From the Guidelines
Hemolytic conditions, such as hemolytic anemia, require prompt diagnosis and treatment to prevent severe complications, including acute kidney injury and death, and the most recent guidelines from the American Society of Hematology 2020 recommend transfusion support for patients with sickle cell disease, including extended matched red cells and avoidance of additional transfusions if possible, to reduce the risk of hyperhemolysis 1.
Key Considerations
- Hemolytic conditions can be caused by various factors, including autoimmune disorders, infections, medications, toxins, or inherited disorders affecting red blood cell structure or function.
- Common symptoms of hemolytic anemia include fatigue, weakness, pale skin, jaundice, and shortness of breath.
- Treatment depends on the underlying cause and may include corticosteroids, immunosuppressants, blood transfusions, or splenectomy in severe cases.
- Prompt diagnosis through blood tests like complete blood count, reticulocyte count, and direct Coombs test is crucial for effective management of hemolytic conditions.
Management of Hyperhemolysis
- Hyperhemolysis can occur with no identifiable antibody and a negative direct antiglobulin test, and recognition is critical to avoid additional transfusions that may worsen the condition.
- IVIg, high-dose steroids, eculizumab, and/or rituximab have been used to treat hyperhemolysis in patients with sickle cell disease, but the optimal management remains unclear 1.
Diagnostic Challenges
- Pyruvate kinase deficiency is a rare cause of chronic hereditary nonspherocytic hemolytic anemia, and diagnosis can be challenging due to the wide variability of the condition and the lack of familiarity with this diagnosis even among hematologists 1.
- A global PK deficiency International Working Group has established recommendations for the diagnosis of PK deficiency, including the use of evidence-based material and peer-reviewed publications 1.
From the Research
Definition and Classification of Hemolytic Anemia
- Hemolytic anemia is defined by the premature destruction of red blood cells, and can be chronic or life-threatening 2.
- It should be part of the differential diagnosis for any normocytic or macrocytic anemia 2.
- Hemolysis may occur intravascularly, extravascularly in the reticuloendothelial system, or both 2.
Causes and Mechanisms of Hemolytic Anemia
- Mechanisms include poor deformability leading to trapping and phagocytosis, antibody-mediated destruction through phagocytosis or direct complement activation, fragmentation due to microthrombi or direct mechanical trauma, oxidation, or direct cellular destruction 2.
- Hemolytic diseases are classified into hemoglobinopathies, membranopathies, enzymopathies, immune-mediated anemias, and extrinsic nonimmune causes 2.
- Extrinsic nonimmune causes include the thrombotic microangiopathies, direct trauma, infections, systemic diseases, and oxidative insults 2.
Diagnosis of Hemolytic Anemia
- Laboratory test results that confirm hemolysis include reticulocytosis, as well as increased lactate dehydrogenase, increased unconjugated bilirubin, and decreased haptoglobin levels 2.
- The direct antiglobulin test further differentiates immune causes from nonimmune causes 2, 3.
- A peripheral blood smear should be performed when hemolysis is present to identify abnormal red blood cell morphologies 2.
Treatment of Hemolytic Anemia
- Corticosteroids are the first-line treatment option for warm autoantibody-related hemolytic anemia 4, 5.
- In patients who develop steroid side effects or do not respond adequately, other immunosuppressives may be preferred 4.
- Rituximab or other monoclonal antibodies may be used instead of splenectomy in therapy-refractory patients 6, 5, 3.
- Plasma exchange (PE) may be utilised in case of severe and refractory anemia, especially in the case of cardiovascular imbalance in fulminant hemolysis 4.