A prospective cross-sectional study of BK virus infection in non-renal solid organ transplant recipients with chronic renal dysfunction

Background: Polyomavirus (primarily BK virus [BKV]) infection is an important cause of chronic renal dysfunction in renal but its possible contribution to chronic renal transplant recipients, dysfunction in non-renal solid organ transplant (NRSOT) recipients has not been fully explored. Methods: We performed a prospective, cross-sectional study of consecutive NRSOT recipients with unexplained chronic renal dysfunction of at least a 3 months duration. Medical records were reviewed, and polymerase chain reaction was used to amplify BKV-specific sequences from serum and urine samples. The potential associations between various demographic and transplant variables and BKV infection were assessed. Results: Thirty-four consecutive NRSOT recipients (23 lung, 8 liver, 2 heart, 1 heart-lung) with chronic renal dysfunction were enrolled at a median of 3.5 years (range 0.3-12.5 years) post transplantation. Five of the 34 (15%) patients had BKV viruria (range 1040-1.8 x 10(6) copies/mL), but none had BKV viremia. BK viruria was associated with mycophenolate mofetil use (5 of 19 [26%] vs. 0 of 15, P = 0.03) and a history of cytomegalovirus disease (3 of 4 [75%] vs. 2 of 30 [7%], P < 0.01). However, the mean estimated creatinine clearance was similar in patients with or without BKV viruria (49 vs. 47 mL/min). Conclusions: BKV viruria was present in a proportion of NRSOT patients with otherwise unexplained chronic renal dysfunction. The possibility that BKV infection might contribute to chronic renal dysfunction in this setting warrants further investigation.