Polyomavirus disease under new immunosuppressive drugs - A cause of renal graft dysfunction and graft loss

Background, Manifest polyomavirus (PV) renal graft infection is a rare comp lication. We diagnosed 5 cases among 70 kidney recipients undergoing transp lants since December 1995; however, there were no cases at our institution before December 1995, Method. To identify risk factors promoting manifest PV graft infection, we compared those 5 patients with kidney recipients who had signs of PV replic ation but no manifest graft infection (n=23, control group). PV replication was judged by the presence of intranuclear inclusion cells in the urine. Results. Before the infection, five of five patients had recurrent rejectio n episodes. All were switched from cyclosporine A to high dose tacrolimus a s rescue therapy. Infection was diagnosed histologically 9+/-2 months postt ransplantation; it persisted and led to graft loss in four of five patients . In control patients, graft function was stable, 1 of 23 patients were swi tched to tacrolimus as rescue therapy, and graft loss occurred in 4 of 23 p atients. Conclusion. Recurrent rejection episodes and high dose immunosuppressive th erapy, including tacrolimus, are risk factors for manifest PV kidney graft infection, which has an ominous prognosis.