Long-Term Outcomes of BK Viremia in Kidney Transplant Recipients

Background: BK viremia (BKV) occurs in 10-30% of kidney transplant (KT) recipients. It has not been shown to adversely impact short and intermediate term graft and patient outcomes, but long term impact is unknown. Methods: We included KT alone recipients between 2008 and 2013 without prior history of KT and those who were alive with a functioning graft beyond 90 days of KT. We split the cohort into BK never positive, transient BKV (<140 days) and persistent BKV (>140 days). Outcomes were graft and patient survival, kidney function, de novo DSA and acute rejection over 10 years of follow up. Survival analysis was performed using Kaplan Meier (KM) analysis. Results: Among 762 patients, there were 596, 68 and 98 patients in BK never positive, transient BKV and persistent BKV groups respectively. There was no difference in GFR at 10 years (p=0.29), acute rejection (p=0.15) and de novo class I DSA development (p=0.75). De novo class II DSA developed more often in persistent BKV group (p=0.03). On KM analysis, there was no difference in graft (p=0.6) and patient survival (p=0.86). Conclusion: BKV does not impact long-term outcomes in KT recipients although there is a higher risk of de novo class II DSA development. - Category BK never positive (N=596) Transient BK viremia (N=68) Persistent BK viremia (N=98) p value Recipient ethnicity: Black 26 (38.2%) 202 (33.9%) 51 (52%) 0.53 Recipient age 53 (11) 51 (13) 52 (12) 0.004 Recipient gender: Female 35 (51.5%) 300 (50.3%) 43 (43.9%) 0.47 Donor age 37 (15) 39 (15) 39 (14) 0.68 Donor gender: Female 35 (51.5%) 300 (50.3%) 43 (43.9%) 0.47 Peak PRA: Class I 30 (36) 42 (31) 55 (35) 0.1 Peak PRA: Class II 61 (29) 49 (30) 67 (29) 0.18