The suppression of the body’s immune defence system allows viral diseases that you may have caught a long time ago to reactivate and cause illness again. These viruses can make you feel quite unwell and in the early stages the symptoms may be very similar to kidney rejection. The virus that is most frequently seen is cytomegalovirus (CMV), usually a ‘flu-like illness that most of us shrug off without ever knowing we have had it. This leaflet will tell you more about CMV. Other viruses that may re-emerge are the Epstein-Barr virus that causes glandular fever, herpes simplex virus (cold sores & genital herpes) and herpes zoster virus (chicken pox & shingles). These viruses are all treatable, though they may cause some anguish.
Sometimes these viruses are present in the donor kidney. However, it is usually considered that a transplanted organ that is known to have CMV, for example, is better than not having a transplant because it is possible to anticipate and treat any symptoms early.
CMV is a member of the herpes virus family which is responsible for conditions such as cold sores and chicken pox. Like other viruses it infects cells by attaching itself to a cell, invading it and taking over the cell, causing the cell to produce virus rather than whatever it is supposed to do.
It is the result of the infected cells bursting open to release new virus to infect other cells and the body’s own reaction to the infection that makes us feel unwell. The number of infected cells and the level of the body’s reaction dictates how we feel.
It can affect almost any organ of the body, the kidney, liver, heart, lungs, eye, stomach, colon and brain, causing inflammation.
A person who is infected and who has a normal immune response will present with ‘flu-like symptoms, a raised temperature, and a cough. In immunosuppressed patients, i.e. transplanted patients, CMV symptoms can vary enormously from mild to very severe because it can affect almost any organ. When it affects the kidney (CMV nephritis) in a kidney transplant patient it may cause elevated creatinine levels. This can be confused with kidney transplant rejection.
CMV is spread by contact with the secretions of an infected person. Once a person has been infected with the virus they never lose it. In healthy humans, CMV does not cause a problem because its activity is combated by the body’s natural defence systems and it remains dormant. However, because the body fights viruses in the same way it tries to reject a new transplant, the immunosuppressant drugs that transplant patients take to stop rejection impair the body’s ability to fight the virus and symptoms can occur.
It can also be passed from a donor kidney to the recipient, if the donor had CMV. CMV positive kidneys are routinely offered to CMV negative patients. This is because the infection can be controlled and the wait for a matched CMV negative organ could be very long. Of course, the transplant patient may have already been infected with CMV themselves and not be aware of it, as it is difficult to diagnose unless a blood sample is taken and tested specifically for the virus.
Both the donor and the recipient of a transplant organ are tested for CMV antibodies before the operation in order to anticipate the need for treatment of CMV after the transplant. The recipient is also tested after surgery.
CMV can be difficult to diagnose as the symptoms are so varied. There are two main tests for CMV, checking for the presence of the virus in the bloodstream or taking a biopsy of the infected organ. However, these tests may not be conclusive and repeat tests may be needed.
A 14 - 21 day course of a powerful antiviral drug called ganciclovir is the treatment of choice for active CMV. As this is given intravenously, directly into the patient’s vein, a hospital admission is required. However, if it is appropriate, a patient can be taught to administer their own ganciclovir allowing them to finish the treatment at home. Unfortunately, CMV can recur.