tailieunhanh - Chapter 126. Infections in Transplant Recipients

The evaluation of infections in transplant recipients involves consideration of both the donor and the recipient of the transplanted organ. Infections following transplantation are complicated by the use of drugs that are necessary to enhance the likelihood of survival of the transplanted organ but that also cause the host to be immunocompromised. Thus, what might have been a latent or asymptomatic infection in an immunocompetent donor or in the recipient prior to therapy can become a life-threatening problem when the recipient becomes immunosuppressed. Pretransplantation Evaluation A variety of organisms have been transmitted by organ transplantation (Table 126-1). . | Chapter 126. Infections in Transplant Recipients The evaluation of infections in transplant recipients involves consideration of both the donor and the recipient of the transplanted organ. Infections following transplantation are complicated by the use of drugs that are necessary to enhance the likelihood of survival of the transplanted organ but that also cause the host to be immunocompromised. Thus what might have been a latent or asymptomatic infection in an immunocompetent donor or in the recipient prior to therapy can become a life-threatening problem when the recipient becomes immunosuppressed. Pretransplantation Evaluation A variety of organisms have been transmitted by organ transplantation Table 126-1 . Careful attention to the sterility of the medium used to process the organ combined with meticulous microbiologic evaluation reduces rates of transmission of bacteria that may be present or grow in the organ culture medium. From 2 to 20 of donor kidneys are estimated to be contaminated with bacteria in most cases with the organisms that colonize the skin or grow in the tissue culture medium used to bathe the donor kidney while it awaits implantation. The reported rate of bacterial contamination of transplanted stem cells bone marrow peripheral blood cord blood is as high as 17 but is most commonly 1 . The use of enrichment columns and monoclonal-antibody depletion procedures results in a higher incidence of contamination. In one series of patients receiving contaminated products 14 had fever or bacteremia but none died. Results of cultures performed at the time of cryopreservation and at the time of thawing were helpful in guiding therapy for the recipient. Table 126-1 Organisms Transmitted by Organ Transplantation and Their Primary Sites of Reactivation Disease3 Blood Lungs Heart Brain Liver Spleen Skin Viruses Cytomegalovirus0 Epstein-Barr virusc Herpes simplex virus Human herpesvirus type 6 Kaposi s sarcoma- associated herpesvirus Hepatitis B and C .