Kidney Transplant
last authored: March 2009, David LaPierre
last reviewed:
Introduction
any type of renal failure
highly sensitized
HLA matched
Reasons Against Kidney Transplants
The age cutoff is..
co-morbidities which are relative contra-indications include cardiovascular disease.
Kidneys come from live-related donors, from brain-dead donors, or from those recently deceased.
Procedure
Panel Reactive Antibody is a blood test used to screen for anti-HLA antibodies in preparation for kidney transplant.
The score, measured from 0-99%, represents the chance of acute rejection.
It is measured using a panel of T and B lymphocytes.
Donated kidneys are usually implanted in the right or left iliac fossa. The renal artery is sutured to the external or internal iliac artery, and the renal vein to the external iliac vein. The ureter is implanted in the bladder wall.
Preventing and Treating Kidney Rejection
Reactivation of latent infections/colonization
- Viruses that may remain latent include herpes zoster, cmv, hpv, ebv and others.
- Bacteria include tuberculosis.
- Fungi?
- Parasites- Toxoplasma gondii infection may be a serious problem.
Cellular-mediated rejection, involving CD4 and CD8 lymphocytes, is resolvable in 95% of cases.
The immune system attacks transplants. To avoid immediate rejection, host and donor kidneys need to have compatible blood types.
Human leukocyte antigens (HLAs) are highly polymorphic. Mismatch, particularly in HLA-A, HLA-B, or HLA-DR, increases risk of rejection.
Immunosuppression inhibits immune responses and reduces chance rejection, but does increase risk of infection or tumour. Important medications include corticosteroids, cyclosporin, azathioprine, mycophenolate, tacrolimus, rapamycin, or other medications.
Other Complications of Transplantation
Early Complications
Early complications can be numerous and hard to distinguish etiologically. Poor renal function can indicate acute rejection, cyclosporin toxicity, or acute tubular necrosis due to ischemia. Biopsy can be helpful in distinguishing cause.
Cellular rejection is cell-mediated and is treated with medications (see below) or antibody therapy. Vascular rejection is more aggressive and is often antibody mediated.
Cytomegalovirus (CMV) infection can cause fever, retinopathy, hepatitis, enteritis, pneumonitis, or thrombopenia.
Post-transplant lymphoproliferative disease is a lymphoma-like condition caused by Epstein-Barr virus. It can go into remission if immunosuppressants are removed.
Chronic Complications
Loss of renal function, or chronic rejection, is due to both immune- and non-immune mechanisms. Cyclosporin nephrotoxicity, hypertension, and recurrent disease (especially focal sclerosing glomerulosclerosis, mebranoproliferative nephropathy, and IgA nephropathy) can all contribute.
Hypertension can result from steroid use, cyclosporin-induced vascocontriction, renin secretion, or renal artery stenosis.
Hyperlipidemia is common with steroid or cyclosporin therapy.
Osteoporosis can follow steroid use.
Elevated parathyroid hormone (PTH) levels can cause phosphaturia, requiring phosphate supplements, and sometimes hypercalcemia.
Skin cancer is a late complication (why?)
Resources and References
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