Nov 07 2010
Pretransplant Screening: Recipient and Donor
Pretransplant latent infections or infectious exposures can lead to a reappraisal of transplant candidacy or, subsequently, alterations in standard post-transplant management. Preexisting infectious conditions in the donor or recipient may appear in the immediate postoperative period during induction immunosuppression, in the initial weeks post-transplant during treatment of rejection episodes, or in the later months post-transplant, depending on the overall net state of immunosuppressives. Incomplete immunizations in the recipient should be corrected prior to transplantation.
General Screening
From the perspective of infectious disease and their consequences, evaluation should include eliciting a history of antibiotic allergies, valvular repairs or replacements, a dental assessment, a preoperative urine culture, and a chest radiograph to exclude active pneumonic processes and identify evidence of prior granulomatous or infectious disorders. A purified protein derivative (tuberculin) skin test with appropriate controls should be applied; however, suboptimal reactivity of skin testing in renal failure patients may lead to false-negative results. Isoniazid (INH) prophylaxis may be indicated with an abnormal chest x-ray result representing old tuberculosis despite a negative skin test. Precise recommendations for dosage an duration of therapy should adhere to the Centers for Disease Control guidelines on INH prophylaxis. Additional preoperative assessment should include a history of sexually transmitted diseases such as syphilis, HSV infection, viral hepatitis, and HIV infection.
Immunizations
Pretransplant candidates lacking standard pediatric or adult immunizations, splenectomized patients, and renal failure patients may benefit from pretransplant vaccinations with influenza, pneumococcal, and hepatitis B, diphtheria-pertussis-tetanus, inactivated polio, and measles-mumps-rubella (MMR) vaccines. Suboptimal efficacy of vaccinations in patients with renal failure must be recognized due to the effects of uremia on the immune system, however. Live vaccines should be avoided in immunocompromised patients (e.g., a renal transplant candidate with an underlying condition requiring immunosuppresive medications) and in patients who have undergone solid organ transplantation. Of particular pretransplant concern are pediatric renal failure patients with incomplete primary immunizations of live viral vaccines such as MMR. The general recommendation of avoiding live, attenuated viral vaccines in allograft recipients precludes the completion of the immunization series, thereby exposing the child to the risk of measles. Consequently, pretransplant immunization offers the opportunity to prevent the post-transplantation risks of live, attenuated viral vaccines. In this respect, measles, MMR and varicella vaccines should, ideally, be administered several months before transplantation. Pretransplant vaccination with a live, attenuated CMV vaccine has been reported to result in a reduction in the severity of CMV disease and improved graft survival in seronegative recipients of a CMV-positive allograft, the group considered to be at highest risk for CMV disease. Administration of this vaccine, however, has not been implemented.