NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

What causes leukopenia?

1. Increased PLTs

2. Decreased WBC

3. Increased RBC

4. Decreased PLTs

The correct answer is: Decreased WBC

Leukopenia is a condition characterized by low white blood cell count. White blood cells are responsible for fighting infections and diseases in the body. A low WBC count can be caused by various underlying conditions, such as certain infections, medicines, or bone marrow disorders. Option A is incorrect because increased platelets (PLTs) would not directly lead to a decrease in white blood cells. Platelets are responsible for blood clotting, not fighting infections or producing white blood cells. Option C is incorrect because increased red blood cells (RBC) would also not directly cause leukopenia. RBCs are responsible for carrying oxygen to the body, not fighting infections or producing white blood cells. Option D is also incorrect because decreased platelets would not necessarily cause a decrease in white blood cells. While platelets are important for blood clotting, they do not directly affect the production or function of white blood cells.