Doenças Cardiovasculares e Diagnóstico

The Impact of Time Post Cardiac Transplant on Gene Expression Profile Scores, an Analysis of 32,043 Tests

Abstract

Bethany A Austin, PJ Arnold and Andrew Kao

Background: Gene Expression Profiling (GEP) has been used since 2005 to identify Orthotopic Heart Transplant (OHT) recipients at low risk of allograft rejection. A rise in GEP scores during the first year post OHT has been previously reported. The purpose of this study is to confirm and better characterize this effect of time post-transplant in a larger, unselected cohort.

Methods: All commercially obtained GEP scores (XDx Inc., Brisbane, CA) collected between January 2005 and September 2011 were included. Clinical data were available for patient age, gender and dates of transplantation and tests.

Results: There were 32,043 GEP tests from 9,272 patients at 108 transplant centers (mean age at testing 54.2 ± 14.7 yrs, 25% women). There was a significant effect of time post transplant on GEP, which rose from 24.7 ± 7.8 at 2-6 months to 28.8 ± 5.8 at 7-12 months (p<0.0001) and 29.6 ± 5.0 (p<0.0001) at 13-24 months, after which it remained stable.

Conclusions: A rise in GEP scores is seen during the first year following OHT, which parallels the time frame of decreased corticosteroid dosing. Further study of this test characteristic may better inform clinical use of GEP testing in conjunction with endomyocardial biopsy.