The Use of AlloMap and AlloSure in Combined Heart-Kidney Transplantation

Abstract

Kidney disease is a common comorbidity seen in heart disease, and so the number of patients undergoing combined heart-kidney transplantation (HKT) continues to increase, as well as the number of waitlisted patients for HKT. Recent evidence suggests a favorable immunomodulatory effect for combined HKT, making these patients ideal candidates for non-invasive monitoring for rejection and injury. The use of gene-expression profile testing (AlloMap®) in HKT recipients vs heat transplant (HT) alone has remained uncertain with earlier reports suggesting higher values in HKT, while more recent reports suggesting equivocal results between the two. Additionally, the profile of donor-derived cell-free DNA (dd-cfDNA) (AlloSure®) in HKT has not yet been evaluated. The Utility of dd-cfDNA in Association with Gene Expression Profiling (D-OAR) registry is a prospective, observation study of HT recipients monitored with AlloMap and AlloSure. The D-OAR registry and prospectively collected data from UCLA Medical Center were assessed for patients who underwent HKT with associated AlloSure and AlloMap scores and compared to patients who underwent HT alone. The cumulative distribution functions of AlloMap and AlloSure scores were stratified by HT vs. HKT. Patients with CMV and acute cellular rejection (≥2R) were excluded from the analysis. There were 300 HT recipients and 14 HKT recipients. Baseline characteristics were similar between groups. The median AlloMap and AlloSure scores for HT recipients (N=300) were 29 and 0.09% respectively, while for HKT recipients (N=14) AlloMap and AlloSure scores were 33.5 and 0.41% respectively. See table 1 CONCLUSION: There were slightly higher AlloMap scores in HKT vs HT patients, while AlloSure results in HKT were significantly higher. Further work to establish baseline parameters and understand changes to these parameters during rejection episodes would benefit HKT patients by allowing non-invasive monitoring for rejection and graft injury.