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Transplant Q&AQuestion: We realize that after our daughter’s liver transplant her immune system will need to be suppressed to prevent rejection of her new liver. But we worry about how vulnerable this will leave her to the threat infectious diseases. What kinds of special precautions will we need to take to protect her?Answer: The body has multiple methods of defending against infection: antibodies, lymphocytes, neutrophils, macrophages, "natural killer cells" and more. Some defend primarily against viruses, others work better against bacteria, parasites or fungi. To the body, a transplanted organ is probably more like a virus than a bacteria — it is a normal cell that has weird things on its surface. For this reason our immunosuppression strategies (cyclosporine and tacrolimus) tend to mostly affect the type of immunity that keeps us from getting viruses. That is why transplanted patients are very susceptible to viruses. To a lesser extent there is also some increased susceptibility to bacterial infections. Precautions against infection must be individualized for each patient. Different patients are on different amounts of immunosuppression. Different transplant centers have different immunosuppression systems. Different regions of the country can have different infection risks. Each patient must ask their own transplant team for their advice. The following comments apply to transplant patients in general. Highest RiskThe more immunosuppression a patient has received the more precautions are necessary. Since the chance of rejection is highest during the first 3 months after a transplant, higher doses of immunosuppression are used, and therefore the risk of infection is highest during this time period. When patients have an episode of graft rejection it is necessary to increase the immunosuppression and this will often markedly increase the risk of infection. Antibody drugs such as ATGAM, OKT3 and Zenapax are given either at the time of a transplant in order to prevent rejection or to treat established rejection. These drugs must be given intravenously. They are very powerful immunosuppressants and markedly increase the risk of infections for months after they are given. Viral InfectionsAs noted, the most common infections after a transplant are viral infections. Patients who are on immunosuppression are always better off staying away from anyone that is ill, especially if that illness is a viral disease. On the other hand, there is usually no point to trying to accomplish this within a household because by the time the recipient’s sibling is ill, the recipient has already been exposed. Viral infections can be new infections such as cold, chicken pox, flu, and intestinal viruses, or they can be reactivation of viruses the patient has already had that were dormant until immunosuppression allowed them to re-emerge. This is especially true for the first few months after a transplant. A hard issue is daycare. Clearly all young children in daycare have more infections than children who stay at home all the time. Again, transplant centers are going to vary, and advice is going to vary depending on the level of immunosuppression the child has received. Daycare is usually permissible, but some centers will advise that the patient not go to daycare during the particularly vulnerable period immediately after the transplant. Bacterial InfectionsBacterial infections such as pneumonia and urinary infections are also fairly common after a transplant and the majority can be easily treated with antibiotics. In general, pets are allowed, but again one should check with one’s own physicians. It is usually recommended that transplant recipients should not come in contact with the feces of cats because of the theoretical risk of encountering a dangerous parasite called "Toxoplasma" that can be carried by cats. This means that a cat in the house is okay, but someone else should change the kitty litter. Dogs are usually okay, but allowing the dog to "kiss" should be discouraged. Birds are also known to carry parasites and it is usually recommend that recipients not clean bird cages or hold the bird. When it has been many years since a transplant special precautions are often not necessary for most transplant recipients, but this is not true in all cases. Chicken poxChicken pox is a special case. All transplant patients are checked for the antibody to chicken pox (which is caused by the virus varicella zoster) prior to transplantation. If the patient is immune to chicken pox, the likelihood of having a problem later on is much less since this virus generally causes chicken pox only once. However, reactivation is possible, but very rare, when severely immunosuppressed. Also, the virus can reactivate later in life as shingles, a viral infection in the nerves. This infection can lead to chronic pain even after the viral infection has ceased. A new chicken pox infection is a very serious matter for a patient on immunosuppression because the virus can cause more than the usual rash in these patients. It can cause a viral pneumonia or hepatitis, and these problems can be life threatening. A vaccine is available for chicken pox and many transplant centers are starting to vaccinate children who will some day need a transplant in order to generate immunity and prevent future infections. The vaccine is a live virus though, so it cannot be given once the child is on immunosuppression. If a transplant recipient who is not immune to chicken pox is exposed to someone infectious for chicken pox, many centers recommend an injection of varicella zoster immune globulin. This immune globulin is an antibody against the virus and will prevent infection, but it must be given within 72 hours of exposure to be effective. If a child on immunosuppression comes down with chicken pox it is usually recommended that they receive an antiviral medication called "acyclovir" intravenously until the virus clears as evidenced by the crusting over of the sores. Dr. Punch is a transplant surgeon at the University of Michigan and a member of the CLASS Scientific Advisory Committee.
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Children’s Liver Association for Support Services
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