Pathology of Red Blood Cells and Bleeding Disorders (Part 2 of 3)

Question 1

what causes megaloblastic anemia?

Answer 1

impaired DNA synthesis

Question 2

what happens in the bone marrow as a result of impaired DNA synthesis?

Answer 2

growth factors signal for increased production and marrow hyperplasia occurs, but hematopoiesis is still ineffective

Question 3

what is the MCV like in megaloblastic anemia?

Answer 3

it is high

Question 4

what are the characteristics of megaloblastic anemia (HGB, HCT, MCV, and reticulocyte count)

Answer 4

low HGB, low HCT, high MCV, and low reticulocyte count

Question 5

what does the peripheral blood smear look like in megaloblastic anemia? ( type of anemia, cell shape, neutrophils)

Answer 5

hypoproliferative anemia, macrocytic anemia, ovalocyte shape RBCs, and neutrophil hypersegmentation

Question 6

what are two common causes of megaloblastic anemia?

Answer 6

B12 and folate deficiencies

Question 7

what is pernicious anemia?

Answer 7

when lymphocytes are directed against gastric parietal cells, which are responsible for secretion of intrinsic factor and intrinsic factor is required for B12 absorption; it is associated with B12 anemia

Question 8

what are the results of pernicious anemia?

Answer 8

chronic atrophic gastritis, megaloblastic anemia, atrophic glossitis, spinal demyelination

Question 9

what neural issues can be seen in pernicious anemia?

Answer 9

paresthesias, gait disturbances, altered vision, taste, smell, dementia, and psychosis

Question 10

diagnosis of pernicious anemia can involve what? (4)

Answer 10

megaloblastic anemia, low b12, IF antibodies, and high levels of homocysteine/MM Co-A

Question 11

what could block the metabolism of folate leading to folate deficiency?

Answer 11

methotrexate (inhibits DHF reductase)

Question 12

diagnosis of folate deficiency can involve? (3)

Answer 12

megaloblastic anemia, low red cell folate, and high levels of homocysteine

Question 13

what type of anemia does iron deficiency cause?

Answer 13

hypochromic microcytic anemia

Question 14

what carries iron to the marrow or into storage?

Answer 14

transferrin

Question 15

in storage sites, what is iron incorporated into?

Answer 15

ferritin

Question 16

in marrow, what is iron incorporated into?

Answer 16

into Hgb for red cells

Question 17

the control of iron happens at what level?

Answer 17

at the absorption level

Question 18

what influences the tipping point between storing the iron or allowing it through the ferroportin channel into the transferrin systemic pool?

Answer 18

hepcidin

Question 19

what happens when plasma iron is low?

Answer 19

hepcidin backs off and ferroportin can take those iron molecules out of the mucosa and put it into the trasferrin pool

Question 20

what happens when there is high plasma iron?

Answer 20

hepcidin destroys ferroportin

Question 21

what does the peripheral smear look like in iron deficiency anemia?

Answer 21

hypoproliferative, microcytic, and hypochromic; anisocytosis

Question 22

what are the etiologies of iron deficiency anemia?

Answer 22

dietary lack, impaired absorption, increased requirement, and chronic blood loss

Question 23

what is the first stage of iron deficiency?

Answer 23

reduced ferritin

Question 24

what are the physical manifestations of IDA?

Answer 24

koilonychia, alopecia, atrophic glossitis, angular cheilitis

Question 25

what are the iron studies consistent with iron deficiency anemia?

Answer 25

low serum iron, low serum ferritin, increased TIBC, and low hepcidin

Question 26

what is anemia of chronic disease?

Answer 26

impaired red blood cell production/ iron utilization in chronic illness such as infection, immune diseases, and malignancy

Question 27

what are the two mechanisms involved in anemia of chronic disease?

Answer 27

inflammatory cytokines increase hepcidin and low erythropoietin

Question 28

what are the features of anemia of chronic disease?

Answer 28

low serum iron, reduced TIBC, increased serum ferritin, and abundant stainable iron in tissues

Question 29

what is aplastic anemia most commonly due to?

Answer 29

drugs, irradiation, and viral infection

Question 30

what rare inherited forms cause aplastic anemia?

Answer 30

Fanconi anemia (DNA repair defect)

Question 31

how do you make the diagnosis of aplastic anemia?

Answer 31

the presentation will be along the lines of pancytopenia: anemia, thrombocytopenia, and leukopenia

Question 32

what will the anemia be like in aplastic anemia?

Answer 32

normocytic but no retic count

Question 33

where do you make the definitive diagnosis of aplastic anemia?

Answer 33

in the bone marrow

Question 34

what is pure red cell aplasia?

Answer 34

when the bone marrow shoes decreased/abnormal erythroid precursors

Question 35

when might pure red cell aplasia be seen?

Answer 35

seen in autoimmune phenomena such as thymoma

Question 36

what is myelophthisic anemia?

Answer 36

space occupation in the marrow (like metastatic cancer, fibrosis, inflammation, necrosis) replace normal hematopoietic cells

Question 37

what occurs in myelophthisic anemia?

Answer 37

abnormal release of erythroid and granulocyte precursors results in leukoerythroblastosis