Classification of Hemolytic Anemia

Immune-Mediated Hemolytic Anemia

Immune-mediated hemolytic anemia (IMHA) is a condition in which the body's immune system mistakenly targets and destroys its own red blood cells, leading to anemia. This process can be mediated by autoantibodies, complement activation, or both.

Causes and Pathophysiology

IMHA can be classified into primary (idiopathic) and secondary forms. Primary IMHA occurs without an identifiable underlying cause, while secondary IMHA is triggered by factors such as infections, malignancies, or medications.

Clinical Features

• Fatigue and weakness
• Pallor
• Jaundice due to hemolysis
• Dark-colored urine (hemoglobinuria)
• Splenomegaly

Diagnosis

Diagnosis involves a combination of clinical evaluation, laboratory testing, and specialized assays such as:

• Complete blood count (CBC) showing anemia and reticulocytosis
• Direct Coombs test (direct antiglobulin test) to detect antibody-coated RBCs
• Peripheral blood smear showing spherocytes
• Lactate dehydrogenase (LDH) and haptoglobin levels to assess hemolysis

Treatment and Management

Treatment depends on the severity and underlying cause of IMHA. Standard management strategies include:

• Corticosteroids (e.g., prednisone) to suppress immune response
• Immunosuppressive drugs (e.g., azathioprine, rituximab) for refractory cases
• Blood transfusions in severe anemia
• Splenectomy in chronic or unresponsive cases
• Treating underlying infections or malignancies

Prognosis

The prognosis of IMHA varies based on severity and response to treatment. Early diagnosis and appropriate therapy improve outcomes significantly.