Question

Why does the spleen light up with in vitro RBC labeling?

A) Due to damage to RBCs during the labeling process.
B) Due to increased uptake of radiotracer by the spleen.
C) Due to the presence of splenic lesions or abnormalities.
D) In vitro RBC labeling does not cause splenic uptake.

Answer 1

The spleen lights up during in vitro RBC labeling due to its role in phagocytizing damaged red blood cells labeled with radiotracers, indicating the removal activity and not necessarily due to splenic lesions or diseases.

Step-by-step explanation:

The spleen lights up with in vitro RBC labeling primarily due to its role in the removal of damaged or old erythrocytes from circulation. During the RBC labeling process, some red blood cells may sustain damage, and these are subsequently phagocytized or consumed by macrophages within the spleen. As such, the radiotracer used in the labeling process accumulates in the spleen, causing it to appear 'lit up' in imaging studies.

This is a reflection of the spleen's healthy function, rather than an indication of disease or lesions; the correct answer is A) Due to damage to RBCs during the labeling process. This process is a part of extramedullary hemopoiesis, wherein the liver and spleen contribute to the generation of formed elements when issues such as marrow disorders, like myelofibrosis, occur.