Renal Transplant: HLA Typing and Graft Failure

Key points

• Renal transplant — HLA typing: the human leucocyte antigen (HLA) system is the human major histocompatibility complex (MHC), encoded on chromosome 6 .
• Do not memorise 'DR > B > A' as a universal modern rule. HLA-A, -B and -DR matching has historical importance, but modern transplant assessment also considers HLA antibodies, donor-specific antibodies and crossmatch results.
• Fixed graft-survival figures such as 90% at 1 year and 60% at 10 years for deceased-donor grafts are outdated and should not be used as universal figures. Outcomes vary by era, donor/recipient factors and transplant programme.
• Living-donor transplantation generally has better graft and patient outcomes than deceased-donor transplantation , but fixed survival percentages should not be memorised.
• HLA class I includes HLA-A, -B and -C; class II includes HLA-DP, -DQ and -DR. A positive crossmatch/donor-specific antibody may indicate substantial antibody-mediated rejection risk and requires specialist transplant assessment.
• MRCP discriminator: HLA typing + crossmatch assesses alloimmune compatibility; a positive crossmatch indicates high immunological risk and generally prevents transplantation unless a specialist strategy is used.
• Exam trap: do not use old fixed graft-survival percentages.