Abstract: PUB222
Deep Phenotypic Cytometry by Time-of-Flight Analysis of Vaccine Responses in Kidney vs. Liver Transplant Recipients
Session Information
Category: Transplantation
- 2001 Transplantation: Basic
Authors
- Dong, Dachuan, VA Palo Alto Health Care System, Palo Alto, California, United States
- Chang, Serena, Stanford University, Stanford, California, United States
- Carraro, Amedeo, University Hospital Trust of Verona, Verona, Italy
- Zaza, Gianluigi, Policlinico Umberto I Hospital, Sapienza University of Rome, Rome, Italy
- Furian, Lucrezia, Azienda Ospedale Universita Padova, Padua, Veneto, Italy
- Cravedi, Paolo, Icahn School of Medicine at Mount Sinai, New York, New York, United States
- Maltzman, Jonathan S., VA Palo Alto Health Care System, Palo Alto, California, United States
Background
Immunosuppressed solid organ transplant recipients respond poorly to vaccinations putting them at increased risk of infection. In most studies, liver transplant recipients (LTRs) have better serological responses to SARS-CoV-2 vaccination compared to those with kidney transplants (KTRs). We investigated underlying differences in relevant populations to explain this difference.
Methods
We obtained serial peripheral blood samples from KTR and LTR receiving SARS-CoV-2 inoculation in 2020-2021. Subjects had no history of SARS-CoV-2 infection or previous vaccination. Samples were timed prior to each of two vaccine doses and one month after the second dose. We compared four groups of subjects – KTRs and LTRs both with and without positive serological responses to vaccination. Samples were analyzed using Cytometry by Time of Flight (CyTOF) including assessment of epigenetic marks on a single cell basis (EpiTOF).
Results
Immunophenotyping revealed largely similar cellular phenotypes in KTRs and LTRs. Notably, we identified that the abundance of gamma/delta T cells strongly associated with positive serological responses to SARS-CoV-2 vaccination, especially in KTR. Conversely, a high basal level of NK cells in in kidney but not liver transplants exhibited poor antibody response. Epigenetic analysis of each cell population is ongoing.
Conclusion
Together, these data suggest potential subsets to explore to improve the efficacy of vaccines or gain a better understanding of cell responses at the organ level for transplant recipients.
Acknowledgment
We are thankful to the Human Immune Monitoring Center (HIMC) at Stanford University for assistance with CyTOF. This work was funded by a grant from the NIH/NIAID (R21AI171923) to PC and JSM.
Funding
- Other NIH Support