Question

Which of the following laboratory findings would you expect in a patient with chronic kidney disease who is unable to produce adequate EPO levels? A. Larger than normal (macrocytic) red blood cells B. Smaller than normal (microcytic) red blood cells C. Normal sized (normocytic) red blood cells D. Fragments of red blood cells (schistocytes)

Short answer

C. Normal sized (normocytic) red blood cells

Step-by-step solution

Understand Chronic Kidney Disease (CKD)

Chronic kidney disease impairs the kidneys' ability to perform their normal functions, including the production of erythropoietin (EPO), a hormone that stimulates red blood cell (RBC) production.

Role of Erythropoietin (EPO)

Erythropoietin (EPO) is primarily produced in the kidneys and is essential for the production of red blood cells. In CKD, reduced EPO levels can lead to decreased RBC production.

Effects of Low EPO Levels on Red Blood Cells

Low levels of EPO result in a reduced production of red blood cells, leading to anemia. This anemia is typically normocytic, meaning the RBCs are of normal size but are fewer in number.

Match Findings with Options

A. Larger than normal (macrocytic) RBCs usually indicate vitamin B12 or folate deficiency, not CKD. B. Smaller than normal (microcytic) RBCs typically suggest iron deficiency anemia. C. Normal sized (normocytic) RBCs are common in anemia of chronic disease, including CKD. D. Schistocytes indicate hemolysis, not specifically related to CKD.

Select the Correct Option

Based on the analysis, the laboratory finding you would expect in a patient with CKD who cannot produce adequate EPO levels is normal sized (normocytic) red blood cells.

Key concepts

erythropoietin (EPO)

Erythropoietin, commonly referred to as EPO, is a hormone produced primarily by the kidneys. Its main function is to stimulate the bone marrow to produce red blood cells (RBCs).
EPO production is triggered by low oxygen levels in the blood. When the kidneys sense low oxygen, they release EPO to increase RBC production, which helps to carry more oxygen throughout the body.
However, in chronic kidney disease (CKD), the kidneys are damaged and can’t produce enough EPO. This leads to a decrease in red blood cell production, contributing to anemia.

normocytic anemia

Normocytic anemia is a type of anemia where the red blood cells are of normal size, but their number is reduced. This is common in chronic diseases, including chronic kidney disease (CKD).
In CKD, the kidneys fail to produce adequate EPO, leading to decreased red blood cell production. The RBCs in normocytic anemia are normal in size, unlike in other types of anemia where RBCs might be unusually large (macrocytic) or unusually small (microcytic).
This type of anemia is important to recognize because its causes and treatments can differ significantly from other types of anemia, which might stem from nutritional deficiencies or other issues.

red blood cell production

Red blood cell production, also known as erythropoiesis, occurs in the bone marrow. Erythropoietin (EPO) plays a crucial role in this process.
When EPO levels are adequate, the bone marrow receives the signal to produce more red blood cells. These cells contain hemoglobin, a protein that carries oxygen throughout the body.
In patients with chronic kidney disease (CKD), the reduced production of EPO leads to fewer red blood cells being produced. Consequently, this results in a lower oxygen-carrying capacity of the blood, often manifesting as fatigue, weakness, and other symptoms related to anemia.

laboratory findings

In the context of chronic kidney disease (CKD) and impaired erythropoietin (EPO) production, certain laboratory findings are typical.
If a patient with CKD can’t produce enough EPO, you would expect to find normocytic anemia, characterized by a reduced number of red blood cells that are normal in size. This differs from other forms of anemia where the red blood cells might be abnormally large (macrocytic) or small (microcytic).
Other laboratory findings might include elevated creatinine and urea levels, indicating poor kidney function, and potentially low hemoglobin levels due to reduced RBC production.
Understanding these laboratory findings helps in diagnosing and managing anemia in CKD patients effectively.