24th June 2023

Pre-transplant factors

Assessment for transplant

Transplant should be considered for all patients with advanced CKD and those on dialysis, as it is recognised to provide a better quality of life and life expectancy. The assessment process in the UK is outlined by NHS Blood and Transplant (NHSBT). It aims to ensure that a patient will be able to tolerate the procedure itself, as well as the immunosuppression thereafter. Assessment includes:

• Blood group, HLA typing, antibody screening
• Viral screening – cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV), hepatitis B and C, human immunodeficiency virus (HIV). Vaccinations against hepatitis B and VZV (if needed) should be offered pre-transplant.
• Psychological evaluation – to evaluate the likelihood that a patient will be compliant with their post-transplant medication and follow-up care.
• Cardiovascular risk – to identify high-risk surgical patients that may not qualify for listing and patients that may be eligible for an angiographic/surgical coronary intervention and listing thereafter.
• Malignancy screen – patients should have been in remission for at least two years before being considered for transplant.
• Risk of renal disease recurrence – disease recurrence of some conditions can reduce the chances of graft survival.
• Other serious comorbidities

Types of organ donation

• Living donation – improved long-term function compared to cadaveric donation:
  • Related donor, e.g. sibling, parent, child
  • Unrelated donor, e.g. friend, spouse or through a paired exchange scheme
• Cadaveric donation:
  • DBD – donation after brain death
  • DCD – donation after circulatory death

Organ matching

• Blood group – organs are generally allocated to a patient of a compatible blood group in a similar manner to blood transfusions. If a patient has antibodies that recognise donor ABO antigens, this can lead to hyperacute rejection. ABO-incompatible transplants are feasible with desensitisation therapy – usually immunosuppression and plasma exchange.
• HLA mismatch – coded on chromosome 6, one of each inherited from each parent, the most important antigens in transplant are HLA-A, HLA-B and HLA-DR. Degree of mismatch for each antigen is used – for example, identical twins would have a 0-0-0 mismatch, whereas a donor: recipient pair who shared none would be a 2-2-2 mismatch.
• Anti-HLA antibodies – a recipient can develop these following blood transfusion, pregnancy, or previous organ transplant. These can lead to the development of organ rejection post-transplant, especially if they are donor-specific antibodies.