Perioperative antithrombotic management is based on risk assessment for thromboembolism and bleeding, and recommended approaches aim to simplify patient management and minimize adverse clinical outcomes.

Early detection of polyomavirus BK (BKV) viremia and reduction of immunosuppression is recommended forBased on subsequent allograft biopsy results and peak BKV-viremia, patients were assigned to three groups: (i) definitive PyVAN (n = 13), (ii) presumptive PyVAN defined by plasma BKV-loads of ≥4 log 10 copies/ml (n = 17) and (iii) low BKV-viremia (n = 8). Clearance of BKV-viremia was achieved in 35/38 patients (92%) and subsequent clinical rejection occurred in 3/35 patients (8.6%), both without any difference among the groups. Patients with definitive Py-VAN had higher peak plasma BKV-loads and required longer time for clearance (8.8 vs. 4.6 vs. 2.9 months; p = 0.001). However, allograft function remained stable from baseline to last follow-up at 34 months (range 18-60) in all three groups with median serum creatinine of 1.6 mg/dl, 1.6 mg/dl and 1.3 mg/dl, respectively. We conclude that screening for BKV-replication and reduction of immunosuppression is an effective strategy to preserve medium-term allograft function even in patients developing definitive PyVAN.

These results support the utility of SAFB for pretransplant risk assessment and organ allocation, and suggest that improvement of the positive predictive value of HLA-DSA defined by SAFB will require an enhanced definition of pathogenic factors of HLA-DSA.

Polyomavirus BK (BKV) is the primary cause of polyomavirus-associated nephropathy (PVAN) in kid-

Clinical Trial Gov Registration number: NCT00860665.