WBC count Flashcards
cellular marker on hematopoietic stem cell
CD34+
two types of stem cells produced by hematopoietic stem cell
myeloid, lymphoid
type of cells produced by lymphoid stem cells
B lymphoblast –> naive B cell –> plasma cell
T lymphoblast –> naive T cell –> CD8+ or CD4+ T cells
type of cells produced by myeloid stem cell
erythroblast –> RBC
myeloblast –> granulocytes (neutrophils, basophils, eosinophils)
monoblast –> monocytes
megakaryoblast –> megakaryocytes
normal WBC count
5-10K
WBC in leukopenia
< 5000
WBC in leukocytosis
> 10,000
classic causes of neutropenia
drug toxicity (e.g. chemotherapy - stop rapidly dividing cells, including neutrophils) severe infection (neutrophils have moved out of the blood into tissue)
cell type most sensitive to whole body radiation
lymphocytes
definition of “left shift”
increased immature neutrophils circulating in blood
marker of immature blood cells
decreased CD16 (Fc receptor)
what is the mechanism of eosinophilia in hodgkins lymphoma?
increased IL-5 production
classic causes of basophilia
CML
classic associations with lymphocytic leukocytosis
viral infections bordetella pertussis (bacterial)
mechanism by which bordetella pertussis causes lymphocytic leukocytosis
lymphocytosis-promoting factor - blocks lymphocytes from leaving blood and entering lymph nodes
viral cause of lymphocytic leukocytosis comprised of CD8+ T cells
EBV (infectious mononucleosis)
2 causes of infectious mononucleosis
EBV (most common cause)
CMV
3 tissues that EBV primarily infects
oropharynx (sore throat)
liver (hepatitis)
B cells
clinical results of CD8+ T cell response to EBV infections
generalized lymphadenopathy (LAD)
splenomegaly
high WBC count with atypical lymphocytes (reactive CD8+ T cells)
what area of the lymph node is hypertrophied in LAD caused by EBV infection
paracortex
which area of spleen is hypertrophied in EBV infection
white pulp - periarterial lymphatic sheath (PALS)
screening test for mononucleosis
monospot
what is detected by monospot test
IgM heterophile antibodies
how long does it take for monospot to be positive
1 week