HLA-B and acute graft versus host disease: They suggested that these remarkable HLA alleles may be potent transplantation immune regulators.8 In a Brazilian population, increased incidence of acute GVHD grade III or higher was positively correlated with HLA-B*35, B*49, B*55 and in patients with extensive chronic GVHD, HLA-A*9, A*24 and A*26 were higher than other patients, while HLA-A*2 was lower.9