Review Question - QID 211019

Action	Numeric Key	Letter Key	Function Key
Choose 1	1
Choose 2	2
Choose 3	3
Choose 4	4
Choose 5	5
Submit Response			Enter
Previous Question			Left Arrow
Next Question		N	Right Arrow
Open/Close Bookmode		C
Open Image			Spacebar

Erythropoietin Overview Mechanism of action QID: 211019 (M1.OMB.18.1)

QID 211019 (Type "211019" in App Search)

A 58-year-old man makes an appointment with his nephrologist because he has been feeling weak and increasingly fatigued over the last month. Specifically, he has not been able to do activities of daily living independently because he feels short of breath after several minutes of activity. His past medical history is significant for rapidly progressive glomerulonephritis that led to kidney failure. He has been on hemodialysis for the last 6 months and has been compliant with attending every dialysis session. Physical exam reveals conjunctival pallor. Laboratory tests are obtained and results are shown below:

Hemoglobin: 8.9 g/dL (normal: 13.5-17.5 g/dL)
Platelet count: 198,000/mm^3 (normal: 150,000-400,000/mm^3)
Mean corpuscular volume: 87 µm^3 (normal: 80-100 µm^3)
Reticulocyte count: 0.1% (normal: 0.5-1.5%)

Based on these findings, the patient is given appropriate treatment to address his symptoms. Which of the following is the most likely mechanism of action for this treatment?

Type & Select Correct Answer

Type in at least one full word to see suggestions list

Activation of receptors on erythroid progenitor cells

66%

86/130

Chelation of heavy metals

6/130

Provision of finished blood products

10/130

Removal of red blood cell clearing organ

8/130

Transplantation of new cells

12/130

Select Answer to see Preferred Response

Review TC In New Tab

This patient with chronic kidney failure that developed a normocytic anemia and low reticulocyte count most likely has anemia of renal failure and was given erythropoietin (EPO). EPO works by activating receptors on erythroid progenitor cells.

EPO is produced by the interstitial cells of the kidney in the peritubular capillary bed. EPO functions by activating receptors on erythroid progenitor cells in the bone marrow, thereby stimulating the production of new red blood cells. Furthermore, EPO increases release of red blood cells from the bone marrow. Decreased synthesis of EPO can lead to anemia in patients with chronic renal failure. This will result in a normocytic anemia with decreased reticulocytes since reticulocytes are newly produced red blood cells. The pharmacologic agent epoetin-alpha is recombinant human erythropoietin that can be used to treat anemia of renal failure.

Incorrect Answers:
Answer 2: Chelation of heavy metals can be used to treat lead poisoning anemia; however, it would not be used in anemia of renal failure.

Answer 3: Provision of finished blood products can be used in patients with genetic deficiencies of hemoglobin production; however, it is not usually required in anemia of renal failure since the bone marrow is normal.

Answer 4: Removal of red blood cell clearing organ (spleen) can be used in patients with hemolytic anemia; however, anemia of renal failure is a problem with underproduction of red blood cells rather than overdestruction.

Answer 5: Transplantation of new cells can be used in patients with bone marrow failure; however, in anemia of normal failure the bone marrow is normal.

Bullet Summary:
Erythropoietin functions by activating receptors on erythroid progenitor cells in the bone marrow and stimulating the production of new red blood cells.

Rating

Please Rate Question Quality

5.0

(1)