Korean J Transplant.  2022 Nov;36(Supple 1):S124. 10.4285/ATW2022.F-2423.

Benefits of switching mycophenolic acid to sirolimus on serological response after a SARS-CoV-2 booster dose among kidney transplant recipients: a randomized controlled trial

• Townamchai N
• Banjongjit A
• Phannajit J
• Jantarabenjakul W
• Paitoonpong L
• Wattanatorn S
• Avihingsanon Y
• Hansasuta P
• Vanichanan J
• Eiam-Ong S

• KMID: 2535640
• DOI: http://doi.org/10.4285/ATW2022.F-2423

Abstract

Kidney transplant recipients (KTRs) have a suboptimal immune response to COVID-19 vaccination due to the effect of immu-nosuppression, mostly mycophenolic acid (MPA). This study was conducted to investigate the benefits of immunosuppressive regimen switching from the standard regimen; tacrolimus (TAC), MPA, and prednisolone to a regimen of mammalian target of rapamycin inhibitor (mTORi), TAC and prednisolone during a period of BNT162b2 vaccine booster dose. A single-center, opened-label randomized controlled trial was conducted in KTRs who received two doses of ChAdOx-1 and a single dose of BNT162b2. The participants were randomly assigned to continue standard regimen (control group, n=14) or switched the regi-men to sirolimus (an mTORi), TAC, and prednisolone (switching group, n=14) starting two weeks before and continuing 2 weeks after a booster dose of BNT162b2. The anti-SARS-CoV-2 S antibody level after vaccination in the switching group was sig-nificantly greater than the control group (4,051.0 [3,142.0–6,466.0] vs. 2,081.0 [1,077.0–3,960.0] BAU/mL, respectively; P=0.01) (Figure). One patient who was initially seronegative and was in the control group remained seronegative after a booster dose. These findings suggest humoral immune response benefits of switching the standard immunosuppressive regimen to the regi-men of mTORi, TAC, and prednisolone in KTRs during vaccination.