Validation of A Gene Expression Signature to Measure Immune Quiescence in Kidney Transplant Recipients in the Clia Setting
Rocky Cheung, Hua Xu, Xia Jin, Wenlan Tian, Kevin G. Pinney, Lihong Bu, Steven Stone, R. Woodward, Nikhil Agrawal, Shamik Dholakia, Ryan T. Phan
Abstract
Aim: Allograft rejection remains a major cause of graft failure in kidney transplantation. Here the authors report the validation of a non-invasive molecular diagnostic assay, AlloMap Kidney, using peripheral blood. Methods: The AlloMap Kidney test is a gene expression profile utilizing the RNA-seq platform to measure immune quiescence in kidney transplant patients. Results/Conclusions: Analytical validation showed robust performance characteristics with an accuracy correlation coefficient of 0.997 and a precision coefficient of variation of 0.049 across testing. Clinical validation from the prospective, multi-center studies of 235 samples (66 rejection and 169 quiescence specimens) demonstrated the sensitivity of 70% and specificity of 66% for allograft rejection, while the negative predictive value was 95% to discriminate rejection from quiescence at 10% prevalence of rejection.