aplastic anemia, a deficiency of all of the formed elements of blood (specifically erythrocytes, leukocytes, and platelets), representing a failure of the cell-generating capacity of bone marrow. Aplastic anemia is often of unknown origin and may involve destruction of bone marrow by exposure to toxic chemicals, ionizing radiation, or some antibiotics. Also spelled aplastic anaemia. Compare alymphocytosis, hemolytic anemia, hypoplastic anemia. See also aleukia, leukopenia.
