White Blood Cells Flashcards
myeloid differentiation steps for wbc?
pluripotent HSC –> common myeloid progenitor –> myeloblast –> granulocyte and monocyte/macrophage
name the granulocytes?
basophils, eosinophils, neutrophils
why are granulocytes called that?
contain granules in cytoplasm that contain agents essential for microbicidal function
growth factors for granulocytes/macrophages
G-CSF
M-CSF
GM-CSF
general steps for erythrocyte formation?
pro erythroblast –> erythroblast –> erythrocyte
features of neutrophil?
segmented/lobulated nucleus
main function of neutrophil?
defence against infection, it phagocytoses and kills micro-organisms
chemotaxis?
steps:
marginatinated in vessel lumen
adhere to endothelium
migration into tissues
MARDi MP
migration, adhesion, rolling, diapedesis, migration, phagocytosis
eosinophil main function?
defence against parasitic infection
important in regulation of Type 1 hypersensitivity reactions
inactivate histamine and leukotrienes released by basophils and mast cells
what do basophil granules contain?
histamine, heparin and proteolytic enzymes
basophil main function?
involved in a variety of immune and inflammatory responses
e.g.
mediation of hypersensitivity reaction
monocyte key roles?
phagocytosis of micro-organisms covered with antibody and complement
phagocytosis of bacteria/fungi
antigen presentation to lymphoid and other immune cells
macrophage?
formed when monocytes migrate to tissues where they develop into macrophages
macrophage and iron link?
macrophages store and release iron
pathway to form lymphocytes?
HSCs –> Common lymphoid progenitor –> NK cells, T lymphocyte/B lymphocyte
journey of lymphocytes?
recirculate to lymph nodes and other tissues and then back to blood
B lymphocyte development?
development includes Ig heavy and light chain gene rearrangement
This leads to production of surface Its against many different antigens
=humoral immunity
then, in order to mature further, they need to be exposed to antigens in lymphoid tissue e.g. lymph nodes
they will then recognise non-self antigens and produce specific Igs and antibodies
T lymphocyte development?
lymphocyte progenitors migrate from foetal liver to thymus which leads to development of T lymphocytes
= cell-mediated immunity
NK cells function?
part of innate immunity
can kill tumour cells and virus-infected cells
can you differentiate between T and B cells easily?
no
what is leukocytosis?
elevated WBC
transient leukocytosis?
suggests a secondary cause
occurs when healthy bone marrow responds to external stimulus e.g. infection, inflammation, infarction
(viral infection, parasitic infection)
persistent leukocytosis?
due to a primary blood cell disorder
leukocyte count is abnormal due to acquired somatic DNA damage affecting a haematopoetic precursor cell
causes blood cancers such as leukaemia, lymphoma or myeloma
leukopenia?
reduced WBC, usually due to neutropenia as neutrophils are most abundant wbc
neutrophilia definition causes
= too many neutrophils
causes: infection, inflammation, infarction
also normal in: pregnancy, following exercise and after administration of corticoids
what can neutrophilia be accompanied by?
toxic changes and left shift
what is left shift?
presence of early myeloid cells
toxic granulation?
heavy coarse granulation of neutrophils
chronic myeloid leukaemia
= myeloproliferative disorder
neutrophilia, basophilia and left shift
why does neutrophilia occur during exercise?
rapid shift of neutrophils from marginated pool to circulated pool
what might left shift look like in neutrophilia?
non-segmented neutrophils/neutrophil precursors in blood
neutropenia causes?
following chemotherapy and radiotherapy
autoimmune disorders
severe bacterial infections
certain viral infections and drugs
might be due to ethnicity e.g. African/Afro-Caribbean ancestry
what is a very low neutrophil count?
< 0.5 x 109/l
neutrophil hypersegmentation
normal neutrophil has between 3 and 5 lobes
hyper segmentation is an increase = right shift
usually due to lack of B12/folic acid
eosinophilia?
too many eosinophils
usually due to allergy/parasitic infection
can occur in CML
basophilia?
too many basophils
usually uncommon and due to leukaemia
monocytosis?
too many monocytes
usually due to infection or chronic inflammation
some types of leukaemia can cause this too
lymphocytosis?
too many lymphocytes
usually due to a viral infection (transient)
can also result from lymphoproliferative disorder (chronic lymphocytic leukaemia) = PERSISTENT
what’s an important cause of lymphocytosis in children?
whooping cough
lymphopenia
too few lymphocytes
important causes:
HIV infection
chemotherapy
radiotherapy
two classes of leukaemia?
myeloid or lymphoid, depends on what causative tissue is
leukaemic cells replace normal haematopoietic stem cells in bone marrow
why does leukaemia occur?
a number of somatic mutations
the cell now has a growth or survival advantage over normal cells
where are the mutations in leukaemia?
oncogenes/sometimes tumour suppressor genes
which two terms are used to classify leukaemia?
chronic/acute
acute means sudden and severe in onset
chronic means disease and deterioration go on for a long time
main types of leukaemia
Acute Lymphoblastic Leukaemia
Acute Myeloid Leukaemia
Chronic Lymphocytic Leukaemia
Chronic Myeloid Leukaemia
