Week 3 formative tutorial Flashcards
what crises would require increased production of white cells
infection
surgery/trauma
cancer
neutrophils function
innate (non-specific) immune system.
kill bacteria - phagocytose and release lysozymes that break down
lymphocytes function
B cells - produce plasma cells releasing antibodies
T cells - cell-mediated immunity. bind to antigen. cytotoxic.
monocytes
develop into macrophages that will gobble stuff.
similar function to neutrophils
eosinophils role
release granules that destroy parasites.
atopic disease - asthma, dermatitis etc have eosinophilia
basophils function
release histamine and inflammatory mediators
histamine vasodilates
give examples of leucocytosis that is not reactive
malignancy of the white cells
- e.g. acute lymphoblastic leukaemia
- e.g. chronic lymphocytic leukaemia
clonality definition
one single cell becomes malignant and all the cells it produces are the same
why is pancytopenia potentially serious?
- neutropenic sepsis
- haemorrhage (because thrombocytopenia) - not worried until pretty low like below 50, 40, 30
iatrogenic cause of pancytopenia
cytotoxic chemotherapy
how does hypersplenism cause pancytopenia
more blood pools in the spleen because it’s big and the sinusoids are big
so much blood in the spleen that there is not so much circulating
commonest cause of pancytopenia
megaloblastic anaemia- B12/folate deficiency
malignant cause of pancytopenia
myelodysplastic syndrome - bone marrow not working properly.
what does a haematocrit of 0.52 mean
52% of blood volume is red cells and the rest is plasma
in true polycythaemia, what would drive the marrow to produce too many red blood cells
primary: myeloproliferative disorders. JAK2 mutation
others:
chronic hypoxia conditions like COPD. High altitude like people living in the Himalayas lol
tumours of the kidney leading to overproduction of erythropoietin
bodybuilders - testosterone abuse. testosterone promotes more red cell production in the bone marrow
myeloproliferative disorders clinical presentation
headaches
blood vision
poor concentration
nosebleeds
red face
gout
hepatosplenomegaly
why would we be concerned if there are too many red blood cells?
stroke
how to reduce haematocrit
regular venesection until reduced below 0.45
can use a gentle chemo drug hydroxycarbamide
what can myeloproliferative disorders transform to
myelofibrosis
AML
what is the difference between thrombocytosis and thrombocytopenia
thrombocytosis - increase in platelets
thrombocytopenia - reduced number of platelets
what are the two broad mechanisms whereby the bone marrow produces too many platelets
reactive (infection, inflammation, trauma, blood loss)
Clonal. (Primary clonal disorder - Myeloproliferative disorders)
