Non-Association of Infectious Exposure and Seasonality with Cardiac Graft Rejection

Abstract

Purpose Graft rejection remains a significant complication following cardiac transplantation. As infection results in elevated immune system activity, we hypothesized that acute rejection events would be more common following infectious exposures and during the winter respiratory virus season. Methods Patients were included who underwent cardiac transplantation at our center in the Midwest, between January 1st, 2014 and December 31st, 2017. The composite endpoint consisted of antibody mediated rejection (AMR), donor specific antibodies (DSA), heart failure readmissions, and death within two years. Infectious events collected during readmissions included a primary infectious diagnosis, positive respiratory virus panel, and other diagnosed or treated infections excluding BK, CMV, and EBV. Results We analyzed 115 patients meeting inclusion criteria. The primary composite endpoint was met by 69 patients (60%). Pre-transplant PRA Class 1 was associated with the composite endpoint (HR 1.03, 95% CI 1.003-1.05, p 0.05). However, patients transplanted during winter - defined as January to March - had worse survival when compared to a composite of other seasons (2-year survival: 75% vs 88.7%, p=0.014) (Figure 1). Freedom from the composite endpoint was not associated with whether a patient had an infectious event (p>0.05). Conclusion Our study did not show any association between infectious exposure and rejection following cardiac transplantation. However, this analysis was likely underpowered to determine this association and national studies are needed.