Outcomes AlloMap Research Articles

Plasma Donor-Derived Cell-Free DNA Levels are Not Affected by Prednisone Dose nor Time after Heart Transplant: Pilot Data from DOAR and SHORE

<h3>Purpose</h3> Gene expression profiling (GEP; AlloMap®) scores can be impacted in the presence of >20 mg/day of prednisone due to effects on steroid-responsive genes (IL-1R2, ITGAM, FLT3) and is not validated for use prior to 55 days post-heart transplant. Donor-derived cell-free DNA (dd-cfDNA) can be used as early as 14 days after heart transplant (HT), but the impact of early use and the impact of steroid dosing has not yet been demonstrated. <h3>Methods</h3> The dd-cfDNA (AlloSure®) from the <i>Donor-Derived Cell-Free DNA Outcomes AlloMap Registry</i> (D-OAR) and <i>Surveillance Heart Care Outcome Registry</i> (SHORE) registries had 17 visits < 55 days and 106 visits 55 - 90 days post-HT. dd-cfDNA was also as analyzed by Kruskal-Wallis for prednisone dose ranges: 0-5, >5-10, >10-15, >15-20, and >20 mg/day (n=1113, 542, 203, 82, and 30). <h3>Results</h3> For those < 55 and >= 55 days post-HT the median dd-cfDNA result was 0.15% (IQR: 0.15-0.15%) and 0.15% (0.15-0.19%), respectively (p=NS). When stratified by prednisone doses (0-5], (5-10], (10-15], (15-20], and (>20, there was also no difference in median dd-cfDNA: 0.12%, 0.12%, 0.15%, 0.15%, and 0.15%, respectively, p=0.7. <h3>Conclusion</h3> This preliminary data suggests that dd-cfDNA levels are not significantly affected when assessed earlier than 55 days post-HT or by varying prednisone dosage. Implementation of dd-cfDNA as an early biomarker of allograft injury and rejection may represent a valuable clinical tool during the early post-HT period.

Impact of cytomegalovirus infection on gene expression profile in heart transplant recipients

Cytomegalovirus (CMV) infection has been implicated in the pathogenesis of allograft rejection in heart transplant (HT) recipients. The effect of a CMV infection on the gene expression profiling (GEP, AlloMap) scores in the absence of acute rejection is not known. Data from 14,985 samples collected from 2,288 adult HT recipients enrolled in Outcomes AlloMap Registry were analyzed. Patients with known CMV serology at the time of HT who had at least 1 AlloMap score reported during follow-up were included. AlloMap scores for those patients with CMV (but no ongoing rejection) were compared with those who were never infected. An exploratory analysis on the impact of CMV on available donor-derived cell-free DNA (AlloSure) was also performed. A total of 218 patients (10%) were reported to have CMV infection after transplantation. AlloMap score in those samples with CMV infection (n = 311) had a GEP score (34; range: 29-36) significantly higher than the GEP score from samples (n = 14,674) obtained in the absence of CMV infection (30; range: 26-34; p < 0.0001). Both asymptomatic viremia and CMV disease demonstrated significantly higher AlloMap scores than no CMV infection samples (median scores: 33, 35, and 30, respectively; p < 0.0001). AlloSure levels, available for 776 samples, were not significantly different (median: 0.23% in 18 samples with CMV infection vs 0.15% in 776 samples without CMV infection; p = 0.66). CMV infection in HT recipients is associated with an increase in AlloMap score, whereas AlloSure results do not appear to be impacted. This information should be considered when clinically interpreting abnormal/high AlloMap scores in HT recipients.

Correlation of Longitudinal Gene-Expression Profiling (GEP) Score to Cytomegalovirus (CMV) Infection: Results from the Outcomes Allomap® Registry

Cytomegalovirus (CMV) infection has been implicated in the pathogenesis of allograft rejection, which is reflected by high gene-expression profiling (GEP) scores. The effect of CMV infection on serial GEP scores in the absence of acute cellular rejection (ACR) is unknown. Data from 14,985 samples collected from 2288 heart transplant (HT) recipients enrolled in Outcomes AlloMap® Registry (OAR) were analyzed. The empirical distribution of GEP scores at the visit closest to CMV infection were compared to GEP scores obtained at other visits via Kolmogorov-Smirnov tests. AlloSure measurements from those who underwent concurrent dd-cfDNA testing were also reviewed. 311 samples were collected from 213 patients with CMV infection at the time of GEP testing. The mean time to CMV infection from transplant was 346 days. Median GEP score at the time of diagnosis of CMV infection was significantly higher when compared to GEP score obtained at other visits (34 v 30, p<; 0.0001) (Figure 1). For patients with samples assessed via AlloMap and AlloSure, there was no significant difference in the distribution of AlloSure measurements at the time of CMV infection (Figure 2). CMV infections in HT recipients are associated with an increase in GEP score independent of associated ACR. The likely mechanism is immune activation/modulation of one or more of the 11 genes in the GEP signature. Hence, CMV status should be considered when clinically interpreting high GEP scores. AlloSure testing in conjunction with AlloMap demonstrates AlloSure is invariant to CMV infection.

