Review Question - QID 211011

This patient with a normocytic, Coombs positive anemia with spontaneous aggregation of red blood cells most likely has warm autoimmune hemolytic anemia, which should be treated with glucocorticoid administration.

Autoimmune hemolytic anemia (AIHA) is a cause of extrinsic hemolytic anemia that is caused by antibody production against red blood cell antigens. These antibodies lead to destruction of red blood cells by the spleen, which results in the characteristic findings of fatigue, low hemoglobin, and splenomegaly. AIHA can be divided into warm and cold subtypes where warm AIHA is mediated by IgG antibodies and cold AIHA is mediated by IgM antibodies. Characteristic lab findings of warm AIHA are positive Coombs tests, which demonstrate that affected red blood cells are coated by antibodies, spherocytes on peripheral blood smear, and spontaneous agglutination of red blood cells at room temperature.

Incorrect Answers:
Answer 1: Avoidance of fava beans would be indicated for glucose-6-phosphate dehydrogenase deficiency; however, this disease would present with jaundice, dark urine, and bite cells on peripheral blood smear.

Answer 2: Chelation therapy would be indicated for lead poisoning anemia; however, this disease would present as a microcytic anemia with neuropathies such as wrist drop.

Answer 3: Chronic blood transfusions would be indicated for macroangiopathic anemias; however, this cause of anemia would present with schistocytes on peripheral blood smear and negative Coombs tests.

Answer 5: Vitamin supplementation would be indicated for vitamin B12 and folate deficiencies; however, these diseases would present with a macrocytic, megaloblastic anemia.

Bullet Summary:
Warm autoimmune hemolytic anemia can demonstrate spontaneous aggregation of red blood cells at room temperature and a positive Coombs test.