Autoimmune Hemolytic Anemia

Autoimmune Hemolytic Anemia (AIHA) is a rare hematological disorder characterized by the production of autoantibodies directed against an individual's own red blood cells (RBCs), leading to their premature destruction and subsequent reduction in blood cell concentration. Under normal physiological conditions, RBCs have a lifespan of ۱۰۰-۱۲۰ days; however, in severe AIHA, this lifespan may be reduced to only a few days. As a result, RBCs undergo accelerated hemolysis, and their intracellular components are released into the bloodstream and surrounding tissues, producing clinical manifestations. AIHA may occur as a primary disorder or as a secondary condition associated with underlying diseases such as Epstein-Barr virus (EBV) infection, lymphoma, systemic lupus erythematosus (SLE), immunodeficiency disorders, rheumatoid arthritis, or ulcerative colitis. The most common clinical manifestations of acute AIHA include dark-colored urine, jaundice, pallor, myalgia, headache, nausea, vomiting, generalized weakness, dyspnea, and tachycardia. Approximately half of all cases are idiopathic (primary) and cannot be attributed to an identifiable underlying cause. In other cases, AIHA arises secondary to comorbid conditions. After excluding other potential etiologies, the diagnosis is established through hematological and biochemical investigations. Laboratory findings typically include reduced hemoglobin levels, reticulocytosis, elevated mean corpuscular hemoglobin concentration (MCHC), spherocytosis on peripheral blood smear, occasional neutropenia and thrombocytopenia, increased osmotic fragility, hyperbilirubinemia, elevated serum lactate dehydrogenase (LDH), decreased haptoglobin and albumin levels, hemoglobinuria, and increased urinary urobilinogen. The direct antiglobulin test (DAT or Coombs test) is the definitive diagnostic tool for confirming AIHA. Management depends on disease severity. Mild cases may resolve spontaneously and require no therapeutic intervention. In more severe cases, treatment strategies include management of underlying conditions, administration of corticosteroids (e.g., prednisone), immunosuppressive agents (e.g., rituximab or azathioprine), splenectomy to reduce RBC destruction, and blood transfusion when necessary.

کلیدواژه ها:

Autoimmune Hemolytic Anemia ، AIHA ، red blood cells ، autoantibodies ، hemolysis ، corticosteroids