Anemia, Aplastic

Risk

•

Incidence in USA: 2000 new cases/y.
- •
  
  Per million up to age 9.
•

Southeast Asia and South Africa have 10-20 times higher incidence.
•

Within USA, related to agricultural areas or petrochemical industry and chemical exposures.

•

Sepsis
•

Coexisting congenital anomalies, especially renal and cardiac
•

Concomitant GI and intracranial hemorrhage
•

Difficulty cross-matching blood products after previous multiple transfusions

•

Self-perpetuating disorder resulting in pancytopenia due to a congenital or acquired loss of hemopoietic pluripotent stem cells.
•

Fanconi anemia is congenital familial marrow hypoplasia associated with intellectual disability and kidney, spleen, and skeletal hypoplasia.
•

Estren-Dameshek anemia is inherited marrow hypoplasia without physical abnormalities.
•

Pathophysiology: Reduction or dysfunction of pluripotent stem cells or their microenvironment from toxic or immunologic causes.
•

Prognosis for long-term survival has increased to 40% to 75% in those treated with antilymphocyte serum and 60% to 80% in those treated with BMT.
•

Two forms of drug-induced aplastic anemia are possible:
- •
  
  Hypersensitivity: Not related to dose or duration.
- •
  
  “Reversible” reaction: Often resolves with discontinuation; severity proportional to dosage.

•

Of cases, 50% to 75% are idiopathic.
•

Fanconi anemia demonstrates autosomal recessive inheritance with heterozygote frequency of 1 in 300,000-600,000 in USA.
•

Drug-induced: Chloramphenicol, NSAIDs, antiepileptics, and gold and sulfa group-containing compounds.
•

Environmental toxins include aromatic hydrocarbons (benzene, naphthalene, toluene, and glue), pesticides (DDT and lindane), and radiation.
•

Infectious causes include hepatitis C, CMV, EBV, HIV, TB, and toxoplasmosis.
•

Sequelae of other processes such as pancreatitis, pregnancy, lupus erythematosus, paroxysmal nocturnal hemoglobinemia, thymoma, and thymic CA.

Only gold members can continue reading. Log In or Register to continue