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Flashcards in RBC Pathology 2 Deck (73):
1

(T/F) Humans are totally dependent on dietary Vitamin B12

True

2

Vitamin B12 is absorbed in what part of the small intestine?

Ileum

3

Intrinsic factor is secreted by parietal cells in the _______ muscosa of the stomach

Fundic

4

Vitamin B12 takes the _____ group from methyltetrahydrofolate and transfers a carbon to homocysteine to form __________

Methyl; methionine

5

___________ delivers vitamin B12 to the liver and other cells of the body

Transcobalamin II

6

2 pathways where vitamin B12 is used

1) Conversion of homocysteine to methionine
2) Isomerization of methylmalonyl CoA to Succinyl CoA

7

In ________ deficiency, both homocysteine and methylmalonic acid are elevated while in ________ deficiency, only homocysteine levels are increased

B12; Folic acid

8

In Vitamin B12 deficiency, accumulation of methylmalonic acid causes demyelination of the _________ and ________ tract of the spinal cord

dorsal and lateral

9

In Vitamin B12 deficiency, provision of folate will improve s/s of _________ but not _______

anemia; neurologic symptoms

10

Enumerate anemias d/t diminished erythropoesis

Megaloblastic anemia, pernicious anemia, iron deficiency anemia

11

Why does folic acid and B12 deficiency cause megaloblastic anemia?

B12 and folic acid are needed in nuclear maturation and DNA synthesis causeing nuclear-cytoplasmic asynchrony

12

Enumerate the common causes of megaloblastic anemia

1) Decreased intake (vegan diet, alcoholics)
2) Impaired absorption
3) Fish tapeworm (competitive uptake)
4) Increased requirements (pregnancy, thyrotoxicosis, cancer, infants)
5) Medication: folic acid antagonists like methotrexate
6) Increased losses (hemodialysis)

13

In PBS of megaloblastic anemia what type of RBC is seen? Which cells are affected?

Macrocytic, hyperchromic RBCs; RBCs, Platelets, WBCs

14

In PBS of megaloblastic anemia what type of neutrophils are seen?

hypersegmented (macropolys)

15

The reticulocyte count is _________ in megaloblastic anemia. What is seen 5 days after IV administration of B12 / folic acid

decreased; striking reticulocytosis

16

In megaloblastic anemia there is bone marrow ___________ that is hypercellular

hyperplasia

17

In the BM of megaloblastic anemia, what is the erythroid:myeloid ratio?

1:1

18

In megaloblastic anemia, MCHC is always elevated (T/F)

false, may be normal to elevated

19

In pernicious anemia, there are autoantibodies against?

Intrinsic factor and/or parietal cells

20

Describe Type I of autoantibodies to intrinsic factor-type of pernicious anemia

Blocks attachment of B12 to IF

21

Describe Type II of autoantibodies to intrinsic factor-type of pernicious anemia

Blocks attachment of B12-IF complex to ileal receptors

22

Describe Type III of autoantibodies to intrinsic factor-type of pernicious anemia

Antibodies recognize the alpha and beta subunits of the gastric proton pump

23

Autoantibodies to gastric parietal cells leads to _____ and __________

Chronic atrophic gastritis; gastric atrophy

24

Enumerate the changes seen in pernicious anemia NOT seen in megaloblastic anemia

1) Achlorhydria
2) Serum antibodies
3) Atrophy of the stomach
4) Beefy red tongue (atrophy of the tongue)

25

Most common nutritional disorder in developing countries

Iron deficiency anemia (IDA)

26

Causes of IDA

1) Low dietary intake (elderly, infants and the mamamayan who cant afford meat =P)
2) Poor absorption
3) Increased demand (pregnancy, children)
4) Chronic blood loss

27

Which type of heme is more well-absorbed?

Heme iron

28

What are the functional forms of iron?

Heme, myoglobin, catalase

29

What is the storage form of iron? Where are they stored?

Ferritin; bone marrow & macrophages (RES)

30

(T/F) Free iron is highly toxic

True

31

What is ferritin? Where is it found? Where is it MAINLY found?

Iron-protein complex; liver, spleen, BM, skeletal muscle; Macrophages

32

Where is the storage form of iron in macrophages derived from?

breakdown of RBCs

33

Where is hepatocyte iron derived from?

plasma transferrin

34

(T/F) Iron is actively excreted

False, there is very limited iron excretion

35

What is the only way that iron can be removed from the body?

Chelation

36

Protein that ihibits absorption of iron in the gut

Hepcidin

37

Hepcidin is increased in these situations

Anemia of chronic disease
Untreated infections

38

PBS in IDA shows _______ ________ RBCs

hypochromic, microcytic

39

If you see hypochromic, microcytic anemia in adults, what do you check for? In children?

