신장이식 후 Polyomavirus 감염의 조기진단과 선행적 면역억제제의 조절효과

Abstract

Purpose: The purposes of this study were to compare the relative efficacy of urine decoy cell (UDC) and polymerase chain reaction (PCR) for the polyomavirus infection (PVI), and to search the efficacy of preemptive immunologic control for PVI in earlier stage before irreversible graft injury. Methods: Between Mar. 2003 to Sep. 2005, 265 patients were monitored for the PVI after kidney transplantation. Of the 265 patients, the results of preemptive immunologic modifications were searched among 222 recipients who had the complete data. Results: Of the total 222 patients, 75 patients (33.8%) were positive for UDCs in at least one examination. Overall cumulative incidence of PVI was 32.9%. According to the episode of acute rejection, the one year incidences of PVI were 51.4% and 29.5% in recipients with and without the episode of acute rejection, respectively (P=0.0047). Using decoy cells as a marker of PV viruria, cytology has a sensitivity of 57.1% and negative predictive value of 74.1%. The specificity and positive predictive value for viruria (not viral nephropathy) are 67.2% and 48.8%. False-negative results occurred in samples with suboptimal cellularity, and a low viral load. Three cases of PV nephropathy (PVN) were documented. From January 2001 to December 2002, when we did not prospectively monitor UDCs, 7 cases of PVN were documented among the 116 recipients. Conclusion: The combination test of UDC and PV PCR should be considered as screening test for PVI due to low positive predictive value of UDC. The modulation of net immunosuppression based on UDC values and PV viral loads may reduce the development of PVN.