Korean J Transplant.  2020 Dec;34(Supple 1):S54. 10.4285/ATW2020.OP-1144.

Usefulness of pre- and post-transplant BK virus-specific ELISPOT assay for predicting the outcome of BK virus infection in kidney transplant recipients

• Ko EJ
• Bae H
• Park KH
• Yang CW
• Chung BH
• Oh EJ

• KMID: 2509197
• DOI: http://doi.org/10.4285/ATW2020.OP-1144

Abstract

Background
To investigate if BK virus (BKV)-specific T cell immunity measured by an interferon-γ enzyme-linked immunospot (ELISPOT) assay at pre- and post-transplant can predict the outcome of BKV infection in kidney transplant recipients (KTRs).
Methods
We included 60 KTRs with BK viremia and checked BKV ELISPOT assay at pre- and post-transplant 1 month, 3 months, and the time of BKV viremia detected. All participants were divided into persistent-viremia group (>3 months) and cleared-viremia group (<3 months) according to sustained duration of BKV infection. We compared pre- and post-transplant BKV-ELISPOT results against five BKV peptide mixes (LT, St, VP1–3), and fluorescence-activated cell sorting (FACS) of immune cell results.
Results
The pre-transplant BKV-ELISPOT results were lower in persistent-viremia group than those of cleared-viremia group (P=0.054). Also, they tends to be lower in BKV-associated nephropathy (BKVN) group compared to those of No-BKVN group (P=0.133). At the time of the first BK viremia detected, BKVN group had tendency of lower St, VP1-ELISPOT results compared to No-BKVN group (P=0.075, P=0.071, respectively). In FACS analysis at the time of viremia, persistent-viremia group showed higher portion of CD8+ T cell, and CD3+CD4+CD57+CD28nullCD161+ cell compared to cleared-viremia group (P=0.014, P=0.019, respectively).
Conclusions
Pre- and post-transplant BKV-ELISPOT assay may be effective in predicting clinical outcomes of BKV infection in terms of clearance of BKV and development of BKVN.