COMPLICATIONS OF KIDNEY TRANSPLANT
Overall, most patients find their quality of life improved greatly following a kidney transplant. About 90 percent of transplanted kidneys survive for at least one year, and about 80 percent survive for three years. The complications may include: I. Surgery related problems such as:
- Bleeding (hemorrhage): Bleeding may occur within 12 hours after operation. It is confirmed by ultrasound which shows a large hematoma (localized collection of blood) around the kidney. The condition can be corrected by operation. Patient may also require blood transfusion.
- Infection: As with any other surgery there may be a risk of infection of the wound, chest, urinary system and the Intravenous sites.
- Vascular thrombosis (formation of thrombus or clot in the blood vessels). Arterial (artery) thrombosis may occur immediately after transplantation or in the first few days. It is confirmed by ultrasound. Venous (vein) thrombosis may occur early or in first few weeks after transplantation. Vascular thrombosis causes an abrupt or sudden loss of function of transplanted kidney.
- Urinary leakage: This may occur as a result of ischemic necrosis(death of tissue due to inadequate blood supply) of the lower part of the ureter(tube like structure connecting the kidney with the bladder). This can cause the ureter to disconnect from the bladder so that when the bladder becomes full the urine leaks in the surrounding area. A localized collection of urine can be seen in the ultrasound. The only treatment is to reconnect the ureter with the bladder by surgery.
II. Acute tubular necrosis (ATN) or delayed kidney function: The transplanted kidney may not start functioning immediately. It may take a few days to weeks to start functioning.Acute tubular necrosis is suspected when the creatinine levels do not decrease even after transplant. Till the new kidney starts functioning the patient is kept on dialysis. III. Increased risk of infection: Because of use of immunosuppressive agents kidney transplant patients are at an increased risk of having infection. These medications decrease the immunity of body so that it is not able to fight off infections effectively. It is important to remember that due to immunosuppression the symptoms of infection may be masked or distorted and fever without obvious cause is common. Infections may occur at different time periods of kidney transplantation.
- First month after kidney transplant: Usual infections in this period include wound infection, urinary tract infection or pneumonia. The treatment basically involves giving antibiotics depending upon the causative organism.
- 1- 6 months after kidney transplant: During this period the patient is at more risk for opportunistic infections (these are unusual infections that do not affect people with normal-functioning immune systems, and are caused by bacteria, parasites, viruses or fungi, which are commonly found in the environment). The most important cause of infection during this period is Cytomegalovirus (CMV). The symptoms may include fatigue, high temperature, aching joints, headaches, visual disturbances, and pneumonia. This CMV virus not only causes CMV infection but also leads to further immunosuppression (decreased immunity) which can further result in the development of more severe infections such as Aspergillus fumigatus (a fungi causing respiratory infection), Listeria monocytogenes (a bacteria responsible for food poisoning) and Pneumocystis carinii (a microorganism causing pneumonia).
- 6 months after kidney transplant: Patients with a well functioning kidney and on low dose maintenance immunosuppressive therapy usually develop infections which commonly occur in the general population such as uncomplicated urinary tract infection, Pneumococcal pneumonia etc. However, patients with poor functioning kidney and receiving large doses of immunosuppression medications (because of kidney rejection) are at an increased risk for serious opportunistic infections such as Nocardia asteroides (a bacteria producing lung infections), Listeria monocytogenes and Pneumocystis carinii.
IV. Kidney rejection:The recipients immune system identifies the donor kidney as foreign and tries to damage it resulting in the non-acceptance (or rejection) of the donor kidney. V. Post-transplant Diabetes Mellitus (High Blood Sugar): Diabetes may sometimes develop (in 10% of cases) after kidney transplantation due to many causes such as use of immunosuppression therapy, weight gain, age of the recipient and family history of Type 2 diabetes. Immunosuppressive medications such as Cyclosporin, Tacrolimus are diabetogenic (causing diabetes) and may develop insulin resistance in the recipient. Prednisone is also believed to play an important role in post-transplant diabetes. The patient is given oral hypoglycemic agents to control glucose levels. 50% of cases may require insulin. VI. High blood pressure: Hypertension after kidney transplantation may be caused by:
- Immunosuppressive therapy: Cyclosporin and Tacrolimus can cause high blood pressure in short and long term. Corticosteroids also increase blood pressure but the effect is dose related. Hence, a low dose long term maintenance therapy usually does not cause hypertension. It is important to remember that hypertension may become better as immunosuppressive drugs are reduced towards the end of first year of transplantation.
