From the Guidelines
Hemolytic refers to the destruction or breakdown of red blood cells, causing hemoglobin to be released into the bloodstream, and its diagnosis involves a comprehensive work-up including history, physical examination, blood chemistry, and specialized tests as outlined in the American Society of Clinical Oncology clinical practice guideline 1. The process of hemolysis can occur due to various causes, including genetic disorders, autoimmune conditions, infections, certain medications, or exposure to toxins.
- Key symptoms of hemolytic conditions include:
- Fatigue
- Weakness
- Jaundice (yellowing of skin and eyes)
- Dark urine
- Shortness of breath When red blood cells rupture prematurely, the body may not be able to replace them quickly enough, potentially leading to hemolytic anemia.
- The diagnostic work-up, as recommended by the American Society of Clinical Oncology 1, should include:
- History and physical examination
- Blood chemistry
- CBC with evidence of anemia, macrocytosis, evidence of hemolysis on peripheral smear
- LDH, haptoglobin, bilirubin, reticulocyte count, free hemoglobin
- Disseminated intravascular coagulation panel
- Autoimmune serology
- Paroxysmal nocturnal hemoglobinuria screening Treatment depends on the underlying cause and may include addressing infections, discontinuing triggering medications, immunosuppressive therapy for autoimmune hemolysis, or blood transfusions in severe cases, as suggested by the guideline 1. The management of hemolytic conditions should prioritize identifying and addressing the underlying cause, and the diagnostic work-up should be comprehensive to ensure accurate diagnosis and effective treatment, as outlined in the American Society of Clinical Oncology clinical practice guideline 1.
From the Research
Definition of Hemolytic Anemia
- Hemolytic anemia is defined by the premature destruction of red blood cells, and can be chronic or life-threatening 2.
- It is characterized by the destruction of red blood cells through warm or cold antibodies, and can occur intravascularly, extravascularly in the reticuloendothelial system, or both 3, 2.
Causes of Hemolytic Anemia
- Hemolytic anemia can be caused by various factors, including genetic, environmental, and miscellaneous factors, such as drugs, infections, and systemic autoimmune diseases 4.
- It can also be caused by autoantibody production, complement activation, monocyte/macrophage phagocytosis, and bone marrow compensation 4.
- Hemoglobinopathies, membranopathies, enzymopathies, immune-mediated anemias, and extrinsic nonimmune causes are also classified as hemolytic diseases 2.
Symptoms and Diagnosis
- Patients with hemolysis may present with acute anemia, jaundice, hematuria, dyspnea, fatigue, tachycardia, and possibly hypotension 2.
- 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, and a peripheral blood smear should be performed to identify abnormal red blood cell morphologies 2.
Treatment and Management
- Treatment for autoimmune hemolytic anemia (AIHA) should be differentiated and sequenced according to AIHA type, such as steroids followed by rituximab for warm AIHA, and rituximab alone or in association with bendamustine or fludarabine for cold forms 4.
- New drugs targeting B-cells/plasma cells, complement, and phagocytosis are in clinical trials, and supportive treatment including vitamin supplementation, recombinant erythropoietin, thrombosis prophylaxis, and the prevention and treatment of infections is essential 4, 5.