Aplastic anemia

Aplastic anemia (AA) is a disease in which bone marrow hematopoietic stem cells and bone marrow microenvironment are severely damaged by the action of physical, chemical, biological or unknown factors, causing bone marrow hematopoietic function to decrease or fail. A group of syndromes characterized by pancytopenia. According to a survey by 21 provinces (municipalities) in China, the annual incidence rate is 0.74 per 100,000 population, which is significantly lower than the incidence of leukemia. The incidence of chronic aplastic anemia is 0.60 per 100,000 population, and acute aplastic anemia is 0.14 per 100,000 population. ; All age groups can develop disease, but it is more common in young adults; the incidence is slightly higher in men than in women.