Lecture 7 - White Blood Cells Flashcards
Neutrophils?
primary granulocyte (90%), 75% of leukocytes, large, 2-5 lobed nucleus and granules
Granulocyte kinetics?
7-10 day maturation in marrow, 6-10 hour circulation in blood
Important regulator of granulocyte production?
G-CSF (filgrastim)
Neutrophil functions?
chemotaxis, phagocytosis, killing of bacteria (oxidative or non-oxidative)
Neutrophil leucocytosis?
feature of infection and inflammation, associated w more immature forms in the blood
Neutropenia?
low neutrophil count, risk of infection (febrile neutropenia)
Monocytes?
<10%, larger than neutrophil, central oval or indented nuclei, granules
Monocyte development?
monoblast -> promonocyte -> monocyte
Monocyte kinetics?
circulates 1-3 days, enter tissues and transforms into different macrophage based on location: kuppfer cells (liver), alveolar macrophages, langerhans cells (skin) and microglial cells (brain)
Monocyte/macrophage functions - Phagocytosis?
chronic infections and intracellular parasites e.g. TB: chemotaxis, opsonisation (Fc and C3 receptors), fusion w lysosomal granules (killing bacteria)
Monocyte/macrophage function - synthetic function?
complement, interferon, cytokines, prostaglandins
Monocyte 3rd function?
antigen protein presentation to T cells as part of adaptive response
Clinical use of monocytes?
count not particularly relevant, monocytosis could be linked to chronic infections or malignancy (leukaemia)
Eosinophils?
similar to neutrophils but bilobar and red staining granules
Eosinophilia?
allergic or hypersensitive reactions (asthma, hayfever, drug interactions), parasite infestations
Basophils?
infrequent cells, deep blue granules, IgE binding site
Basophil functions?
close relationship with mast cells, granules release histamine, SRS-A and ECF-A, Type-I hypersensitivity
Lymphocytes?
thin rim of agranular cytoplasm, small, 2/3-3/4 T cells, rest B cells and small amount of NK cells
B and T cell development?
bone marrow derived but mature in primary lymphoid organs: bone marroe (B cells) and thymus (T cells)
Secondary lymphoid organs?
where antigen proteins are presented for generation of adaptive immune response - lymph nodes, spleen, bone marrow and lymphoid tissue throughout body
Lymph node enlargement?
reactive (viral infections, local bacterial infection) or malignant (lymphoma or metastatic spread)
Lymphocytosis?
reactive (infectious mononucleosis - viral) or malignant (chonic lymphocytic leukaemia)
Lymphopenia (low lymphocytes)?
HIV infection (diagnosed with CD4 positive T cells), congenital immune defects, steroid therapy, severe bone marrow failure
