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 transplant recipients, but its possible contribution to chronic renal 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.

Detection of Epstein-Barr virus DNA in sera from transplant recipients with lymphoproliferative disorders.

Early diagnosis of Epstein-Barr Virus (EBV)-associated posttransplant lymphoproliferative disease (PTLD) is important because many patients respond to reduction in immunosuppression, especially if PTLD is detected at an early stage. Previous studies have found elevated EBV DNA levels in blood from patients with PTLD, but these assays required isolation of cellular blood fractions and quantitation. We evaluated the presence of cell-free EBV DNA in serum from solid-organ transplant recipients as a marker for PTLD. Five of 6 transplant recipients with histopathologically documented PTLD had EBV DNA detected in serum at the time of diagnosis (sensitivity = 83%), compared with 0 of 16 matched transplant recipients without PTLD (specificity = 100%) (P < 0.001 [Fisher's exact test]). Furthermore, EBV DNA was detected in serum 8 and 52 months prior to the diagnosis of PTLD in two of three patients for whom stored sera were analyzed. Detection of EBV DNA in serum appears to be a useful marker for the early detection of PTLD in solid-organ transplant recipients. Further studies to define the role of such assays in evaluating solid-organ transplant patients at risk for PTLD are warranted.