37 - Impact Of Target Tacrolimus Levels On BK Polyomavirus DNAemia And Allograft Rejection Among Pediatric Kidney Transplant Recipients
Saturday, April 23, 2022
3:30 PM – 6:00 PM US MT
Poster Number: 37 Publication Number: 37.235
Hou-Xuan Huang, Emory University School of Medicine, Decatur, GA, United States; Pamela D. Winterberg, Emory University School of Medicine, Atlanta, GA, United States; Roshan P. George, Emory University School of Medicine, Atlanta, GA, United States; Anastacia Serluco, Children's Healthcare of Atlanta, Atlanta, GA, United States; Rochelle Liverman, Children's Healthcare of Atlanta, Atlanta, GA, United States; Inci Yildirim, Yale University, New Haven, CT, United States; Rouba Garro, Emory Univsersity and Children's Healthcare of Atlanta, atlanta, GA, United States
Pediatric Nephrology Fellow Emory University School of Medicine Decatur, Georgia, United States
Background: BK Polyomavirus (BK) DNAemia is a common infectious complication after kidney transplant (KT) and if uncontrolled can lead to BK-associated nephropathy, irreversible damage, and graft loss. Close monitoring of serum BK PCR and graft function with preemptive reduction of immunosuppression is the main suggested approach to prevent BK nephropathy.
Objective: We evaluated the impact of targeting lower tacrolimus levels on the incidence of BK DNAemia and rejection rate in pediatric KT recipients at our center.
Design/Methods: We conducted a retrospective chart review of 151 episodes of KT between 01/2013-12/2018 expanding upon a quality improvement project implemented in March 2015 to decrease target tacrolimus levels by 25% prompted by a cluster of early-onset BK DNAemia cases. Of the 129 patients included in analysis, 46 were in the pre-intervention cohort, and 83 were in the post-intervention cohort. All patients received induction with basiliximab and methylprednisolone and maintained on steroid based immunosuppressive regimen.
Results: Median age at KT [13(IQR 7 – 16) years], sex (65% male), and race (58% White, 34% Black) were not significantly different between cohorts. Overall, 53% of patients received deceased donor KT, 21% had underlying urologic disorder, and 13% had prior urologic procedures. 32.6% (42/129) of patients developed BK DNAemia within 18 months post-KT. The post-intervention cohort had non-significant lower incidence of early-onset BK DNAemia within 100 days post-KT (0.15 vs. 0.21 per 100 patient-days), longer median time to first detected BK DNAemia [139 (IQR 56 - 181) vs. 78 (IQR 59 - 184) days], shorter duration of BK DNAemia [59 (IQR 29 - 83) vs. 123 (IQR 57 - 301) days], and lower median peak viral load [16015 (IQR 3236 - 39185) vs. 30688 (IQR 1716 - 58541) DNA copies/mL]. More patients in the post-intervention cohort had at least one episode of biopsy-proven rejection within 18 months post-KT (42% vs. 37%, p=0.56) and earlier development of donor-specific antibody (DSA) (p=0.042).Conclusion(s): The revised immunosuppression protocol with lower target tacrolimus levels resulted in reduction of early-onset BK DNAemia cases and more rapid clearance of BK DNAemia without reaching statistical significance. However, we observed a slight increase of rejection and earlier development of de novo DSA in the post-intervention cohort which may portend worse long-term graft survival. Modification of early immunosuppression to prevent viral infection in children should be balanced against possible increased risk of rejection. Table 1. Tacrolimus trough targets by week post-KT for the pre- and post-intervention cohorts Figure 1. Incidence rate of BK DNAemia within 100 days post-KT