White blood cells Flashcards
Neutrophils - general info
AKA - polymorphs, PMN’s, segmented neutrophils
large = 10-15micometers diameter
dense nucleus w 2-5 lobes
granules in cytoplasm
make up about half of the white cell count
Neutrophil timeline
7-10 days maturation in the marrow
circulate for 6-10 hours in the blood then migrate into tissues where perform phagocytic function
Why don’t we transfuse granulocytes to patients undergoing chemo, when we can give them RBC’s and platelets
they have too short a circulation time…
What is a a left shift?
In a patient where the marrow is under stress e.g. responding to infection or inflammation, may see some more immature forms that you would normally see in the marrow –> are released in the peripheral blood
Leukemias.. in a blood film?
arise from the very early stages of myeloid development, proliferation of immature cells that replace the marrow and spill over into the blood
Regulation of granulopoiesis
Haematopoietic growth factors, IL-3 stem cell factor, GM- CSF, and G-CSF (granulocyte colony stimulating factor) –> used to treat neutropenia
Neutrophil function
- chemotaxis
- phagocytosis
- killing of bacteria - using enzymes stored in granules, can be oxidative or non-oxidative
clinical relevance
Neutrophil leukocytosis
- feature of infection and inflammation
- may be associated with a left shift i.e more immature forms of blood
Patients with low neutrophil count = neutropenia
–> could be idiosyncratic e.g. reaction to a drug you’ve prescribed, OR expected consequence or complication from chemotherapy
At risk of infection = febrile neutropenia –> particularly of the skin / rest tract
Neutrophil function defects rare
What are the phagocytes?
Granulocytes: neutrophils, eosinophils, basophils
Monocytes
What are the lymphocytes?
B an T lymphocytes and NK cells
Monocyte kinetics
Circulates for 1-3 days Enters tissue and transforms into macrophage Related cells throughout the body - Kupffer (liver) - Alveolar macrophages - Langerhans skin cells - mIcroglial cells (brain)
Monocytes - clinical relevance
Infrequent
Monocytosis
- relative - chronic infections e.g. TB, osteomyelitis
- Malignant - acute myeloid leukaemia (monoblastic sub type) chronic myelomonocytic leukaemia (CMML)
Monocytes basic info
large cell = 15-20 micrometers
central oval or indented nuclei
blue - grey cytoplasm with granules
monocytes / macrophage function
chronic infections, intracellular parasites e.g. TB
- chemotaxis
- Opsonisation
- Phagocytosis and ingestion
- killing off ingested bacteria by fusion with monocytic lysosomal granules
phagocytic cells
synthetic functions
–> complement interferons, cytokines e.g. TNF, IL-1, growth factors, prostaglandins
Antigen presentation
Eosinophil basic info
bilobed nucleus
Red staining granules
Developmental stages similar to neutrophils
Eosinophilia
allergic or hypersensitivity rections e.g. hayfever, asthma, drug reactions, parasitic infections –> gut parasites (refugees, travellers in 3rd world countries)
Basophil basic info
Infrequent cells in blood
Deep blue granules over nucleus
IgE binding sites
Related to mast cells
Basophil function
Granules - histamine, SRS-A, ECF-A
Type I hypersensitivity - degranulate
close relationship with mast cells
Lymphocytes - basic info
about 10 microms diameter - small mature cells High N:C ratio Condensed chromatin nuclei thin rim of granular cytoplasm
B vs T lymphocytes
65-80% T cells
5-15% B cells
Morphologicallyidentical, identify by cell surface markers
Lymphocyte cells functions
Lymphoid cells - specific immune responses
B cells - plasma cells = antibody production
T cells - cell mediated immunity
CD4 positive T helper cells
CD8 positive T cytotoxic cells
Primary lymphoid organs
Lymphocyte bone marrow derived but maturation occurs in primary lymphoid organs
B cells = bone marrow
T cells = thymus (learn to recognise self from non-self)
secondary lymphoid organs
migrate from primary lymphoid organs to secondary lymphoid tissues
- lymph nodes
- spleen
- lymphoid tissue thought the body e.g. gut, respiratory tract etc
- bone marrow
Lymph node enlargement: clinical relevance
Reactive: e.g. viral infection, local bacterial infection
Malignant e.g. of lymphoid tissues (lymphoma) or metastatic spread
Lymphocytosis
= inc in lymphocytes
Reactive = viral infections e.g. infectious mono –> lymphocytes have changed shape, look more like monocytes
Malignant e.g. chronic lymphocytic lukemia, look normal in morphology, just massively increased in number
