From the Guidelines
Haemolytic markers, including lactate dehydrogenase (LDH), haptoglobin, reticulocyte count, unconjugated bilirubin, and hemoglobinuria, are essential for identifying and monitoring hemolysis, and should be used in conjunction with clinical history, family history, and other laboratory tests to diagnose and manage hemolytic disorders. The most important haemolytic markers include:
- Lactate dehydrogenase (LDH)
- Haptoglobin
- Reticulocyte count
- Unconjugated bilirubin
- Hemoglobinuria When hemolysis occurs, LDH levels increase while haptoglobin decreases as it binds to free hemoglobin 1. Reticulocyte count rises as the bone marrow responds by producing more red blood cells 1. Unconjugated bilirubin increases due to the breakdown of hemoglobin, and hemoglobinuria may be present when free hemoglobin appears in urine 1. These markers are particularly useful in diagnosing conditions like autoimmune hemolytic anemia, sickle cell disease, thalassemias, and drug-induced hemolysis 1. The pattern of these markers can help differentiate between intravascular hemolysis (occurring within blood vessels) and extravascular hemolysis (occurring in the spleen or liver) 1. Regular monitoring of these markers is essential in patients with known hemolytic disorders to assess disease activity and treatment effectiveness 1. In addition to these markers, other laboratory tests, such as complete blood count, RBC morphology, and markers of hemolysis, should be used to diagnose and manage hemolytic disorders 1. Clinical history, family history, and the time of last blood transfusion should also be taken into account when interpreting the results of these tests 1. Overall, a comprehensive approach that includes clinical evaluation, laboratory testing, and monitoring of haemolytic markers is necessary for the effective diagnosis and management of hemolytic disorders.
From the Research
Haemolytic Marker
- Haemolytic anemia is characterized by the premature destruction of red blood cells, which can occur intravascularly or extravascularly 2, 3
- The diagnosis of hemolytic anemia is established by:
- Reticulocytosis
- Increased unconjugated bilirubin and lactate dehydrogenase
- Decreased haptoglobin
- Peripheral blood smear findings 2
- Laboratory test results that confirm hemolysis include:
- Reticulocytosis
- Increased lactate dehydrogenase
- Increased unconjugated bilirubin
- Decreased haptoglobin levels 3
- The direct antiglobulin test can further differentiate immune causes from nonimmune causes of hemolytic anemia 3
- A peripheral blood smear should be performed to identify abnormal red blood cell morphologies, such as spherocytes or schistocytes 2, 3