What laboratory result is typically low in hemolytic anemia due to warm or cold agglutinin disease?

In hemolytic anemia, particularly in conditions like warm or cold agglutinin disease, haptoglobin levels are typically low. Haptoglobin is a protein that binds free hemoglobin released into the plasma when red blood cells are destroyed. In hemolytic processes, especially in autoimmune hemolytic anemia, the rapid breakdown of red blood cells leads to an increase in free hemoglobin, which depletes haptoglobin levels as it binds to the hemoglobin.

When the haptoglobin is consumed due to increased hemolysis, the serum haptoglobin concentration decreases. Measuring haptoglobin levels can serve as an indirect marker of the hemolysis process occurring in patients with hemolytic anemia.

On the other hand, enzymes like lactate dehydrogenase (LDH) may be elevated in hemolytic anemia as they are released from lysed red blood cells, and reticulocyte counts typically increase as the bone marrow responds to anemia by producing more immature red blood cells. Platelet counts can vary depending on the etiology of the hemolysis and are not directly linked to haptoglobin levels. Thus, low haptoglobin is a hallmark laboratory finding in hemolytic anemia associated with warm or cold aggl