Leucocytes responses (Yr 3) Flashcards
what are the five main leucocyte types?
neutrophils
monocytes
lymphocytes
eosinophils
basophils
what leucocytes are granulocytes (granules with polylobed nuclei)?
neutrophils
eosinophils
basophils
what is the main function of neutrophils and eosinophils?
involved in innate immunity (phagocytosis)
what part of the smear is assessed when looking at cell counts and morphology?
monolayer
what is usually the most abundant leucocyte?
neutrophil
what is the morphology of a mature nucleus?
3-5 lobed nucleus
clear/pale pink cytoplasm
how do banded (immature) neutrophils appear?
U shaped nucleus with parallel sides
what is the role of neutrophils?
kill/inactive bacteria, yeast, fungi, parasites
eliminate infected/transformed cells
modulate immune response
what are the pools of neutrophils in the body?
bone marrow (proliferative, maturation, storage)
blood
tissue
what regulates production of neutrophils?
cytokines and growth factors
how long does it take for a neutrophil to mature?
7 days
what is toxic change to neutrophils and how is it caused?
inflammation accelerates neutrophil maturation causing them to be misshapen
what is the blood transit time of neutrophils?
6-10 hours
what is the first manifestation in blood if haemopoiesis stops?
neutropenia (shortest lifespan)
what is a left shift?
inflammation causing more immature (banded) neutrophils to be present in circulation
what are the two types of left shift?
regenerative
degenerative
what is a regenerative left shift?
neutrophilia with lots of banded neutrophils
what is a degenerative left shift?
normal/low neutrophil count with increased immature cells (inability to meet inflammatory process)
how is a degenerative left shift associated with prognosis?
poor prognostic indicator
what are the overall causes of neutrophilia?
physiological (stress, adrenalin)
acute inflammatory response
stress/corticosteroid induced
paraneoplastic
what causes physiological neutrophilia?
increased blood flow from adrenalin/fear causes mature neutrophils to be redistributed from the marginated pool on the edge of vessels to the circulating pool
what are the features of a stress leukogram?
mature neutrophilia
monocytosis
lymphopenia
eosinopenia
how can the neutrophilia associated with the acute inflammatory response present?
can be with or without a left shift
can be regenerative or degenerative
what causes toxic change of neutrophils?
reduced maturation time in the bone marrow due to intense stimulation of myelopoiesis
what are some causes of neutrophil dysfunction?
immunodeficiency syndromes (inherited)
diabetes mellitus
neoplasia
FeLV
what are the basic causes of neutropenia?
overwhelming demand
reduced/ineffective production
(some rare disease)
when does overwhelming demand of neutrophils occur leading to a neutropenia?
severe bacterial infection (pyometra, peritonitis, pyothorax)
what are some causes of reduced haemopoiesis?
bone marrow hypoplasia
after chemotherapy
parvovirus infection (transient)
oestrogens
neoplasia
what is the main functions of eosinophils?
kill parasite
control hypersensitivity reactions
allergies and inflammation
what are the functions of basophils?
potentiate inflammation and hypersensitivity
histamine release
(respond with eosinophils)
what is the function of monocytes?
they are circulating precursors to macrophages, responsible for phagocytosis
what can cause monocytosis?
often reflect chronic inflammation
acute inflammatory response
necrotic tissues
immune mediated disease
part of stress leukogram
what is the most common change to leucocytes when there is acute inflammation?
neutrophils with a left shift
where do T cells mature?
thymus
what happens to B lymphocytes in response to antigenic stimulation?
become plasma cells that release immunoglobulins
what are the types of T lymphocytes?
T-helper cells
cytotoxic T cells
T-regulatory cells
what can cause lymphocytosis?
physiological (adrenalin)
prolonged immune stimulation
youth
lymphoproliferative disease
post-vaccination
hypoadrenocorticism
what can cause lymphopenia?
corticosteroid (shifts lymphocytes from circulation)
viral disease
loss of lymph (effusions)
sepsis/endotoxaemia
lymphoma
