Chapter 126. Infections in Transplant Recipients (Part 1) pdf

Chapter 126. Infections in Transplant Recipients (Part 1) Harrison's Internal Medicine > Chapter 126. Infections in Transplant Recipients Infections in Transplant Recipients: Introduction 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 Disease a Bl ood L ungs H eart B rain Liver/S pleen S kin Viruses Cytomega lovirus b + + ± ± + ± Epstein- Barr virus c + + ± ± + ± Herpes simplex virus + ± + + Human herpesvirus type 6 + + + + Kaposi's sarcoma– associated herpesvirus + ± ± + Hepatitis B and C viruses + Rabies virus d + West Nile virus + + Fungi Candida albicans + + + + Histoplas ma capsulatum + + + + Cryptococ cus neoformans + + + ± + Parasites Toxoplas ma gondii e + + + Strongyloi des stercoralis f,g + Trypanoso ma cruzi g + Plasmodiu m falciparum g + Prion Diseases Creutzfeld t- Jakob disease (CJD) h + Variant CJD/bovine spongiform encephalopathy i + a +, well documented; ±, probably occurs. b Cytomegalovirus reactivation is pron e to occur in the transplanted organ. The same may be true for Kaposi's sarcoma–associated herpesvirus. c Epstein- Barr virus reactivation usually presents as an extranodal proliferation of transformed B cells and can be present either as a diffuse disease or as a mass lesion in a single organ. d Rabies virus has been transmitted through corneal transplants. e T. gondii usually causes disease in the brain. In hematopoietic stem cell transplant recipients, acute pulmonary disease may also occur. Heart transplant recipients develop disease in the allograft. f Strongyloides "hyperinfection" may present with pulmonary disease— often associated with gram-negative bacterial pneumonia. g While transmission with organs has been described, it is unusual. h CJD (sporadic and familial) has been transmitted with corneal transplants. Whether it can be transmitted with blood is not known. i Variant CJD can be transmitted with transfused non- leukodepleted blood, posing a theoretical risk to transplant recipients. . Chapter 126. Infections in Transplant Recipients (Part 1) Harrison's Internal Medicine > Chapter 126. Infections in Transplant Recipients Infections in Transplant Recipients: Introduction. Introduction 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. through corneal transplants. e T. gondii usually causes disease in the brain. In hematopoietic stem cell transplant recipients, acute pulmonary disease may also occur. Heart transplant recipients