[Ruth Cuadra]

Hi, Nicole.

Here's some basic info about MCV and RDW:

MCV (mean corpuscular volume) measures average size of red blood cells (RBCs).

When RBCs are larger than normal (macrocytic), MCV is elevated. This can happen in the case of anemia caused by chemotherapy or vitamin B12 deficiency.

When RBCs are smaller than normal (microcytic), MCV is decreased. This can happen in the case of anemia from iron deficiency.

RDW (red cell distribution width) measures the variation in the red blood cell size. In aplastic anemia, the amount of variation in size and shape of RBCs causes an increase in the RDW. High MCV and high RDW usually go together.

Evan's MCV of 105 is slightly above the normal range of about 80-100. An MCV over 105 or less than 85 is typical with aplastic anemia. High MCV is a sign of bone marrow stress but is not a prognostic indicator, meaning that it doesn't indicate that the disease is worsening. It's reasonable that Evan's MCV would be lower after a transfusion because he's received blood with normal sized cells which, when combined with his own cells, brings down the average of the cell sizes.

Hope this helps.

Ruth