CHAPTER 20: DISORDERS OF IRON KINETICS AND HEME METABOLISM Flashcards
(1) The mother of a 4-month-old infant who is being breastfed sees her physician for a routine postpartum visit. She expresses concern that she may be experiencing postpartum depression because she does not seem to have any energy. Although the physician is sympathetic to the patient’s concern, she orders a CBC and iron studies seeking an organic explanation for the patient’s symptoms. The results are as follows:
CBC: all results within reference intervals except
RDW = 15%
Serum iron: decreased
TIBC: increased
% transferrin saturation: decreased
Serum ferritin: decreased
Correlate the patient’s laboratory and clinical findings. What can you conclude?
a. The results of the iron studies reveal findings consistent with a thalassemia that was apparently previously undiagnosed.
b. The patient is in stage 2 of iron deficiency, before frank anemia develops.
c. The results of the iron studies are inconsistent with the CBC results, and a laboratory error should be suspected.
d. There is no evidence of a hematologic explanation for the patient’s symptoms
b. The patient is in stage 2 of iron deficiency, before frank anemia develops.
(2) A bone marrow biopsy was performed as part of the cancer staging protocol for a patient with Hodgkin lymphoma. Although no evidence of spread of the tumor was apparent in the marrow, other abnormal findings were noted, including a slightly elevated myeloid-to-erythroid ratio. WBC and RBC morphology appeared normal, however. The Prussian blue stain showed abundant stainable iron in the marrow macrophages. The patient’s CBC revealed a hemoglobin of 10.8 g/dL, but RBC indices were within reference intervals. RBC morphology was unremarkable. These findings would be consistent with:
a. Anemia of chronic inflammation
b. Sideroblastic anemia
c. Thalassemia
d. Iron deficiency anemia
a. Anemia of chronic inflammation
(3) A bone marrow biopsy was performed as part of the cancer staging protocol for a patient with Hodgkin lymphoma. Although no evidence of spread of the tumor was apparent in the marrow, other abnormal findings were noted, including a slightly elevated myeloid-to-erythroid ratio. WBC and RBC morphology appeared normal, however. The Prussian blue stain showed abundant stainable iron in the marrow macrophages. The patient’s CBC revealed a hemoglobin of 10.8 g/dL, but RBC indices were within reference intervals. RBC morphology was unremarkable.
Predict the iron study results for the patient.
a. Serum Iron Level: Dec; TIBC: Inc; % Transferrin Saturation: Dec; Serum Ferritin Level: Dec
b. Serum Iron Level: Inc; TIBC: Normal; % Transferrin Saturation: Inc; Serum Ferritin Level: Normal
c. Serum Iron Level: Inc; TIBC: Inc; % Transferrin Saturation: Normal; Serum Ferritin Level: Inc
d. Serum Iron Level: Dec; TIBC: Dec; % Transferrin Saturation: Normal; Serum Ferritin Level: Normal
d. Serum Iron Level: Dec; TIBC: Dec; % Transferrin Saturation: Normal; Serum Ferritin Level: Normal
(4) A 35-year-old white woman went to her physician complaining of headaches, dizziness, and nausea. The headaches had been increasing in severity over the past 6 months. This was coincident with her move into an older house built about 1900. She had been renovating the house, including stripping paint from the woodwork. Her CBC results showed a mild hypochromic, microcytic anemia, with polychromasia and basophilic stippling noted. Which of the following tests would be most useful in confirming the cause of her anemia?
a. Serum lead level
b. Serum iron level and TIBC
c. Absolute reticulocyte count
d. Prussian blue staining of the bone marrow to detect iron stores in macrophages
a. Serum lead level
(5) In men and postmenopausal women whose diets are adequate, iron deficiency anemia most often results from:
a. Increased need associated with aging
b. Impaired absorption in the gastric mucosa
c. Chronic gastrointestinal bleeding
d. Diminished resistance to hookworm infections
c. Chronic gastrointestinal bleeding
(6) Which one of the following individuals is at greatest risk for the development of iron deficiency anemia?
a. A 15-year-old boy who eats mainly fast food and junk food
b. A 37-year-old woman who has never been pregnant and has amenorrhea
c. A 63-year-old man with reactivation of tuberculosis from his childhood
d. A 40-year-old man who lost blood during surgery to repair a fractured leg
a. A 15-year-old boy who eats mainly fast food and junk food
(7) Which of the following individuals is at the greatest risk for the development of anemia of chronic inflammation?
a. A 15-year-old girl with asthma
b. A 40-year-old woman with type 2 diabetes mellitus
c. A 65-year-old man with hypertension
d. A 30-year-old man with severe rheumatoid arthritis
d. A 30-year-old man with severe rheumatoid arthritis
(8) In what situation will increased levels of free erythrocyte protoporphyrin be present?
a. Gain of function mutation to one of the enzymes in the heme synthesis pathway
b. A mutation that prevents heme attachment to globin so that protoporphyrin remains free
c. Any condition that prevents iron incorporation into protoporphyrin IX
d. When red blood cells lyse, freeing their contents into the plasma
c. Any condition that prevents iron incorporation into protoporphyrin IX
(9) In the pathogenesis of the anemia of chronic inflammation, hepcidin levels:
a. Decrease during inflammation and reduce iron absorption from enterocytes
b. Increase during inflammation and reduce iron absorption from enterocytes
c. Increase during inflammation and increase iron absorption from enterocytes
d. Decrease during inflammation and increase iron absorption from enterocytes
b. Increase during inflammation and reduce iron absorption from enterocytes
(10) Sideroblastic anemias result from:
a. Sequestration of iron in hepatocytes
b. Inability to incorporate heme into apohemoglobin
c. Sequestration of iron in myeloblasts
d. Failure to incorporate iron into protoporphyrin IX
d. Failure to incorporate iron into protoporphyrin IX
(11) In general, the hereditary hemochromatoses result from mutations that impair:
a. The manner in which developing red cells acquire and manage iron
b. The hepcidin-ferroportin iron regulatory system
c. The TfR-Tf endocytic iron acquisition process for body cells other than blood cells
d. The function of divalent metal transporter in enterocytes and macrophages
b. The hepcidin-ferroportin iron regulatory system
(12) In the erythropoietic porphyrias, mild anemia may be accompanied by what distinctive clinical finding?
a. Gallstones
b. Impaired night vision
c. Unintentional nighttime leg movements
d. Heightened propensity for sunburn
d. Heightened propensity for sunburn
