Iron, B12 and Folate Deficiencies

Question 1

Is hereditary spherocytosis accompanied by microcytosis?

Answer 1

no, cell may appear smaller on slide only because they are spherical and have a reduced cross-sectional area, the MCV is not reduced

note shift cells are also common in spherocytosis

Question 2

Bite cell is characteristic of which cellular deficiency?

Answer 2

G-6-PD deficiency due to oxidative stress the cell can’t handle (damage to hemoglobin)

*note in patients with G-6-PD with acute hemolysis or recent transfusion, G-6-PD levels may appear normal

Question 3

What is the molecular mechanisms for hereditary spherocytosis?

Answer 3

mutation in RBC cytoskeletal protein ankyrin leading to spectrum deficiency, causing membrane instability

gradual loss of membrane increased RBC hemoglobin concentration, reduced surface area/volume ratio causes decreased deformability and leaky membrane requires more ATP (deficiency in K+ pumps)

Question 4

What is the molecular pathology involved in g-6PD deficiency.

Answer 4

impairs generation of NADPH by the pentose phosphate pathway which impairs generation of reduced glutathione (helps protect cell membrane and hemoglobin from damage by reactive oxygen species)

Question 5

Describe the abnormality given the the following lab results:
low serum iron, slightly low TIBC, low % saturation and high ferritin.

Answer 5

anemia of inflammation

Question 6

Describe the abnormality given the the following lab results:
low serum iron, slightly high TIBC, low % saturation and low ferritin.

Answer 6

iron deficiency anemia

Question 7

Describe the abnormality given the the following lab results:
high serum iron, low TIBC, high % saturation and very high ferritin.

Answer 7

iron overload, possibly hemochromatosis

Question 8

What lab abnormalities would you be looking for in a patient that you suspect is iron deficient?

Answer 8

low iron, high TIBC, low ferritin

reticulocyte count inappropriately low (marrow is not compensating) and normocellular marrow

Question 9

In a patient were megaloblastic changes are apparent on smear, larger RBC and hyperhsegmented PMN

Answer 9

macrocytic anemia, possibly caused by B12 or folate deficiency

the bone marrow would appear severely megaloblastic with giant bands, hyperhsegmented PMNs and very megaloblastic erythroids (ineffective hematopoiesis)