PATH 201 - LECTURE 5

what is haematopoiesis controlled by

cytokines and growth factors

what are leucocytes

white blood cells

what are the three main types of white blood cells

granulocytes

monocytes

lymphocytes

what lineage do granulocytes come from

myeloid

what lineage do monocytes belong to

myeloid

what lineage do lymphocytes belong to

• lymphoid

which of the white blood cells are polymorphonuclear

all the granulocytes

• neutrophils

• basophils

• eosinophils

which of the white blood cells are mononuclear

lymphocytes and monocytes

what does polymorphonuclear mean

• poly means many

• morpho means shapes

• nuclear means nucleus

• so the many different shapes of the nucleus

what colour is the granules of a neutrophil

pink

what do the granules of neutrophils contain and what does this allow them to do

• lysosyme and superoxide which allows them to phagocytose and kill things

describe the nucleus of a mature neutrophil

• segmented 2-5 lobes

describe what neutrophils do

• theyre phagocytic

• recruited by chemokines (IL-8)

• have complement receptors

• secrete antimicrobials and neutrophil extracellular traps

how long are neutrophils in the tissue

24-72 hours

what is it called when we have a lot of neutrophils

neutrophillia

what causes neutrophillia

• bacterial infection

• inflammation

• drug induced (steroids)

• malignancy (myeloid leukemia)

what is too few neutrophils called

neutropenia

when do we see neutropenia

• viral infection

• severe bacterial infection (all of them have been utilised)

• immunosuppresion

• drug toxicity

• african and middle eastern individuals

what am i looking at

• neutrophils

• with pale cytoplasm and pink almost neutral granules

what am i looking at

neutrophils that have taken up some bacteria

describe the nucleus of eosinophils

segmented with 2-3 lobes

describe the granules of eosinophils

large, refractile, orange

• contains major basic protein

• eosinophil cationic protein

• peroxidase

what is the function of eosinophils

• Immune defence against parasites and pathogens

• phagocytic

what is eosinophilia

• infiltration of eosinophils

what is eosinophilia caused by

allergic reactions, asthma, parasitic infections, malignant disease of myeloid cells

describe the nucleus of basophils

• bilobed

describe the granules of basophils

dark purple

• histamine

• leukotrienes

• heparin

• vasoactive mediators

describe what a basophil does

• weakly phagocytic

• inflammatory role

• allergic role

• binds IgE

what is the cause of basophilia

• blood cancer (chronic myeloid leukemia)

• anaphylaxis

• insect/snake venom

describe the nucleus of monocytes

• kidney shaped nucleus

what colour is the cytoplasm of monocytes

blue/grey

what do monocytes become in tissue

• macrophages

how long do monocytes circulate for

20-40 hours

what is monocytosis

• lots of monocytes

what causes monocytosis

• any long chronic infection

• tubercolosis

• glandular fever

• myelodysplastic syndrome

do all macrophages some from monocytes

• no

• there is also macrophages that that are fetal derived

what are functions of macrophages

• phagocytosis

• produce proinflammatory cytokines

• present antigen to T cells

• initiate healing

describe the nucleus of lymphocytes

• non segmented

what do T cells do

• CD4 secrete cytokines

• CD8 induce apoptosis

what do B cells do

produce antibody

is there more B cells or more T cells

T cells

why is lymphocytosis normal in children

because everything children see is new

when do we see lymphocytosis in adults

• with many acute viral infections and whooping cough

• malignancy (chronic lyphocytic leukemia)

what is lymphopenia

• when there is fewer than normal lymphocytes

when do we see lymphopenia

• drug therapy against autoimmune disease

• AIDS

• severe stress

what do natural killer cells do

• activated by low MHC-I or receptors on target ells

• induce apoptosis on target cells

what do natural killer T cells do

• see antigen presented on CD1

• produce lots of cytokines

What is granulopoiesis

• production and maturation of granulocytes in the bone marrow

how long does the maturation and production of granulocytes take (granulopoiesis)

• 10 days in the bone marrow

how long does a neutrophil.granulocyte spend in the blood

1 day

where does a neutrophil go after circulating in the blood for one day

• they either become marginated - which means they sit at the edge of the blood vessels until they are recruited by excercise or teh release of adrenaline

• or they retreat to the tissues

how long do neutrophils spend in the tissues

3-5 days

what mediates granulopoiesis of neutrophils

• stem cell factors and growth factors like IL-3 help the blast cell divide

• GMCF’s (granulocyte macrophage stimualting factors help mature these cells

how does a haemotology analyser work?

