Systematic microbiological tests in kidney transplantation and their value in predicting posttransplantation infection.

Background. Immunosuppressive therapy has many side effects among which is an increased infectious risk for the recipient. Transmission of pathogens from the graft to the recipient has not been well evaluated; there are no guidelines regarding the need for microbiological tests on the graft prior to transplantation. We routinely performed such tests to evaluate the risk and determine whether a patient should receive preemptive antibiotic therapy after transplantation. We herein have reported our preliminary results. Materials and Methods. We reviewed 150 consecutive renal transplantations from cadaveric heart-beating donors. Microbiological tests were systematically performed not only on the preservation solution, but also on graft: artery, vein, ureter, and perirenal fat. We reviewed the recipient's medical history for clinically significant infectious episodes in the first month after transplantation. Results. Thirty-one percent of all microbiological tests were positive with 23 patients showing multiple positive tests, 74% of which were concordant. We documented 3 cases of direct graft-to-recipient pathogen transmission, all of which presented with 3 positive concordant tests. Graft Culture prior to transplantation is often positive, but in more than half of the cases positive tests are either isolated or discordant. We only treated patients with concordant test results, no adverse consequence was observed among the untreated patients. Transmission occurred only in patients with at least 3 concordant tests. Conclusions. Multiple microbiological tests on the graft prior to transplantation seemed useful to determine which patients would benefit from preemptive antibiotic therapy. Further studies may help to define which microbiological tests are the most important.