Which laboratory findings support hemolysis in autoimmune hemolytic anemia?

• A. Elevated LDH, reticulocytosis, decreased haptoglobin
• B. Decreased LDH, reticulocytopenia, increased haptoglobin
• C. Normal LDH and bilirubin
• D. Low unconjugated bilirubin, high haptoglobin

Answer: (A)

Hemolysis causes red blood cells to break down, releasing their contents into the blood. This releases enzymes like LDH from the cells, so LDH levels rise. Free hemoglobin from destroyed cells binds to haptoglobin, and that complex is cleared from circulation, lowering the amount of haptoglobin available in the serum. Meanwhile, the body tries to compensate for anemia by ramping up red cell production, leading to more reticulocytes in the blood—reticulocytosis. Putting these together, elevated LDH, reticulocytosis, and decreased haptoglobin form a classic lab pattern that supports ongoing hemolysis in autoimmune hemolytic anemia.

Patterns that don’t fit include low LDH (not showing cell breakdown), reticulocytopenia (poor marrow response), or high haptoglobin (not consistent with the consumption that happens during hemolysis). Normal LDH and bilirubin would also be inconsistent with active hemolysis.