From the Guidelines
Lab findings in hemolytic anemia typically include decreased hemoglobin and hematocrit, elevated reticulocyte count, increased lactate dehydrogenase (LDH), decreased haptoglobin, elevated unconjugated bilirubin, and presence of schistocytes or spherocytes on peripheral blood smear. These findings reflect increased red blood cell destruction and compensatory bone marrow response. The elevated LDH and decreased haptoglobin indicate ongoing hemolysis, while increased reticulocytes show the bone marrow's attempt to replace lost red cells. Schistocytes or spherocytes on blood smear can help identify the specific type of hemolytic anemia. Some key laboratory findings in hemolytic anemia are:
- Decreased hemoglobin and hematocrit
- Elevated reticulocyte count
- Increased lactate dehydrogenase (LDH)
- Decreased haptoglobin
- Elevated unconjugated bilirubin
- Presence of schistocytes or spherocytes on peripheral blood smear Additional tests may include:
- Positive direct Coombs test (in autoimmune hemolytic anemia) 1
- Abnormal osmotic fragility test (in hereditary spherocytosis) 1
- Hemoglobinuria and hemosiderinuria For accurate diagnosis and management, a complete blood count, reticulocyte count, and peripheral blood smear should be performed initially, as recommended by recent studies 1. Follow-up tests can be ordered based on these results to determine the underlying cause of hemolysis. It is essential to consider the patient's clinical presentation, medical history, and family history when interpreting laboratory results, as emphasized in recent guidelines 1. In cases where the diagnosis is unclear, further testing, such as molecular analysis or bone marrow examination, may be necessary to confirm the diagnosis of hemolytic anemia 1.
From the Research
Laboratory Findings in Hemolytic Anemia (HA)
The laboratory findings in Hemolytic Anemia (HA) include:
- Reticulocytosis, which indicates an increased production of red blood cells to replace the destroyed ones 2, 3, 4
- Increased lactate dehydrogenase (LDH) levels, which is a sign of red blood cell destruction 2, 3, 4
- Increased unconjugated bilirubin levels, which is a byproduct of red blood cell breakdown 2, 4
- Decreased haptoglobin levels, which is a protein that binds to free hemoglobin in the blood 2, 4
- Elevated erythrocyte adenylate kinase (EAK) levels, which is a red cell specific enzyme released from damaged red cells 3
- Abnormal red blood cell morphologies on peripheral blood smear, which can help identify the underlying cause of hemolysis 2, 4
- Increased indirect bilirubin, which is a sign of hemolysis 5
- Decreased hemopexin levels, which is a protein that binds to free hemoglobin in the blood 4
- Hemoglobinemia, hemoglobinuria, and hemosiderinuria, which occur in severe and rapid intravascular hemolysis 4
Diagnostic Tests
Diagnostic tests for Hemolytic Anemia (HA) include:
- Direct antiglobulin test, which differentiates immune causes from nonimmune causes 2
- Serum EAK assay, which is a highly sensitive and specific test for the diagnosis of hemolytic anemia 3
- Reticulocyte count, which indicates an increased production of red blood cells to replace the destroyed ones 2, 3, 4
- Peripheral blood smear, which can help identify abnormal red blood cell morphologies 2, 4
- Measurement of serum bilirubin, LDH, and haptoglobin levels, which are signs of red blood cell destruction 2, 3, 4