Hematopoiesis, Stem Cell Disorders Flashcards Preview

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Flashcards in Hematopoiesis, Stem Cell Disorders Deck (32):
1

two defining characteristics of stem cells

self renewal and differentiation

2

totipotent

germ cells. capable of differentiating into anything

3

pluripotent

has the ability to differentiate into multiple things

4

what is the potency of human stem cells?

pluripotent

5

example of totipotent cell?

morula

6

normal stem cell division

1:1 balance, 1 self renewing daughter cell and 1 lineage specific daughter cell

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example of stem cell division with two differentiated cells

aplastic anemia

8

example of stem cell division with two self renewing cells

leukemia

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HSC division

rare cells with rare divisions. numbers remain constant throughout life

10

if stem cells don't divide often, which cells have the tremendous replicative capacity?

lineage specific progenitor cells (i.e. myeloid/lymphoid progenitor cells)

11

what do hematopoietic SCs divide into?

common lymphoid or myeloid progenitors

12

what differentiates a progenitor cell from a stem cell?

progenitor cells divide a ton but don't self renew

13

what is the general environment that provides growth stimulation to HSCs?

marrow stroma

14

two types of marrow stroma niches

endosteal and perivascular

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endosteal niche

promotes quiescent self-renewal

16

perivascular niche

promotes active differentiation

17

which cytokines regulate hematopoiesis?

interleukins (ILs) and colony stimulating factors (CSFs)

18

GM-CSF (granulocyte/macrophage)

important CSFs for all cells of the myeloid lineage. stimulate differentiation, proliferation, and mobilization.

19

cytotoxic injury to stem cells

chemotherapy and radiation kill rapidly dividing, undifferentiated cells. cytopenias are therefore expected side effects

20

EPO (erythropoietin)

produced in the kidney and stimulates RBC production

21

Effects of aging on HSCs

lower regenerative capacity, move more to perivascular niche, increased peripheral mobilization, myeloid skewed differentiation, increased self renewal capacity

22

effects of aging on marrow

decreased cellularity (increased adiposity), impaired osteoclast/blast function, increased leukemias & anemias

23

aplastic anemia

bone marrow failure due to suppression or disappearance of multi potent progenitor cells. Leads to cytopenias with any combo of anemia, thrombocytopenia, neutro/leukopenia

24

causes of acquired aplastic anemia?

idiopathic (autoimmune, SC defects), cytotoxic injury (chemotherapy, radiation, drugs), viral (hep, CMV, EBV, varicella)

25

treatment for aplastic anemia?

immunosuppressive therapy (IST), if IST fails, then HSC transplantation

26

when would you treat aplastic anemia with HSC transplantation first?

if a pediatric patient has a matched sibling

27

fanconi anemia

congenital stem cell defect in which there is a double stranded DNA repair defect. short stature, cancer predisposition, radial anomalies.

28

dyskeratosis congenita

congential stem cell defect in which there is a telomerase defect leading to increased cell apoptosis, skin dyspigmentation, oral leukoplakia, hair/nail dystrophy. fast growing cells affected

29

autologous transplantation

high dose chemotherapy followed by stem cell rescue from patients own HSCs. GM-CSF mobilizes HSCs into periphery, they are then removed and replaced after chemo. can only be used to treat non-stem cell problems

30

allogeneic transplantation

non-self HSC donor. HLA matched. used to replace faulty HSCs

31

GVHD

graft vs host disease. donor t cell attacks host tissue

32

graft rejection

host t cell attacks donor HSCs