Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is one of the most common causes of acquired hemolytic anemia. It can present with normocytic or macrocytic anemia which can result from both intravascular and extravascular hemolysis. For effective management, it is important to differentiate it from other types of hemolytic anemias such as red cell membrane defects, enzyme defects, certain hemoglobinopathies, and micro-angiopathic hemolytic anemia. The pathophysiological features of different types of AIHA and role of Tregs, which are now considered to play an important role in immune tolerance, are discussed. In this chapter, a clinical case scenario is presented followed by step-by-step evidence-based approach to utilize specialized and advanced tests to unravel the final diagnosis of AIHA. A comprehensive description of disease process and correlation with the results of investigations are presented in question–answer format. Salient points are summarized for quick revision.