Thalassemia can lead to which characteristic finding on a blood smear?

Thalassemia is a group of inherited blood disorders characterized by reduced hemoglobin production. One of the characteristic findings on a blood smear in patients with thalassemia is the presence of target cells. These are erythrocytes that have a central area of hemoglobin surrounded by a clear ring and then a peripheral area of hemoglobin, resembling a target. Target cells are often seen in conditions where there is a decrease in hemoglobin concentration relative to the cell membrane, which can occur in thalassemia due to the imbalance in globin chain production.

The presence of target cells can also be observed in other conditions, such as liver disease and iron deficiency anemia, but their association with thalassemia is particularly notable due to the pathophysiological mechanisms involved. In thalassemia, the ineffective erythropoiesis and altered lipid composition of the red cell membrane structure contribute to the formation of these cells.

While other types of abnormal red blood cells may appear in various hemolytic anemias or other conditions, target cells remain a hallmark of thalassemia, making this finding significant in the diagnosis and evaluation of the disease.