The Effect of Pre-Transplant Mechanical Circulatory Support Devices on the Post-Transplant dd-cfDNA and GEP in Heart Transplantation

Evidence around sensitization and increased risk of rejection from use of pre-transplant mechanical circulatory support (MCS) devices remains conflicting. Some evidence suggests devices cause inflammation and association with increased antibody production, which has been shown to be associated with AMR, CMR, and early onset of microvasculopathy at one year post-heart transplant. However other evidence suggests no difference or increased risk of adverse outcome using pre-transplant MCS devices. dd-cfDNA (AlloSure) has been shown to rise in advance to the new formation of de-novo anti-HLA antibodies, with changes in AlloMap also seen in patients who become newly sensitized. The aim of this study was to review MCS patients post-transplant with AlloSure and AlloMap to assess if they had different patterns from those who had no MCS, to support suggestion of early post-transplant complications. Patients who were enrolled in Outcomes AlloMap® Registry (OAR) and the dd-cfDNA extension (D-OAR) were included in this analysis if pre-transplant MCS history was recorded and signs or symptoms of rejection during a visit with an accompanying blood draw were absent (i.e. no biopsy accompanied the visit or if a biopsy occurred it yielded Grade 0R). A total of 282 patients met these criteria, 130 had pre-transplant MCS and 152 did not. A total of 652 samples were collected where both AlloSure and AlloMap scores were obtained. The cumulative distribution of AlloSure and AlloMap scores were assessed via a two-sample Kolmogorov-Smirnov test to determine if differences were observed that may be attributed to mechanical assist support prior to transplant. No difference in the distribution of AlloMap scores from patients that received pre-transplant mechanical support versus those that did not was observed, similarly for AlloSure measurements, there was no statistically significant difference in the distribution of AlloSure scores between those that receive pre-transplant mechanical assist support versus those that do not receive support. Pre-transplant MCS does not correlate with increased dd-cfDNA or GEP score, suggesting the adverse outcomes seen early post-transplant are unlikely to be due to MCS devices.

Differential Gene Expression by Race and Impact on Risk after Heart Transplantation

Purpose African Americans (AA) have worse survival compared to Caucasians post heart transplantation (HTx). The aim of this analysis was to evaluate racial differences in gene expression and the impact on survival and a composite outcome of death, re-Tx, hemodynamic rejection and graft dysfunction in the Outcomes AlloMap Registry (OAR). Methods AA and Caucasians who had a baseline (BL) and at least 1 follow-up (FU) test within the first year of HTx were included. The KM method with delayed entry was used to describe difference in outcomes. Multivariable cox hazard regression was used to evaluate the associations of GEP score, MARCH8, FLT3 and tacrolimus levels with each outcome, and stratified cox models were developed to quantify the race-specific associations. Results Among 992 eligible recipients, 777 (78%) were Caucasian and 215 (22%) AA. Compared to Caucasians, AA were significantly younger (55 vs 59 yrs), with higher rates of DCMP (68% vs 49%), multiorgan Tx (7% vs 1%), sensitization (>10% PRA 17% vs 10%) and HLA mismatches (6 vs. 7, p=0.02). AA had increased adjusted mortality risk HR 1.16, p Conclusion AA have a significantly higher mortality risk after HTx than Caucasians, even in the low risk OAR population. AA and Caucasians had differential gene expression of MARCH8 and FLT3 genes and differential risk associated with the expression of these genes.

Infectious complications after heart transplantation in patients screened with gene expression profiling.

The risk of infection after heart transplantation is highest within the first year and represents the leading cause of early mortality. In this cohort of patients enrolled in the Outcomes AlloMap Registry (OAR), we sought to describe infection episodes (IEp) resulting in hospitalization, in the early (<1 year) and late (≥1 year) post-transplant period and determine the impact of immunosuppression on incidence of infection. The primary aim was to assess the incidence and nature of IEp. The secondary aim was to evaluate the effect of potential risk factors, such as recipient age; sex; body mass index; panel-reactive antibodies; cytomegalovirus (CMV) primary mismatch; prednisone, tacrolimus, and sirolimus levels; and gene expression profile (GEP) score, in the development of IEp. The OAR comprises 1,504 patients, of whom 220 patients (14.6%) had an IEp during a median follow-up period of 382 days (interquartile range [IQR] 230 to 579 days). The cause-specific 5-year hazard ratio for any infection was 2.029 (p = 0.12). The pattern of early infection was consistent with nosocomial and opportunistic causes, whereas later infection was consistent with late-onset opportunistic and community-acquired etiologies. Sixty-two percent of the infections occurred early. In the time-dependent analysis, higher prednisone dose (log prednisone, hazard ratio [HR] 1.30, p = 0.022) was the most significant risk factor for all IEp. In the OAR cohort, the majority of infections occurred within 1 year after transplantation. Clinicians may consider more aggressive prednisone withdrawal in low-risk patients to reduce IEp.

Risk evaluation using gene expression screening to monitor for acute cellular rejection in heart transplant recipients.