- Presence of diseased native kidneys: The risk of high blood pressure is less in recipients where the nativekidneys (recipients own kidney) were removed before transplant operation. Severe hypertension due to diseased native kidney can be controlled by surgical removal of the native kidneys.
- Dysfunction of the transplanted kidney: Impaired function of the transplanted kidney due to chronic rejection can cause severe hypertension.
- Renal artery stenosis (narrowing): 5-10% of post-transplant hypertension are caused by renal artery stenosis. Diagnosis is confirmed by angiography and treatment involves angioplasty (dilatation of the narrowed artery) or bypass surgery in some cases.
VII. Hyperlipidemia: Kidney transplant patients frequently develop increased total cholesterol, LDL (low density lipoprotein) and triglyceride levels. This may be caused due to improper diet, medications (such as Corticosteroids, Cyclosporin and Tacrolimus), anti-hypertensive therapy and obesity. Hyperlipidemia is more severe in the early part after transplantation, when the dose of immunosuppressants is high. Aggressive treatment of hyperlipidemia is essential as 55% of transplant patients usually die because of heart related diseases. VIII. Cardiovascular disease: Coronary artery disease, peripheral vascular disease and cerebrovascular disease are all more frequent in transplant patients as compared to the general population. The main risk factors responsible include age of the recipient, tobacco use, diabetes, high blood pressure, increased cholesterol (hyperlipidemia) and family history. Other factors that further contribute to cardiovascular disease include increasing doses of corticosteroids, earlier episodes of kidney rejection, pre-existing left ventricular hypertrophy. Attempts should be made to rectify these risk factors. IX. Skin problems: The fungal infections that commonly occur after kidney transplant include candidiasis, pityriasis versicolor and dermatophyte infection of skin and nails. Topical antifungal agents are used to treat the infections. Warts are extremely common (>50% patients) in transplant patients. They may even contribute to the development of squamous cell carcinoma (a type of skin cancer). Reactivation of herpes simplex and herpes zoster is also common in transplant patients. X. Gastrointestinal problems may include:
- Peptic ulcers: Because of reduced corticosteroid use the risk of peptic ulcer has become less common after transplant. However, recipients previously suffering from peptic ulcer should be put on a preventive therapy with H2-antagonists for first 6 months after transplantation.
- Chronic Hepatitis especially caused by hepatitis B virus is progressive and fatal. However infection with hepatitis C is also a concern as recipient are on immunosuppressive therapy.
XI. Erythrocytosis (an abnormal increase in red blood cells): This condition is seen in about 10-15% of transplant patients about 1 year after kidney transplantation.It usually results from dysregulated erythropoietin (a hormone produced by the kidneys that regulates the production of red blood cells) produced by the native kidneys especially in patient with polycystic native kidneys. ACE inhibitors have been found to be very effective in treating erythrocytosis and is now considered a standard therapy.
XII. Malignancy: An increased risk of cancer is the most distressing adverse effect of immunosuppressive therapy. The incidence is approximately 100 times greater than in the general population. The commonly occurring cancers include cancer of skin and lips, lymphoma (such as non-Hodgkin’s lymphoma) and in females, cancer of cervix. Because skin cancers are relatively more common patient are advised to use protective sunscreens and undergo careful skin examinations. Women are advised to get a pelvic examination and Pap smear done annually.
XIII. Gout: Kidney transplant patients have approximately a 10% risk of developing gout (deposition of needle-like crystals of uric acid in the joint spaces especially of the great toe causing pain, redness and swelling).About 55% of patients on Cyclosporin develop asymptomatic (i.e. no symptoms) hyperuricemia (increased uric acid levels in blood). This may be caused by improper kidney function (leading to poor excretion of uric acid), cyclosporin use (which promotes uric acid retention) and simultaneous use of diuretics. Colchicine is given during the acute attacks of gout. NSAIDs can lead to acute kidney failure, hence they are avoided. Allopurinol is to be used to prevent future attacks. Because Allopurinol can prolong the metabolism of Azathioprine (one of the immunosuppressants) it is essential that the dose of Azathioprine is reduced in patients taking it.