- Donor characteristics: receiving a kidney allograft from a donor with any of the following characteristics: a) cold ischemic time exceeding 36 hours; b) age < 5 years old; c) for donors after brain death (DBD), age >70 years old; d) for donors after cardiac death (DCD) age >70 years old; e) ABO blood type incompatible against the recipient; f) 0 0 0 HLA-A -B -DR mismatch against the recipient by National Health Service Blood and Transplant (NHSBT criteria; g) T- and/or B-cell positive crossmatch by complement dependent cytotoxicity or flow cytometry against the recipient. Note :- (In some situations it may be that a pre-existing T- and/or B-cell positive crossmatch by complement dependent cytotoxicity or flow cytometry against the recipient will only be fully revealed immediately after the transplant; in such situations they will be recorded as having met exclusion criteria and withdraw from further involvement in the study; h) serology positive for hepatitis B (except hepatitis B surface antibody and prior vaccination), hepatitis C or human immunodeficiency virus (HIV)