Chronic blood loss; thalassemia or IDA

40

BM in IDA shows __________ sideroblasts

decreased

41

In IDA, serum ____ and _____ are decreased and ______ is increased

Fe and ferritin; TIBC

42

What is the response to treatment in IDA

Reticulocytosis in 3 days

43

Give s/s of IDA

koilonychia, pica, alopecia, atrophic glossitis, atrophic gastritis

44

What constitutes the Plummer Vinson Syndrome?

Esophageal webs + atrophic gastritis + IDA with depressed Hb, Hct, MCV, serum Fe, ferritin

45

Anemias d/t BM failure

aplastic anemia

46

Aplastic anemia is a syndrome of?

chronic primary hematopoetic failure and attendant pancytopenia

47

In the diagnosis of aplastic anemia, the BM shows? PBS shows? and the reticulocyte count is (decreased / increased)?

hypocellular with fat and no hematopoetic elements; Pancytopenia; Decreased

48

2 treatments for aplastic anemia

transplant, immunosuppressive therapy

49

Causes of aplastic anemia

hereditary (Fanconi's anemia)
Idiopathic (Stem cell defects)
Acquired

50

Give some acquired causes of aplastic anemia

Drugs (chloramphenicol, phenytoin, carbamazapine), Chemicals, infections (CMV, parvovirus, etc), Whole body irradiation

51

The normal histology of the bone marrow shows ___ % fat and ___% hematopoetic cells

50%; 50%

52

How do you histologically differentiate tumoral BM vs BM in aplastic anemia?

Tumoral is hypocellular with no fat while Aplastic anemia is hypocellular with more fat (than hematopoetic cells)

53

Enumerate the clinical features of aplastic anemia

1) Pancytopenia
2) Progressive weakness, pallor, dyspnea
3) Thrombocytopenia
4) Splenomegaly
5) RBCs are slightly macrocytic, normochromic

54

What is a primary BM disorder wherein only the erythroid progenitors are suppressed? What is it usually associated with?

Pure red cell aplasia; neoplasms, thymoma, large granular lymphocytic leukemia

55

Give other causes of anemia

Myelophtisic anemia, chronic renal failure, diffuse liver disease, neoplasia, hypithyroid disease

56

What type of RBC is diagnostic of myelophthisic anemia

teardrop shaped RBC

57

Give the anemias associated with decreased MCHC, MCV and MCH

IDA, thalassemia, Anemia of chornic inflammation

58

Give the anemias associated with increased MCHC, MCV and MCH

Pernicious anemia, B12 deficiency, Folate deficiency

59

Give the anemias associated with normal MCHC, MCV and MCH

Hemolytic anemia, aplastic anemia, Polycythemia

60

Which anemia has an increase in color (MCHC) but a decrease in size (MCV)?

Spherocytosis

61

Polycythemia is an increase in _____ with a corresponding increase in ______

RBCs; Hemoglobin

62

What are the 3 types of polycythemia? What is the difference between them?

Relative ( Volume is decreased but RBC not actually increased); Absolute (increase in total RBC); Stress polycythemia (individuals are usually hypertensive, obese & anxious)

63

Primary absolute polycythemia results from?

An intrinsic abnormality oh hematopoetic precursors, neoplastic condition

64

Secondary absolute polycythemia results from?

Increased erythropoetin secretion that may be compensatory or pathologic

65

Give some tumors that produce erythropoetin

renal cell CA, hepatocellular CA, cerebellar hemangioblastoma

66

How do you differentiate between primary and secondary absolute polycythemia?

Primary has decreased erythropoetin which is increased in secondary

67

Type of polycythemia where there is an increase in marrow production of myeloid progenitors but lymphocytes are not increased

Polycythemia vera

68

Polycythemia vera is d/t a mutation of ______ causing erythropoetin receptors to become ______

JAK2 tyrosine kinase; hypersensitive

69

In the laboratory diagnosis of polycythemia vera, what are the values of: RBC, WBC, Platelets, Hct; What is seen in the PBS?

RBC (6M); WBC (12000 - 50000); Platelets (=/> 500000); Hct (=/> 60%); PBS shows Panmyelosis

70

Incidence of polycythemia vera is higher in?

Males, middle aged to elderly

71

S/S of polycythemia vera

Cyanosis, pruritus, peptic ulcer, plethoric headache, dizzines, hypertension

72

Complications of polycythemia vera

Thrombosis, Bleeding, Hyperuricemia, Myelofibrosis

73

Treatment for polycythemia vera

Regular phlebotomy