What type of blood cells are primarily affected in aplastic anemia?

Aplastic anemia is characterized by the failure of the bone marrow to produce sufficient blood cells, which can affect all hematopoietic lineages. The condition leads to a significant reduction in the production of red blood cells, white blood cells, and platelets, resulting in pancytopenia.

In this disorder, the bone marrow is typically hypoplastic or even aplastic, which means it contains fewer blood-forming stem cells to produce all types of blood cells—erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). The lack of red blood cells can cause anemia, leading to fatigue and weakness. The decrease in white blood cells increases the risk of infections, while the reduction in platelets can lead to bleeding and bruising.

Thus, the impact of aplastic anemia is systemic, affecting the production of all major blood components, making the correct answer encompass all types of blood cells.