Abstract: FR-PO1136
Assessment of the Banff Working Group Classification of Definitive BK Polyomavirus Nephropathy
Session Information
- Transplantation: Clinical - Post-Transplant Complications
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 1902 Transplantation: Clinical
Authors
- Kowalewska, Jolanta, Eastern Virginia Medical School, Norfolk, Virginia, United States
- Mirza, Alamgir, Eastern Virginia Medical School, Norfolk, Virginia, United States
- Simpkins, Jaclyn, Eastern Virginia Medical School, Norfolk, Virginia, United States
- Troyer, Dean, Eastern Virginia Medical School, Norfolk, Virginia, United States
- Perkowska-Ptasinska, Agnieszka, Medical University of Warszaw, Warsaw, Poland
- Lin, Mercury Y., Cedars Sinai Medical Center, Los Angeles, California, United States
- Kapp, Meghan E., Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Fogo, Agnes B., Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Durlik, Magdalena, Medical University of Warszaw, Warsaw, Poland
- Ciszek, Michal, Medical University of Warsaw, Warsaw, Poland
- Deborska-Materkowska, Dominika, Medical University of Warszaw, Warsaw, Poland
- Kuczynski, Daniel, Medical University of Warszaw, Warsaw, Poland
- McCune, Thomas R., Nephrology Associates of Tidewater, LTD, Norfolk, Virginia, United States
Background
The Banff Working Group on Polyomavirus Nephropathy (PVN) proposed a classification of definitive PVN based on polyomavirus replication/load level and the extent of interstitial fibrosis. This study is to test the classification using independent cohorts of patients with PVN in renal allograft biopsies, and to analyze the significance of other variables that may play a role in the outcome of PVN, namely presence of tubular basement membrane deposits (TBMD) and peak level of plasma BK particles by PCR.
Methods
Four institutions participated in this study. Patients with kidney allograft biopsy-proven PVN with at least 24 months follow up were identified. Clinical data was captured and biopsies were scored according to the Banff PVN classification. Statistical analysis was performed using multivariable logistic regression and analysis of covariance (ANCOVA) to assess dichotomous and continuous outcomes, respectively.
Results
145 patients met the criteria for the study. 25 (17%) biopsies were classified as Class 1; 97 (68%) as Class 2; and 20 (14%) as Class 3. Baseline serum creatinine (Scr) levels were elevated and similar regardless of class, with Class 1 mean 1.78 mg/dl , Class 2 1.62 mg/dL, and Class 3 1.78 mg/dL. At the time of diagnostic biopsy the median change in Scr was parallel across classes of PVN (increase in Scr 0.60, 0.52, and 0.60 respectively, p=0.57). At 24 months, median Scr change from baseline increased numerically, as also seen in previous reports (increases 0.45, 0.75 and 1.2, p=0.29). In this cohort overall graft failure was 22% (compared to 30% previously reported), and was equally distributed amongst classes (25%, 20% and 25%). TBMD were found in a subset of all PVN classes (10%, 10% and 20%), and were associated with a trend toward worse outcomes (p=0.15). The highest mean number of plasma BK particles was seen in PVN Class 3, but was not statistically different from other classes.
Conclusion
The proposed classification of PVN is promising for evaluation of allograft biopsies; however, the classes do not stratify and identify patients at increased risk of allograft loss. Additional parameters need to be identified to determine risk for adverse allograft outcome.