An application of the 2018 Banff Classification for BK polyomavirus-associated nephropathy in renal transplantation.

Abstract

There is still a lack of a recognized morphological classification of BK viral nephropathy (BKVN) which can better reflect the clinical manifestations and prognosis. We retrospectively analyzed the data of 53 patients with BKVN in our center from January 2011 to December 2018 and evaluated the new Banff 2018 classifications' predictive value for the graft prognosis. The period between transplantation and BKVN diagnosis lasted for 10.3months (IQR, 5.3-21.9months). The main reason (92.5%) for puncture was the increase of blood serum creatinine. Of the 53 patients diagnosed with BKVN, 100% were positive for urinary BK virus-DNA, and the viral load was 1.4×108 copies/mL (IQR, 3.7×104 -1.3×1011 copies/mL); 75.5% were positive for blood BK virus-DNA, and the viral load was 3.3×104 copies/mL (IQR, 0-2.8×107 copies/mL). There were five cases in class 1, 31 cases in class 2, and 17 cases in class 3; the viral load of urine BK was 3.3×108 , 1.4×108 , and 6.3×107 copies/mL (P>.05); the viral load of blood BK was 3.3×104 , 3.3×104 , and 3.3×104 copies/mL (P>.05); the 1-year graft survival rates were 100%, 90.3%, and 52.9%, respectively (P<.05). BKVN mostly occurs within 1year after transplantation. There is no correlation between BK virus load in hematuria and pathological damage at the time of diagnosis. The 2018 Banff Classification for BKVN can better indicate the prognosis of graft.