Background: BK virus renal allograft nephropathy (BKVAN) in the setting of simultaneous kidney-pancreas transplantation (SKPT) has been inadequately studied and reported. We analyzed our data on the incidence of BKVAN and its outcome in SKPT recipients at University of Pittsburgh Medical Center (UPMC) and affiliated centers and report significant differences compared to previous studies.
Methods: This study used retrospective review and case studies.
Results: A review of 243 consecutive SKPT recipients from January 1, 1996 to December 31, 2004 identified seven cases (three females; ages = 23-54 yrs) of BKVAN following SKPT (incidence = 2.9%). The immunosuppressive protocols during this period were divided into: Period I (pre-August 2001) with no antibody induction and Period II (post-August 2001) with alemtuzumab or antithymocyte globulin induction with steroid avoidance. One BKVAN case was diagnosed in Period II (incidence = 1.4%). Six of seven patients were treated with intravenous cidofovir (0.20-0.50 mg/kg) every two to four weeks over one to six months. Three patients lost the renal allograft 8-22 months following diagnosis of BKVAN, whereas four patients had prolonged allograft survival. Pancreatic function was well preserved in five; one patient lost the pancreatic function due to surgical complications and one has had partial preservation.
Conclusions: There was a relatively lower incidence of BKVAN among SKPT patients at our center. Although overall graft loss rate was comparable to other series, BKVAN patients had a slightly prolonged graft life. The BKVAN incidence was further reduced in patients receiving modified immunosuppression with antibody preconditioning. The underlying reasons may include less toxic immunosuppressive protocols, earlier diagnosis and the use of antiviral therapy.