Background: BK virus (BKV) is a polyomavirus that is associated with nephropathy and graft loss among kidney transplant recipients. The role of BK virus in nonrenal solid organ transplant recipients has not been clearly established; only anecdotal case reports have been published.
Methods: From August 2005 to September 2007, all liver transplant (OLT) recipients who gave their consent were enrolled in this prospective longitudinal study. BK viral load was measured using real-time quantitative polymerase chain reaction assays of urine and plasma, using samples collected at week 1 and months 1, 3, 6, 9, 12, 15, 18, 21, and 24 posttransplantation. We also collected demographic and clinical data, including serum creatinine and immunosuppressive therapy.
Results: The mean age of the 62 patients was 51.4 years including 14 (22.5%) women. Hepatitis C infection was present in 24 patients (38.7%). BK viruria was detected in 14.5% of 290 samples, corresponding to 13 patients (21%). BK viremia was detected in 5.1% of 317 samples, corresponding to 11 patients (18%). Almost all cases of BK viremia (91%) occurred in the first 3 months after OLT. BKV viremia was more common among patients experiencing a rejection episode (10.6 vs 40%, P = .01). We did not observe a relationship between single episodes of BKV replication and renal function: median plasma creatinine 1.1 mg/dL in patients without versus 1.2 mg/dL with BKV viremia. The three patients with persistent viremia displayed renal insufficiency; one of them died due to multiorgan failure of unknown origin.
Conclusions: BKV is frequently detected in OLT recipients (viruria 21% and viremia 18%) early after transplantation. It is more common among patients with rejection episodes. Persistent BKV viremia may be related to renal dysfunction in OLT patients.