In alpha thalassemia, what are the usual results for mean corpuscular volume (MCV) and red cell distribution width (RDW)?

In alpha thalassemia, the usual results for mean corpuscular volume (MCV) and red cell distribution width (RDW) are characterized by a decreased MCV alongside an increased RDW.

Alpha thalassemia results from a genetic mutation that affects the production of alpha globin chains, leading to a form of microcytic anemia. The decreased MCV reflects the smaller size of the red blood cells, which is a hallmark of microcytic anemias, including thalassemias.

In addition, the RDW is typically increased in alpha thalassemia as the body attempts to compensate for the ineffective erythropoiesis and the presence of a mix of red blood cells of varying sizes (anisocytosis). The variability in red blood cell sizes contributes to a higher RDW, reflecting the presence of both normal-sized and smaller microcytic cells.

This combination of a decreased MCV and an increased RDW is important for differentiating alpha thalassemia from other types of anemia, as it helps clinicians guide further diagnostic testing and management strategies.