Autoimmune Hemolytic Anemia Guidelines

Diagnosis and Pathophysiology

More than 90% of autoimmune disorders produce polyclonal high-affinity IgG via T-cell-mediated mechanisms, contributing to warm autoimmune hemolytic anemia (AIHA) 1
IgG-opsonized red blood cells undergo extravascular hemolysis via antibody-dependent cellular cytotoxicity, primarily in the spleen 1
In CLL-associated AIHA, patients with immune-mediated cytopenias have better outcomes than those with bone marrow infiltration 1

Warm AIHA can be idiopathic (primary, 50% of cases) or secondary to lymphoproliferative disorders, autoimmune diseases, or drugs, and is typically treated with corticosteroids as the first-line treatment 1, 3
The American College of Physicians recommends corticosteroids as the first-line treatment for warm AIHA, with an expected response rate of 70-80% 3
Rituximab is recommended as second-line treatment for steroid-refractory or relapsed warm AIHA cases, with response rates of 60-80% 3
Cold Agglutinin Disease is characteristically treated with rituximab, rather than splenectomy, and avoidance of cold exposure is an important supportive measure 2, 4
The European Society for Medical Oncology suggests that rituximab combined with glucocorticoids is often effective for severe manifestations of Cold Agglutinin Disease 2, 4

The direct antiglobulin test (DAT/Coombs) is positive for IgG (with or without complement) in warm AIHA, and hemolysis markers include elevated LDH, low haptoglobin, elevated indirect bilirubin, and elevated reticulocyte count 3
Cold agglutinins or cryoglobulins may affect IgM level determination, which can complicate diagnosis 3

Treatment of the underlying cause (such as CLL or lymphoproliferative disorder) is indicated when autoimmune cytopenia does not respond to conventional therapy, as recommended by the American Society of Hematology 4, 3