Gene expression profiling (GEP) was developed for non-invasive surveillance of acute cellular rejection. Despite its widespread use, there has been a paucity in outcome data for patients managed with GEP outside of clinical trials. The Outcomes AlloMap Registry (OAR) is an observational, prospective, multicenter study including patients aged ≥ 15 years and ≥ 55 days post-cardiac transplant. Primary outcome was death and a composite outcome of hemodynamically significant rejection, graft dysfunction, retransplantation, or death. Secondary outcomes included readmission rates and development of coronary allograft vasculopathy and malignancies. The study included 1,504 patients, who were predominantly Caucasian (69%), male (74%), and aged 54.1 ± 12.9 years. The prevalence of moderate to severe acute cellular rejection (≥2R) was 2.0% from 2 to 6 months and 2.2% after 6 months. In the OAR there was no association between higher GEP scores and coronary allograft vasculopathy (p = 0.25), cancer (p = 0.16), or non-cytomegalovirus infection (p = 0.10). Survival at 1, 2, and 5 years post-transplant was 99%, 98%, and 94%, respectively. The composite outcome occurred in 103 patients during the follow-up period. GEP scores in dual-organ recipients (heart-kidney and heart-liver) were comparable to heart-alone recipients. This registry comprises the largest contemporary cohort of patients undergoing GEP for surveillance. Among patients selected for GEP surveillance, survival is excellent, and rates of acute rejection, graft dysfunction, readmission, and death are low.

Gene Expression Profiling for Cardiac Transplant Recipients: Results from the Outcomes AlloMap® Registry

Transplant registries may facilitate collection of comprehensive and unbiased real-world data to enhance the available body of evidence on short and long-term outcomes of patients. We share the results of patients managed with gene expression profiling (GEP) using the Outcomes AlloMap® Registry (OAR).

Patterns of Gene Expression in High GEP Score Samples Correlated with Clinical Factors in the Outcomes AlloMap Registry

Gene expression profiling (GEP, AlloMap) has become the standard of care in heart transplant patient management with over 100,000 performed. OAR is a prospective observational heart transplant registry study with integrated GEP testing to elucidate factors that contribute to favorable long term outcomes. Gene subsets were examined for correlation with clinical factors with the goal of identifying those associated with expression patterns that shed light on the underlying mechanisms of acute cellular rejection.

(149) - Impact of Cytomegalovirus Infection on Longitudinal Gene-Expression Profiling Score: Results from the Outcomes AlloMap® Registry

(149) - Impact of Cytomegalovirus Infection on Longitudinal Gene-Expression Profiling Score: Results from the Outcomes AlloMap® Registry

(66) - Initial Analysis of the Donor-Derived Cell-Free DNA - Outcomes AlloMap Registry (D-OAR) Study in Heart Transplant Recipients Undergoing Surveillance for Rejection

(66) - Initial Analysis of the Donor-Derived Cell-Free DNA - Outcomes AlloMap Registry (D-OAR) Study in Heart Transplant Recipients Undergoing Surveillance for Rejection

(831) - Gender-Mismatched Heart Transplants and Gene-Expression Profiling Score--Lessons From the Outcomes AlloMap® Registry (OAR)

(831) - Gender-Mismatched Heart Transplants and Gene-Expression Profiling Score--Lessons From the Outcomes AlloMap® Registry (OAR)

(812) - Gene-Expression Profiling to Monitor for Rejection - Which Patients Are Being Offered This Strategy?

Clinical outcomes associated with rejection surveillance with gene-expression profiling (GEP) have been demonstrated to be non-inferior to biopsy in randomized controlled trials of selected risk patients. With increasing adoption of GEP, we provide the first out-of-trial experience characterizing the risk profile and outcomes of patients managed with a GEP strategy using the Outcomes AlloMap® Registry (OAR).

(293) - Correlation of Longitudinal Gene-Expression Profiling (GEP) Score to Cytomegalovirus (CMV): Infection: Results From the Outcomes AlloMap® Registry (OAR)

Purpose Cytomegalovirus (CMV) infection has been implicated in the pathogenesis of allograft rejection, which is reflected by high gene-expression profiling (GEP) scores. The effect of CMV infection on serial GEP scores in the absence of acute cellular rejection (ACR) is unknown. Methods Data from 14,985 samples collected from 2288 heart transplant (HT) recipients enrolled in Outcomes AlloMap® Registry (OAR) were analyzed. The empirical distribution of GEP scores at the visit closest to CMV infection were compared to GEP scores obtained at other visits via Kolmogorov-Smirnov tests. AlloSure measurements from those who underwent concurrent dd-cfDNA testing were also reviewed. Results 311 samples were collected from 213 patients with CMV infection at the time of GEP testing. The mean time to CMV infection from transplant was 346 days. Median GEP score at the time of diagnosis of CMV infection was significantly higher when compared to GEP score obtained at other visits (34 v 30, p Conclusion CMV infections in HT recipients are associated with an increase in GEP score independent of associated ACR. The likely mechanism is immune activation/modulation of one or more of the 11 genes in the GEP signature. Hence, CMV status should be considered when clinically interpreting high GEP scores. AlloSure testing in conjunction with AlloMap demonstrates AlloSure is invariant to CMV infection.