Epidemiology And Demographics

AA can occur at any age, but the peak incidence is in early adulthood. It is not clear whether the often described second peak in the sixth to seventh decades of life may be a result of the diagnostic overlap of AA and MDS that affects older individuals and can mimic AA, especially if the marrow is hypocellular.1-3 The incidence of AA in the United States and Europe is comparable at around 4/106 individuals.4-6 In East Asia, the incidence of AA appears to be significantly higher, an early observation made by Dr Dameshek. This endemic occurrence of AA in the Far East led to many theories as to how this disease relates to PNH, also more prevalent in this part of the world, and to the search for geographically related epidemiologic factors, such as endemic pathogens. The extensive epi-demiologic studies performed in Thailand did not yield specific clues, but disproved speculations as to the role of hepatitis viruses in the etiology of classic idiopathic AA.7 AA has been described in Africa and India, where it may be also more prevalent than in the West, but exact epidemiologic studies are not available. In the United States, AA does not appear to show an ethnic predilection.

0 0

Post a comment