Lab Tests and Clinical Presentation of Hemolytic Anemia

Question 1

Vitamin B12 and folate deficiencies

Answer 1

Coenzymes for DNA synthesis –> defective maturation due to inadequate synthesis of DNA
VitB12: homocysteine to methionine

Question 2

Vitamin B12 deficiency arise due to

Answer 2

Decreased intake
Impaired absorption
Diffuse intestinal disease
Increased requirement
Fish tapeworm

Question 3

Folate deficiency arise due to

Answer 3

Decrease intake
Impaired absorption
Increased loss
Increase requirement
Impaired use (antagonists)

Question 4

What is the major form of Vit B12 deficiency

Answer 4

Pernicious anemia because of a lack of intrinsic factor leading to malabsorption

Question 5

Normal B12 absorption

Answer 5

Cobalamin released from bound form via pepsin
Binds to cobalophilins or R binders
Broken down in the intestine by pancreatic proteases
Binds to IF and adheres to IF specific receptors on ileal cells
B12 enters mucosal cell and taken up by transcobalamin II which delivers it to the liver

Question 6

Vit B12 Malabsorption Causes

Answer 6

Failure to produce IF

Atrophic gastritis: loss of gastric mucosa where the parietal cells are which secrete the IF – no IF

Question 7

Type I, II, III antibodies

Answer 7

I: block binding of B12 to IF
II: block bind of IF or IF-VitB12 to ileal cell receptors
III: binds to the gastric proton pump on parietal cells

Question 8

Features of Pernicious Anemia

Answer 8

Leukopenia
Thrombocytopenia
Neurological changes
Inability to absorb oral cobalamin

Question 9

Folate deficiency = NO

Answer 9

No neurological defects
Purine synthesis
Methionine from homocysteine
Deoxythymidylate monophosphate

Question 10

Iron deficiency anemia

Answer 10

Most common nutritional deficiency

Question 11

80% of functional iron is found

Answer 11

Hemoglobin, myoglobin, catalase

Question 12

15-20% of iron

Answer 12

Storage Pool

Ferritin and hemosiderin

Question 13

Transferrin

Answer 13

transport iron from the plasma to the bone marrow or liver

Question 14

Two types of iron

Answer 14

Heme iron: from hgb, myoglobin

Non-heme: supplements

Question 15

Heme vs Non-heme iron absorption

Answer 15

Heme: released via gastric muscles and taken up by dueodenal mucosal cells
Non: DMT1 reduces to F2+ through apical membrane and transported to transferrin via ferroportin and hephaestin

Question 16

Define Hepcidin

Answer 16

Iron absorption regulator

Inhibits iron transfer from the enterocyte to plasma by binding to ferroportin

Question 17

Causes of iron deficiency

Answer 17

Dietary lack
Impaired absorption
Increased requirement
Chronic blood loss
Microcytic and hypochromic RBC

Question 18

Aplastic anemia

Answer 18

Pancytopenia (decrease WBC, RBC, plts) associated with anemia, neutropenia, throbocytopenia due to chemical or drugs
Suppressed myloid stem cells

Question 19

Aplastic anemia pathogenesis

Answer 19

Production of interferon gamma and TNF-alpha which suppress proliferation and differentiation

Question 20

Anemia of chronic disease

Answer 20

Reduced erythroid proliferation and impaired iron utilization –> mimic iron deficiency (<200 IBC)
Hypocellular bone marrow - cannot reuse iron

Question 21

What illness cause chronic disease anemia

Answer 21

Chronic microbial infections (OM, endocarditis, lung)
Chronic immune disorder (RA)
Hodgkin disease and cancer (lung and breast)

Question 22

MCV

Answer 22

Hct*10/RBC
Increased in B12 and folate
Decreased in iron

Question 23

MCH

Answer 23

Hgb*10/RBC
Increased in folate
Decreased in iron

Question 24

MCHC

Answer 24

Hgb*100/Hct

Decreased in iron