Urinary donor-derived cell-free DNA as a non-invasive biomarker for BK polyomavirus-associated nephropathy

This study investigated whether donor-derived cell-free DNA (ddcfDNA) can be used to differentiate BKPyVAN. Target region capture sequencing was applied to detect the ddcfDNAs of 12 recipients with stable graft function 22 with type I TCMR, 21 with proven BKPyVAN and 5 with possible PyVAN. We found that urinary ddcfDNA levels were upregulated in recipients with graft injury whereas plasma ddcfDNA levels were comparable for all groups. The median urinary concentrations and fractions of ddcfDNA in proven BKPyVAN recipients were significantly higher than those in type I TCMR recipients (10.4 vs. 6.1 ng/mL,P<0.001 and 68.4% vs. 55.3%,P=0.013, respectively). Urinary ddcfDNA fractions (not concentrations) were higher in the BKPyVAN-pure subgroup than in the BKPyVAN-rejection-like subgroup (81.30% vs. 56.64%,P=0.025). With a cut-off value of 7.81 ng/mL, urinary ddcfDNA concentrations distinguished proven BKPyVAN from type I TCMR (area under the curve (AUC)=0.848, 95% confidence interval (95% CI): 0.734 to 0.963). These findings suggest that urinary ddcfDNA is a non-invasive biomarker which can reliably differentiate BKPyVAN from type I TCMR.
Source: Journal of Zhejiang University. Science. B. - Category: Universities & Medical Training Source Type: research