[Autoimmune hemolytic anemias].

Area of Science:

• Hematology
• Immunology
• Internal Medicine

Background:

• Autoimmune hemolytic anemias (AIHA) are rare acquired hemolytic anemias caused by autoantibodies against red blood cell surface antigens.
• Diagnosis is confirmed by a positive direct antiglobulin test (DAT), though exceptions exist (non-regenerative cases, negative DAT).

Purpose of the Study:

• To differentiate between warm and cold antibody AIHA.
• To outline the distinct causes and treatment strategies for each AIHA subtype.

Main Methods:

• Classification of AIHA based on antibody type (warm vs. cold) and DAT results (IgG, C3d).
• Review of common etiologies and established treatment protocols for each subtype.

Main Results:

• Warm antibody AIHA (IgG positive DAT) is often associated with B-cell chronic lymphoid leukemia, immune deficiency, lupus, or drugs; initial treatment involves corticosteroids, with rituximab as second-line therapy.
• Cold antibody AIHA (C3d positive DAT) includes post-infectious types and cold agglutinin disease; treatment focuses on cold protection, as corticosteroids and splenectomy are ineffective.

Conclusions:

• Effective AIHA management requires distinguishing between warm and cold antibody types due to differing underlying causes and treatment responses.
• Rituximab and chemotherapy are indicated for severe anemia, particularly in cold antibody AIHA cases unresponsive to initial measures.