Korean J Transplant.  2022 Nov;36(Supple 1):S254. 10.4285/ATW2022.F-3946.

Urine exosomal bkv-miR-B1-5p and BK virus nephropathy in kidney transplant recipients

• Jung SW
• Cho WH
• Seo JW
• Kim JS
• Kim CD
• Chung BH
• Park JB
• Kim YH
• Lee SH

• KMID: 2535471
• DOI: http://doi.org/10.4285/ATW2022.F-3946

Abstract

Background
Urine exosomal bkv-miR-B1-5p was associated with BK virus (BKV) nephropathy (BKVN), but its serial post-transplantation changes and predictability for BKVN have not been determined in kidney transplant recipients (KTRs).
Methods
Urine exosomal bkv-miR-B1-5p and urine BKV DNA were measured at 2 weeks and 3, 6, and 12 months posttransplant in 83 KTRs who stratified into biopsy-proven BKVN, presumptive BKVN, BKV viruria, and no evidence of BKV reactivation. Joint models, Cox proportional hazard models, and receiver operating characteristic curve (ROC) were used to investigate each urine assays predictability for a composite of biopsy-proven or presumptive BKVN, and biopsy-proven BKVN.
Results
The urine exosomal bkv-miR-B1-5p and urine BKV DNA loads showed similar posttransplant time-course changes. Joint models showed independent predictability of both urine assays for subsequent BKVN. In multivariable Cox analyses incorporating single timepoint value of 2-week posttransplant, urine exosomal bkv-miR-B1-5p, but not urine BKV DNA, was significantly associated with BKVN development. In ROC analyses, the area under the curve of urine exosomal bkv-miR-B1-5p was larger than that of urine BKV DNA.
Conclusions
Urine exosomal bkv-miR-B1-5p has predictability for BKVN development and may identify KTRs at risk for BKVN whose urine BKV DNA loads otherwise would have missed.