What laboratory finding is associated with macrocytic anemia?

Macrocytic anemia is characterized by the presence of enlarged red blood cells, which is typically indicated by an elevated mean corpuscular volume (MCV). One laboratory finding that may be associated with macrocytic anemia is the presence of Howell-Jolly bodies. These are small remnants of nuclear material within red blood cells that are usually removed by the spleen. In cases of macrocytic anemia, particularly when linked to certain types of megaloblastic anemia or splenic dysfunction, the presence of Howell-Jolly bodies can be indicative of ineffective erythropoiesis or a compromised spleen's ability to filter out these cellular remnants.

The low reticulocyte count can accompany various anemias and reflect the bone marrow's response to anemia, but it is not specific to macrocytic anemia. The normal MCV directly contradicts the definition of macrocytic anemia, which is by definition characterized by high MCV. Low hemoglobin levels are present in all forms of anemia but do not specifically indicate macrocytic anemia without contextual information on cell size or volume. Thus, Howell-Jolly bodies are the most relevant finding in the context of macrocytic anemia.