Gene expression profiling scores in dual organ transplant patients are similar to those in heart-only recipients.

BACKGROUND

Serial gene expression profiling (GEP) may reduce the need for endomyocardial biopsies for detecting acute cellular rejection (ACR) after transplantation, but its performance in dual organ transplant recipients is currently unknown.

METHODS

We analyzed 18 months of follow-up in a national cohort of 27 dual organ recipients (18 heart-kidney, 8 heart-liver, 1 heart-lung) matched to 54 heart-only recipients for gender, age, and time to first GEP (AlloMap®) test. ACR, antibody-mediated rejection (AMR), cytomegalovirus infections, biopsies, and longitudinal GEP scores were evaluated.

RESULTS

During the first 90 days post-transplant, the mean GEP score for dual organ recipients was 25.2 ± 9.1, vs. 23.5 ± 7.7 for heart-only recipients (P = 0.48), with final GEP scores being 29.1 ± 6.1 and 32.3 ± 3.4, respectively (P = 0.34). GEP scores increased over time (P < 0.001) at a similar rate (P = 0.33) for both groups. One heart-only recipient had treated ACR (GEP score = 17). Fourteen subjects had cytomegalovirus infection, 8 of whom were dual-organ. During follow-up, mean GEP score among patients with cytomegalovirus infection was 32.3, compared to 26.7 (p < 0.001) in patients without cytomegalovirus. Only 4 (2%) of 233 biopsies were positive for mild AMR; all occurring in 2 heart-only recipients (GEP scores = 18-33).

CONCLUSIONS

This largest cohort to date suggests that dual organ transplantation alone should not be reason to omit GEP testing from post-transplant medical management, as the two groups' scores did not differ significantly. Confirming that GEP scores increase over time for heart-only and dual organ recipients and in the presence of cytomegalovirus infection, our work shows promise for the use of serial GEP testing in dual organ recipients.