Classification and therapeutic approaches in autoimmune hemolytic anemia: an update

Autoimmune hemolytic anemia (AIHA) is an uncommon autoantibody-mediated immune disorder that affects both children and adults. The diagnosis of AIHA relies mainly on the direct antiglobulin test, which is a highly sensitive and relatively specific test. The classification of AIHA is based on the pattern of the direct antiglobulin test and on the immunochemical properties of the autoantibody (warm or cold type), but also on the presence or absence of an underlying condition or disease (secondary vs primary AIHAs) that may have an impact on treatment and outcome. The distinction between AIHAs due to warm antibody (wAIHA) and AIHAs due to cold antibody is a crucial step of the diagnostic procedure as it influences the therapeutic strategy. Whereas corticosteroids are the cornerstone of treatment in wAIHA, they have no or little efficacy in cold AIHA. In wAIHA that is refractory or dependent to corticosteroids, splenectomy and rituximab are both good alternatives and the benefit-risk ratio of each option must be discussed on an individual basis. In chronic agglutinin disease, the most common variety of cold AIHA in adults, beyond supportive measures, rituximab given either alone or in combination with chemotherapy may be helpful. In this article, the classification of AIHA and the recent progress in therapeutics are discussed.