, COPD) = polycythaemia
Increased production with no stimulus (malignancy); leukaemia, lymphoma
Redistribution; steroidss
What is the difference between thrombocytosis and thrombophilia?
Thrombocytosis; increased platelet count
Thrombophilia; increased tendency to form a thrombus/ clot
What is anaemia?
Lack of RBC/ Hb
Describe some marrow activity definitions?
Increased production = hyperplasia
Disordered production = dysplasia
Low production = hypoplasia
No production = aplasia
What is the erythron?
Cellular mechanism that generates RBC
Describe erythropoietin and the feedback loop
Interstitial fibroblasts near the peritubular capillaries and the PCT detect hypoxia flowing through the kidney and increase erythropoietin activity
Erythropoietin stimulates cell division of red cell precursors and recruits more cells to red cell production in the marrow
What is erythroid hyperplasia?
More “machinery” to produce red cells
What are the “raw materials” for RBC production?
Iron store = haem
Globin synthesis
B12 and folate
What does the reticulocyte count tell you?
How quickly red cells are being made; erythroid hyperplasia
Will you get a change in bilirubin or retic count in secondary polycythaemia?
No; change happens gradually
