Date: Saturday, May 30, 2020
Session Time: 3:15pm-4:00pm
Presentation Time: 3:30pm-4:00pm
*Purpose: We have shown a higer CMV infection rate in kidney Tx patients (KTx Pts) who were converted to BLT <1yr than >1yr post-Tx. Viral infections are controlled by cell-mediated and antibody-mediated immunity. Costimulatory molecule inhibition by BLT affects both, inhibiting viral specific T cell, B cell and antibody development. Here, we investigate the effect of BLT on humoral immunity by measuring anti-CMV IgG (CMV IgG) and total IgG levels pre- and post-viremia in KTx Pts with vs. without BLT.
*Methods: Archived plasma samples from 12 Pts who were converted to BLT <1yr post-Tx (median 2.8 M, 0.5-9.2M post-Tx) between 2012 and 2019 and 26 pts without BLT (CTRL), with CMV viremia (>30 copies/PCR) were measured for CMV IgG and total IgG levels. 5/12 BLT and 9/26 CTRL Pts were HLA-sensitized and received desensitization. 85% of Pts in both groups received lymphocyte depleting induction and viral prophylaxis for 6M post-Tx.
*Results: Overall, 1st viremia was detected at similar time post-Tx (6M post-BLT [8.8M post-Tx] in BLT, 6M post-Tx in CTRL Pts). Viremia duration was significantly longer in BLT than CTRL Pts, and this trend was greater in sero- (R-) than sero+ (R+) BLT Pts. Seroconversion was significantly delayed in R- BLT than R- CTRL Pts. In R+ Pts, pre-viremia CMV IgG and total IgG levels were significantly lower in BLT than CTRL, and post-viremia CMV IgG levels were also significantly lower in BLT although there was no difference in post-viremia total IgG. In R- Pts, post-viremia CMV IgG levels were significantly lower in BLT than CTRL Pts, while there was no difference in total IgG levels.
*Conclusions: Delayed seroconversion in R- and lower levels of pre- & post-viremia CMV IgG in R- and R+ BLT Pts resulted in extended duration of CMV viremia, indicating less anti-CMV humoral immunity in this Pt population. Attention to this increased risk using PCR and CMV IgG monitoring is required to minimize CMV infection and associated morbidities in this Pt population.
To cite this abstract in AMA style:Shin B, Ammerman N, Sethi S, Vo A, Jordan SC, Toyoda M. Conversion to Belatacept (BLT)- from Calcineurin Inhibitor (CNI)-Based Immunosuppression During the First Year Post-Transplant (<1yr Tx) Increases Risk for CMV Infection Through Inhibition of Anti-CMV Humoral Immunity [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/conversion-to-belatacept-blt-from-calcineurin-inhibitor-cni-based-immunosuppression-during-the-first-year-post-transplant/. Accessed September 21, 2020.
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