From the Guidelines
Hemolysis can be classified into mild, moderate, and severe degrees, with severe hemolysis, also known as hyperhemolysis, being a life-threatening condition that requires immediate attention and potentially aggressive treatment, including avoidance of additional transfusions and consideration of extended matched red cells, as well as medications like IVIg, high-dose steroids, eculizumab, and/or rituximab 1. The degrees of hemolysis are typically characterized by the extent of red blood cell destruction, with mild hemolysis involving minimal destruction and often not causing significant clinical symptoms.
- In mild hemolysis, laboratory findings may show slightly elevated indirect bilirubin, reticulocytosis, and minimal decrease in hemoglobin levels.
- Moderate hemolysis involves more significant red cell destruction, with noticeable symptoms like jaundice, fatigue, and laboratory evidence of anemia, elevated lactate dehydrogenase (LDH), and decreased haptoglobin.
- Severe hemolysis, or hyperhemolysis, presents with marked anemia, significant jaundice, potential organ damage, and may require immediate intervention, including blood transfusions with extended matched red cells that lack the offending antigen, as well as other treatments like IVIg, high-dose steroids, eculizumab, and/or rituximab, as suggested by the American Society of Hematology 2020 guidelines for sickle cell disease 1. The degree of hemolysis is crucial for determining appropriate management, which ranges from observation for mild cases to aggressive treatment for severe cases, and recognizing hyperhemolysis is critical to avoid worsening of hemolysis and potential induction of multiorgan failure and death 1.
From the Research
Degrees of Hemolysis
The degrees of hemolysis, or the breakdown of red blood cells, can vary in severity and cause.
- Hemolysis can be induced by two general mechanisms: intravascular lysis due to complement fixation, trauma, or other extrinsic factors, and removal of red cells from the circulation by the mononuclear-phagocytic system due to intrinsic defects or bound immunoglobulins 2.
- The severity of hemolysis can range from mild to severe, with severe cases resulting in hemoglobinemia, hemoglobinuria, and hemosiderinuria 2.
- Conditions associated with significant lysis of red cells in the circulation include incompatible transfusion, G6PD deficiency, PNH, severe burns, and certain infections 2.
- Hemolytic anemias can be acute or chronic, with acute cases requiring emergency diagnosis and management 3.
- The treatment of hemolysis depends on the underlying cause, with supportive therapy and treatment of the underlying condition being the primary goals 2, 3.
Classification of Hemolysis
Hemolysis can be classified based on the mechanism of red cell destruction, with two main categories:
- Intravascular hemolysis, where red cells are destroyed within the blood vessels 2.
- Extravascular hemolysis, where red cells are removed from the circulation by the mononuclear-phagocytic system 2.
Clinical Presentation
The clinical presentation of hemolysis can vary depending on the severity and cause, but common symptoms include:
Note that the provided studies do not explicitly mention "degrees of hemolysis" but they do discuss the severity and causes of hemolysis, which can be used to infer the different degrees of hemolysis 5, 4, 2, 6, 3.