CD34 and Alzheimer disease: After autologous HSCT, 29 of 347 patients developed at least one secondary AD, and after allogeneic HSCT, 3 of 16 patients developed secondary AD, including autoimmune hemolytic anemia, acquired hemophilia, autoimmune thrombocytopenia, antiphospholipid syndrome, thyroiditis, Graves’ disease, myasthenia gravis, RA, et al. The authors further performed multivariate analysis and found that the risk factors for secondary AD were: (1) SLE as primary AD and (2) ATG use plus CD34+ graft selection.