Osmosis video - Warm autoimmune hemolytic anemia and cold agglutinin (NORD)

Warm autoimmune hemolytic anemia, or WAHA, and cold agglutinin disease, or CAD, are autoimmune hemolytic anemias characterized by the production of autoantibodies that cause early destruction of healthy red blood cells.

In WAHA, hemolysis occurs at the body temperature, whereas CAD is triggered by cold temperatures. Symptoms vary based on severity and include dizziness, palpitations, dark urine, pale skin, jaundice, and fatigue. Individuals with WAHA may also develop an enlarged spleen or deep vein thrombosis whereas individuals with CAD may experience the Raynaud phenomenon (a condition in which small blood vessels in the fingers and toes constrict).

Diagnosis involves a thorough clinical examination, including blood and specialized testing to identify the presence of anemia resulting from hemolysis. The Coombs test confirms the presence of autoantibodies associated with WAHA or CAD. Treatment is supportive and varies based on symptoms, and may include prednisone and other immunosuppressive or chemotherapy agents, and blood transfusions in severe cases.