From the Guidelines
Hemolytic anemia is classified into two main categories: inherited and acquired forms, with inherited forms including disorders of the red blood cell membrane, hemoglobinopathies, and enzyme deficiencies, and acquired forms divided into immune-mediated and non-immune causes. The classification of hemolytic anemia is crucial for determining the appropriate treatment and predicting the disease course. Inherited hemolytic anemias include:
- Disorders of the red blood cell membrane, such as hereditary spherocytosis and elliptocytosis
- Hemoglobinopathies, like sickle cell disease and thalassemias
- Enzyme deficiencies, particularly glucose-6-phosphate dehydrogenase deficiency and pyruvate kinase deficiency, as discussed in the study by Bianchi et al. 1 Acquired hemolytic anemias are divided into:
- Immune-mediated types, which include autoimmune hemolytic anemia (warm or cold antibody types), alloimmune hemolytic anemia (like transfusion reactions), and drug-induced immune hemolytic anemia
- Non-immune acquired causes, including mechanical hemolysis (from prosthetic heart valves or microangiopathic conditions), infections (malaria, babesiosis), toxins, burns, and certain medications that directly damage red blood cells, as mentioned in the study by Bianchi et al. 1 Understanding the mechanism of hemolysis helps guide management decisions, and the classification is essential for determining the appropriate treatment, which varies significantly depending on the underlying cause, as noted in the guidelines for the diagnosis and treatment of chronic lymphocytic leukemia 1.
From the Research
Classifications of Hemolytic Anemia
Hemolytic anemia can be classified based on various factors, including the cause, location, and mechanism of hemolysis. The main classifications are:
- Hereditary or acquired defects 2
- Corpuscular or extracorpuscular defects 2
- Intravascular or extravascular hemolysis 3, 4
- Immune-mediated or nonimmune causes 3, 4
Hereditary Classifications
Hereditary hemolytic anemias can be further classified into:
- Hemoglobinopathies (e.g., sickle cell anemia, thalassemia) 3, 4
- Membranopathies (e.g., hereditary spherocytosis) 3, 4
- Enzymopathies (e.g., glucose-6-phosphate dehydrogenase deficiency) 3, 4, 5
Acquired Classifications
Acquired hemolytic anemias can be classified into:
- Autoimmune hemolytic anemia (AIHA) 2, 3
- Microangiopathic hemolytic anemia (e.g., thrombotic thrombocytopenic purpura, hemolytic-uremic syndrome) 2, 3
- Infection-related hemolytic anemia (e.g., malaria, babesiosis) 3
- Drug-induced hemolytic anemia 3, 5
- Extrinsic nonimmune causes (e.g., direct trauma, oxidative insults) 4