What is hemolytic anemia?

What is hemolytic anemia?

• A. Anemia caused by the destruction of RBCs
• B. Anemia caused by underproduction of RBCs
• C. Anemia due to iron deficiency
• D. Anemia due to kidney failure

Answer: (A)

Hemolytic anemia is anemia caused by the destruction of red blood cells. In this condition, RBCs are destroyed faster than the bone marrow can replace them, leading to a fall in hemoglobin. The body responds by ramping up erythropoiesis, so you see a rise in reticulocytes as the marrow works to compensate. Because RBCs are being destroyed, certain lab and clinical clues appear: haptoglobin falls as it binds free hemoglobin, lactate dehydrogenase (LDH) rises from cell breakdown, and indirect (unconjugated) bilirubin increases, which can cause jaundice. If destruction is ongoing, you might also see dark urine from hemoglobin or bilirubin and sometimes splenomegaly due to increased splenic clearance of damaged cells. This differs from underproduction forms of anemia, where the problem is insufficient RBC production by the bone marrow. For example, iron deficiency causes microcytic anemia because iron is needed for hemoglobin synthesis, and kidney failure can cause anemia by reduced erythropoietin production. In those scenarios, the reticulocyte count is typically low or inappropriately low for the degree of anemia, reflecting reduced production rather than increased destruction.

Hemolytic anemia is anemia caused by the destruction of red blood cells. In this condition, RBCs are destroyed faster than the bone marrow can replace them, leading to a fall in hemoglobin. The body responds by ramping up erythropoiesis, so you see a rise in reticulocytes as the marrow works to compensate.

Because RBCs are being destroyed, certain lab and clinical clues appear: haptoglobin falls as it binds free hemoglobin, lactate dehydrogenase (LDH) rises from cell breakdown, and indirect (unconjugated) bilirubin increases, which can cause jaundice. If destruction is ongoing, you might also see dark urine from hemoglobin or bilirubin and sometimes splenomegaly due to increased splenic clearance of damaged cells.

This differs from underproduction forms of anemia, where the problem is insufficient RBC production by the bone marrow. For example, iron deficiency causes microcytic anemia because iron is needed for hemoglobin synthesis, and kidney failure can cause anemia by reduced erythropoietin production. In those scenarios, the reticulocyte count is typically low or inappropriately low for the degree of anemia, reflecting reduced production rather than increased destruction.