Abstract 2987: Relationship Between Peripheral Blood Mononuclear Cell Gene Expression and QTc-Interval During Acute Cellular Allograft Rejection After Heart Transplantation
Background: Myocardial Infiltration by immune cells creates local inflammatory response including edema leading to morphologic changes reflected in the form of EKG changes. QTc-interval prolongation has been described as a potential noninvasive tool for detection of acute cellular cardiac allograft rejection. Gene expression profiling (GEP) test developed and validated to rule out ISHLT grade 2R/3A rejection is based on 11 genes related to immune mechanisms in peripheral blood mononuclear cells (PBMCs). We hypothesized that GEP test score correlates positively with QTc-interval in different ISHLT grades.
Methods: A data set of 120 GEP tests from 58 patients (78% M), who underwent endomyocardial biopsy and EKG on the day of GEP test, was retrospectively analyzed. Samples were grouped by ISHLT grades, mean GEP score and QTc-interval were calculated and Spearman correlation analysis was used to calculate the correlation coefficient (R) for individual groups.
Results: The mean age was a 57±11 years with a mean time post-heart transplant (HTx) of 3±2.9 years. There was gradual increase in the correlation coefficient (R value), mean GEP score and QTc-interval with the higher grades of rejection.
Conclusions: GEP score correlates with QTc-interval in rejection process and a strategy based on their combination may prove to be a sensitive non-invasive tool to rule out acute cellular rejection.