Kidney transplantation or renal transplantation is the organ transplant of a kidney into a patient with end-stage kidney disease. Kidney transplantation is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantation depending on the source of the donor organ.
Living-donor kidney transplants are further characterized as genetically related (living-related) or non-related (living-unrelated) transplants, depending on whether a biological relationship exists between the donor and recipient.
Exchanges and chains are a novel approach to expand the living donor pool. In February 2012, this novel approach to expand the living donor pool resulted in the largest chain in the world, involving 60 participants organized by the National Kidney Registry. In 2014 the record for the largest chain was broken again by a swap involving 70 participants.
The indication for kidney transplantation is end-stage renal disease (ESRD), regardless of the primary cause. This is defined as a glomerular filtration rate below 15 ml/min/1.73 m2. Common diseases leading to ESRD include renovascular disease, infection, diabetes mellitus, and autoimmune conditions such as chronic glomerulonephritis and lupus; genetic causes include polycystic kidney disease, and a number of inborn errors of metabolism. The commonest 'cause' is idiopathic (ie unknown).
Diabetes is the most common known cause of kidney transplantation, accounting for approximately 25% of those in the United States. The majority of renal transplant recipients are on dialysis (peritoneal dialysis or hemodialysis) at the time of transplantation. However, individuals with chronic kidney disease who have a living donor available may undergo pre-emptive transplantation before dialysis is needed. If a patient is put on the waiting list for a deceased donor transplant early enough, this may also occur pre-dialysis. Contraindications include both cardiac and pulmonary insufficiency, as well as hepatic disease and some cancers. Concurrent tobacco use and morbid obesity are also among the indicators putting a patient at a higher risk for surgical complications.
Kidney transplant requirements vary from program to program and country to country. Many programs place limits on age (e.g. the person must be under a certain age to enter the waiting list) and require that one must be in good health (aside from the kidney disease). Significant cardiovascular disease, incurable terminal infectious diseases and cancer are often transplant exclusion criteria. In addition, candidates are typically screened to determine if they will be compliant with their medications, which is essential for survival of the transplant. People with mental illness and/or significant on-going substance abuse issues may be excluded.
HIV was at one point considered to be a complete contraindication to transplantation. There was fear that immunosuppressing someone with a depleted immune system would result in the progression of the disease. However, some research seem to suggest that immunosuppressive drugs and antiretrovirals may work synergistically to help both HIV viral loads/CD4 cell counts and prevent active rejection.
Journal of Clinical chemistry and Laboratory Medicne