AUTHOR=DeWolfe David , Aid Malika , McGann Kevin , Ghofrani Joshua , Geiger Emma , Helzer Catherine , Malik Shaily , Kleiboeker Steve , Jost Stephanie , Tan Chen Sabrina TITLE=NK Cells Contribute to the Immune Risk Profile in Kidney Transplant Candidates JOURNAL=Frontiers in Immunology VOLUME=Volume 10 - 2019 YEAR=2019 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.01890 DOI=10.3389/fimmu.2019.01890 ISSN=1664-3224 ABSTRACT=Background: A previously proposed immune risk profile (IRP), based on T cell phenotype and CMV serotype, is associated with mortality in the elderly and increased infections post-kidney transplant. To evaluate if NK cells contribute to the IRP and if the IRP can be predicted by a clinical T cell functional assays, we conducted a cross sectional study in renal transplant candidates to determine the incidence of IRP and its association with sepcificNK cell characteristics and ImmuKnow® value. Material and Methods: 65 subjects were enrolled in 5 cohorts designated by age and dialysis status. We determined T and NK cell phenotypes by flow cytometry and analyzed multiple factors contributing to IRP. Results: We identified 14 IRP+ (CMV seropositivity and CD4/CD8 ratio < 1 or being in the highest quintile of CD8+ senescent (CD28-/CD57+) T cells) individuals equally divided amongst the cohorts. Multivariable linear regression revealed a distinct IRP+ group. Age and dialysis status did not predict immune senescence in kidney transplant candidates. NK cell features alone could discriminate IRP- and IRP+ patients, suggesting that NK cells significantly contribute to the overall immune status in kidney transplant candidates and that a combined T and NK cell phenotyping can provide a more detailed IRP definition. ImmuKnow® value was negatively correlated to age and significantly lower in IRP+ patients and predicts IRP when used alone or in combination with NK cell features. Conclusion: NK cells contribute to overall immune senescence in kidney transplant candidates.