Which of the following is not associated with a responsive anemia?

• A. Reticulocytosis
• B. Poikilocytosis
• C. Anisocytosis
• D. Polychromasia

Answer: (B)

Regenerative (responsive) anemia is a situation where the bone marrow actively increases red blood cell production in response to loss or destruction. The hallmarks you look for are reticulocytosis (more reticulocytes on the smear) and polychromasia (you can see immature cells with bluish, RNA-rich cytoplasm). Anisocytosis, or a mix of different cell sizes, also fits because the young reticulocytes are larger than mature cells and contribute to size variation. Poikilocytosis, which is variation in cell shape, isn’t a defining feature of the regenerative response; it reflects shape abnormalities that occur in various other conditions rather than the marrow’s regenerative burst. So poikilocytosis is not associated with a responsive anemia, whereas reticulocytosis, polychromasia, and anisocytosis are.