1205. Clinical Characteristics and Outcomes of Early vs Late BK Virus Nephropathy in Kidney Transplant Recipients
Session: Poster Abstract Session: Transplant: Epidemiology of Infections in Transplant Patients and Other Patients with Impaired Immunity
Friday, October 9, 2015
Room: Poster Hall
  • BKVNPoster.pdf (246.0 kB)
  • Background: BK virus nephropathy (BKVN) is a major cause of graft dysfunction and failure in kidney transplant (KT) patients. Current guidelines recommend screening every 3 months during the first 2 years post-transplant and reducing immunosuppression upon detection of BK viremia. Although BKVN generally occurs within the first year after KT (“early BKVN”), small studies have described late-onset BKVN, defined as first diagnosis greater than 1 year post-KT. However, the clinical characteristics and outcomes of late compared to early BKVN have not been systemically assessed. The purpose of this study was to describe and compare clinical characteristics and outcomes in early vs late BKVN in KT recipients.

    Methods: We retrospectively assessed the timing, clinical characteristics, screening adherence, and outcomes of early and late BKVN (biopsy-proven or presumptive [plasma BKV >10,000 DNA copies/mL) in a cohort of 671 consecutive patients who received a KT between 2008-2013 at a single US transplant center. Proportions were compared using fisher exact test with p<0.05 considered significant.

    Results: Biopsy-proven [15 (15.5%)] or presumptive [82 (84.5%)]) BKVN was diagnosed in 97 patients (14.5%) at a median of 8.89 months post-KT. The number and percent of early vs late-onset was 80 (82.5%) and 17 (17.5%), respectively. Clinical characteristics (demographics, induction immunosuppression, rejection episodes) and outcomes (graft loss, renal dysfunction, death) were similar between the two groups (p >0.05 for all comparisons). Among those with late BKVN, 14 (82%) had no evidence of BK viremia within the first year post-KT while 3 (18%) had viremia detected but at a level <10,000 copies/mL. Adherence to screening was significantly lower in the late vs. early BKVN group: 72 (90%) vs. 11 (65%), respectively, p = 0.015.

    Conclusion: In the era of BKV screening, late-onset BKVN accounts for a significant proportion of BKVN overall. Late-onset BKVN is associated with lower screening adherence, implying that it represents progression of undiagnosed earlier onset BKV infection. Improved first year screening adherence post-KT may decrease the incidence of late-onset BKVN. Recommendations for BKV screening beyond the first year after KT should be reassessed.

    Kathryn Whitaker, MD1, Ajit Limaye, MD, FIDSA2 and Cynthia Fisher, MD, MPH2, (1)Internal Medicine, University of Washington, Seattle, WA, (2)Department of Medicine, University of Washington, Seattle, WA


    K. Whitaker, None

    A. Limaye, None

    C. Fisher, None

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