• distinguishes white blood cells based on how they scatter light

• each dot on the graph represents one cell and cells with similar properties are grouped together

what is forward scatter measure (haemotology analyser)

• measures cell size

• low forward scatter means small cell

• high forward scatter means large cell

what does side scatter measure (haemotology analyser)

• measures internal complexity

• things like granulation, nuclear lobation etc

• more complex cells will have more side scatter

what is the best way to identify cells

• immunophenotyping

how does immunophenotyping work

• an antibody that recognises a marker is created (eg CD4 on a T cell)

• the antibody has fluorescnet properties

• and so when it goes through the flowcytometer, they fluorescence of the antibody is detected and it tells us which cell is present

interpret this scatter plot

• so the top scatter plot is the result of a haemotology analyser

• the x axis is representing forward scatter - as you go along, its representing larger cells

• teh y axis is representing side scatter - as you go along, it is representing more internally complex cells

• it is colour coded as well

• the dark blue for example is granulocytes, they are the largest and most complex cell present

• the bottom graph is after staining the cells with a leukocyte antigen (CD45)

• as we go along the X axis, the expression of the antigen on the cells is increasing

• we can see the black cluster, representing blast cells have low complexity (being lower on the Y axis) and low levels of CD45 expression (being less along the x axis)

what is a leukopenia

deficiency of white blood cells

what are the two types of proliferative disorders (in terms of diseases fo white blood cells)

• reactive

• neoplastic

what are the 2 neoplastic proliferative disorders of white blood cells

• myeloid neoplasms

• lymphoid neoplasms

what is clonal proliferation

• when cells have uncontrolled growth and fail to die

what happens when clonal proliferation gets out of hand

• it begins to replace normal marrow and infiltrate into other tissues, replacing and destroying normal cells

what impacts is it going to have on the body if clonal proliferation spreads into the bone marrow and replacing and destroying the normal cells and tissue

• the body is oing to be heavily impacted on its ablity to deliver oxygen and fight off infections

what am i looking at

• there is 2 abnormal looking leukocytes

• and then the cell with little white circles in it is a macrophage - we know that because of the vacuoles present

what are reactive proliferative disorders due to

• infection and inflammation

where do malignant blood cells grow (from blood cancers)

• in the bone marrow

• they accumulate there as well

what does the effect of blood cancer depend on

the type of cell affected

describe the effect of blood cancer of granulocytes and lymphocytes

• the often start in the bone marrow and spill into the blood

• some lymphocytes occupy the lymph nodes (lymphoma)

describe the effect of blood cancer of plasma cells

they stay in the bone marrow, and cause myeloma

overall what is the result of blood cancers

• bone marrow failure

• replacement of normal marrow spaces

• reduced RBCs - anaemic

• reduced neutrophils - prone to infection

• reduced platelets - prone to bleeding

• 
  

what am i looking at

hyper cellular marrow due to blood cancer

• full of one clonally proliferated cell

what are the different lymphoid neoplasms

• acute lymphoblastic leukaemias (ALL

• chronic lymphocytic leukaemia (CLL

• lymphomas

describe acute lymphoblastic leukaemias

• blastic - is generally referring to growth

• it is proliferation of immature, rapidly growing B and T (lymphoid) cells in the bone marrow

describe chronic lymphocytic leukaemia

• cytic generally is too much of something

• proliferation of mature lymphoid cels in the bone marrow

between acute lymphoblastic and chronic lymphocytic leukaemia, which one is more aggressive

• acute

describe lymphomas

• solid tumours of proliferating lymphocytes inthe lymph nodes, spleen or the blood

what am i looing at

lymphoma cells

what are the myeloid neoplasms

• acute myeloid leukaemia (AML)

• myeloproliferative neoplasms (MPN)

• myelodysplastic syndromes (MDS

describe myeloid leukaemia

• immature rapidly diving blasts

describe myeloproliferative neoplasms

• mature cells

describe myelodysplastic syndroms

• to do with abnormal cells

what am i looking at

• acute myeloid leukaemia

• lots of blast cells

what am i looking at

• myeloproliferative neoplasms

• more differentiated cell types

what am i looking at

an abnormal neutrophil from someone with myelodysplastic syndrome

what is the survival of ALL/AML (acute leukaemia’s) without treatment

4-8 weeks

what does treatmeant for acute leukaemia’s involve

• intensive chemo

• stem cell transplant

what is the prognosis against acute leukaemia’s for children and adults

• pretty good for children

• not good for adults

what am i looking at

• left is promyelotic acute leukaemia (can see proliferation of one cell)

• right is normal

what am i looking at

• left is acute lymphobasltic leukaemia

• right is normal

what is rhe msot common cancer in children

Acute lymphoblastic leukaemia ALL

is B-ALL or T-ALL more common

B-ALL

what are signs and symptoms of ALL

• anaemia (weakness and fatigue)

• thrombocytopenia (bleeds and bruising)

• neutropenia (infections

what is the genetic characteristic of chronic myeloid leukameia (CML)

• it is characterised by the presence of a chimeric ABL gene

• it causes constitutive expression of a BCR-ABL tyrosine kinase

• it drives proliferation of myeloid precursors

describe the morphology of CML (chronic myeloid leaukaemia

• high white cell count

• spectrum of myeloid cells (from blasts to mature cells)

what happens to the spleen due to CML

• splenomegaly

• it gets infiltrated with blood cells

• blood cells start growing outside the bone marrow - extramedullary haematopoiesis

• increased cell burden can impair blood supply and cause painful splenic infarcts.

what is the peak age at which CML is seen

25-60y

how is CML treated

tyrosine kinase inhibitors

what is follicular lymphoma (FL)

• a tumour arising from germinal centre B cells