Autoimmune Hemolytic Anemia

Autoimmune Hemolytic Anemia is a topic covered in the Washington Manual of Medical Therapeutics.

To view the entire topic, please or purchase a subscription.

The Washington Manual of Medical Therapeutics helps you diagnose and treat hundreds of medical conditions. Consult clinical recommendations from a resource that has been trusted on the wards for 50+ years. Explore these free sample topics:

Washington Manual

-- The first section of this topic is shown below --

General Principles

Definition

Autoimmune hemolytic anemia (AIHA) results from autoantibodies targeted to antigens on the patient’s RBCs, resulting in either extravascular hemolysis (removal of RBC by tissue macrophages in the liver or spleen) or complement-mediated intravascular hemolysis.

Classification

There are two main types of AIHA: warm and cold AIHA. Warm AIHA antibodies interact best with RBCs at 37°C, whereas cold antibodies (or cold agglutinins) are most active at temperatures below 37°C and almost always fix complement.

Etiology

  • Warm AIHA is usually caused by an IgG autoantibody. It may be idiopathic or secondary to an underlying process (i.e., lymphoma, chronic lymphocytic leukemia [CLL], collagen vascular disorder, or drugs [see Table 21-5]).
  • Cold AIHA (or cold agglutinin disease [CAD]) is typically caused by an IgM autoantibody.
    • The acute form of CAD is often secondary to an infection (Mycoplasma, Epstein–Barr virus).
    • The chronic form is due to a paraprotein associated with lymphoma, CLL, or Waldenström macroglobulinemia (WM) in approximately one-half of cases and is primary (idiopathic) in the others.

-- To view the remaining sections of this topic, please or purchase a subscription --