ABO and graft versus host disease: The demographic and clinical characteristics of PGF and GGF patients, including age, gender, underlying disease, disease status pre-HSCT, median time from diagnosis to HSCT, source of stem cells, transplanted total nucleated cell dose, CD34+ cell dose, donor HLA match, sex/ABO mismatch, pre-HSCT cycles of chemotherapy, preparative regimens, GvHD prophylaxis and history of GvHD and CMV status, were comparable (Table 1).