Omić Haris, Kläger Johannes Phillip, Herkner Harald, Aberle Stephan W, Regele Heinz, Weseslindtner Lukas, Schrag Tarek Arno, Bond Gregor, Hohenstein Katharina, Watschinger Bruno, Werzowa Johannes, Strassl Robert, Eder Michael, Kikić Željko
Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
Department of Pathology, Medical University of Vienna, Vienna, Austria.
Front Med (Lausanne). 2022 Jan 6;8:791087. doi: 10.3389/fmed.2021.791087. eCollection 2021.
The absolute BK viral load is an important diagnostic surrogate for BK polyomavirus associated nephropathy (PyVAN) after renal transplant (KTX) and serial assessment of BK viremia is recommended. However, there is no data indicating which particular viral load change, i.e., absolute vs. relative viral load changes (copies/ml; percentage of the preceding viremia) is associated with worse renal graft outcomes. In this retrospective study of 91 biopsy proven PyVAN, we analyzed the interplay of exposure time, absolute and relative viral load kinetics, baseline risk, and treatment strategies as risk factors for graft loss after 2 years using a multivariable Poisson-model. We compared two major treatment strategies: standardized immunosuppression (IS) reduction ( = 53) and leflunomide ( = 30). The median viral load at the index biopsy was 2.15E+04 copies/ml (interquartile range [IQR] 1.70E+03-1.77E+05) and median peak viremia was 3.6E+04 copies/ml (IQR 2.7E+03-3.3E+05). Treatment strategies and IS-levels were not related to graft loss. After correction for baseline viral load and estimated glomerular filtration rate (eGFR), absolute viral load decrease/unit remained an independent risk factor for graft loss [incidence rate ratios [IRR] = 0.77, (95% 0.61-0.96), = 0.02]. This study provides evidence for the prognostic importance of absolute BK viremia kinetics as a dynamic parameter indicating short-term graft survival independently of other established risk factors.
绝对BK病毒载量是肾移植（KTX）后BK多瘤病毒相关性肾病（PyVAN）的一项重要诊断替代指标，建议对BK病毒血症进行连续评估。然而，尚无数据表明哪种特定的病毒载量变化，即绝对病毒载量变化与相对病毒载量变化（拷贝数/毫升；前一次病毒血症的百分比）与肾移植预后较差相关。在这项对91例经活检证实的PyVAN的回顾性研究中，我们使用多变量泊松模型分析了暴露时间、绝对和相对病毒载量动力学、基线风险以及治疗策略作为2年后移植肾丢失风险因素之间的相互作用。我们比较了两种主要治疗策略：标准化免疫抑制（IS）减量（n = 53）和来氟米特治疗（n = 30）。索引活检时的病毒载量中位数为2.15E+04拷贝/毫升（四分位间距[IQR] 1.70E+03 - 1.77E+05），病毒血症峰值中位数为3.6E+04拷贝/毫升（IQR 2.7E+03 - 3.3E+05）。治疗策略和IS水平与移植肾丢失无关。在校正基线病毒载量和估计肾小球滤过率（eGFR）后，绝对病毒载量每单位下降仍是移植肾丢失的独立危险因素[发病率比[IRR] = 0.77，（95%CI 0.61 - 0.96），P = 0.02]。本研究为绝对BK病毒血症动力学作为一个动态参数的预后重要性提供了证据，该参数可独立于其他既定风险因素指示短期移植肾存活情况。
