Hypoplastic anemia is a broad category of anemias characterized by decreased production of red blood cells. Congenital hypoplastic anemia, also called aplastic anemia, is a condition that results from injury to the blood stem cells. As a result, there is a reduction in all blood cell types with this type of anemia (pancytopenia). The cause of aplastic anemia is unknown. The current thinking is that it may be associated with an autoimmune process in which the body reacting against its own cells.1 Drugs that have been associated with stem cell injury include estrogen, phenylbutazone, meclofenamic acid, phenobarbital, phenytoin, colchicine, chloramphenicol, thiacetarsamide, and albendazole (a broad-spectrum anthelmintic).
Signs arise as the consequence of bone marrow failure and the loss of blood cell production. Low red blood cell count (anemia) leads to fatigue and weakness. Low white cell count (leukopenia) causes an increased risk of infection. Low platelet count (thrombocytopenia) results in bleeding, especially of mucus membranes and skin.1 Aplastic anemia is treated with androgens, high-dose methylprednisolone, cyclosporine A (CyA), antithymocyte globulin (ATG), antilymphocyte globulin (ALG), hematopoietic growth factors such as G-CSF, and bone marrow transplantation.2
- Idiopathic aplastic anemia. MedlinePlus
- Masanao Teramura, M.D., Hideaki Mizoguchi, M.D. Special Education. The 'Oncologist, Vol. 1, No. 3, 187-189, June 1996
- Mary Anna Thrall. Veterinary Hematology and Clinical Chemistry