white cells

Question 1

what cells are derived from common myeloid progenitors?

Answer 1

myeloid cells- i.e. not lymphocytes

megakaryocytes, erythrocytes, mast cells, myeloblasts

Question 2

what do myeloblasts differentiate into?

Answer 2

granulocytes

basophils, neutrophils, eosinophils, monocytes

Question 3

What is a band form?

Answer 3

Left shift neutrophil

Question 4

In which granulocyte progenitors does cell division occur?

Answer 4

myeloblasts, promyelocytes, myelocytes

Question 5

in which granulocytes does cell division not occur

Answer 5

metamyelocytes or band forms

Question 6

what is the main function of the neutrophil?

Answer 6

phagocytosis and killing of micro organisms

Question 7

what is chemotaxis?

Answer 7

first step in neutrophil migration to tissues

neutrophils become marginated in the vessel lumen and adhere to the endothelium and migrate into tissues

Question 8

what happens after cytokine priming to neutrophils?

Answer 8

phagocytosis

Question 9

what is the eosinophil’s main function?

Answer 9

defence against parasitic infection, also important in regulation of hypersensitivity reactions (inactivate histamine and leukotrienes released by basophils and mast cells)

they also do all neutrophil functions

Question 10

what do basophils do?

Answer 10

release histamine and leukotrienes in the mediation of immediate-type hypersensitivity reactions when coated with IgE

modulate inflammatory responses by releasing heparin and proteases

Question 11

what do the granules of a basophil store?

Answer 11

histamine, heparin and proteolytic enzymes

Question 12

what are mast cells?

Answer 12

similar to basophils but reside in tissues rather than circulation

Question 13

what is the monocyte’s function

Answer 13

phagocytosis of micro-organisms covered with antibody and complement

phagocytosis of bacteria and fungi (Fc mediated)

antigen presentation to lymphoid and other immune cells

Question 14

what is another role of macrophages?

Answer 14

they can store and release iron

Question 15

what cells are derived from the common lymphoid progenitor?

Answer 15

natural killer cells, small lymphocytes

Question 16

where do B lymphocytes originate?

Answer 16

fetal liver and bone marrow

Question 17

what does subsequent B cell maturation require?

Answer 17

exposure to antigens in lymphoid tissue, eg lymph nodes

Question 18

where do T lymphocytes come from?

Answer 18

migrate from foetal liver to the thymus

Question 19

what do natural killer (NK) cells do?

Answer 19

kill tumour cells and virus infected cells

Question 20

what does transient leukocytosis suggest?

Answer 20

Reactive/secondary cause

occurs when normal/healthy bone marrow responds to an external stimulus (e.g. infection/ inflammation/ infarction)

Question 21

what does persistent leukocytosis suggest?

Answer 21

Primary blood cell disorder

leukocyte count abnormal due to acquired somatic DNA damage affecting a haematopoietic precursor cell giving rise to blood cancer

Question 22

which cell count does leukocytosis and leukopenia result from usually?

Answer 22

changes in the neutrophil count since it is the most abundant leukocyte in circulation

Question 23

causes of neutrophilia

Answer 23

infection (usually bacterial), inflammation, infarction or other tissue damage

normal feature in pregnancy, could be seen following exercise and after the administration of corticosteroids

Question 24

what other abnormalities in the blood film could neutrophilia be accompanied by?

Answer 24

toxic changes and left shift- early myeloid cells e.g. metamyelocytes being present in the blood

Question 25

what is toxic granulation of neutrophils?

Answer 25

heavy, coarse granulation of neutrophils

Question 26

what is CML

Answer 26

myeloproliferative disorder primary blood cancer associated with neutrophilia, basophilia and left shift

Question 27

what is left shift

Answer 27

an increase in non-segmented neutrophils/ there are neutrophil precursors in the blood

Question 28

causes of neutropenia

Answer 28

chemo/radiotherapy autoimmune disorders, severe bacterial infections viral infections, drugs sometimes could be physiological (e.g. benign ethnic neutropenia in people with African/Afro-Caribbean ancestry)

Question 29

how many lobes should a normal neutrophil nucleus have?

Answer 29

3 to 5

Question 30

what is neutrophil hypersegmentation (right shift) caused by

Answer 30

megaloblastic anaemia (vit b12 or folic acid deficiency)

Question 31

what is the usual cause of eosinophilia?

Answer 31

allergy/ parasitic infection, asthma, eczema, drugs can occur in CML and other forms of leukaemia

Question 32

what is the usual cause of basophilia?

Answer 32

usually due to leukaemia

Question 33

cause of monocytosis

Answer 33

infection (particularly chronic bacterial infection) chronic inflammation some times of leukaemia

Question 34

causes of lymphocytosis?

Answer 34

response to viral infection (transient) lymphoproliferative disorder e.g. CLL (persistent)

Question 35

what is the lymphocyte count threshold for lymphopenia?

Answer 35

< 1 x 10 ^9 /L

Question 36

important causes of lymphopenia

Answer 36

HIV infection chemotherapy radiotherapy corticosteroids severe infection could develop transient lymphopenia

Question 37

why does leukaemia occur

Answer 37

somatic mutations occurring in primitive cell which has a growth/ survival advantage over normal cells mutations give rise to a clone which replaces normal cells mutations may mean cell may not require usual growth factors, disturbance in proliferation/maturation, failure of apoptosis mutations are in oncogenes or tumour suppressor genes

Question 38

ALL characteristics

Answer 38

blasts- immature lymphoid cells progenitors Aquire mutations, usually in genes encoding TFs affects cells ability to mature but proliferation continues, leads to accumulation of blast cells usually seen in childhood (results from somatic mutations in utero

Question 39

CLL characteristics

Answer 39

mature lymphoid cells steady expansion of clone cells which are functionally useless replacement of normal cells by leukaemia clone usually seen in the elderly

Question 40

AML characteristics

Answer 40

myeloid blast cells

Question 41

CML characteristics

Answer 41

mature myeloid cells results from activation of signalling pathways by fusion protein BCR-ABL1

Question 42

clinical features of leukaemia due to accumulation of abnormal cells?

Answer 42

leukocytosis bone pain (if acute) hepatomegaly splenomegaly lymphadenopathy (if lymphoid) thymic enlargement (if T lymphoid) skin infiltration

Question 43

metabolic effects of leukaemic cell proliferation

Answer 43

hyperuricaemia and renal failure weight loss low grade fever sweating

Question 44

crowing out of normal haemopoiesis

Answer 44

fatigue, lethargy, pallor, breathlessness (caused by anaemia) fever and other features of infection (neutropenia caused) bruising, petechiae, bleeding (caused by thrombocytopenia)

Question 45

when can a loss of normal immune function be observed in leukaemia?

Answer 45

when the patient has CLL