Final answer:
The presence of RBC polychromasia on a blood film can be used to validate a reported increased reticulocyte count from a hematology analyzer, as it indicates immature erythrocytes, aligning with an increased reticulocyte production.
Step-by-step explanation:
Determining the validity of a reported increased reticulocyte count from a hematology analyzer can be supported by evaluating a blood film. The presence of RBC polychromasia is a relevant indicator to validate an increased reticulocyte count. Polychromasia refers to the presence of immature erythrocytes (reticulocytes) that exhibit a bluish tint with Wright or Giemsa stain due to residual RNA. These younger red blood cells are larger and more colorful than the older, more pallid ones. Since reticulocytes are immature RBCs normally released from the bone marrow into the bloodstream, the presence of polychromasia dovetails with an increased reticulocyte count.
Other indicators mentioned, such as nucleated RBCs, RBC anisocytosis, and decreased red blood cell density in the monolayer, may be associated with various hematological conditions but are not specific for assessing reticulocyte count. Therefore, the correct answer is D) The presence of RBC polychromasia.