Lymphocyte size
Lympocyte recirculation - blood
Most are T lymphocytes
- CLP and MLP
Lymphocyte recirculation - lymph nodes
Enter cortices via specialized postcapillary venules
Lymphocyte recirculation - tissue
Blastogenesis, recirculate, or die
- migration from vessels to tissue similar to neutrophils
Lymphocyte recirculation - blood concentration
Production (stem cell or blastogenesis)
Lymphocytosis
Chronic inflammatory
Physiologic lymphocytosis
Lymphoproliferative disease
Leukemia
Marked lymphocytosis, with cells displaying immature features
Hypoadrenocorticism
Due to lymphocytosis
Young animal lymphocytosis
Puppies, kittens, calves, foals
- cattle: increases until 1 year old and then gradually decreases up to 2 x URL
Lymphopenia due to acute inflammatory
Change in lymphocyte kinetics decreasing CLP
- may be caused by stress, but not documented
Lymphopenia due to steroid
Change in lymphocyte kinetics, decreasing CLP
Lymphopenia due to depletion
Loss of lymphocytes due to incomplete circulation
- repeated chylothoracic fluid removal in cats
Lymphopenia due to lymphoid hypoplasia or aplasia
Congenital or acquired
Lymphopenia due to lymphoma
Decrease production or altered kinetics
Monocytes
Stem cell (CFU-GM)
Mononuclear phagocyte system
Inflammatory monocytosis
Acute and chronic inflammation
- cytokine stimulation: production and release
Monocytosis due to steroid
Common in dogs and cats, minimal horses and cattle
- shift from MMP to CMP
Neoplastic monocytosis
Monocytosis secondary to immune-mediated neutropenia
Monocytes and neutrophils share common progenitor
Monocytosis due to cyclic hematopoiesis
Mild during neutropenic cycles
- herald increase neutrophil concentration
_____ treatment may increase production of neutrophils and monocytes
G-CSF